MMS CI Case 2 Questions

A researcher is studying the effects of pepsin, which is expressed as pepsinogen by gastric chief cells, an important protein digesting enzyme in the stomach. After genetically modifying the chief cells to inhibit secretion of pepsinogen in a population of lab rats, their goal is to study the impact this inhibition has on pepsin in relation to protein digestion. Thus, which of the following macromolecules is most likely no longer hydrolytically cleaved due to the absence of pepsin? A. collagen B. keratin C. elastin D. fibronectin E. myoglobin

A "One of the important features of pepsin is its ability to digest the protein collagen, an albuminoid protein that is affected little by other digestive enzymes. Collagen is a major constituent of intercellular connective tissue of meats." Also important to note is that this digestion occurs in the stomach and only initiates the breakdown of proteins, whereas the bulk of digestion primarily occurs in the small intestine by pancreatic enzymes.

A patient presents with intermittent diarrhea and abdominal pain in the ER. Upon taking her history she indicates she has been out of the country in the last month to many different areas of the world. The stool of the patient is analyzed and reports findings of small trophozoites containing 1-2 nuclei. The pathogen is identified as an ameba but the structure of the trophozoite is like a flagellate. The patient is prescribed an antimicrobial agent. What is the pathogen in question? A. Dientamoeba fragilis B. Cryptosporidium C. Balantidium Coli D. Cystoisospora E. Trichomonas vaginalis

A It is an ameba but the structure of the trophozoite being similar to a flagellate, along with the symptoms makes this the correct answer.

A 69 year old male hikes the Afghanistan mountains to visit the local village medical man. The patient waited a month before making the trip to the doctor to see if he would get better on his own. He had an ulcer on his right hand that was intensely pruritic, ulcerated, and crusted on the perimeter. The village medical man sees the characteristic ulcer and treats the patient with an injection of a pentavalent antimonial compound, sodium stibogluconate (Pentostam). Which of the following is the most likely vector that caused the patient's ulcer? A. Sandfly B. Tsetse fly C. Ixodes tick D. Blackflies E. Anopheles mosquito

A The patient presents with the cutaneous form of Leishmania, based on the description of the intensely itchy, ulcerated lesion on this hand. The first sign of cutaneous leishmaniasis is a red papule at the bite site that appears 2 weeks to 2 months after initial exposure. Leishmania is most commonly seen in the Middle East (Afghanistan, Algeria, Iran, Iraq, Syria). The main drug to treat this condition is a pentavalent antimonial compound, sodium stibogluconate (Pentostam), fluconazole, and miltefosine. The vector for Leishmania is the (female) sandfly.

A 32 year old male visits his doctor's office after returning from a trip abroad. He tells his doctor that he has had persistent diarrhea since his return and notes eating raw seafood while abroad. The doctor takes a stool sample and finds a large number of parasites that are usually associated with being nonpathogenic. Which organism did the doctor find and what would be prescribe to treat his patient? A. Blastocystis and metronidazole B. E. Polecki and metronidazole C. Blastocystis and vancomycin D. E. Nana and erythromycin E. E. Histolytica and iodoquinol

A is correct because blastocystis has been debated recently as to whether or not it causes symptoms due to it being found in symptomatic and asymptomatic patients. In the presence of a symptomatic patient with no other parasites present blastocystis can be thought of as the causative agent. Metronidazole is the correct drug for treating this infection

A 4-year-old male presents to the clinic with symptoms of abdominal pain, cough, seizures, and pruritic skin lesions. Upon physical exam, the child is observed to have hepatosplenomegaly. The patient and his family recently moved to the area and he was enrolled in preschool, and his parents state that the patient has especially loved the petting zoo they have at the school, consisting of dogs, chickens, and cats that live on the property. Following diagnostic blood tests, the patient is found to have elevated eosinophil levels. How might the patient have contracted this nematode? a) Playing with infected animals at school b) Contaminated clothing/toys at the school c) Inhaling the infected egg-laden dust in the family's new home d) Playing outside with bare feet e) Eating a piece of infected bacon

A - B. procyonis NLM is transmitted by infected dogs, cats, or raccoons. It can cause a variety of symptoms, the most prevalent being cough, wheezing, fever, rash, anorexia, seizures, fatigue, and abdominal discomfort. Hepatosplenomegaly is also observed on physical exam. Diagnostic tests include fecal examination of infected animals, and eosinophilia. Treatment is available, but there are no known survivors of NLM who are neurologically intact, and death often occurs without prompt diagnosis due to respiratory failure, cardiac arrhythmia, or brain damage.

A 28-year-old female presents to the ED complaining of profuse watery diarrhea (rice water stools), fatigue, and increased thirst. The patient reveals she went on a trip to Bangladesh to visit her grandmother and returned back to the United States, 2 days ago. The ER physician runs a series of lab tests and the results revealed the patient's symptoms are consistent with Vibrio Cholerae. The patient's symptoms are caused by the cholera toxin. What is the mode of action of the cholera toxin? A) Activation of adenylate cyclase, increasing intracellular cAMP B) Activation of guanylate cyclase, increasing cGMP C) Protein synthesis inhibition D) Ribosylation of small GTPases (Rho) E) M cell invasion

A - The Cholera toxin is phage mediated and has an AB subunit. The A subunit activates the Gs protein along with adenylate cyclase causing cAMP concentration to rise. Intracellular cAMP triggers CFTR to open and releases Cl- ions into the intestinal lumen, resulting in an accumulation of chloride, bicarbonate, and sodium. The accumulation of ions forces water to be pumped in the intestinal lumen causing massive diarrhea.

A 25 year old male patient presents to a clinic in Nepal one rainy day with complaints of diarrhea and abdominal cramping having lasted a week. The patient shares that he has been unable to eat recently, but usually enjoys fresh salads he buys weekly from his local farmers market. Having seen these symptoms in several other patients this week, you suspect Cyclospora cayetanensis due to a local contaminated crop of spinach. A wet mount is necessary for diagnosis. Presence of which microscopic results would confirm the diagnosis of Cyclospora cayetanensis? A. Spherical oocysts 8-10 μm in diameter B. A large trophozoite with a pseudopod C. Flask shaped oocysts D. Elliptical oocysts 15-25 μm in diameter E. Oocysts containing five sporocysts

A - Cyclospora cayetanensis would appear as wavy, spherical oocysts 8-10 μm in diameter. Cyclospora cayetanensis do not have a trophozoite form. The oocysts contain two sporocysts, with each containing two sporozoites.

A mother brings her 3 year old child to the pediatrician with a chief complaint of pruritus and loss of sleep. She informs the pediatrician that she recently enrolled her child in day care and that many of the other children share the same symptoms. The pediatrician diagnosed the child with Enterobius vermicularis and treated them accordingly. However, the child comes back 2 days later but now with complaints of abdominal pain, flatulence and intermittent diarrhea. This time the pediatrician treats the child with doxycycline and alleviates his symptoms. What is the responsible organism for the second set of symptoms? A. Dientamoeba fragilis B. Giardia duodenalis C. Entamoeba histolytica D. Clostridium difficile E. Necator Americanus

A - Dientamoeba fragilis can be transmitted via the fecal-oral and oral-anal route or it can be transmitted inside the eggs of Enterobius vermicularis. Therefore, one way to reduce D. fragilis infections is to eradicate Enterobius vermicularis.

A 6 year old child is sent home from daycare due to a fever and watery diarrhea. After two days the child's mother noticed the watery diarrhea had progressed to bloody diarrhea and decided to take the child to the doctor. The doctor performed tests to differentiate Shigella from Enteroinvasive E. coli, prior to diagnosing the child with Shigellosis. What is one characteristic that is different between Shigella and Enteroinvasive E. coli? A. Enteroinvase E. coli does not produce toxins B. Shigella does not produce toxins C. Enteroinvasive E. coli is only spread through person to person contact D. Enteroinvasive E. coli does not progress into bloody diarrhea E. Shigella is highly resistant to gastric acid

A - EIEC is bacteriologically similar to Shigella, but EIEC does NOT produce toxins. Shigella can possess shiga toxin as a virulence factor to inhibit eukaryotic protein synthesis.

A pig farmer enters the clinic with complaints of abdominal pain and tenderness, watery stools with blood and pus for the past few days. He claims it most likely isn't food related since his wife and kids have been eating the same thing and had no issues that week. Upon further examination and one stool sample later, it has been revealed that his feces contain large trophozoites with cilia and a large macronucleus. What might the route of transmission of the suspected species found in his feces be? A. Fecal-oral B. Respiratory C. STD D. Direct skin penetration E. Arthropod bite

A - He is a pig farmer and so most likely he has come in contact with pig feces, meaning this is the species B.coli. Its mode of transmission is fecal-oral and ingestIon of the infectious cyst allows the trophozoite form to invade the mucosal lining of the GI tract and cause blood, pus, watery stool along with abdominal pain and tenderness. When the stool sample was taken, a big indicator that it was B. coli is that it contained very large trophozoite and had cilia everywhere and a prominent macronucleus. While it most commonly found in pigs and monkeys, pig feces would be more likely to be owned than having a monkey.

A 23 y.o. Female presents to her PCP with scant watery vaginal discharge, itching, burning, and painful urination for the past week. She reports being sexually active with her boyfriend. Microscopic examination of the vaginal discharge will most likely reveal which of the following: A. Trophozoites with flagella and short undulating membrane B. Cysts and trophozoites C. Small trophozoites with one or two nuclei and karyosome consisting of granules D. Large trophozoites with cilia and macronucleus and cysts E. Oocysts

A - Laboratory Diagnosis shows trophozoite with flagella and short undulating membrane (refer to figure 73-6). flagellate's four flagella and short, undulating membrane are responsible for motility. T. vaginalis exists only as a trophozoite and is found in the urethras and vaginas of women and the urethras and prostate glands of men.

A healthy 25 year old male ate a big hamburger for dinner and his body is in the process of digesting the fats he has eaten. What enzyme is responsible for the majority of triglyceride digestion from this meal? A. Pancreatic Lipase B. Lecithin C. Bile Salts D. Pepsin E. Maltase

A - Pancreatic lipase is the main enzyme responsible for the digestion of triglycerides which occurs in the small intestine.

