What Opportunistic Infections Do You Get With HIV?

Medically Reviewed by Jonathan E. Kaplan, MD on February 12, 2024
3 min read

If you have HIV, treating it early with antiretroviral medicines will help your immune system and allow you to stay in good health. But untreated HIV, over the course of years, will harm your immune system and can lead to opportunistic infections. "Opportunistic" means they take advantage of the weaker immune system of someone with HIV. People with healthy immune systems aren't bothered by them.

HIV attacks CD4 cells, which find and destroy bacteria, viruses, fungi, and other germs. Without enough CD4 cells to fight them off, infections can lead to illnesses, cancers, and brain and nerve problems. Certain opportunistic infections are signs that your HIV has become AIDS.

If your CD4 count stays up, opportunistic infections are less likely to be a problem. This is why you must continue to take your HIV medicines. 

If your CD4 count is low, your doctor may want you to take preventive drugs in addition to your antiretroviral medicines to lessen your chances of getting sick. If you do get sick, you can take medicines to help your body fight some of these infections.

Almost any disease can become an opportunistic infection when your immune system is weak. Some are more common than others, and depending on your CD4 count, some are more likely to occur.

  • Candidiasis or thrush, a fungal infection in your mouth, throat, or vagina
  • Cryptococcus neoformans (crypto), a fungus that can lead to meningitis, a serious inflammation of the membranes that surround your brain and spinal cord
  • Cryptosporidiosis and microsporidiosis, infections of microscopic animals called protozoa that mess up your gut
  • Cytomegalovirus (CMV), a virus that causes eye disease and can lead to blindness. It can also cause severe diarrhea and ulcers.
  • Herpes simplex, a group of viruses that cause sores around your mouth (cold sores) and on your genitals
  • Mycobacterium avium complex (MAC), bacteria that cause fevers, problems with digestion, and serious weight loss
  • Pneumocystis pneumonia (PCP), a fungus that causes a deadly lung infection
  • Progressive multifocal leukoencephalopathy (PML), a virus that affects your brain
  • Toxoplasmosis, a disease caused by a parasite that can lead to encephalitis, which is an inflammation of the brain, as well as blurry vision and eye damage
  • Tuberculosis (TB), a bacterial infection that attacks your lungs. It can also invade other organs and lead to meningitis.

Men are three times more likely than women to develop a cancer called Kaposi's sarcoma.

Women have a greater chance of getting certain infections like HPV that can lead to cancers of the reproductive system such as cervical cancer.

The most important way to prevent opportunistic infections is to take your HIV medicines and keep your CD4 count from becoming low.  If you are starting with a low CD4 count (less than 200 cells per microliter of blood), you can take steps to lower your chances of getting these infections. 

  • Take your HIV medicines and see your doctor regularly to make sure that they are working and that your immune system remains strong.  Take other medicines and get vaccinated as recommended by your doctor.
  • Wash and cook all of your food well. Avoid raw or undercooked meats and eggs, and unpasteurized dairy. Thoroughly clean and disinfect your hands, knives, cutting boards, and counters where you make food.
  • Have someone else handle cat litter or pick up dog waste, or use gloves if you do. Keep cats indoors so they don't bring in germs that could harm you.
  • Use a towel on shared gym equipment and a different towel to dry yourself.
  • Try not to swallow water in pools, lakes, or streams.
  • If you're a woman, get regular pelvic exams and Pap tests to spot infections, precancers, and cancers.

You can get lab tests to find out which germs are already in your body. This will help your doctor know what medicines or vaccines you need in addition to your HIV drugs.

If you have a low CD4 count, keep a record of your symptoms, and pay attention to:

  • Fever for more than 2 days
  • Bad diarrhea
  • Difficulty breathing
  • Weight loss
  • A change in vision
  • Problems with your mouth, skin, or breathing

Call your doctor when you have new or unusual symptoms. Don't wait for your next scheduled visit.

Because the HIV virus makes copies of itself more quickly when you have an opportunistic infection, early treatment is important. It will help you avoid the serious consequences of infection as well as preserve your immune system.

Follow through with all of the treatment. Don't quit early. Your doctor might also prescribe medication to prevent the infection from coming back, and if your immune system recovers, you may be able to stop taking that.