Parasitology Questions

The adult tapeworm of Ehinococcus granulosus is found in the intestine of _________________.

Dogs

When malaria smears are requested, what patient information should be obtained?

Travel history, antimalarial medication, date of return to United States

A 45-year-old hunter developed fever, myalgia, and periorbital edema. He has a history of bear meat consumption. The most likely causative agent is _____________

Trichinella spiralis

Parasitic organisms that are most often transmitted sexually include ___________.

Trichomonas vaginalis

Which of the following is the best technique to identify Dientamoeba fragilis in stool?

Trichrome-stained smear

A 60-year-old Brazilian patient with cardiac irregularities and congestive heart failure suddenly dies. Examination of the myocardium revealed numerous amastigotes, an indication that the cause of death was most likely __________.

Thypanosomiasis with Trypanosoma cruzi

Patients with severe diarrhea should use "enteric precautions" to prevent nosocomial infections with _________.

Cryptosporidium spp.

The term internal autoinfection can be associated with the following parasites: _______________.

Cryptosporidium spp. and Strongyloides stercoralis

An immunocompromised patient continues to have diarrhea after repeated ova and parasites (O&P) examinations (sedimentation concentration, trichrome permanent stained smear) were reported as negative; organisms that might be responsible for the diarrhea include ________________.

Cryptosporidium spp. and microsporidia

Parasite stages that are immediately infection for humans on passage from the gastrointestinal tract include _______________.

Cryptosporidium spp. oocysts

Within the United States, sporadic mini-outbreaks of diarrheal disease have been associated with the ingestion of strawberries, raspberries, fresh basil, mesclun (baby lettuce leaves), and snow peas. The most likely causative agent is ________________.

Cyclospora cayetanensis

Protozoan cysts were seen in a concentration sediment and tentatively identified as Entamoeba coli. However, the organisms were barely visible on the permanent stained smear because _______________.

E. coli cysts were present but poorly fixed

The incorrect match between disease and symptoms is ________________.

Enterobiasis - dysentary

The most prevalent helmith to infect humans is _____________.

Enterobiusvermicularis, the pinworm

Confirmation if an infection with microsporidia can be achieved by seeing _______________.

Evidence of polar tubule

Plasmodium vivax and Plasmodium ovale are similar because they _________________.

Exhibit Schuffner's dots and have a true relapse in the life cycle

Microsporidia have been identified as causing severe diarrhea, disseminated disease in other body sites, and ocular infections. Routes of infection have been identified as _______________.

Ingestion, inhalation, and direct contamination

The incorrect match between method and method objective is ____________.

Knott's concentration - the recovery of operculated helminth eggs

Microsporidial infections can be confirmed using ______________.

Light microscopy an modified trichrome stains

A transplant patient on immunosuppressive drugs developed increasing diarrhea. The most likely combination of disease and diagnostic procedure is ________________.

Microsporidiosis and modified trichrome stain

Which microfilariae are usually not found circulating in the peripheral blood?

Onchocerca volvulus

Upon examination of stool material for Cystoisospora belli, one would expect to see ___________.

Oocysts that are modified acid-fast variable

There are a few procedures considered STAT in parasitology. The most obvious situation would be __________.

Blood films for malaria

Toxoplasma gondii is characterized by _______________.

Possible congenital infection and ingestion of oocysts, along with cosmopolitan distribution and possible difficulties with interpretation of serologial results

The formalin-ether (ethyl acetate) concentration procedure for feces is used to demonstrate ______________.

Protozoan cysts and helminth eggs

Visceral larva migrans is associated with which of the following organisms?

Toxocara - serology

Ingestion of which of the following eggs will result in infection?

Toxocara canis

Cysts of Iodamoeba butschlii typically have ____________.

A large glycogen vacuole

Organisms (and infections) that under normal conditions cannot be transmitted in the laboratory are ______________.

Ascaris lumbricoides - ascariasis

An entamoeba histolytica trophozoite has the following characteristics: ______________.

Central karyosome in the nucleus, ingested RBCs, and clear pseudopodia

When humans have hydatid disease, the causative agent and host classification are _____________.

Echinococcus granulosus - accidental host

The incorrect match between organism and the appropriate diagnostic procedure is _____________.

Echinococcus granulosus - routine ova and parasite examination

"Cultures of parasites are different from bacterial cultures; no quality control is needed." This statement is _____________.

False, and organism and media controls need to be set up

Which specimen is the least likely to provide recovery of Trichomonas vaginalis?

Feces

A 12-year-old girl is brought to the emergency department with meningitis and a history is swimming in a warm-water spring. Motile amoeba that measure 10 um in size are seen in the CSF and are most likely ______________.

Naegleria fowleri

An immunosuppresed man has several episodes of pneumonia, intestinal pain, sepsis with gram-negative rods, and a history of military service in Southeast Asia 20 years earlier. The most likely cause is infection with _______________.