A 22-year-old female presents to her primary care physician of a fever of 100.1 degrees Fahrenheit, abdominal pain and vomiting. Upon physical examination, the patient was also found to have rose spots on her chest and abdomen. The patient mentions that two weeks prior to her appointment, the patient had returned from a vacation to India with her family. What is the initial pathology of the bacteria causing the patient's symptoms? A. invasion of the small intestinal M cells B. toxin release and activation of adenylate cyclase C. overgrowth of the bacteria in the colon D. attachment to the surface of CD4+ T-cells E. release of cytotoxins

A - Salmonella enterica typhi are resistant to gastric acid and will initially invade the body through the small intestinal M cells. The bacteria can also spread via the lymphatics and bloodstream and can colonize in the gallbladder resulting in being a chronic carrier; colonization of the gallbladder is frequently associated with gallstones.

A 23-year-old woman comes into the free health clinic with her boyfriend to get screened for any sexually transmitted infections. She has a history of several STDs in the past. The routine screening ordered for this woman included screening for Trichomonas vaginalis infection. Which one of the following would you recommend as the preferred screening test for detecting T. vaginalis infection? A. Microscopic examination for trophozoites B. Growth on media C. Gram staining D. Dark field microscopy E. Whiff/Amine test

A - The preferred diagnostic method for T. Vaginalis is microscopic examination of vaginal or urethral discharge for characteristic trophozoites.

A 17-year-old teenager presents to the clinic with complaints of watery diarrhea, vomiting and stomach pain. He reports being at a party about 6 hours earlier that day where food was served. The meal included fried rice, meat and vegetables that seemed rather raw. After 32 hours the patient's health seemed to be back to normal. Given the signs and symptoms displayed by the patient, which of the following organisms most likely caused his illness? A. Bacillus cereus B. E. coli C. Salmonella typhi D. Vibrio parahaemolyticus E. Norovirus

A - The signs and symptoms of this patient indicate a case of food poisoning. Bacillus cereus is a common food poisoning pathogen that produces toxins that the patient ingested which resulted in the rapid onset of vomiting and diarrhea. B. cereus is also commonly found in undercooked rice, meat and vegetables. Food poisoning also clears up on its own, hence the 32-hour recovery period.

Mariah decides to celebrate her 21st birthday in Malaysia where she and her 6 best friends attend a cookout in the community where they ate roast pork, mango margaritas and/or a local vegetable dish. When she returned home 6 hours later, she had diffuse abdominal pain, watery nonbloody diarrhea, nausea, and vomiting. Two of her other friends also had similar symptoms. Her vegetarian friend did not get sick at all and her remaining friends did not show any symptoms. Mariah and her sick friends go to the doctor who suspects a parasitic infection. This is confirmed by the results of a wet mount stool specimen. All of the collected stool specimen had the same pathogen and only contained sporocysts. What pathogen is responsible for Mariah and her friends getting sick and what is most likely the source of the pathogen? A) Sarcocystis spp.; infected meat B) Cystisopora spp.; mango margaritas C) Heliobacter pylori; local vegetable dish D) COVID19; mango margaritas E) HPV; infected meat

A) This is the correct answer. Sarcocystis spp can be isolated from pigs and cattle so the source of the pathogen here would be the infected meat from the community cookout. This infection is consistent with the clinical presentation (nausea, vomiting, diarrhea, abdominal pain). Infection may not always present clinical signs.

A 25 year old female comes to the clinic complaining of vaginal itching, discharge, and discomfort with urination. She tells the physician that she is sexually active and has been experiencing these symptoms for the past 7 days. The gynecological exam reveals a strawberry cervix and thin, frothy, and green vaginal discharge that is malodorous. The vaginal pH is 5.3. The physician prescribes her metronidazole. What parasite is most likely causing this patient's condition? A. Trichomonas vaginalis B. Toxoplasma gondii C. Trypanosoma brucei D. Entamoeba histolytica E. Giardia

A- thin, frothy, and green vaginal discharge + increased vaginal pH + strawberry cervix= trichomoniasis

A 70-year-old woman presents to her clinic with watery diarrhea and abdominal cramps for the past week. She was hospitalized few weeks ago for pneumonia and treated with penicillin. Physical examination reveals lower abdominal tenderness. The initial laboratory evaluation of the stool reveals the presence of leukocytes. What is the most likely causative agent and the virulence factor(s) responsible for the symptoms? A. Clostridium Difficile -toxin A (enterotoxin) and toxin B (cytotoxin) B. Shigella - Shiga toxins (Stx1 and Stx2) C. Clostridium Difficile - Heat labile toxin (LT-I or LT-II) D. EHEC - Heat labile toxin (LT-I or LT-II) Y. enterocolitica- M cell invasion

A. C. difficile is the main cause of nosocomial diarrhea in adults in the US. Most common antibodies implicated in the development of C. difficile infection are clindamycin, cephalosporins, fluoroquinolones, and penicillin. The virulence factors that lead to the diarrhea and abdominal pain are toxin A and B.

A researcher is studying the digestion of proteins in the stomach. The researcher decides to focus the study on the activity of pepsin, an enzyme in the stomach which initiates digestion, at different levels of pH. During one observation of the stomach acid, it is noted that pepsin is inactive. Which of the following is the explanation for the inactivation of pepsin? A. The stomach acid was too basic B. The stomach acid was too acidic C. The stomach acid was between 2.0 and 3.0 D. All of the above E. None of the above

A. CORRECT: Pepsin favors an acidic environment so an alkaline solution would cause the enzyme to remain inactive.

A patient presents to an Urgent Care Clinic with extreme diarrhea. The physician there is aware that whenever significant amounts of intestinal secretions are lost to the exterior the sodium reserves of the body can sometimes be depleted to lethal levels within hours. Normally, however, less than 0.5% of the intestinal sodium is lost in the feces each day. Most likely, why is this? A. Rapid absorption of sodium through the intestinal mucosa B. Reabsorption of sodium in the renal system C. Excessive intake of sodium on a daily basis D. Sodium cotransporter between the ECF and ICF E. Isosmotic absorption of water

A. The rapid absorption of sodium through the intestinal mucosa is the best answer here because the question is asking specifically about the GI system. The intestinal mucosa is responsible for the phenomenon of rapid absorption of sodium in order to keep the sodium levels in the body at homeostasis.

21M presents to his PCP with complaints of constipation. He also reports not urinating very much, and when he does it is dark yellow. He is extremely active and plays club soccer, football, and basketball every week. He admits that he often forgets to drink water while playing. He is otherwise healthy. Which characteristic of the large intestine is most responsible for allowing more complete absorption of electrolytes and water than the small intestine? A. Tighter tight junctions B. Presence of gut flora C. It is longer, which allows more time for absorption D. More villi E. Secretion of bicarbonate ion

A. The tight junctions between the epithelial cells of the large intestine are much tighter than those of the small intestine. This prevents back-diffusion of ions, allowing large intestinal mucosa to absorb sodium and chloride ions far more completely than in the small intestine. Absorption of sodium and chloride ions creates an osmotic gradient across the large intestinal mucosa, resulting in absorption of water. With dehydration, the large intestine absorbs more water, resulting in hard, dry, lumpy stool and constipation.

A patient returns from a tropical vacation still experiencing Diarrhea, bloody stool, fever and abdominal pain. The cause of this particular infection is determined to be a protozoan. What is the method of transmission of the protozoan infection? A.Consuming fecally contaminated water B. Bite from sand fly C. Contact with the saliva of an infected animal D. Swimming in contaminated water E. Bite from the reduviid bug

A: Entamoeba histolytica is a protozoan that can cause diarrhea, blood stool, fever and adbdominal pain, which are outlined in the case above. It is not a typical cause for diarrhea in the US, so it is likely the patient would have acquired the infection while traveling. The infection is spread through fecal-oral transmission.

A 28 years old female presents to the Emergency Room with complaints of pain with urination accompanied with bloody urine. She recently studied abroad in Africa and while she was there, she did develop acute dermatitis while she was there, but she has been back in the US for a month now she didn't think it was important. The physician suspects she is suffering from a parasitic Schistosoma haematobium infection. What test would the physician use to confirm the diagnosis? a. presence of eggs in a urine sample b. Presence of eggs in a blood smear c. presence of eggs in the stool d. CT scan e. tape test

A: Schistosoma haematobium is a helminth that invades the bladder and lays it eggs resulting in the presence of eggs in the urine

A 26-year-old female arrived at the ED with complaints of bloody diarrhea, abdominal pain, and fever which onset 2 days ago. In the patient's history, she denied recent travel and reported no changes to her diet but noted that 4 days ago, she was at a neighborhood cookout where she ate grilled chicken, hot dog, and potato salad. Lab results revealed that the patient's symptoms were caused by the bacteria Campylobacter jejuni, most likely from eating undercooked chicken. Which of the following is not a virulence factor of Campylobacter jejuni? A. Motility via flagella B. Pili C. Adherence D. Release of cytotoxin E. Mucosal invasion

B - C. jejuni does not have pili, therefore pili is not a virulence factor of C.jejuni, making this choice the correct answer. The other 4 choices are properties that contribute to the virulence of C. jejuni.

A 22 year old female begins working on a fruit farm where she decided to eat an unwashed peach. She later learned that she consumed Ascaris lumbricoides eggs on the peach that grew from contaminated soil. What would need to be detected or what diagnostic test was used in order to arrive at this definite conclusion? A. Colorless growth on Sorbitol-MacConkey Agar B. Detection of eggs in stool sample C. CBC D. Thiosulfate citrate bile salts sucrose agar E. Blood smear

B - Ascaris lumbricodes is a nematode that sheds eggs in the feces of infected individuals and allows spread via the direct fecal-oral route. Therefore, eggs would be visible in a stool sample.

