Crypto and HIV/AIDS

Although a relatively minor illness in healthy individuals, cryptosporidiosis can be fatal in immunocompromised patients. It can lead to severe diarrhea and wasting, which are resistant to treatment. It is estimated that 15-20% of AIDS patients are also infected with crypto.

Healthy Host	Host with HIV/AIDS
Sporozoites normally invade jejunum and ileum	Sporozoites can invade stomach, duodenum, colon, and biliary tract
Immune response consists of cell-mediated responses	Little immune response is generated
Parasite is cleared from host	Infection can reappear if CD4 cell count drops below 200
Infection results in general GI symptoms	Infection can cause death

The appearance of symptoms is closely linked with the CD4 count in an HIV patient. If the CD4 count is above 200, the patient might feel better in two to three weeks, but the parasite will still persist in the body. If the CD4 count drops below 200, symptoms may reappear. In recent years, however, it has been determined that HAART therapy can clear crypto from an individual with AIDS by reconstituting the immune system.

Scientists are also researching other drug options to treat crypto infections in immunocompromised individuals. One drug that has shown promise in early trials using animal models is nitazoxinide, or NTZ. It has a dose-dependent effect on reduction of oocyst shedding, thus lowering the potential for transmission.

People with AIDS should be careful to avoid contact with human waste. Washing your hands is the single most effective way of preventing crypto transmission. There are concerns about drinking water supplies, and AIDS patients should check with their local water department to determine if special precautions need to be taken.

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