HIV and Toxoplasmosis: What to Know

Medically Reviewed by Melinda Ratini, MS, DO on April 15, 2022
5 min read

Toxoplasmosis is a common infection of the central nervous system in people with HIV. It’s caused by the parasite Toxoplasma gondii. (T. gondii). You’re at a higher risk for toxoplasmosis if you aren’t getting proper treatment for your condition. That’s because HIV can weaken your immune system. This makes it harder for your body to fight infections.

To understand how common toxoplasmosis is, you need to know how many people test positive for the T. gondiiparasite. About 10% of U.S. adults have the parasite. But up to 80% of the adult population may test positive for it in certain European, Latin American, and African countries.

If you have HIV, test positive for the parasite, and your CD4 count is under 100 cells/microL, you have about a 30% chance of reactivated toxoplasmosis (which means the infection won’t be dormant in your body).

You may be more or less likely to get toxoplasmosis based on your age. One study of U.S. women with HIV found that females aged 50 and older were more likely to test positive for T. gondii than younger women.

In the U.S, T. gondii is more common in non-Hispanic Black people than in non-Hispanic white populations. People born outside of the U.S. are also at higher risks for the parasite.

The good news is that from 1999 to 2004, the number of cases went down from 14% to 9% for people born in the U.S. between the ages of 12 and 49.

You get toxoplasmosis by eating oocysts. They’re most commonly found in soil and cat poop. The oocysts can enter your body if you handle either of these and don’t properly wash your hands before preparing food or eating.

After you eat T. gondii oocysts, they begin to spread throughout your body. They’ll begin to encyst – become closed inside a cell – and stay dormant inside your body your entire life.

You can get toxoplasmosis in other ways too, such as:

  • Eating contaminated fruits and vegetables
  • Eating undercooked meat with oocysts from an infected animal
  • Transmission from an infected pregnant or nursing person to their child
  • Transmission from an organ transplantation if the donor was infected

Undercooked meat is the main reason for infection in Asia, Europe, and the U.S. A study linked T. gondii infection to raw or undercooked ground beef, lamb, and unpasteurized goat’s milk.

Your risk of infection also goes up if you work with meat or own three or more kittens.

If you have a healthy immune system and have toxoplasmosis, you usually won’t have any symptoms. But if your immune system is suppressed, especially in the case of AIDS, your toxoplasmosis may not stay dormant. It can reactivate and lead to disease. This tends to happen when your CD4 count goes below 100. CD4 cells help your immune system fight infections.

If you have HIV and have never had T. gondii, you’ll most likely develop a severe infection if you get the parasite. If you’ve had the parasite before and have HIV, you may still have a serious infection. Symptoms could include:

  • Headache
  • Confusion
  • Bad coordination
  • Nausea
  • Vomiting
  • Fever

In people living with HIV, toxoplasmosis is the most common cause of extensive brain lesions, or damage to your brain. In addition to toxoplasmosis symptoms, you can get other complications. These include:

  • Seizures
  • Lung issues that could be similar to (and sometimes confused with) tuberculosis or pneumocystis jiroveci pneumonia, a common infection in people with AIDS.
  • Ocular toxoplasmosis, or blurred vision due to severe inflammation in your retina
  • Eye infections that can lead to blindness
  • Encephalitis, a severe brain infection (If you don’t get treatment for this illness, it can be fatal.)

Your doctor will use a blood test to figure out if you have toxoplasmosis. A positive result means that you either currently have an infection or you were once infected. More tests can tell which is the case.

To treat toxoplasmosis in people with HIV, doctors use the medicine leucovorin (folinic acid), alongside:

  • Pyrimethamine (Daraprim). This medication is usually for malaria. It works by interfering with folic acid. It is taken with leucovorin to help prevent bone marrow suppression it can cause.
  • Sulfadiazine. This is an antibiotic that you’ll use with pyrimethamine.

Or your doctor may prescribe clindamycin (Cleocin) instead of sulfadiazine.

There are many things you can do to reduce your risk of infection with T. gondii.

To lower your chances of food exposure, cook all your foods to their safe temperatures. Use a food thermometer to find the internal temperature of your cooked meats. Don’t eat meat until it’s fully cooked.

The United States Department of Agriculture (USDA) suggests that you cook different types of meat at different temperatures. Follow these guidelines:

Whole cuts of meat. Cook these to at least 145 F. Measure the temperature with a thermometer in the thickest part of the meat. Allow your meat to rest for 3 minutes before you carve or eat it. It’s important to let your meat rest. During this time, its temperature stays constant or rises, which kills pathogens.

Ground beef. Cook to at least 160 F. You don’t need to let ground meat rest.

Poultry. Cook poultry, including ground meat, to at least 165 F. Let whole pieces of poultry rest for 3 minutes before you carve or eat it.

Other ways to lower your risk of toxoplasmosis include:

  • Freeze your meat days before you cook it, which can greatly lower your risk of infection.
  • Fully wash or peel your fruits and vegetables before you eat them.
  • Clean your cutting boards, countertops, dishes, utensils, and hands with hot, soapy water after they touch poultry, raw meat, seafood, or any unwashed food.

You should also:

  • Avoid drinking untreated water.
  • Use gloves when you garden or if you come into contact with soil or sand.
  • Keep any outdoor sandboxes covered.
  • Only feed your cats canned or dried commercial cat food or fully cooked table food. Never give them raw or undercooked meat.
  • Keep your cat indoors.
  • Don’t adopt or play with stray cats or kittens.

Change your cat litter daily if you have a weakened immune system. If you can get someone else to change your cat’s litter, do so. If no one else can, wear disposable gloves and wash your hands well with soap and warm water afterward.