AIDS-defining illnesses: pneumonia, meningitis, etc.

AIDS-defining illnesses are illnesses that occur in people living with HIV. They are one of the indications that HIV has progressed to AIDS, the most severe form of the disease.

AIDS-defining illnesses can vary in severity, and some occur more frequently than others. According to Centers for Disease Control and Prevention (CDC)they are less common now since the introduction of antiretroviral therapy (ART).

However, some may still develop an AIDS-defining illness if:

  • they don’t know they have HIV
  • they do not take ART
  • ART is unable to kill the virus

Doctors can also diagnose AIDS when CD4 counts fall below 200 cells per milliliter (ml), if they develop certain opportunistic infections, or both. Common AIDS-defining illnesses include:

Pneumocystis jiroveci pneumonia (PPJ)

A fungus called Pneumocystis jirovecii causes this type of pneumonia. It is a major cause of infection in people living with HIV, with nearly 400,000 cases worldwide each year.

Symptoms include:

  • cough
  • shortness of breath on exertion
  • fever
  • tachycardia

Doctors may prescribe a combination of intravenous (IV) antibiotics for serious infections. People at increased risk for PJP may need antibiotics to prevent a deadly infection before it develops.


A group of fungi known as candidiasis can cause candidiasis infections. One of the most common fungi is Candida albicans. While candidiasis can affect many parts of the body, doctors associate oral infections with immunocompromised people.

People with this infection may experience difficulty or pain when swallowing food. Doctors will recommend an antifungal treatment to treat it.


Coccidioides the fungus can cause coccidioidomycosis or, as it is sometimes called, “valley fever”. Infection can occur if someone inhales the fungal spores.

People with this infection may generally feel unwell or have no symptoms. Antifungal medications, such as azoles and amphotericin B, can treat this infection.

Cryptococcal meningitis

This form of meningitis results from a fungal infection that causes inflammation of the brain and spinal cord.

HIV-associated cryptococcal meningitis is responsible for approximately 150,000 to 200,000 deaths per year. People with the disease may experience:

  • fever
  • headache
  • confusion
  • nausea
  • behavioral changes

Doctors can prescribe antifungal treatment starting with a combination of liposomal amphotericin B and flucytosine. Long-term use of fluconazole is important to rebuild the body’s immune system. People generally respond to treatment and symptoms improve.


This disease is caused by the fungus Histoplasma capsulatum. It can enter the lungs and cause infection long after initial contact with the fungus.

Symptoms may resemble those of the flu, including fever, weight loss, and fatigue. Histoplasmosis becomes AIDS defining when the fungus spreads outside the lungs and affects other parts of the body. This can cause an enlarged liver or spleen, lung symptoms, and adrenal gland problems.

Treatment may involve intravenous liposomal amphotericin followed by administration of the antifungal drug itraconazole for severe cases.


Cryptosporidium, a type of parasite, causes cryptosporidiosis. It causes severe diarrhea and abdominal pain. Doctors treat it with antiparasitic drugs, such as nitazoxanide and azithromycin.


Toxoplasmosis is a Toxoplasma gondii infection. This parasite lives in animal feces and contaminated food.

When the CD4 count drops dramatically, less than 50 ml cubes, there is an increased risk of developing encephalitis, or brain inflammation, due to toxoplasmosis. Preventive measures include the administration of drugs, especially if antibodies against the parasite are present in the blood.

Cytomegalovirus (CMV)

CMV infections can affect many parts of the body. When it affects the eye, it causes CMV retinitis. Without treatment, the disease can progress rapidly.

CMV can cause increased floaters in the eye or loss of peripheral vision. However, not all individuals show symptoms. There is a range of oral and intravenous antiviral drug options that can be effective against CMV infections.

Mycobacterium avium complex (MAC)

Mycobacteria cause MAC. In a person with AIDS, the infection can spread throughout the body. Symptoms may include fever, night sweats, abdominal pain that lasts for several weeks. MAC usually affects people with low CD4 counts less than 50 microliters.

How a doctor prevents and treats MAC depends on each individual’s situation. If a person is not already on antiretroviral therapy, a doctor can initiate it immediately. If this is not possible, they may be given medication to prevent generalization of MAC.

If someone has an infection, doctors may use a combination of antimycobacterial drugs, such as azithromycin or clarithromycin.

Tuberculosis (TB)

Tuberculosis occurs due to Mycobacterium tuberculosis bacteria. The World Health Organization (WHO) estimates that tuberculosis is the cause of death in 13% people with AIDS. It leads to lung infections and can cause coughing, fatigue, weight loss and fever.

Recommendations for treating TB in people living with HIV are the same as for treating adults without the virus. A doctor can prescribe the following anti-tuberculosis drugs in specific treatment regimens:

  • isoniazid
  • rifampin
  • ethambutol
  • pyrazinamide

Salmonella sepsis

people can get Salmonella from contaminated food or water sources. In people with HIV, the bacteria can enter the bloodstream and travel to other parts of the body, causing serious illness.

People tend to have symptoms of gastroenteritis with this disease. Doctors may prescribe an antibiotic called fluoroquinolone to treat it.


People living with HIV can suffer from persistent lung infections. Various bacteria, viruses and fungi can cause this. Therefore, it is advisable to get vaccinated annually against influenza, PCV13 and PCV23 to help prevent this.

HIV-related leukoencephalopathy

Human polyomavirus 2, or JC virus, causes this disease in people living with HIV. Symptoms may vary but may include:

  • clumsiness
  • progressive weakness
  • visual and voice changes

There are limited treatment options for this disease. The main therapeutic approach is to reverse the response of the damaged immune system to HIV infection.

HIV wasting syndrome

Wasting refers to the involuntary loss of more than ten% of a person’s body weight over 30 days, as well as weakness and diarrhea. There are no standard treatment options for this syndrome.

About Bradley J. Bridges

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