FoEM CBR22- Infectious Disease Exam
Dx and Tx: Fish tank granuloma
Mycobacterium marinum, Tx: Clarithromycin + Ethambutol OR Rifampin
Dx: Rose thorn injury and rash
Sporothrix schenckii. Tx: Itraconazole (amphotericin B if systemic)
Dx and Tx: Dog and cat bite with rapid infection
Pasteurella multocida. Tx: Amoxicillin-Clavulanate (augmentin —> "dog-mentin")
Dx: Reptile bites and infection
Salmonella
Dx: Sickle cell disease and joint pain
Salmonella osteomyelitis
Dx: Cat scratch fever
Bartonella henselae. Tx: doxy; azithromycin in pregnancy
Dx and Tx: Human bite and infection
Eikenella corrodens. Tx: amoxicillin-clavulanate
Dx: Gastroenteritis on a cruise ship
Norwalk virus
Dx: Gastroenteritis at a daycare
Rotavirus, (remember, there is a vaccine now).
Compare general Dx and Tx of toxin-mediated vs. invasive bacterial diarrheal illness
Toxin: abrupt onset, watery, non-bloody; Tx IVF, ± loperamide, ± Cipro (prolonged/severe ssx).
Invasive: gradual onset, bloody, systemic sx; Rx: IVF, ± Cipro UNLESS kids or elderly patients with
possible E. coli O157:H7 (can increase risk of HUS)
Dx: Watery diarrhea + eggs/mayo
Staph. aureus (toxin)
Dx: Watery diarrhea + fried rice
Bacillus cereus (toxin)
Dx and Tx: Diarrhea + flatulence + recent hiking and drinking from a freshwater stream
Giardia lamblia. Parasitic infection. Test for it w/ a stool antigen (not ova and parasite). Tx:
Metronidazole / tinidazole. People who are risk: hikers, children at daycare, and oral-anal sexual
conduct.
, Dx: Watery diarrhea + travel
Enterotoxigenic E. coli (toxin, ETEC); if no blood in diarrhea, give 1 dose of Cipro 750 mg. If pt traveled
to southeast Asia this is likely campylobacter and give 1,000 mg of azithromycin
Dx: Watery diarrhea + meat/poultry
Clostridium perfringens (toxin)
SSx, Dx, Tx: Watery diarrhea + dark meat fish + rash/itching
Scombroid (histamine fish toxicity). Dark fleshed, peppery tasting fish: tuna, mahi-mahi, mackerel.
Excess histidine on fish broken down by bacteria to histamine. SSx: Histamine ingestion leads to
anxiety, flushing, headache, palpitations, vomiting. Tx: antihistamines
Dx: Watery diarrhea + carnivorous fish + neuro ssx
Ciguatera (toxin causes neuro ssx) - "hot cold reversal"
Dx: Bloody diarrhea + undercooked eggs/chicken + relative bradycardia
Salmonella typhi (invasive), cafeteria outbreaks, classically with high fever and relative bradycardia;
can cause osteomyelitis in sickle cell patients.
Dx: Bloody diarrhea (severe) + high fever + institutionalized
Shigella (invasive); can cause seizures in kids
Dx and Tx: Bloody diarrhea + followed by weakness
Campylobacter (invasive). Associated: appendicitis mimic & Guillain-Barré; Tx: Azithro/Erythro
(resistance to cipro)
Dx: Bloody diarrhea + farm animals + appendicitis ssx
Yersinia (invasive); pseudoappendicitis (appy mimic) can cause terminal ileitis
Dx: Bloody diarrhea + undercooked seafood + alcoholic who gets very sick
Vibrio parahaemolyticus (invasive)
Dx: Bloody diarrhea + poorly cooked ground beef/raw milk
E. coli O157:H7, associated with TTP (adults) and HUS (kids); NO ANTIBIOTICS
Dx: Rice-water stools + contaminated water
Vibrio cholerae (toxin). Oral rehydration tablets.