Postmortem findings for a recently deceased HIV-positive 23 year-old patient showed evidence of multiple brain abscesses, trophozoites and cysts present in their brain. Three days before they passed away, they presented to the emergency department and the resident on duty collected several specimens from the patient and sent them to be cultured. These cultures had proven difficult to grow on agar plates specific for two different types of amebic organisms. Finally, the microbiologist was successful in recovering the specimen in tissue culture using a mammalian cell line. What was the causative agent and form of encephalitis that the patient had? A. Acanthamoeba; chronic granulomatous encephalitis B. Balamuthia; chronic granulomatous encephalitis C. Naegleria; acute primary amebic meningoencephalitis D. Naegleria; chronic granulomatous encephalitis E. Acanthamoeba; acute primary amebic meningoencephalitis

B - Balamuthia organisms produce granulomatous amebic encephalitis and multiple brain abscess, primarily in immunocompromised individuals -- the resulting disease is chronic granulomatous encephalitis. Furthermore, both trophozoites and cysts are found in tissues. Finally, Balamuthia do not grow on agar plates used for Naegleria and Acanthamoeba, but have been recovered in tissue culture using mammalian cell lines.

A swine farmer in Kansas was working with his live stock on a particularly hot day. Having run out of water, he quickly scooped some water from the animals water supply before making the lengthy trip to refill his bottle at his house. Some time later he began to experience some abdominal pain, watery stool with blood and pus, and anorexia. What is he infected with? A) Salmonella Typhi B) B. Coli C) C. Coli D) Shigella sonnei E) E. Coli

B - Balantidium Coli (B. Coli) is a fecal-oral transmitted ciliate infection, found in water supplies contaminated with swine fecal matter. Symptoms of the disease include abdominal pain and tenderness, anorexia, tenesmus, nausea, and watery stools with blood and pus.

A 23-year-old male presents to his PCP with complaints of chills, recurrent febrile attacks, and swollen genitalia. Swelling is also noted upon palpation of posterior cervical nodes and examination of his upper extremities reveal lymphangitis. Patient reports that he had been backpacking through Southeast Asia approximately 5mo ago. Peripheral blood smear reveals presence of sheathed microfilariae. What is the organism responsible for the patient's symptoms? A) O. volvulus B) B. malayi C) L. loa D) T. trichuria E) M. ozzardi

B - Brugia malayi is the only organism that causes lymphadenitis in the groin (particularly, the scrotum and testis in males) and produces sheathed microfilariae. B. malayi is found primarily in Malaysia, India, Thailand, Vietnam, and parts of China, Korea, Japan, and many Pacific Islands. Larvae migrate to lymph nodes upon infection and mature worms produce sheathed larval microfilariae that make their way into the blood circulation. Lymphadenitis results from inflammatory response to presence of molting adolescent worms and dead/dying adults within lymphatic vessels.

A 27 year old woman was making chocolate chip cookies for her mother. After she made them she felt sick and was experiencing watery diarrhea. She goes to the doctor after experiencing these symptoms and she tells him she consumed some of the raw cookie dough which was made with raw eggs. An H2S test revealed a positive result. What is the virulence factor of this pathogen? A. Production of 2 shiga-like toxins (Stx1 & Stx2) encoded on phage B. Invasion of M cells of the small intestine C. Production of heat-labile and heat-stable enterotoxins (LT1 and Sta) D. Production of exotoxins that disrupt the tight junctions in intestinal epithelial cells E. Binding of the toxin to the presynaptic nerve terminal preventing acetylcholine release

B - Due to the clues about consumption of raw eggs and H2S positive lab finding, the pathogen is Salmonella. Salmonella acts by invading the small intestine specifically the M cells which are a thinner layer of mucus where the pathogen is then taken up and replicates inside a phagocytic cell.

A 27 year old male presents to the Emergency Department with abdominal pain and diarrhea. After a series of tests, the physician discovers flask-shaped ulcerations of the intestinal mucosa. A microscopic examination of the patient's stool confirms the physician's suspicions. What stage of the microorganism is responsible for the formation of these ulcers? A. Oocysts B. Trophozoites C. Sporozoites D. Cysts E. Sporocysts

B - Entamoeba histolytica is directly associated with "flask-shaped ulcerations" especially along the intestinal mucosa. Entamoeba histolytica is an amoeba, which has two life cycle stages: the active motile feeding trophozoites and the quiescent infective cysts. Trophozoites are responsible for cytolysis and tissue necrosis, which lead to the formation of these ulcers.

A 4-year-old male is brought to his pediatric ophthalmologist when his mother notices the child complaining of light sensitivity, blurry vision and frequently squinting to favor one eye. The mother is worried as her son already struggles with hearing loss and seizures. Upon examination, the ophthalmologist notes inflammation and retinal scarring suggestive of chorioretinitis; it is suspected that the infection was originally acquired transplacentally. Histological examination of a tissue sample shows the formation of a cyst with trophozoites. What is the essential reservoir for the suspected organism? A. Birds B. Felines C. Humans D. Mosquitos E. Bats

B - Felines are the essential reservoir for the coccidian, intracellular parasite Toxoplasmosis gondii. The organisms develop within feline intestinal cells after which they are passed in oocysts in feces. Ingestion of feces-contaminated products go on to cause infection and tissue damage (cell destruction, organism reproduction, and cyst formation) within humans or other animals. Note: T. gondii can be transmitted transplacentally. Infection during the first trimester is typically fatal; infection after the first trimester may manifest months to years later with chorioretinitis, retardation, seizures, microcephaly, and hearing loss (among others).

A few months ago, a farmer in sub-Saharan Africa switched over to an organic fertilizer that is feces-based. After a long morning, the farmer's 10-year-old daughter danced around barefoot in the fields and then went straight to soccer practice. Once she was home, she immediately took off her cleats because her feet were so itchy. A few weeks later, she complained of abdominal pain, diarrhea, loss of appetite, fatigue, and shortness of breath. What was she infected with? A. Entamoeba histolytica B. Hookworm C. Pinworm D. Trypanosoma brucei gambiense E. Onchocerca volvulus

B - Hookworm is found worldwide but most commonly in moist, warm areas, so the location of this case can help give you an idea. It is mainly spread by walking barefoot on soil or grass and the girl danced around barefoot in the soil/field (this is a big hint). Those with hookworm initially develop a ground itch and often have GI issues, which explains her abdominal pain and diarrhea. When the infection is more severe, it can cause iron deficiency anemia due to blood loss at the site of attachment and this can be accompanied by cardiac issues, which led to the girl's shortness of breath.

A patient presents to the urgent care clinic with concern of a persistent ulcer with raised edges that is located on the patient's leg. The patient informs the physician of recent travel to Brazil and recalls being bitten by a "strange looking fly" while hiking. The physician performs a tissue biopsy for identification of the organism. Which organism is most likely to have caused this ulcer? A) Trypanosoma rhodescience B) Leishmania braziliensis C) Trypanosoma cruzi D) Giardia Lamblia E) Clonorchis sinensis

B - Leishmania braziliensis is a protozoal infection found in Latin America and the Middle East. It is transported to humans through the bite of a sandfly and the skin findings are consistent with a persistent ulcer with raised edges. Diagnosis of this organism is performed through a tissue biopsy.

A 47-year-old male reports to his PCP for the second time in two weeks after continuing to present with general malaise, headache, chills, and weakness. The man previously reported to his physician after being bit by a tick while on a service trip on Africa. The physician suspected the man had been infected by Plasmodium falciparum after seeing rings form within erythrocytes on a blood smear and prescribed him chloroquine. Since the man still seems to be having symptoms what do you suggest the man needs in terms of treatment? A. Needs a higher dose of chloroquine B. Needs to be prescribed an antiprotozoal C. Needs to be on chloroquine for a longer amount of time D. No medication is needed, and eventually the symptoms will subside E. Needs a blood transfusion

B - Plasmodium falciparum and Babesia microti can sometimes be mistaken for one another since they both come from the Ixodes tick. They both present rings in erythrocytes when looking at blood smears. In this case since the chloroquine is not working and we see there rings in erythrocytes we know that instead of Plasmodium falciparum it is Babesia microti causing the infection and the only way to fight it is by taking an antiprotozoal.

1. A 36-year-old patient presents to his PCP with complaints of a fever, chills, general malaise, vomiting, and headaches. Patient notes that he returned 12 days ago from a visit to sub-Saharan African and the symptoms started 3 days ago. After detecting the Plasmodium species on a Giemsa stain blood smear and confirming the patient has malaria, what chemoprophylaxis does the PCP indicate to take? a. Chloroquine phosphate b. mefloquine c. ivermectin d. metronidazole e. oseltamivir

B - Plasmodium falciparum that causes malaria in sub-Saharan Africa is particularly chloroquine-resistant, so the PCP provided mefloquine as the drug of choice for chloroquine-resistant treatment of Plasmodium falciparum.

A 21-year-old male presents to the Emergency Department complaining of fever, gastrointestinal distress, and muscle pain. A complete blood count is preformed, and the patient presents with marked eosinophilia. Upon taking the patients history the physician recalls that the patient has just moved out on his own after college and was recently experimenting with new pork dishes for dinner. What is the patient diagnosed with? What was the likely cause of infection? a) Ascaris lumbricoides; undercooked, dried, or smoked pork b) Trichinella spiralis; undercooked, dried, or smoked pork c) Enterobius vermicularis; undercooked beef d) Trichinella spiralis; seafood e) ETEC; Enterotoxigenic Escherichia coli

B - The correct answer is B because in the case description marked eosinophilia is mentioned and this is characteristic of Trichinella spiralis. Other clues to the correct answer are the pork ingestion, fever, and gastrointestinal distress. The correct answer is also B regarding the source of infection because pork products have the highest prevalence of Trichinella spiralis.

