Etiology and evaluation of diarrhea in AIDS: A global perspective at the millennium

Table 2 Laboratory tests used to investigate diarrhea in HIV -infected patients

Stool studies

Stool cultures (Salmonella, Shigella, Campylobacter)

Toxin (Clostridium difficile)

Stool for ova and parasites (Giardia lamblia, Entamoeba histolytica)

(using saline, iodine, trichrome and acid-fast stains)

Stool stains:

a. Modified Kinyoun acid-fast (Cryptosporidium and Isospora belli)

b. Concentrated stool (Zinc sulfate, Shether sucrose flotation)

Fecal fat

Giardia antigen

Blood studies

CD4 cell count

White blood cell and differential

Creatinine, electrolytes

Liver function tests

Total albumin

Blood cultures (Mycobacterium avium-complex)

Tissue and fluids

Duodenal aspirate (Giardia lamblia, microsporidia)

Biopsy: duodenum, jejunum, ileum, colon, rectum

Biopsy stains:

a. Hematoxylin-eosin

b. Giemsa or methenamine silver (fungi)

c. Methylene blue-azure II-basic fuchsin (microsporidia)

d. Fite (mycobacteria)

Immunohistochemical stains (Cytomegalovirus)

In-situ hybridization (CMV)

DNA amplification (CMV)

Electron microscopy for cryptosopridia, adenovirus

Touch preparation

Culture of colonic mucosal biopsy

a. Cytomegalovirus

b. Herpes simplex virus

c. Bacteria