Rash causing Microbes

wood tick (dermacentor adersoni) or dog tick(dermacentor variabilitis) (R. Rickettsii)

A 12-year-old boyscout who returned from a summer camping trip in Oklahoma 3 days ago presents with fever, lethargy, headache, and abdominal pain. Petechial lesions are noted on the palms of his hands and feet. How did he get this infection?

lower animas, birds (R. Rickettsii)

A 12-year-old boyscout who returned from a summer camping trip in Oklahoma 3 days ago presents with fever, lethargy, headache, and abdominal pain. Petechial lesions are noted on the palms of his hands and feet. What are the natural reservoirs for the causative microbe?

Rhabdoviridia family: helical ribnuceloprotein core unsegmented ss(-)RNA (conrains RNA dependent RNA pol --->replication is entirely in cytoplasm) (Rabes)

A 19yo boy comes to office complaining of fever, nausea, vomiting, difficulty swallowing, photophobia, and head ache. You take a saliva sample for viral isolation. What is the morphology and genetic makeup of the microbe you expect to find?

Aedes aegypti mosquito (Dengue)

A 20 year old girl comes to your office complaining of back, muscle, retro-orbital and joint pain. She has a fever and head as well. She says she was visiting family in Ecuador just last week. You think she may have been infected by a flavi virus. How did she get the virus?

replicates in vascular endothelium, monocytes, macrophages--->cytokine release--->viremia--->antibody dev--->resolution (Dengue)

A 20 year old girl comes to your office complaining of back, muscle, retro-orbital and joint pain. She has a fever and head as well. She says she was visiting family in Ecuador just last week. You think she may have been infected by a flavi virus. What's the pathogenesis of this virus?

She develops lifelong neutraizing antibody but infection with another serotype is enhanced by this prior immunity and can cause Dengue Hemorrhagic Fever or Dengue Shock Syndrome. (Dengue)

A 20 year old girl comes to your office complaining of back, muscle, retro-orbital and joint pain. She has a fever and head as well. She says she was visiting family in Ecuador just last week. You think she may have been infected by a flavi virus.What kind of immunity does she get against this virus?

House mouse mite (R. akari)

A 22yo male comes in with chills, fever, malaise, headache, and myalgia. His skin reveals the following lesion. It was once a red papule. How did he get this infection?

Serology: complement fixation, indirect immunofluorescence, latex agglutination (R. akari)

A 22yo male comes in with chills, fever, malaise, headache, and myalgia. His skin reveals the following lesion. It was once a red papule. How do you diagnose the suspected microbe?

Ricketssiae multiply in endothelial cells of blood vessels--> endothelial prolif----> leakage, thrombosis, perivascular infiltaration---> VASCULITIS (R. akari)

A 22yo male comes in with chills, fever, malaise, headache, and myalgia. His skin reveals the following lesion. It was once a red papule. What cell types are infected by the causative microbe and how does that affect the host?

Rickettsiae are smalle rod shaped bacteria petidoglycan and diaminopimelic acid (DAP) obligate intracellular parasites (R. akari)

A 22yo male comes to your practice in New York City with chills, fever, malaise, headache, and myalgia. His skin reveals the following lesion. It was once a red papule. What is the morphology of the causative agent?

From legs and extremeties centrally to trunk (R. Rickettsii)

A 26-year-old male with no significant past medical history goes camping with several friends in Virginia. Several days after returning, he begins to experience fevers, headaches, myalgias, and malaise. He also notices a rash on his wrists and ankles (FIgure A). What is the natural progression of the rash?

Doxycycline (R. Rickettsii)

A 26-year-old male with no significant past medical history goes camping with several friends in Virginia. Several days after returning, he begins to experience fevers, headaches, myalgias, and malaise. He also notices a rash on his wrists and ankles (FIgure A). Which of following should be initiated for treatment of his condition?

deer tick (Ixodes scapularis) or Dog tick (D. variabilis) (Ehrlichia) **Note the morula in inflammatory cell

A 30yo male comes to you office with a fever, headache, and myalgia. His labs reveal leukopenia, a low platelets. His peripheral smear is in the image. How did he get this infection?

