Bacterial Gastroenteritis

Bacterial Gastroenteritis
Bacterial gastroenteritis is a bacterial infection (e.g., salmonella) in the intestines that causes nausea, vomiting, cramps, and diarrhea. It is the most common infectious cause of diarrhea in North America and Western Europe and usually results from contaminated food or water.

Patients with bacterial gastroenteritis are treated with an antibiotic and a clear-liquid or bland diet until symptoms improve. Interestingly, AZT is effective against salmonella and may be used as a preventative treatment.

Clostridium difficile
C. difficile is a bacterium that causes diarrhea in people following treatment with antibiotics. Because many patients with HIV are treated with antibiotics, they are at increased risk for developing C. difficile diarrhea, which is often profuse, watery, and foul-smelling, and may contain mucus or blood. This condition usually is treated with metronidazole, vancomycin, or neomycin. If left untreated, it can lead to serious illness.

Parasitic Infections

Amoeba
Microscopic, parasitic amoeba can cause severe diarrhea. Patients usually become infected by drinking contaminated, unpurified water. Amoeba can also be transmitted sexually if there is oral contact with feces.

An amoebic infection requires treatment with two antibiotics, metronidazole and iodoquinol, to destroy and remove the adult amoeba and amoebic cysts.

Giardia
Giardia is a water-borne parasite that inhabits streams and wells and can be found in unpurified drinking water. Like amoeba, giardia can be transmitted sexually if there is oral contact with feces.

Giardia can cause severe, often foamy diarrhea, and many patients with giardia have foul-smelling "sulfur burps." Treatment usually involves metronidazole.

Cryptosporidiosis
Cryptosporidiosis is caused by a microorganism known as Cryptosporidium parvum. Like amoeba and giardia, C. parvum lives in feces. People can become infected by eating contaminated food or water, and it can be transmitted sexually, if there is oral contact with feces.

Before the use of antiretroviral therapy, many HIV patients had cryptosporidiosis, and it was very difficult to treat. Now, the condition is rare in patients who are taking antiretrovirals. Treatment includes paromomycin, either alone or combined with azithromycin.

Preventing Parasitic Infections

Preventing the spread of parasitic infection involves practicing safe oral-anal sex, which involves the following:

• Using a protective barrier to avoid oral contact with feces
• Adequately cleaning sex toys or disposing of non-reusable sex toys after anal contact
• Washing hands and fingers adequately after anal or fecal contact