AIDS-Defining Illnesses

AIDS-defining illnesses (ADIs) are cancers and opportunistic infections that can affect people with advanced HIV (human immunodeficiency virus). Opportunistic infections are ones caused by infectious agents (germs) that wouldn’t normally make you sick but have an opportunity to do so when your immune system is weakened.

Healthcare providers use CD4 cell counts (a type of T cell that HIV destroys) and AIDS-defining illnesses as criteria to stage HIV, or determine how far the illness has progressed. If you have HIV and an AIDS-defining illness, you have stage 3 HIV (AIDS).

For some people, a diagnosis of an AIDS-defining condition leads to an HIV diagnosis. But having an AIDS-defining illness doesn’t mean you have HIV. While some ADIs mostly affect people with HIV or a weakened immune system, many ADIs can affect people who don’t have underlying health conditions.

What are the types of AIDS-defining illnesses?

Types of AIDS-defining illnesses include infectious diseases (like fungal, bacterial, parasitic and viral infections), certain cancers and some neurological conditions.

Fungal infections

AIDS-defining fungal infections include:

• Pneumocystis pneumonia (PCP)
• Candidiasis of your bronchi, esophagus, trachea or lungs
• Coccidioidomycosis that’s spread outside of your lungs (disseminated/extrapulmonary)
• Chronic intestinal cryptosporidiosis (lasting more than a month)
• Cryptococcosis in organs other than your lungs (extrapulmonary)
• Histoplasmosis that’s spread outside of your lungs (disseminated/extrapulmonary)

Bacterial infections

AIDS-defining bacterial infections include:

• Tuberculosis (Mycobacterium tuberculosis) in people age 6 and older
• Other Mycobacterium infections, including Mycobacterium kansasii and Mycobacterium avium complex (MAC) that have spread outside of your lungs (disseminated/extrapulmonary)
• Multiple or recurrent bacterial infections in kids younger than age 6
• Recurrent nontyphoid Salmonella septicemia (when a Salmonella infection enters your blood and spreads throughout your body)

Parasitic infections

AIDS-defining parasitic infections include:

• Toxoplasmosis in your brain (except for infants under 1 month old)
• Chronic intestinal cystoisosporiasis that lasts more than a month

Viral infections

AIDS-defining viral infections include:

• Herpes simplex bronchitis, pneumonitis or esophagitis (except for infants under 1 month old)
• Herpes simplex ulcers that last longer than a month
• Cytomegalovirus disease (in organs other than your liver, spleen or lymph nodes), including cytomegalovirus retinitis (except for infants under 1 month old)
• Progressive multifocal leukoencephalopathy

Cancers

Low T cell counts can put you at higher risk for cancers caused by viruses or ones that affect your immune system. AIDS-defining cancers in people with HIV include:

• Kaposi sarcoma
• Burkitt lymphoma
• Invasive cervical cancer
• Immunoblastic lymphoma
• Primary lymphoma of the brain

Other conditions

Other AIDS-defining conditions include:

• Recurrent pneumonia (in adults and kids age 6 and older). Pneumonia is a lung infection that can be caused by viruses, bacteria or fungi.
• HIV encephalopathy. This is when HIV affects your brain’s ability to function.
• HIV wasting syndrome. Wasting syndrome causes weight loss and weakness.

What are the most common AIDS-defining illnesses?

The most common AIDS-defining illnesses include:

• Pneumocystis pneumonia
• Kaposi sarcoma
• HIV wasting syndrome
• Esophageal candidiasis
• Mycobacterium avium complex infections
• Tuberculosis

What are the symptoms of AIDS-defining illnesses?

Symptoms of AIDS-defining illnesses depend on the disease causing them. Some common symptoms of infections include:

• Fever
• Headache
• Muscle aches
• Sore throat
• Shortness of breath
• Rash
• Diarrhea
• Confusion or other mental changes

What causes AIDS-defining illnesses?

