Diarrhea

Chronic diarrhea is a major problem in HIV infected children. Organisms responsible for diarrhea include :-

Chronic diarrhea lasts for > 14 days and is associated with weight loss. Treatment consists of correction of dehydration and nutritional rehabilitation (as per IMCI) as well as treatment of specific organism causing the diarrhea.

Cryptosporidium

Cryptosporidium protozoa invade the gut mucosa causing profuse non bloody watery diarrhea leading to dehydration and malnutrition. Three common species infecting humans are C. hominis, C. parvum, and C. meleagridis. It is transmitted by ingestion of oocysts excreted in the feces of infected humans and animals. The parasite tends to affect the jejunum and terminal ileum (7). Cryptosporidium can migrate into the bile duct and result in inflammation of the biliary epithelium, cholecystitis and cholangitis.

Diagnosis :

 Microscopic examination of stool sample with modified acid fast stain for detection of acid-fast positive oocysts. Immunoflorescence and ELISA of stool are more sensitive and specific. At least 3 stool samples should be submitted for oocyst evaluation as oocyst excretion can be intermittent.

Treatment :

 Immune restoration after HAART frequently results in clearance of Cryptosporidium. No consistently effective therapy exists for cryptosporidiosis in HIV infected children. Agents that can be tried are:

• Nitazoxanide
  • In children 1-3 years : 100 mg by mouth twice daily for 3 days
  • In children 4-11 years : 200 mg by mouth twice daily for 3 days
• Pararomycin : 25-35 mg/kg/day in 3-4 divided doses (period unknown)
• Azithromycin : 10 mg/kg on Day 1 & then 5 mg/kg PO OD for 2-10 days

Prophylaxis

• Advocate proper hand washing
• Drinking water should be boiled and filtered. (Filters capable of removing particles 1 um in diameter)
• Rifabutin or Clarithromycin when taken as prophylaxis against MAC has been found to protect against cryptosporidiosis (38, 39). However, studies are not extensive to recommended these drugs as chemoprophylaxis for cryptosporidiosis.

Microsporidia

Microspora are obligate spore forming protozo?a that cause moderate to severe diarrhea with weight loss. They are transmitted by feco-oral route due to contamination of food or water. Diagnosis is established by examination of concentrated stool or duodenal aspirate with modified trichrome stain.

Treatment

Immune restoration after HAART frequently results in clearance of microsporidia. No consistently effective therapy exists for microsporidia. Agents used:

• Albendazole :- 7.5 mg/kg/dose BD (max dose : 400 mg BD)
• Nitazoxanide
  • 1-3 years: 100 mg by mouth twice daily x 3 days
  • 4-11 years: 200 mg by mouth twice daily x 3 days
• Fumagillin: It is an antibiotic derived from the fungus Aspergillus fumigatus. (Dose = 20 mg/dose three times daily for 2 weeks). Adverse effects include dose related bone marrow toxicity. Fumagillin is not available in India.

Prophylaxis

•  Advocate proper hand washing
• No chemoprophylaxis is known to prevent microsporidiosis.

Isospora Belli & Cyclospora
These organisms are rare causes of chronic diarrhea in HIV infected children. Diagnosis is established by characteristic oocytes on microscopic examination of the stool with modified acid fast stain.

Treatment for Isospora

• TMP/SMX - 20 mg/kg/day of TMP in 4 divided doses for 10 days and then twice a day for 3 days.
• Pyrimethamine with folinic acid can be used in patients allergic to sulfonamide.

Treatment of Cyclospora

                        TMP/SMX - 10 mg/kg/day of TMP in 2 divided doses for 7 days.

Prophylaxis

• Advocate proper hand washing
• Drinking water should be boiled and filtered
• TMP/SMX used as prophylaxis for PCP also protects against Isospora and cyclospora.
• Secondary prophylaxis with TMP/SMX [150 mg/m2/day of TMP] is recommended to prevent relapse.

Treatment and Diagnosis of Amoebiasis, Giardiasis, bacterial and viral infections is the same as that of an HIV uninfected child. No chemoprophylaxis is advocated.