Diarrhea in HIV pts

Diarrhoea is common in patients with HIV. This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections or non-OI

Possible causes

• Cryptosporidium + other protozoa (most common, usually watery)
• Cytomegalovirus (mostly when CD4 < 50, usually bloody because of CMV colitis which causes deep ulcers eroding into blood vessels)
• Mycobacterium avium intracellulare
• Giardia

non-infectious causes (e.g  Kaposi sarcoma or lymphoma of the GI tract)

Hematochezia and lower abdominal cramps are usually due to colonic infection with CMV, Clostridium difficile, Shigella, E. histolytica, or Campylobacter.

Cryptosporidium

Cryptosporidium is the most common infective cause of diarrhoea in HIV patients (especially if CD4 count < 180 cells/mm3). It is an intracellular protozoa and has an incubation period of 7 days. Presentation is very variable, ranging from mild to severe (profuse, watery) diarrhoea.

A modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium.

Treatment is generally supportive - for patients with advanced HIV and cryptosporidiosis, initiation of antiretroviral therapy (ART) is the primary intervention. If diarrhoea is severe then the antimicrobial nitazoxanide may be used.

CMV colitis

In a HIV +ve patient, bloody diarrhoea and a normal stool examination are highly suspicious for CMV colitis and warrant a colonoscopy with biopsy.

CMV may also cause esophagitis, gastritis, colitis, proctitis, or small bowel disease.

Colonoscopy shows multiple mucosal erosions and colonic ulceration.

Biopsy shows the presence of large/giant cells with eosinophilic intranuclear and basophilic intracytoplasmic inclusions ("owl's eye" effect)

Tx: