HIV infection weakens your immune system, making you highly susceptible to a large number of bacterial, viral, fungal and parasitic infections. You may also be vulnerable to certain types of cancers. But treatment with anti-retroviral drugs has markedly decreased the number of opportunistic infections and cancers affecting people with HIV. It's now more likely these infections will occur in people who have not had treatment.
Parasitic infections
- Pneumocystis carinii pneumonia (PCP). Although anti-retroviral drugs have helped reduce the number of cases of PCP, it remains one of the most common opportunistic infections affecting people with AIDS in the United States. PCP attacks the lungs, making it difficult to breathe. Signs and symptoms include a cough that doesn't go away, fever and trouble breathing.
- Toxoplasmosis. This potentially deadly infection is caused by Toxoplasma gondii, a parasite spread primarily by cats. Infected cats pass the parasites in their stool, and the parasites may then spread to other animals. Humans generally contract toxoplasmosis by touching their mouths with their hands after changing cat litter or by eating raw or undercooked meat, especially pork, lamb and venison. Once you're infected, the parasites can spread to every organ in your body, including your heart, eyes and lungs. For many people with AIDS, toxoplasmosis leads to encephalitis, an infection of the brain. Signs and symptoms may include disorientation, seizures, and difficulty walking or speaking.
- Cryptosporidiosis. This infection is caused by an intestinal parasite that's commonly found in animals. You contract cryptosporidiosis when you ingest contaminated food or water. The parasite grows in your intestines and bile ducts, leading to severe, chronic diarrhea in people with AIDS.