Dx and Tx: Profuse diarrhea after recent antibiotics
Clostridium difficile (invasive). Tx: PO vanco is first line now
Dx: Diarrhea + AKI ± low platelets
E. coli O157:H7 causing TTP/HUS
Dx and Tx: Fish tank granuloma
Mycobacterium marinum, Tx: Clarithromycin + Ethambutol OR Rifampin
Dx: Rose thorn injury and rash
Sporothrix schenckii. Tx: Itraconazole (amphotericin B if systemic)
Dx and Tx: Dog and cat bite with rapid infection
Pasteurella multocida. Tx: Amoxicillin-Clavulanate (augmentin —> "dog-mentin")
Dx: Reptile bites and infection
Salmonella
Dx: Sickle cell disease and joint pain
Salmonella osteomyelitis
Dx: Cat scratch fever
Bartonella henselae. Tx: doxy; azithromycin in pregnancy
Dx and Tx: Human bite and infection
Eikenella corrodens. Tx: amoxicillin-clavulanate
Dx: Gastroenteritis on a cruise ship
Norwalk virus
Dx: Gastroenteritis at a daycare
Rotavirus, (remember, there is a vaccine now).
Compare general Dx and Tx of toxin-mediated vs. invasive bacterial diarrheal illness
Toxin: abrupt onset, watery, non-bloody; Tx IVF, ± loperamide, ± Cipro (prolonged/severe ssx).
Invasive: gradual onset, bloody, systemic sx; Rx: IVF, ± Cipro UNLESS kids or elderly patients with
possible E. coli O157:H7 (can increase risk of HUS)
Dx: Watery diarrhea + eggs/mayo
Staph. aureus (toxin)
Dx: Watery diarrhea + fried rice
Bacillus cereus (toxin)
Dx and Tx: Diarrhea + flatulence + recent hiking and drinking from a freshwater stream
Giardia lamblia. Parasitic infection. Test for it w/ a stool antigen (not ova and parasite). Tx:
Metronidazole / tinidazole. People who are risk: hikers, children at daycare, and oral-anal sexual
conduct.
, Dx: Watery diarrhea + travel
Enterotoxigenic E. coli (toxin, ETEC); if no blood in diarrhea, give 1 dose of Cipro 750 mg. If pt traveled
to southeast Asia this is likely campylobacter and give 1,000 mg of azithromycin
Dx: Watery diarrhea + meat/poultry
Clostridium perfringens (toxin)
SSx, Dx, Tx: Watery diarrhea + dark meat fish + rash/itching
Scombroid (histamine fish toxicity). Dark fleshed, peppery tasting fish: tuna, mahi-mahi, mackerel.
Excess histidine on fish broken down by bacteria to histamine. SSx: Histamine ingestion leads to
anxiety, flushing, headache, palpitations, vomiting. Tx: antihistamines
Dx: Watery diarrhea + carnivorous fish + neuro ssx
Ciguatera (toxin causes neuro ssx) - "hot cold reversal"
Dx: Bloody diarrhea + undercooked eggs/chicken + relative bradycardia
Salmonella typhi (invasive), cafeteria outbreaks, classically with high fever and relative bradycardia;
can cause osteomyelitis in sickle cell patients.
Dx: Bloody diarrhea (severe) + high fever + institutionalized
Shigella (invasive); can cause seizures in kids
Dx and Tx: Bloody diarrhea + followed by weakness
Campylobacter (invasive). Associated: appendicitis mimic & Guillain-Barré; Tx: Azithro/Erythro
(resistance to cipro)
Dx: Bloody diarrhea + farm animals + appendicitis ssx
Yersinia (invasive); pseudoappendicitis (appy mimic) can cause terminal ileitis
Dx: Bloody diarrhea + undercooked seafood + alcoholic who gets very sick
Vibrio parahaemolyticus (invasive)
Dx: Bloody diarrhea + poorly cooked ground beef/raw milk
E. coli O157:H7, associated with TTP (adults) and HUS (kids); NO ANTIBIOTICS
Dx: Rice-water stools + contaminated water
Vibrio cholerae (toxin). Oral rehydration tablets.
Dx and Tx: Profuse diarrhea after recent antibiotics
Clostridium difficile (invasive). Tx: PO vanco is first line now
Dx: Diarrhea + AKI ± low platelets
E. coli O157:H7 causing TTP/HUS