A patient and his sister returned home from a trip to Nantucket Island 2 weeks ago. They recount hiking and spending time along the trails on the island. Both the patient and his sister had been feeling "under the weather" for the past 5 days, before developing fevers. The patient recalls feeling worse than his sister yesterday; he noticed that his face looked very pale in the mirror and he felt extremely fatigued. Bloodwork for the patient revealed an elevated reticulocyte count while the sister's bloodwork revealed a normal reticulocyte count. Blood smears of both the patient and his sister were examined. The sister's blood smear appeared to be negative while the patient's blood smear revealed ring forms, tetrads and paired merozoites. What would be the best treatment for this patient? A. Suramin and Melarsoprol B. Clindamycin and Quinine C. Chloroquine and Primaquine D. Pyrimethamine and Sulfadiazine E. Pentamidine and Ketoconazole

B - The patient and his sister visited Nantucket Island, one of the locations where babesiosis is prevalent - specifically disease caused by B. microti. Both the patient and his sister described general symptoms that can be associated with various cases of parasitemia. The patient's elevated reticulocyte count points to hemolytic anemia which can occur in more severe stages of babesiosis infection. The patient's blood smear confirms babesiosis due to tetrads within the RBCs, which is a distinguishing factor between infections caused by Plasmodium species and Babesia species. Because the patient is experiencing a more severe level of parasitemia by B. microti, Clindamycin and Quinine would be the best treatment. The sister's blood smear appeared to be negative even as she showed symptoms because she most likely had a lower degree of parasitemia than the patient.

Bryce cut his vacation to South America short because he started feeling muscle pains, photophobia, nausea and vomiting. When he returned home, he sprung a fever of 105° F, began sweating and shaking, but the symptoms passed. After 48 hours he began feeling the same symptoms and decided to go to the doctor. The doctor suspects "benign tertian malaria." If this were true, what would be the optimal time to draw blood for a blood film? A. At the onset of symptoms B. Midway between paroxysms C. At the height of a paroxysm D. After photophobia symptoms begin E. A blood film can only be taken after death

B - These symptoms are characteristic of both P. vivax and P. ovale. The book refers to P. vivax as "benign tertian malaria" (so this would be the better answer), although P. ovale can have tertian attacks as well. However, the distinction between those two organisms is actually not important for this particular question. For this question, you must know how the infection progresses. Both plasmodia infect immature RBCs and cause paroxysms. For this blood film, you are trying to determine the organism inside of the immature RBCs. The time when the greatest number of intracellular P. vivax or P. ovale will be inside the immature RBCs is midway between paroxysms.]

A 28-year-old man comes in for an appointment with his primary care physician with complaints of fever, urticaria, and severe pruritus. He had moved to the United States 6 months ago from the Volta river basin where he worked near the streams. After physical examination, subcutaneous nodules were found on the head and neck, and blood tests revealed eosinophilia. Which laboratory test would confirm the diagnosis for the suspected organism? A. Flooding the nodule with water to recover larval worms B. Microfilariae in skin snip preparations C. Cysts in a stool sample D. Protozoa present in a wet prep E. Trypomastigote stage in a blood smear

B - This man is suffering from an infection with Onchocerca volvulus. It is transmitted through the bite of the blackfly, and it is most common in men from the Congo and Volta river basins in Africa. Initial symptoms are fever, urticaria, and eosinophilia with the patient having very itchy skin. Subcutaneous nodules can develop anywhere on the body but are most dangerous on the head and neck because they can lead to "river blindness." Diagnosis is confirmed by demonstration of microfilariae in skin snip preparations from infrascapular or gluteal regions.

A 24-year-old female reports to her OB-GYN with a chief complaint of frothy yellowish, green discharge. Reveals having multiple sexual partners over the past couple years. Upon examination a strawberry cervix was noted with the causative agent resembling a flagellated protozoan on a wet prep. Which of the following is the most likely genital infection contracted by this patient? A. Vulvovaginal candidiasis B. Trichomonas vaginalis C. Gardnerella vaginalis D. Treponema pallidum E. Herpes Simplex virus 2

B - Trichomonas vaginalis is an anaerobic flagellated protozoan commonly attributed to sexually transmitted infections. Presents with a frothy yellowish, green discharge paired to a positive whiff test upon laboratory analysis.

A 40-year-old male visits his physician and presents with epigastric pain and tenderness as well as vomiting. Examination of concentrated stool samples reveals larval worms that can be distinguished from hookworms by two morphological features. Results of the stool sample confirm infection with Strongyloides stercoralis. This particular nematode burrows into the mucosa of the intestines and releases its larvae into the lumen of the bowel. Which two morphological features would distinguish an infection with S. stercoralis from that of a hookworm? A. Mouthpart location and size of head B. Length of buccal cavity and genital primordium C. Segmentation and distinct shape D. Undulating membrane and nuclei on the tail region E. Larval sheath and microfilariae

B - it is the length of the buccal cavity and the genital primordium that distinguishes the larva form of Srongyloides stercoralis from hookworms when visualizing them.

A researcher is studying the different digestive enzymes in the human body. He is focused on one enzyme in particular: ptyalin. To study the efficacy of this enzyme he tests how much of its substrate (starch) gets hydrolyzed in the mouth. Due to the short amount of time food is spent in the mouth, it turns out ptyalin is only able to hydrolyze about 5% of all the starches. This means it is not very efficacious and there must be other enzymes to digest starches later in the digestive system of the human body. What are the product(s) of the breakdown of starch by ptyalin? A. Glucose alone B. Maltose and 3-9 glucose polymers C. Fructose and Glucose D. Maltose alone E. Galactose and Glucose

B - ptyalin is also known as salivary amylase and it hydrolyzes starch into maltose and small glucose polymers - mainly 3-9 molecules in length.

A 23 year old male presents to his physician with complaints of fever, chills, headaches and vomiting after returning from travel in West Africa. The patient admits that he did not receive any prophylactics or immunizations before his trip, as he "didn't know he was supposed to." What type of treatment should the patient receive for his illness? A. Diphenoxylate and loperamide B. Chloroquine C. Azithromycin D. Metronidazole E. No treatment needed- self limiting

B- The patient is most likely exhibiting symptoms of a p. Falciparum infection, which is most commonly treated with the drug Chloroquine.

A 25-year-old graduate student has finished school for the semester and decides to take a vacation. He goes to Nepal but has a hard time getting to his hotel due to the intense rain from the airport to the hotel, which happens a lot this time of year. The next day he goes on a hike, improperly prepared. He gets thirsty and pulls water from a local stream but treats the water with chlorine tablets before he drinks it. Later, he develops some mild nausea and watery diarrhea. What is the most likely organism the student has? A. Crytosporium parvum B. Cyclospora cayetanensis C. Giardia duodenalsis D. Dientamoeba fragilis E. Toxoplasma gondii

B. Cyclospora species' Epidemiology is widely distributed throughout the world, although there are places where it is endemic (Nepal). There is compelling evidence this organism is ingested through contaminated water, with higher rates of transmission during the rainy season. Similar to other parasites such as Cryptosporidium. It is resistant to chlorination. The mild nausea and watery diarrhea symptoms are also shared with other organisms, but only Cyclospora cayetanensis, the only documented species of the Cyclospora Sp. to infect humans has all these characteristics.

A patient presents to the emergency room with abdominal cramps, vomiting, and diarrhea. Most patients with diarrhea should be treated primarily with which of the following types of therapy? A. Intravenous Fluid Therapy B. Oral Fluid Therapy C. Antimicrobial Therapy D. Virotherapy E. All of the above

B; Most patients who suffer from diarrhea become dehydrated. Best way to rehydrate a person quickly is through oral fluid therapy.

The small intestine is one of the primary sites of nutrient absorption in the human body. Which of the following is not responsible for increasing the mucosal surface area/assisting with absorption? A.) Villi B.) Microvilli C.) Flagella D.) Brush Border E.) Folds of Kerckring

C The villi, microvilli, and folds of kerckring are all modifications that optimize the surface area of the small intestine to essentially increase efficiency of biological processes. "Thus, the combination of the folds of Kerckring, the villi, and the microvilli increases the total absorptive area of the mucosa perhaps 1000-fold, making a tremendous total area of 250 or more square meters for the entire small intestine—about the surface area of a tennis court."

A 32 year old male with AIDS presents to the clinic complaining of loose, foul-smelling stools, fatigue, and malaise. Careful examination of a concentrated stool sediment and special acid-fast staining reveal the parasite, Cystoisospora belli. What is the diagnostic stage of this parasite that is present in fecal specimens? A. Cysts and large trophozoites containing cilia and macronucleus B. Trophozoites only C. Oocysts D. Cysts and trophozoites E. Small trophozoites with 1 to 2 nuclei and central karyosome consisting of granules

C oocysts - Both sexual and asexual reproduction in the intestinal epithelium can occur, resulting in tissue damage. The end product of gametogenesis is the oocyst, which is the diagnostic stage present in fecal specimens. This parasite has been reported with increasing frequency in both healthy and immunocompromised patients. This is probably due to the increased awareness of disease caused by Cystoisospora spp. in patients with AIDS. Disease most commonly mimics giardiasis, with a malabsorption syndrome characterized by loose, foul-smelling stools. Chronic diarrhea with weight loss, anorexia, malaise, and fatigue can be seen. Careful examination of concentrated stool sediment and special staining with iodine or a modified acid-fast procedure reveal the parasite (pages 723 - 724). We would also see oocysts in Cyclospora species (page 726).

A 27 year old male had a large cheeseburger for dinner with fries, a large Pepsi, and a slice of pie for dessert. With regard to fat absorption, what is responsible for transporting triglycerides into the thoracic lymph duct? A. Micelles B. Lipase C. Chylomicrons D. Microvilli E. Endoplasmic Reticulum

C After monoglycerides and fatty acids form triglycerides in the cell's smooth ER, they are released in the form of chylomicrons into the thoracic duct and subsequently empty into the circulating blood.

A patient has been diagnosed with Addison's disease. Addison's disease is characterized by low levels of aldosterone and cortisol. Which of the following will result in the intestine due to decreased aldosterone levels? A. Increased sodium absorption B. Increased activity of SGLT cotransporter C. Decreased chloride absorption D. Decreased loss of sodium chloride in the feces E. Increased activity of sodium/amino acid cotransporter

C Sodium gets absorbed in the basolateral side by the Na/K pump. Chloride also gets absorbed in the basolateral side.