Strongyloides stercoralis

Select the most sensitive recovery method for Acanthamoeba spp. from lens care solutions or corneal biopsies.

The use of non-nutrient agar cultures seeded with E. coli

Eye infections with Acanthomoeba spp. have most commonly been traced to ____________.

Use of contaminated lens care solutions

Which parasite cause eosinophilic meningoencephalitis, a form of larva migrans causing fever, headache, stiff neck, and increased cells in the spinal fluid?

Angiostrongylus cantonensis

The following organisms are linked with specific, relevant information. The incorrect combination is ________________.

Balantidium coli - common within the United States

Two helminth eggs that may resemble one another are _____________.

Diphyllobothrium latum and Paragonimus westermani

Autofluorescence requires no stain and is recommended for the identification of ______________.

Cyclospora cayetanensis oocysts

In a condition resulting from the accidental ingestion of eggs, the human becomes the intermediate rather than the definitive host. The correct answer is ______________.

Cysticercosis

An operculated cestode egg that can be recovered from human feces is _________________.

Diphyllobothrium latum

In infections with Taenia solium, humans can serve as the _____________.

Either the definitive or the intermediate host

A Gram stain from a gum lesion showed what appeared to be amoeba. A trichrome smear showed amoeba within a single nucleus and partially digested PMNs. The correct identification is ________________.

Entoamoeba gingivalis

Charcot-Leyden crystals in stool may be associated with an immune response and are thought to be formed from the breakdown product of ____________.

Eosinophils

One of the following protozoan organisms has been implicated in waterborne and foodborne outbreaks within the United States. The suspect organism is ______________.

Giardia lamblia

Organisms thay should be considered in a waterborne outbreak of diarrheal disease include _______________.

Giardia lamblia and Cryptosporidium spp

Organisms that should be considered in a nursery school outbreak of diarrhea include ______________.

Giardia lamblia, Dientamoeba fragilis, and Cryptosproidium spp.

The incorrect match between organism ad characteristic is ______________.

Hymenolepis nana - striated shell

Humans can serve as both the intermediate and definitive host in infections caused by _________________.

Hymenolepsis nana

The microsporidia are protozoans (now classified with the fungi) that have been implicated in human disease primarily in ________________.

Immunocompromised patients

Oocysts of Cryptosporidium spp. can be detected in stool specimens using ________________.

Modified Ziehl-Neelsen acid-fast stain

The incorrect match between symptoms and disease is ______________.

Myalgias - trichuriasis

The examination of sputum may be necessary to diagnose infection with ________________.

Paragonimus westermani

Massive hemolysis, blackwater fever, and central nervous system involvement are most common with ________________.

Plasmodium falciparum

Babesia has been implicated in disease from both splenectomized and nonsplenectomized patients. Morphologically, the parasites resemble _________________.

Plasmodium falciparum rings

In a patient with diarrhea, occasionally Entamoeba histolytica/E. dispar (four nucleated cysts, no chromatoidal bars) are identified as being present; however, these cells, which are misdiagnosed as protozoa, are really _____________.

Polymorphonuclear leukocytes (PMNs)

Examination of 24-hour unpreserved urine specimen is sometimes helpful in the recovery of _______________.

Schistosoma haematobium eggs

The incorrect match between organism and characteristic is _____________.

Schistosoma mansoni - egg with a terminal spine

The miracidial hatchling test helps to demonstrate the viability of eggs of ____________.

Schistosoma species

In a pediatric patient, the reccomended clinical specimen for recovery of Enterobius vermicularis is the ___________.

Series of scotch tape preparations

Characteristics of the rhabditiform (noninfective) larvae of Strongyloides stercoralis include a ________________.

Short buccal capsule and large genital primordium

Eating poorly cooked pork can lead to an infection with ___________.

Taenia solium and Trichinella spiralis

When staining Cystoisospora belli oocysts with modified acid-fast stains, the important difference between these methods and the acid-fast stains used for acid-fast bacilli (AFB) is _______________.

The decolorizer is weaker than acid alcohol used for AFB decolorizer

Which of the following statements is true regarding onchocerciasis?

The diagnostic test of choice is the skin snip

Primary infections with the microsporidia may originate in ______________.

The gastrointestinal tract

After returning from a 2-year stay in India, a patient has eosinophilia, an enlarged left spermatic cord, and bilateral inguinal lymphadenopathy. The most likely clinical specimen and organism match is __________________.

Thick blood films - microfilariae

A helminth egg is described as having terminal polar plugs. The most likely helminth is ______________.

Trichuris trichiuria

The incorrect match between the organism and one method of acquiring the infection is _______________.

Trypanosoma brucei rhodesiense - bite of a sand flea