Super antigens: link T cell receptor to MHC class II leading to non-specific T-cell activation---> massive cytokine release Septic Shock: LPS binds LPS-binding protein--->complex binds CD14 on monocytes, macrophages, and endothelial cells--->proinflam cytokine release (Staph Aureus & Strep Pygenes)

A 34-year-old female presents to the emergency room via ambulance after she began experiencing nausea, vomiting, and diarrhea this morning. Her husband reports that she began to complain of sudden-onset fever and chills that started earlier today, as well as the development of a sunburn-like rash. He states that she appeared short of breath and confused and soon after collapsed. Her vital signs in the emergency department are: T 38.5 deg C, HR 134, BP 80/42, RR 24, SpO2 94% RA. Physical examination is significant for nonpurulent conjunctivitis, rapid breathing, and a diffuse, macular, erythematous rash (shown in Figures A and B) that involves the trunk, extremities, palms/soles, and mucus membranes. A pelvic examination is conducted as well, with removal of a tampon from the vaginal vault. What is the mechanism behind the toxins that cause toxic shock syndrome and the mechanism for septic shock?

Thorough flushing of the wound Passive immunization w/in 24hrs (human RIG) Vaccination (INACTIVATED- 5shots in a month intramuscularly) (Rabes)

A 4 year old child is playing in the backyard. A racoon runs towards him and bites him. How should you treat him?

Daily tick checks since the tick needs to feed for at least 24 hours before mature spirochetes are injected into the host (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. How could this infection been prevented?

Ixodes dammini deer tick (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. How did he get this infection?

microbial persistance--> immune response--->bystander response (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. How is the damage sustained by this kind of infection?

He is in stage 1: erythema migrans Stage2: palsies. aseptic meningitis, joint pain, fatigue, fever malaise stage 3: arthritis, memory and mood changes (chronic neuro involvement) (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. How would the infection progess if left untreated?

Those CHRONICALLY infected have HLA=DR4 & IgG to OspA (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. Is there a genetic component to this infection?

amoxicillin or Doxycycline (if >8yo) (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. What is the appropriate treatment?

spirochete (Borrelia burgdorferi)

A 6-year-old boy presents to his PCP with the finding shown in Figure A. His father thinks it has been there for about a day. The boy denies other symptoms, although his father remarks that he had a headache last night and seems a bit more fatigued than usual. The family lives in a wooded area, has not traveled at all recently, and has no pets. He has no significant past medical history and no known drug allergies. What is the morphology of the causative agent?

inhaled mouse feces and urine Four corners NM, AZ, CO, UT (Hanta virus) causes hemorragic fever and/or pulmonary shock syndrome

A group of college students go camping in colorado for weeks 3 of them come down with a persistent cough, fever, myalgia, and petechiae. They reported that the cabin was gross when they first got there, but they cleaned it. They had no history of bug bites. How and where are they most likely to contract this illness?

head louse often associated with crowded conditions & poor hygiene (R. prowazekii)

A marine deployed at Ecuador presents to the emergency clinic with "the worst headache of his life," accompanied by fevers, chills, malaise, photophobia, and a macular/papular rash spread across his trunk, face, and upper extremities (not on palms or soles). He said it started on his chest. His labs were positive for typhus antibody. How did he get the infection?

Endemic- R. typhii milder (R. prowazekii=epidemic)

A marine deployed at Ecuador presents to the emergency clinic with "the worst headache of his life," accompanied by fevers, chills, malaise, photophobia, and a macular/papular rash spread across his trunk, face, and upper extremities (not on palms or soles). He said it started on his chest. His labs were positive for typhus antibody. What is the endemic counterpart to this infection caused by?

Brill-zinsser disease (mild recrudescent infection in folks taht had epidemic typhus yrs ago) (R. prowazekii)

A marine deployed at Mt. Fuji presents to the emergency clinic with "the worst headache of his life," accompanied by fevers, chills, malaise, photophobia, and a macular/papular rash spread across his trunk, face, and upper extremities (not on palms or soles). He said it started on his chest. His labs were positive for typhus antibody. What complication is it at risk for in the future?

droplet inhaled-->incubate 7-21days--->replicates in respiratory epithelium-->viremia--->systemicinfection (including CNS)--->cough, coryza, conjuctivitis, koplik spots---> T cell response (DTH)--->maculopapular rash (Measles/Rubeola)

A young couple brings their newly adopted 2-year-old son to the pediatrician because he has a temperture of 104 degrees F and a rash. The report that the rash began at his head and face and spread downward to include the hands and soles. The mother reports that prior to developing the rash the child had cough, inflammed lips, and red eyes. Describe the natural progression of this infection.