A 32-year-old male patient presents to the clinic with complaints of abdominal cramps, nausea, vomiting, and watery diarrhea. The patient has recently traveled to Costa Rica for a business trip and started experiencing these symptoms two days after the trip. What organism is most likely responsible for these symptoms? A. Clostridium Difficile B. Yersinia Enterocolitica C. Enterotoxigenic Escherichia coli D. Shigella E. Entamoeba Histolytica

C - Enterotoxigenic E.Coli is the most common cause of traveler's diarrhea. This is usually found in tropical/semitropical developing countries. The most common symptoms are abdominal cramps, nausea, vomiting, and watery diarrhea.

A 68 year old male has an upcoming birthday, and is very excited. However, he has been diagnosed with metabolic syndrome which explains his significantly low HDL levels from last week's bloodwork. Even though he has been advised to watch his diet, he devours cake, ice-cream, and a delicious, greasy birthday dinner. Which of the following best explains the mechanism of fat digestion from his delicious birthday dinner? A. Fat is primarily digested by lingual lipase in the stomach, and only absorbed later in the colon B. Fat emulsification involves polar head groups of bile salts projecting inward in micelle formation, allowing absorption in the duodenum C. Fat is emulsified in the by bile acids, and then digested by pancreatic lipase in the small intestine D. Fat is made more readily fragmentable by lecithin, and absorbed as VLDLs into the enterocyte E. Fat is emulsified in the small intestine by bile acids, and then digested by pancreatic amylase

C - Fat emulsification mainly involves the pancreatic secretion of bile acid. Bile acid emulsifies fat, exposing polar head groups to be more readily digested by pancreatic lipase in the small intestine, forming fatty acids and 2-monoglycerides.

A 25-year-old male presents to the emergency room with complaints of abdominal pain, cramping, and colitis with diarrhea. The patient indicates that he has recently returned from a mission trip in Africa. He states that he had been diligent about drinking water from only sanitized and packaged water bottles. However, he does recall getting an iced drink from a local vendor toward the end of his trip. Lab testing and stool samples indicate that the patient has been infected with an organism that leads to flask-shaped ulcerations of the intestinal mucosa and extensive local necrosis in the large intestine. The basis for the extensive local necrosis and tissue destruction is attributed to which of the following? A. Invasion of trophozoites into the mucosal lining B. Trophozoite attachment to intestinal villi C. Production of a cytotoxin D. Sexual and asexual reproduction of organism in the intestinal epithelium E. Trophozoite multiplication by binary fission

C - Flask shaped ulcerations are characteristic of Entamoeba histolytica which can be transmitted through consumption of contaminated water (including ice cubes). Once ingested, the cysts pass through the stomach, where exposure to gastric acid stimulates the release of trophozoites. The trophozoites divide and produce extensive local necrosis in the large intestine. The basis for the tissue destruction is attributed to the production of a cytotoxin.

Carbohydrates are primarily absorbed in the form of monosaccharides, such as glucose. Absorption of glucose occurs in the intestinal tract via a glucose-sodium cotransporter. If sodium wasn't present, what effects, if any, would this have on intestinal glucose absorption? A. Intestinal absorption of glucose will not be affected B. Intestinal absorption of glucose will slow down C. Intestinal absorption of glucose will not occur D. Intestinal absorption of glucose will speed up E. Intestinal absorption of glucose will slow down, adapt, and then return to normal

C - Glucose absorption across the intestinal membrane occurs via secondary active transport using a glucose-sodium cotransporter. The glucose-sodium cotransporter uses secondary active transport by utilizing the gradient set up by the Na+ K+ ATPase on the basolateral side. If sodium was absent, the sodium gradient that the glucose-sodium cotransporter relies on wouldn't be present and glucose absorption would not occur.

A patient presents to the emergency department after having water, noninflammatory diarrhea that now has bright red blood in it. Patient stated that he attended a family picnic 3 days ago with home cooked meals and developed symptoms and developed symptoms yesterday. The patient recalls that he did not see one of their family members wash their hands before serving food. The physician determines that the patient is suffering from acute shigellosis caused by shigella. How does this organism cause bloody stool? A. Destruction of the stomach lining B. Hemolysis of intravascular blood C. Invasion of colonic tissue D. Formation of hemorrhoids E. The patient's bloody diarrhea is unrelated to shigella.

C - Shigella invades the colonic epithelium which is what causes the characteristic trait of bright red bloody stool.

In central Africa, a 24 year old male visits the office with complaints of fever and pain coming from an ulcer on his leg. The patient looks abnormally hyperactive and has a large bump on the right posterior side of his neck. What is the vector that could've caused these symptoms? A. Sandfly B. Epimastigote C. Tsetse fly D. Trypomastigote E. Promastigote

C - The disease is African Trypanosomiasis caused by Trypanosoma brucei gambiense and the question is talking about what carried the parasite to cause the infection. The ulcer is the bite mark and acute phase patients are hyperactive. The large bump on the right posterior side is a swollen lymph node called Winterbottom's sign.

A 32-year-old patient presents to her primary care physician with a fever, chills, and swollen lymph nodes. The patient denies any recent travel outside of the USA, but further prompting reveals she traveled to Central Africa one year prior. Which of the following is an accurate part of the causative agent's life cycle? A) The larvae will hatch in the small intestine and later migrate to the large intestine B) The larvae will grow in the alveoli C) The larvae will mature in the lymphatic system D) The larvae will migrate to cecum and penetrate mucosa E) The larvae will mature in the retroperitoneal space

C - The patient has Bancroft Filariasis from the organism Wuchereria bancrofti. The organism can be transmitted to humans from mosquito bites in Central Africa. The incubation period is three to twelve months. The organisms, in a mosquito, will move through the stomach to reach the proboscis. When the infected mosquito takes a blood meal from a human, the organisms will enter the human and migrate to the lymphatic system where they will mature. The adult male will then fertilize the female. Microfilariae will be produced and will enter circulation where a mosquito taking a blood meal can pick them up.

A 25-year-old male patient presents to the emergency room with symptoms of fever, headache, and day-time sleepiness. A swelling of the lymph nodes (Winterbottom's sign) is also observed. A review of the patient's history indicates that he recently immigrated to the US from Ghana, West Africa, seventeen days ago. When asked if he remembers anything peculiar that happened before he immigrated, he states that he noticed a bug bite on his arm the day before travelling. He is diagnosed with West African sleeping sickness. Which of the following is most likely the vector through which he got the disease? A. Reduviid bug B. Trypanosoma brucei gambiense C. Tsetse fly D. Trypanosoma brucei rhodiense E. Trypanosoma cruzi

C - The patient has been diagnosed with West African sleeping sickness, also known as African Trypanosomiasis. The infection is caused by the Trypanosoma brucei species, which are spread through an insect vector, the Tsetse fly.

A 40-year-old female presents to the hospital for a lung transplant. During her evaluation in pre-op, routine blood tests, as well as serological screenings for blood protozoa were conducted. Among the patient's results, elevated IgG antibodies and low IgM antibodies were seen. During the doctor's evaluation, the patient mentioned that she had 2 indoor/outdoor cats at home and thought that she washed her hands every time that she cleaned their boxes but wasn't 100% sure. If the doctor was to biopsy the patient's original lung tissue after surgery, what would he see that would confirm his diagnosis based on the information mentioned above? A. Leishmania amastigote B. Trypomastigote with an undulating membrane C. Toxoplasma gondii tachyzoites and cysts with bradyzoites D. Multiple ring forms in erythrocytes E. Naegleria trophozoites

C - The symptoms above indicate that the patient has latent Toxoplasma gondii. Cats are the essential reservoir host for this organism, and since the cats go outside at times, it is likely that they had injected the organism from an infected rodent. Since the patient wasn't sure if she washed her hands each time that she cleaned out their litter boxes, it is likely that she contracted the organism through contact with the cats' poop. A biopsy of infected tissue will show Toxoplasma gondii tachyzoites and cysts with bradyzoites.

Bruce Wayne arrives to the ER with symptoms of a parasitic infection. Unfortunately, the lab had a power outage and tests cannot be run at this time. Because of this the doctor takes an extensive patient history to hopefully narrow down what organisms it may be. Which of the following history questions has the correct organism associated with it? A. Do you own any cats? (Plasmodium falciparum) B. Have you noticed any mosquito bites on you? (Toxoplasma gondii) C. Do you own any cats? (Toxoplasma gondii) D. Have you gone swimming in warm water recently? (Plasmodium falciparum) E. Have you noticed any mosquito bites on you recently? (Naegleria fowleri)

C - Toxoplasma gondii is a coccidian parasite that can infect humans. The main reservoir for this parasite is felines, and commonly the common house cat. In gathering the history of someone with a suspected parasitic infection learning the patient has cats may point towards a T. gondii infection.

A 2-year-old female is taken to the pediatrician by her mother as she has been experiencing diarrhea for the last three days and has been increasingly fatigued. Her mother is concerned that she may be dehydrated. Her mother informs the physician that she has been going to daycare daily for the last 6 months and there are a few other children with similar symptoms. What is the incubation period of the bacteria causing her symptoms? A. 1-5 days B. 3-4 days C. 6-72 hours D. 2-7 hours E. 3-7 days

C - the incubation period for shigella is 6-72 hours. Shigella has the highest attack rate in infants and young children in childcare centers

A 6-year-old male arrived at the emergency room accompanied by his parents who stated that he has abdominal pain and distention. Due to irritation and straining during defecation his rectum had prolapsed. This family lives in a remote area with no running water or sanitary sewer. It was stated that they receive food from neighboring unregulated farms. Which is most likely the cause of his condition? A. Dracunculus medinensis B. Enterobius vermicularis C. Trichuris trichiura D. Dirofilaria immitis E. Trinella spiralis

C -Trichuris trichiura is the correct answer because infections with many larvae may produce abdominal pain and distention. Additionally, this can cause a prolapsed rectum in children due to irritation and straining. He also has poor sanitation which indicates that he could have been in contact with human feces.

