Having HIV weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections (OIs). OIs are serious infections that take advantage of your weak immune system. These infections are less common and less severe in healthy people.

People who have AIDS, the most severe stage of HIV infection, have badly damaged immune systems. This puts them especially at risk for OIs. Getting certain OIs is one of the ways that people can get diagnosed with AIDS.

OIs are becoming less common in people with HIV because of effective HIV medicines. But some people with HIV still develop OIs for different reasons:

• They may not know they have HIV, so they aren't getting treatment for it
• They know that they have HIV but are not taking treatment
• Their HIV treatment may not be working properly

There are many types of OIs:

• Bacterial infections, including tuberculosis, Salmonella infection"/>, and Mycobacterium avium complex"/> (MAC)
• Viral infections, such as cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1)
• Fungal infections, like yeast infections, Pneumocystis carinii pneumonia"/> (PCP), and histoplasmosis
• Parasitic infections, such as cryptosporidiosis and toxoplasmosis

Having HIV can make infections harder to treat. People with HIV are also more likely to have complications from common illnesses such as the flu.

If you develop an OI, there are treatments available such as antiviral, antibiotic, and antifungal drugs. The type of medicine your health care provider prescribes will depend on which OI you have.

After the OI has been successfully treated, you may still need to take the same medicine or another medicine to prevent the OI from coming back.

The best way to prevent OIs infections is by taking your HIV medicines. Other steps you can take to help prevent OIs include:

• Avoiding exposure to contaminated food and water:
  • Don't undercooked eggs, unpasteurized dairy products or fruit juices, or raw seed sprouts
  • Don't drink water directly from a lake or river
• Talking to your provider about medicines and vaccines that prevent certain OIs
• Preventing exposure to other sexually transmitted infections (STIs) by using condoms every time you have sex
• Washing your hands thoroughly with warm, soapy water after any contact with human or animal feces (poop)
• Not sharing needles, syringes, or other drug injection equipment