Koplik spots on the buccal mucosa Measles (Rubeola)

A young couple brings their newly adopted 2-year-old son to the pediatrician because he has a temperture of 104 degrees F and a rash. The report that the rash began at his head and face and spread downward to include the hands and soles. The mother reports that prior to developing the rash the child had cough, inflammed lips, and red eyes. How could you have identified the illness before the rash appeared?

-Bacterial superinfection -Postinfectious meningo-encephalitis -Subacute sclerosing panencephalitis (SSPE) -Progressive infections encephalitis Measles (Rubeola)

A young couple brings their newly adopted 2-year-old son to the pediatrician because he has a temperture of 104 degrees F and a rash. The report that the rash began at his head and face and spread downward to include the hands and soles. The mother reports that prior to developing the rash the child had cough, inflammed lips, and red eyes. What are possible complication of this infection?

Paramyxovirus ss(-)RNA enveloped VIRULENCE: Hemagglutinin-neuraminidase (HN) factor (F) fusion-->induces syncitia & multinucleated giant cell Matrix protein (M protein)-->viral assembly Measles (Rubeola)

A young couple brings their newly adopted 2-year-old son to the pediatrician because he has a temperture of 104 degrees F and a rash. The report that the rash began at his head and face and spread downward to include the hands and soles. The mother reports that prior to developing the rash the child had cough, inflammed lips, and red eyes. What family is the causative agent in? What does that mean for its genome and virulence factors?

T cells target infected enothelial linking of vessels Measles (Rubeola)

A young couple brings their newly adopted 2-year-old son to the pediatrician because he has a temperture of 104 degrees F and a rash. The report that the rash began at his head and face and spread downward to include the hands and soles. The mother reports that prior to developing the rash the child had cough, inflammed lips, and red eyes. What mechanism causes the rash?

Respiratory droplet transmission---> Pili--->attach epithelial cells---> mild pharyngitis or bacteremia seeding organs---> petechial rash/purpura (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. Describe the pathogenesis of the most likely bacterial agent.

gram negative diplococci culture on Thayer-Martin Media Ferments maltose and glucose (note gonorrhe doesn't ferment maltose) oxidase positive capsule polysach latex agglutination (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. The bacteria most likely causing these symptoms would be demonstrated via what features in a laboratory?

polysaccharide capsule resists phagocytosis by neutrophils endotoxin/LPS IgA protease (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. What are the virulence factors of the bacteria most likely causing this infection?

SIC Gram negative shock Waterhouse friderichsen syndrome (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. What complications can he be at risk for?

college freshman military infants 6 months to 2 years (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. Which groups are at highest risk for this?

Group B is most prevelent in the US C, Y, W135, & A are covered in the vaccine (N. Meningitidis)

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. Which strain is most prevalent in the US and is it covered in the vaccine?

Remains close to bite site---> enters muscle---> replicates---> infects peripheral nerves---> retrograde axonal tranport--> dorsal root ganglion---> brain (hippocampus, brainstem, cerebellum) (Rabes)

An autopsy is done on a 72yo patient who died following a week of fever, nausea, vomiting, headache, and lethargy that progressed to hallucinations, delirium, and seizures. How does the causative agent cause infection?

Rabes saliva-->viral isolation negri body detection (excess nucleocapsid) from a biopsy of nape of neck

This is a post mortem finding on patient autopsy. How could you have diagnosed this ante-mortem?

Arenavirus- ambisense RNA, enveloped Lassa fever virus Machupo Junin

You are on a mission in West Africa. You have patient with fever, bleeding from the gum and ears with petichiae. She is a maid for the governer's daughter and was sent to clean for her since her apartment was gross and full of mice. What could this be caused by and what kind of genome does it have?

Filovirus- negative RNA, enveloped Marburg Ebola

You go on a trip to the amazon. You go camping in an area full of monkeys. one of your camp mates develop petechiae and starts bleeding out of his gums and ears. What might he have?