A patient who came to the hospital complaining of abdominal pains, cramps, steatorrhea, foul-smelling watery diarrhea. He said that symptoms started around 2 week after eating uncooked broccoli at a restaurant near a lake in Canada. The physician suspected that the patient might have gotten in contact with water that has been contaminated with feces. He ran the patient through different lab tests including stool O & P. After looking at lab results, the patient was given metronidazole. Which organism do you think the patient was infected with? A) E.Histolytica B) Trichomonas C) Giardia D) ETEC E) EHEC

C is the correct one, a person can get in contact with giardiasis through drinking water, or uncooked vegetables. Incubation period is 1—4 weeks. Sudden onset, foul-smelling diarrhea, abdominal cramps, steatorrhea. The stool O& P test is a lab test that's usually performed to detect Giardia. It can be treated by metronidazole.

A 26 year old female enters the emergency clinic with complaints of abdominal cramps, flatulence and foul-smelling watery diarrhea. Upon further questioning it was found that the patient had been on a hiking trip where they attempted to consume untreated water from a mountain stream. Which of the following routes of transmission did the patient most likely acquire this organism? A. Respiratory transmission B. Zoonotic Transmission C. Consumption of untreated contaminated water D. Oral-anal route E. Sexual Transmission

C- Giardia duodenalis (G. duodenalis) has a sylvatic distribution and is commonly acquired through the consumption of contaminated water. While giardia can be acquired through ingestion of uncooked vegetables/fruits and through person-to-person spread, untreated water is the most common way to acquire G. duodenalis.

Nancy C., female, 43-year-old, arrived to the emergency room with complaints of an extremely painful nodule on her left ankle. Upon examination, the attending physician determined the nodule to be a pruritic Calabar swelling. The last time Nancy traveled out of the country was 14 months ago, in which she was exploring the congo river basin on her honeymoon. What is the likely causative agent and the vector? a) ​L.loa and blackflies b) L.loa and monkeys c) L. loa and Chrysops, Mango fly d) Wucheria bancrofti and mosquito e) Trichinella and rabid ferrets

C- L. loa and Chrysops, Mango fly

A 30-year-old patient went to the hospital because he was not feeling well. The patient had recently traveled to Africa, and was experiencing daily chills, fevers, severe nausea, vomiting, and diarrhea. The doctor ordered thick and thin blood films suspecting a malaria infection. The results showed a high-grade parasitemia consisting of ring forms. Infected RBCs were not enlarged or distorted. Three or even four small rings were seen, as well as appliqué or accolé forms within the individual erythrocytes. What species of Plasmodium was responsible for this patient's symptoms? A. Plasmodium knowlesi B. Plasmodium vivax C. Plasmodium falciparum D. Plasmodium ovale E. Plasmodium malariae

C- P. falciparum invades any RBC at any stage in its existence causing high grade parasitemia. Infected RBCs do not enlarge and become distorted. Multiple merozoites can infect a single erythrocyte (three or even four small rings may be seen). This species is often seen in the host cell at the very edge or periphery of the cell membrane. This is called the appliqué or accolé position and is distinctive for this species.

A 23-year-old male visits an urgent care after complaints of nausea, vomiting, and diarrhea. Upon physical examination, the physician notes that the patient was scratching their foot, which revealed an irritated rash as well as a non-productive cough. Originally, the patient attributed his rash to ground-bees as they are common for him in his backyard. The physician orders a CBC and OVP. Lab results find that the patient has minor blood loss and non-bile stained segmented eggs are found in his stool. What drug or treatment would be the most beneficial to treat this patient? A. Ivermectin B. Antihistamines C. Mebendazole D. DEC E. Symptomatic

C- This patient has Ancylostoma Duodenale (hookworm), it penetrates the skin (commonly barefoot feet) in sub-tropical/tropical climates when the skin comes into contact with the soil. The itchy rash was caused by the filiform larvae penetrating the skin, goes into circulation where the adult worm can attach the small intestine causing these symptoms. The feeding worms in the small intestine explain why the patient has blood loss. Treatment is albendazole or mebendazole with pyrantel pamoate as an alternative.

A 42 year old patient presents to the emergency room with abdominal pain, cramping, with multiple bloody stools per day and a slight fever. Upon observation, the abdomen is rigid and distended with a suspected elevated diaphragm. A stool sample was taken and trophozoites and cysts were found in the sample, as well as gram negative rods. Which of the following is responsible for removing the trophozoites from the blood? A. Spleen B. Kidneys C. Liver D. Gallbladder E. Diaphragm

C- the liver is responsible for removing the trophozoites from the blood as they pass through the liver. This commonly presents with abscess formation as well as hepatomegaly and elevation of the diaphragm

A 30 y/o male presents to ED with abdominal pain, diarrhea, nausea and vomiting. Onset began a week ago and progressively worsened. He notes daily EtOH use with a history of alcohol abuse. On exam patient in severe distress with distended abdomen, severe abdominal tenderness to palpation and jaundice. Labs showed low pancreatic amylase level and he was diagnosed with alcoholic pancreatitis. What significance does low pancreatic amylase have? A. Decreased conversion of Lactose to Galactose B. Decreased conversion of Sucrose to fructose C. Decreased conversion of Starch to Maltose D. Decreased conversion of Maltose to Glucose E. Increased conversion of Starch to Maltose

C. Pancreatitis causes a reduction in the amount of amylase secreted by the pancreas. The reduced amylase reduces the conversion of starch to Maltose and decreases absorption in the intestine.

An 18-month-old girl is brought to her PCP. She was recently adopted from South America and brought home with her new parents in the US. Her parents initially brought her in because they noticed she was experiencing chills, fever, and has been severely fatigued, even upon just waking up. Physical exam notes a rash and edema around her eyes. Given her recent history you diagnose this rash as Romaña's Sign and begin to determine your course of treatment. What organism is responsible for this disorder? A. Plasmodium falciparum B. Leishmania donovani C. Trypanosoma cruzi D. Trypanosoma brucei E. Naegleria fowleri

C: the clue in this question is Romaña's Sign which is indicative of acute Chagas disease (American trypanosomiasis), which is caused by Trypanosoma cruzi. Other clues are her age and noted symptoms. Chagas disease is most common in children under 5 years of age and is endemic to North, Central, and South America.

A college student comes into the ER with complaints of abdominal pain, nausea, vomiting. While taking the student's history, the physician learns that the college student has recently traveled to Cancun, Mexico. The college student explains that his bowel movement have occurred 3 times a day for the past week. What type of diarrhea is the college student experiencing and what is the mechanism responsible for his symptoms, respectively? A. Acute diarrhea, release of neurotoxins B. Persistent diarrhea, attachment to the brush border of intestinal epithelium C. Acute diarrhea, attachment to the brush border of intestinal epithelium D. Persistent diarrhea, release of cytotoxins E. Persistent diarrhea, release of neurotoxins

C: Based on the student's symptoms, the student has a form of acute diarrhea. Acute diarrhea is defined as an increase in frequency in bowel movements, typically 3 or more times day which lasts less than 14 days. The symptoms, along with the student's travel history indicate that the student has enterotoxigenic E. coli (ETEC). ETEC must adhere to the gastrointestinal tract to establish an infection. In order to achieve this, they produce virulence factors that allow the organism to attach at the brush border of intestinal epithelium

A recent immigrant and dairy farmer from northern Europe, visits the outpatient clinic for the first time. She's experiencing both nausea and vomiting, but decided to come in due to pharyngitis and arthralgia. Further questioning reveals she has experienced no fever or diarrhea. Physical examination also reveals erythema nodosum on the front of her legs below the knee. The physician orders a stool sample, and the pathogen responsible grows on Yersinia-selective agar. What complication is possible following infection? A. Guillain-Barre B. Hemolytic-uremic syndrome C. Reactive arthritis D. Toxic megacolon E. Bloody diarrhea

C; potential complications following Yersinia infection include: reactive arthritis, urethritis, conjunctivitis, myocarditis, erythema nodosum, and kidney disease.

A 32 year old male patient visits his primary care doctor for an annual physical check-up. While his doctor was ordering a lab test to check his cholesterol level, she asked him whether he has eaten anything since last evening, to which he responded yes. The patient completely forgot about the fasting instructions and ate a big breakfast this morning. All of the components of his meal, which includes macromolecules of lipid, carbohydrate and protein, are broken down into monomers inside of his body by which of the following chemical reactions: A. Neutralization reaction B. Displacement reaction C. Combustion reaction D. Hydrolysis reaction E. Condensation reaction

D Digestion of all 3 major types of food (carbohydrate, fat and protein) involve the same process of hydrolysis to break down complex molecules into smaller constituents for absorption. The only difference lies in the types of enzymes required for each type of food.

A woman presents to the emergency room with abdominal pain, diarrhea, and vomiting. After inspection of her diarrhea, the physician notes the stool is clear with small flecks of mucus and looks like rice-water. What pathogen is the most likely cause of these stools and how should the patient be treated? A. Campylobacter jejuni, erythromycin B. Campylobacter jejuni, rehydration and electrolytes C. Noncholeraic Vibrio, fluoroquinolone D. Vibrio cholerae, rehydration and electrolytes E. Enterotoxigenic Escherichia coli, fluoroquinolone

D Classic symptoms of Vibrio cholerae include abdominal pain, rice-water stools, and vomiting. Massive fluid loss due to diarrhea can result in dehydration and loss of electrolytes, with possible death occurring 3-4 hours after onset.

A 19-year-old visits his primary care physician after experiencing problems with his eyes. He wears contacts every day and admits that he does not take them out every night as instructed. His physician takes scrapings from his eye and observes ameba with both trophozoites and cysts present in the tissue. What organism is most likely responsible for his eye infection? A. Naegleria B. Escherichia coli C. Toxoplasma gondii D. Acanthamoeba E. Plasmodium falciparum

D - Acanthamoeba is a free-living ameba that can be found in soil or contaminated water. It is associated with the incorrect cleaning of contact lenses or contact with contaminated dust. The ameba has trophozoites and cysts that are found in its tissue.