HIV is a virus that destroys T cells — part of your immune system that helps fight infections. If you have too few T cells, your body can’t fight infections like it normally would. This can cause you to get sick with things that people with healthy immune systems don’t. It can also lead to certain cancers of your immune system or ones that are caused by viruses.

Antiretroviral therapy (ART), the treatment for HIV, is very effective at keeping your immune system healthy. But you can get an ADI while on ART if:

• You aren’t able to consistently take your medications
• Your medications aren’t working well
• You have an ADI without symptoms before starting ART (when you first start ART, it can sometimes cause an immune reaction and allow infections to become symptomatic (immune reconstitution inflammatory syndrome)

How are AIDS-defining illnesses diagnosed?

How your provider diagnoses an AIDS-defining illness depends on your symptoms. They may test your blood or other body fluids or perform a biopsy. They may also use imaging to look for changes in your lungs or other organs.

If you’re diagnosed with an AIDS-defining illness without an HIV diagnosis, a provider might also test you for HIV or other causes of a weakened immune system.

What tests will be done?

Tests and procedures your provider might use include:

• Blood tests
• Nasal swab
• Biopsy
• Sputum test (you cough up mucus from your lungs to test for infections)
• Stool test
• Chest X-ray
• CT scan
• Lumbar puncture (spinal tap)
• HIV test

How are AIDS-defining illnesses treated?

Treatment depends on the type of illness you have and your specific situation. If you aren’t on antiretroviral medications, you may begin treatment right away or within two to four weeks of starting treatment for opportunistic infections.

If you already have an HIV diagnosis and are on ART, your provider may perform tests to check how well your medications are working.

Treatment for specific ADIs could include:

• Antibiotics for bacterial infections
• Antifungals for fungal infections
• Antiparasitics for parasitic infections
• Surgery, radiation or chemotherapy for cancers

Can AIDS-defining illnesses be prevented?

Antiretroviral therapy is very effective at keeping viral loads low, which increases your T cell counts. This keeps your immune system healthy enough to fight off infections, including viruses that cause HIV-related cancers.

Other ways to reduce your risk of infections include:

• Preventive medications. Your provider might prescribe preventive medications, like antibiotics and antifungals, to reduce your risk of certain infections.
• Vaccination. Ask your provider which vaccinations you should get and if there are any you should avoid.
• Screenings. Your provider might recommend regular screening for certain cancers and infectious diseases.
• Don’t share drug injection equipment. This includes needles and syringes for prescription and non-prescription drug use.
• Good hygiene. Wash your hands frequently, especially before preparing food or eating, and after going to the bathroom. Don’t share food, drinks or personal items with other people.
• Food safety. Don’t consume undercooked eggs, unpasteurized milk (or food made from it, like cheese or ice cream) and unpasteurized juices. Wash or peel fruits and vegetables before eating.
• Avoid drinking or contact with untreated water. This includes getting water in your mouth while swimming in lakes or other natural water sources and drinking untreated tap water. If you’re visiting an area where you’re unsure if the water is treated, drink bottled water and use it for cooking.

What can I expect if I have an AIDS-defining illness?

Having an ADI increases your risk of dying from an AIDS-related complication. But the number of deaths from AIDS-related infections has come down a lot in recent years. About 1 in 4 people with HIV die from AIDS-related complications. With early antiretroviral therapy, many people with HIV no longer progress to AIDS.

When should I see my healthcare provider?

If you have HIV, attend all of your scheduled appointments with your provider. Let them know about new or worsening symptoms or if you’re having trouble taking your ART medications as prescribed. Ask them about steps you can take to prevent infections and what to do if you have symptoms of an infection.

When should I go to the ER?

Go to the emergency room if you’ve been exposed to HIV or if you have signs of serious illness, including:

• Fever over 103 degrees Fahrenheit (40 degrees Celsius)
• Difficulty breathing
• Severe vomiting or diarrhea
• Chest pain
• Confusion or disorientation
• A wound that’s hot, red, swollen, painful or not healing

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

• How do I take my medications?
• What should I do if I miss a dose?
• What can I do to prevent infections?
• What symptoms should I look out for?
• When should I go to the ER?