A 27-year-old, HIV-positive, male comes to his physician wit

[kailash]

A 27-year-old, HIV-positive, male comes to his physician with a 2-day history of fever, profuse watery diarrhea and abdominal cramps. His current medications include zidovudine, didanosine, indinavir, trimethoprim-sulfamethoxazole and clarithromycin. His CD4 count is 45/cubic mm of blood. His vitals are, PR: 102/min; RR: 14/min; Temperature: 37.9C(100.2F); BP: 105/70mm Hg. He is started on fluid and electrolyte support. What will be the most appropriate next step in his management?

A. Stop antibiotics and send stool for clostridium difficle toxin assay
B. Colonoscopy and biopsy of the ulcers
C. Stool examination
D. Start empirical antibiotic for gram negative organisms
E. Loperamide and lactose-free diet until diarrhea subsides

[kailash]

Explanation: Answer C

Diarrhea, in HIV-infected patients, can be due to multiple etiological agents like Salmonella, Shigella, Campylobacter, Clostridium difficile, Giardia, Cryptosporidium, Mycobacterium avium complex and Cytomegalovirus. Therefore, an etiologic diagnosis must be made before starting antibiotic therapy. Stool examination (Choice C) should be done first in all HIV-infected patients with diarrhea for bacterial culture, ova and parasites. Colonoscopy and biopsy of the ulcers (Choice B) is reserved for those with persistent diarrhea and negative stool examination. Antibiotic therapy (Choice D) is begun once a diagnosis is established. Lactose free diet and loperamide (Choice E) are used when diarrhea is persistent and no cause is found. It is more likely that an infective organism-causing diarrhea than antiviral/antibiotic medication induced. So, for his given CD4 count it is not appropriate to stop either TMP+SMX or clarithromycin when the cause is less likely because of the medications. However, you can just send stool for C.difficle assay