A 45-year-old female visited the ER because she was suffering from a Respiratory Tract infection and the doctor prescribed her to take Ciprofloxacin 500 mg orally every 12 hours to help relieve the symptoms. After a week, the female patient was admitted to the ED with a fever of 103.5 Farheinhiet and complains of abdominal cramps and was dehydrated. The stool sample collected was watery diarrhea with leukocytes presented in the stool but no signs of any blood. The doctor ordered the patient to stop taking the ciprofloxacin and recommend her to take Metronidazole which will be an effective solution. Which of the following pathogenesis would best match the symptoms shown in the patient? A. Enteroinvasive E.coli (EIEC) B. Schistosomiasis C. Enterohemorrhagic E.coli (EHEC) D. C.difficile E. Yersinia

D - C.difficile because it is associated with all the symptoms provided such as the stool texture being watery diarrhea with leukocytosis and abdominal cramps and dehydration. Even with the patient taking the antibiotic ciprofloxacin which was one of the main causes of her getting C.difficile.

A 33-year-old female was visiting her family in Asia over the summer. She was used to her filtered water here in the states, but her family instructed her that it was safe to drink water from the nearest step well. She came back to the states with no symptoms and carried on with her life. About a year later, she noticed a blister started to form on the side of her foot and went to her doctor immediately. She described a burning sensation and intense pain in her foot where the blister was located. What is the infectious form of the organism described? a) Trophozoites b) Cercariae c) Trypomastigotes d) Copepods e) Promastigotes

D - Dracunculus medinensis is a tissue-invading nematode depending on fresh-water and a copepod (microcrustacean) of the genus Cyclops. The copepod, which contains the larvae, is ingested in drinking water and the infection is initiated with liberation of the larvae in the stomach. These larvae penetrate the wall of the digestive tract and migrate to the retroperitoneal space, where they mature. The fertilized female migrates to the extremities and causes an ulcer which will be so painful and cause such a burning sensation that the host will go to the nearest water (for example: step well mentioned in this question). On contact with water, the larvae are released. The larvae are ingested by copepods in the water. The copepods are ingested by another individual and the cycle continues.

A 4 y/o boy arrives to the emergency department with his mother with complaints of a high fever and fatigue. During a physical exam, the physician notices a rash and edema around the boy's eyes and face. The patient's mother explains to the physician that they recently moved to the United States from Venezuela 3 days ago. What form in the life cycle of this parasite differs from the other Trypanosoma parasites and could help in confirming a diagnosis? A. Promastigote B. Epimastigote C. Trypomastigote D. Amastigote E. Trophozoites

D - From the question, we can see that the patients symptoms align with Trypanosoma cruzi. This parasite leads to Chagas disease caused by the Reduviid bug. This disease is most common in younger children in South and Central America. One of the earliest signs of Chagas disease is the development of Romaña sign, which is characterized as a rash and edema surrounding the eyes and face. During the life cycle of T. cruzi, there is an additional form (amastigote) that develops. This is the intracellular form with no flagellum and no undulating membrane. A biopsy of lymph nodes, liver, spleen, or bone marrow may demonstrate the organism in the amastigote stage.

A patient is told by their physician that they are lacking an enzyme that is essential for digesting a major protein found in the connective tissue of meats. This digestion allows for other enzymes to penetrate ingested meats, and without it, meats may be poorly digested. What is the enzyme and which protein fibers does it digest? A. Trypsin; collagen fibers B. Pepsin; elastin fibers C. Chymotrypsin; collagen fibers D. Pepsin; collagen fibers E. Trypsin; elastin fibers

D - Pepsin digests collagen fibers, which are major constituents of the connective tissue of meats. If pepsin is missing from the stomach juices, ingested meats are less likely to be penetrated by other digestive enzymes and can be poorly digested.

A 12 year old male from Honduras visits the optometrist with complaints of blurred vision, migraines, and ocular pruritus. During the optometrist eye exam, they find ocular larva migrans. They immediately prescribe albendazole to prevent blindness. What is the mode of transmission for the associated diagnosis? A. Walking barefoot B. Ingestion of contaminated water C. Arthropod bite D. Cat feces E. Ingestion of undercooked meat

D - The child was diagnosed with Toxocara cati/canis. The optometrist finding of ocular larva migrans and the patient's associated symptoms, specifically blurred vision, alludes to the diagnosis. The most common treatment for T. cati, is albendazole. He was treated to prevent blindness which can occur years after the initial contact with the nematode.

A parasitologist visited a clinic in Nigeria to help eliminate some of the factors causing local malaria infections. He was notified one day that a 3 year-old died from severe kidney damage, just a week after being bit by a mosquito. Which Plasmodium species most likely caused the infection and subsequent death of the child? A. P. vivax B. P. ovale C. P. malariae D. P. falciparum E. P. knowlesi

D - The incubation period of P. falciparum is the shortest of all plasmodia, ranging from 7-10 days, and does not extend for months to years. It is also most likely to result in death if left untreated. P. falciparum clinically manifests as initial flu-like symptoms but then can progress to severe toxic cellular debris (blood cells), liver and kidney damage, and cerebral damage.

A 65-year-old man came back from Malaysia celebrating he and his wife's retirement. While visiting they went on a jungle safari. Upon boarding the plane, he had a fever, headache, abdominal pain, and a productive cough. Thinking nothing of it, he went home to get some rest. The next day, he had another fever accompanied by chills. His wife took him to the urgent care and the attending physician ordered a blood test. Upon viewing the blood smear under a light microscope, fine ring forms and double chromatin dots were present. Although this parasite is difficult to detect on its own, which parasite would you most likely treat it as? A. P. vivax B. P. ovale C. P. malariae D. P. falciparum E. T. brucei

D - The lab diagnosis is similar to that seen in P. falciparum so it could be hard to specifically detect P. Knowlesi. Also, rapid detection tests aren't recommended for P. Knowlesi because of the unreliable results and low sensitivity. However, P. knowlesi can be extremely severe even though it could go misdiagnosed and should therefore be managed as if it's P. falciparum.

A 25-year-old woman has recently returned to the United States after spending a week in Ethiopia. Over the next few days, she experiences chills and fever that reappear periodically and decides to visit the doctor. After a few laboratory tests, it was revealed that the red blood cells were oval shaped with a ragged cell border. There was also a presence of Schuffner dots throughout the cytoplasm. What laboratory test was used to identify this information and lead to a diagnosis? A. Rapid Diagnostic tests (RDTs) B. PCR C. Serological Test D. Thick and Thin Blood Films E. Drug Resistance Tests

D - The patient had recently visited Africa, where Plasmodium Ovale is prominent. The patient experiences chills and a fever that reappear periodically, showing that paroxysms are present. P. Ovale causes paroxysms that last 48 hours, cause symptoms of chills, fever and other malarial rigors (muscle pain, vomiting, headache). The blood tests (using thick and thin blood films) revealed oval-shaped red blood cells with ragged borders and Schuffner dots, all indicative of P. Ovale physiology and structure.

A 46-year-old male has presented to his primary care physician with digestive issues and serious pain in his heart. The patient has taken it upon himself to become a master of WebMD and diagnosed himself with esophageal cancer. After multiple tests and treatment with omeprazole, it was confirmed severe heartburn. After carefully educating the patient about avoiding fats and chocolate; what part of the patient's digestive tract is the poorest absorptive area only absorbing a few highly lipid soluble substances? A. Valvulae conniventes B. Large intestine C. Pancreas D. Stomach E. Small intestine

D - The stomach because it lacks the typical villus type of absorptive membrane and because the junctions between the epithelial cells are tight junctions only allowing substances absorbed in small quantities.

A couple present to the clinic after returning from a cruise in the Caribbean. They both complain of fever, chills, vomiting and diarrhea. Due to the recent travel history and adequate time spent in close quarters, the physician believes the two patients have winter vomiting disease. What is the family and genome of this virus? A. Orthomyxovirus, SS -RNA B. Paramyxovirus, SS -RNA C. Rotavirus, DS RNA D. Calicivirus, SS +RNA E. Flavivirus, SS +RNA

D - The virus that is causing the symptoms is referred to as Norovirus which is a part of the calicivirus family. The big indicator in this question is that they recently went on a cruise. Norovirus is highly contagious and one of the most common causes of gastroenteritis in adults. It has been the cause of epidemic on cruise ships before.

A 45-year-old Caucasian male presents to his primary care physician complaining of diarrhea, fatigue and joint pain for the past month. He also mentions that he has been steadily losing weight for the past 6 months. He denies any recent changes to his diet. A PAS stain and an acid-fast stain are performed, which confirm the physician's diagnosis. Which of the following is a characteristic of the disease described by the patient's symptoms? A. FOXP3 gene mutation B. Purulent pseudomembranes C. Attaching and effacing (A/E) lesions D. Foamy macrophages with gram-positive microbes E. NKG2D and MIC-A interaction

D - Whipple disease is a disease most common in Caucasian males. The main clinical symptoms are diarrhea, joint pain and weight loss. Whipple disease is diagnosed by a positive period acid-Schiff (PAS) stain, which shows the presence of foamy macrophages filled with gram-positive microbes in the intestinal lamina propria.

Which of the following transporters absorbs sodium across the basolateral membrane in the intestinal epithelium? A. Sodium-Glucose Co-transporter B. Sodium-Hydrogen Exchanger C. Sodium-Chloride Symporter D. Sodium-Potassium ATP-ase pump E. Sodium-Amino Acid Co-transporter

D - the Na-K ATPase pump is found in the basolateral membrane in the intestinal epithelium (see Figure 66-8 on page 839 for all the transporters in the intestinal epithelium)

A 13-year-old patient presents to his primary care physician with his mother with concerns of his diarrhea, bloating, loss of appetite, and weight loss over the past couple weeks. The mother states that the only recent change is that they switched to a ketogenic diet. What could be the cause of the patient's symptoms? A. The patient's sodium co-transporter is not functioning properly. B. The patient's unable to absorb his monosaccharides via facilitated diffusion. C. The patient's secondary active transport system is not functioning properly. D. The patient does not have enough functioning micelles. E. The patient is unable to directly absorb short-chain fatty acids.

D - the patient is having difficulty with absorbing fat since the ketogenic diet is a high fat diet. His micelles are unable to ferry these fats. In the presence of an abundance of micelles, fat absorption is high, but when there is a low abundance of micelles, fat absorption is low.

