HIV Disease Progression

 

 

Many people with primary or acute (early) HIV infection have no symptoms. Others may experience an “acute retroviral syndrome” characterized by fever, fatigue, headache, and enlarged lymph nodes. These symptoms usually disappear within a week to a month, and can be easy to mistake for a bout of the flu. During this initial period HIV is believed to be very easy to transmit.

 

After HIV enters the body, it infects various types of cells, primarily targeting a type of immune system cell called CD4 cells. These cells—also called T-helper cells—play an important role in coordinating the body’s immune defenses. HIV enters CD4 cells and uses the cell’s machinery to produce new viral particles (virions), eventually killing the host cell.

 

HIV disease progresses slowly, and people with HIV may be asymptomatic (without symptoms) for ten years or longer. Infants and children infected with HIV tend to become ill sooner. As more and more CD4 cells die, immune function is reduced and the body is less able to fight infections and cancers. As this happens, people may develop symptoms such as swollen lymph nodes, fever, fatigue, and weight loss. These early symptoms may come and go. A minority of people do not develop symptoms even without treatment.

 

Some HIV/AIDS Symptoms

• Swollen lymph nodes

• Fever; night sweats

• Fatigue

• Headache

• Nausea

• Diarrhea

• Loss of appetite

• Weight loss; wasting

• Skin rashes; red or purple blotches on skin

• Thrush; vaginal yeast infections; fungal nail infection

• Mental impairment; memory loss

AIDS is the advanced stage of HIV disease. Once the CD4 count falls below 200—and especially if it drops below 50—people become susceptible to a variety of opportunistic illnesses (OIs). These are infections or cancers that usually do not cause symptoms in healthy people, but may cause serious illness in people with compromised immune systems. There are over twenty AIDS-defining conditions. HIV positive people with CD4 cell counts below 200 are classified as having AIDS even if they do not have OIs. The classic symptoms of AIDS—such as persistent diarrhea, night sweats, wasting, skin conditions, and mental impairment—are usually due to OIs. (However, as describe below, the drugs used to treat HIV can themselves cause side effects such as nausea, diarrhea, and skin rash.) Children with HIV may experience delayed development or “failure to thrive.” Diseases such as cervical cancer, hepatitis C, herpes, and tuberculosis may be much more aggressive in people with HIV, and are considered AIDS-related illnesses even though they also occur in people without HIV.

 

In recent years the incidence of OIs has fallen due to improved anti-HIV treatments. Effective treatment can keep HIV under control and help prevent the loss of CD4 cells. With appropriate treatment, some people may be able to hold off late-stage disease and the development of OIs indefinitely.

 
Some AIDS-Related Opportunistic Illnesses

• Candidiasis (thrush, yeast infection): a fungal infection characterized by white patches in the mouth, difficulty swallowing, and in women, vaginal irritation and thick, white discharge.

• Cytomegalovirus (CMV): a virus that can infect the retina of the eye (vision loss), the large intestine(diarrhea), the throat (painful swallowing), the lungs (pneumonia), and the brain (confusion and altered mental state).

• Cryptococcal meningitis: a fungal infection of the brain characterized by severe headaches, alteredmental state, and possibly seizures.

• Cryptosporidiosis: a parasite, often spread through contaminated water, that can cause nausea,severe diarrhea, and wasting.

• Histoplasmosis: a fungal infection that can cause fever, fatigue, weight loss, and difficulty breathing.

• Kaposi’s sarcoma: a cancer characterized by red or purple blotches on the skin or mucousmembranes; may also affect internal organs.

• Lymphoma: a cancer of the lymphatic system that may affect the lymph nodes, brain, or gastrointestinal tract; symptoms include swollen lymph nodes, fever, fatigue, and weight loss.

• Mycobacterium avium complex (MAC): a bacterial infection characterized by fever, night sweats, fatigue, diarrhea, and weight loss.

• Pneumocystis carinii pneumonia (PCP): a parasite that infects the lungs, causing fever, dry cough, shortness of breath.

• Toxoplasmosis: a parasite that infects the brain, causing fever, severe headaches, altered mental state, seizures, and coma.