Private Ryan, a 21-year-old male serving in the United States army pays a visit to his primary care physician during his return home for the Thanksgiving holiday. His chief complaint to his doctor is that he had a red papule on his arm during his deployment in Iraq. After about 2 weeks, the papule began to ulcerate and gradually leaked a thin, serous material. Based on this clinical description, what vector did Private Ryan come in contact with? A. Dirt fly B. Tsetse Fly C. Ixodes Scapularis D. Lutzomyia Sandfly E. Anopheles Mosquito

D -Lutzomyia is the genera of sandfly species that causes Leishmania. Private Ryan's skin lesions fits the clinical description of a cutaneous leishmania. Additional, his military background, as well as his site of recent deployment, fit the geographical niche where cutaneous Leishmania infections occur.

A researcher is studying glucose uptake through the intestinal epithelium. Using animal subjects, he removes the Na/K ATPase transporters on the basolateral side of the epithelial cell membrane. What will happen to the transport of glucose on the apical side in these animals? A. Glucose will enter the cell through an exchange with HCO3- B. Glucose will enter the cell through facilitated diffusion C. Nothing changes D. Glucose will not enter the cell due to the buildup of sodium in the cell E. Glucose will use paracellular diffusion to enter the interstitial fluid

D- There is no sodium gradient to cotransport glucose and sodium into the interior of the cell because the level of sodium in the cell is very high compared to the outside

A 26-year-old female patient presents to the emergency department with bloody diarrhea (dysentery). The patient is a mother of 2 young children in daycare who have similar symptoms. What is a likely organism and category of the diarrhea? A. V. cholerae- enterotoxin B. V. cholerae- cytotoxin C. Shigella dysenteriae- enterotoxin D. Shigella dysenteriae- cytotoxin E. Shiga toxin- producing strain of E. coli (STEC)- enterotoxin

D. Shigella is a cytotoxin that is frequently spread through day care facilities. A cytotoxin causes dysentery as described in the question compared to an enterotoxin which causes watery diarrhea via a cAMP mechanism.

A 24-year-old female presents to the emergency department with complaints of fever, myalgia, abdominal pain, headache followed by acute watery diarrhea. A routine stool culture showed evidence of inflammation with positive fecal leukocytes and lactoferrin. When asked if she had change anything in her diet, she noted that she recently switched from being fully vegetarian to incorporating lean proteins into her diet such as chicken breast. What is a complication related to the bacteria that she is infected with? A. Hemolytic -uremic syndrome B. Thrombotic thrombocytopenia purpura C. Reiter's Syndrome D. Guillain-Barre Syndrome E. Amebic abscess

D. Acute watery diarrhea, fever, abdominal pain, and fecal evidence of inflammation from positive fecal leukocytes and lactoferrin indicates she is infected with Campylobacter jejuni. Guillain-Barre Syndrome is a complication associated with Camplyobacter jejuni.

A 20-year-old female presents to urgent care with complaints of bloating, gas, and abdominal pain. The patient reports that she is lactose intolerant and forgot to take a Lactaid pill prior to consuming ice cream a few hours prior to the visit. Which of the following is the function of the deficient enzyme that is causing the patient's symptoms? A. Breaks down sucrose into glucose and galactose B. Breaks down lactose into fructose and galactose C. Breaks down maltose into two glucose molecules D. Breaks down lactose into glucose and galactose E. Breaks down sucrose into fructose and glucose

D. The patient has a lactase deficiency. Lactase breaks down lactose into glucose and galactose.

In order to neutralize the acids created by bacteria in the large intestine, which of the following is necessary for this function ? A ) Na+/glucose co-transporter B ) bile salts C ) Vitamin K D ) Na+/H counter-transporter E ) bicarbonate/chloride counter-transporter

E ) bicarbonate/chloride counter-transporter [this counter-transporter, present in the large intestine, will secrete bicarbonate in order to neutralise acids created by bacteria. In doing so, it will also absorb Cl-]

A 21-year-old male by the name of Peter Parker accompanied his girlfriend to Africa to protect her as she foolhardily embarked upon a month-long journalism trip with no regard for her safety or health. His girlfriend (MJ) as usual got herself entangled with some dangerous criminals and contracted benign tertian malaria. Peter Parker, being a scientist himself, immediately diagnosed her based on her symptoms of a recurring pattern of chills, fever, and malarial rigors. What is the name for these set of symptoms? A. Hibby-Jibbies B. Febrile Periodicity C. Quotidian D. Exoerythrocytic Cycle E. Paroxysms

E - Paroxysms are approx. 48-hour cycles of infection, replication, and cell lysis. These cause cyclic chills, fever, and malarial rigors. The severity of these paroxysms can vary anywhere from mild chills all the way to a severe persistent fever of 106 degrees Fahrenheit with overwhelming exhaustion

A 71 year old man presents to the ER with diarrhea and intense pain in the joints. He notes symptoms began while harvesting strawberries and herding cattle as his primary occupation is farming. He also suspects to have lost weight recently and reports an increased tendency to experience food cravings. After ordering a CBC, the doctor notes an increase in macrophages. Physical exam is not notable with exception of pain during lymph node examination. Which of the following answers is most likely associated with the patient's condition? A. Increased lymph drainage B. Upregulation of macrophage synthesis in lymph nodes C. Accumulation of granulocytes D. Increased absorption in small intestine E. Lymphatic obstruction

E - The patient is likely suffering from Whipple Disease given the triad of clinical symptoms he is experiencing, notably diarrhea, weight loss, and arthralgia. Pathogenesis of Whipple Disease is best described by an accumulation of bacteria-laden macrophages within the mesenteric lymph nodes, thereby leading to lymphatic obstruction.

A 37-year-old female presents to the clinic complaining of nausea, abdominal pain, and diarrhea. During the patient interview, she states the symptoms did not begin until after she moved back to her childhood home to help her aging parents run their cattle farm. Due to the general nature of her symptoms, a stool sample is taken for examination. Microscopy shows the presence of sporocysts in her stool. What is the method of treatment for this patient? A. Metronidazole, followed by iodoquinol B. Doxycycline C. Trimethoprim-sulfamethoxazole D. Pyrimethamine and Sulfadiazine combination E. There is no known treatment method

E - There is no known treatment for intestinal, or muscular, sarcocystosis. Sarcocystis can be isolated from cattle, so her current occupation would point to this as a possible diagnosis. The discovery of sporocysts in the stool confirms the diagnosis of sarcocystosis. Sarcocystis oocysts will rupture before being passed, leaving sporocysts in the stool. While highly similar, Cystoisospora spp. oocysts will not rupture before passage, which means that only oocysts would be observed in the stool (NOT sporocysts) had this infection resulted from Cystoisospora spp..

A 45-year-old female with a history of left toe amputation, uncontrolled diabetes, and left eye blindness presents to the emergency department complaining of right upper quadrant abdominal pain. Lab work performed in the ED showed elevated ALT and AST. Gastroenterology and general surgery were consulted on the case prior to general surgery taking lead and opting for surgical intervention of suspected gallstones following a positive ultrasound. Following initial incisions of the patient's abdominal wall, "knobby coated" oval eggs were observed by operating room staff. Which of the following organs is NOT affected during the migration of this organism? a) Lung b) Liver c) Small Intestine d) Heart e) Spleen

E- The correct answer is spleen. The organism here is Ascaris lumbricoides. These worms are notorious for migrating through the body to the liver and causing issues with liver function and gallstones. The spleen is not one of the structures known to be affected by Ascaris lumbricoides

Upon being picked up from daycare, the parents of a 4 year-old male noticed the child showing exacerbated agitation around his perianal region, as displayed by excessive itching and irritation. Upon examination by his pediatrician, the child's diagnosis was confirmed with the tape test. What family of parasitic helminths does the causative organism belong to? a. Trypanasoma Cruzi b. Ancylostoma duodenale c. Trichuris Trichiura d. Onchocerca volvulus e. Enterobiasis

E: The child was infected with an acquired pinworm, belonging to the family enterobiasis, while at daycare. These helminths most often present with perianal pruritus and can be easily diagnosed in the clinic by a scotch tape test looking for evidence of the ova on the tape.

Twenty-year-old Mary Jane Watson comes into the hospital with a paroxysms of fever, chills, and malarial rigors that appear generally every 48 hours or so, as best as her boyfriend can tell. She tells that she has just gotten back from Africa on a month-long journalism trip and the symptoms hit her just as she was getting home. Blood smears show the enlarged RBCs with Schüffner dots and golden-brown hemozoin pigment granules. The doctors also find that she is indeed positive for the Duffy blood group antigen on the RBC surface. What bacteria is MJ infected with? A. Babesia microti B. Leishmania columbiensis C. Leishmania peruviana D. Plasmodium falciparum E. Plasmodium vivax

E: In our question, we know that our patient was in Africa and is suffering malaria-like symptoms. Key word is malarial rigors. This rules out A, B, and C. Plasmodium vivax's primary receptor is the Duffy blood group antigen on the surface of RBCs, which is the final defining feature. It also has Schüffner dots and golden-brown hemozoin pigment granules, while Plasmodium falciparum does not. P. vivax also has shorter fever cycles (48 hours) while P. falciparum has cycles of up to 72 hours.

A 27-year-old male is brought into the Urgent Care Clinic by his parents with complaints of muscle pain, fever, and rigors. His parents inform you that he has been "acting strange" and has unintentionally lost a lot of weight within the last week. Upon obtaining a travel history they explain how they returned the previous week from visiting their family in Africa. The physician suspects the patient has a parasitic infection by T. b. rhodesiense which is confirmed by blood and spinal fluid examination. Which of the following is not a characteristic of T. b. rhodesiense? A. Myocarditis B. Kidney damage C. Rapid CNS disease D. Rapidly fatal E. Winterbottom sign

E: Myocarditis, kidney damage, rapid CNS disease and being rapidly fatal are all characteristics of T. b. rhodesiense except for Winterbottom sign. Lymphadenopathy is uncommon, and CNS invasion occurs early in the infection, with lethargy, anorexia, and mental disturbance. T. b. gambiense has a slower progression and is characterized by swelling of the lymph nodes known as Winterbottom sign.