HIV infects the body’s T helper cells, which help coordinate the actions of immune system cells. HIV attaches itself to the CD4 protein of the T helper cell. It then enters the cell and reproduces itself. The copies then infect other cells and the process continues. This process reduces the amount of available T helper cells, thereby causing the weakened immune system. During this process, which can take several years, there are four stages of HIV infection that take place: 1) primary infection, 2) asymptomatic stage, 3) symptomatic HIV infection, and 4) progression from HIV to AIDS (Avert, 2008).
1. Primary HIV Infection This stage only has the duration of a few weeks, and is frequently misdiagnosed as the flu virus. The immune system responds to the presence of the virus. HIV antibodies and cytotoxic lymphocytes are produced in a process called seroconversion. An HIV antibody test, performed before this process is complete, may produce a false negative result (Avert, 2008). 2. Asymptomatic Stage This stage can have a duration of 10 years. There are no symptoms present during this stage. Antibody tests can produce a positive result. HIV is active in the body’s lymph nodes.
The viral load test, which measures HIV genetic material in the lymph nodes, is important in treating HIV infection (Avert, 2008). 3. Symptomatic HIV Infection Over time, HIV has been working to destroy the immune system. Now, as the immune system is failing, many symptoms appear. Symptoms will start out mild, but as the immune system fails further, the symptoms will get worse (Avert, 2008). This stage’s symptoms are caused by opportunistic infections and cancers, which are normally prevented by the immune system (Avert, 2008). Aegis (2001) provided a list of the most common opportunistic infections and cancers associated with HIV infection:
• Mycobacterium Avium Complex – a bacteria that causes respiratory tract infection • Salmonellosis – a bacterial infection from ingesting contaminated food or water • Syphilis and Neuroshyphilis – caused by sexually transmitted diseases • Tuberculosis – a bacterial infection that affects the lungs and lymphatic system • Bacillary angiomatosis – causes tumor-like masses in the bone, skin, liver, and other organs; considered an AIDS defining condition • Aspergillosis – a fungi infection of the lungs and sinuses • Candidiasis – causes vaginal yeast infection • Coccidiodomycosis – causes infection in the lungs
• Cryptococcal Meningitis – usually involves the brain and lungs; advance stages involve any organ • Histoplasmosis – causes fungal infection in the lungs and other internal organs • Kaposi’s Sarcoma – causes lesions on lymph nodes, mouth, gastrointestinal tract, lungs, and other internal organs; most common AIDS-related cancer • Systemic non-Hodgkin’s Lymphoma – infects lymph nodes, central nervous system, liver, and bone marrow • Primary CNS Lymphoma – infects the central nervous system; causes paralysis on one side of the body, seizures, confusion, and memory loss; considered an AIDS defining condition
• Cryptosporidiosis – infection of intestines by parasite contracted by ingesting contaminated food or water • Isosporiasis – intestinal disease caused by parasitic infection • Microsporidiosis – includes many parasite species infections harmful to HIV patients • Pneumocystis Carinii Pneumonia – a lung infection; considered an AIDS defining condition • Toxoplasmosis – a brain infection contracted by ingesting contaminated food or water • Cytomegalovirus – a herpes-type virus that attacks the eyes, colon, and throat • Hepatitis – can cause serious problems to an HIV patient • Molluscum Contagiosum – causes an outbreak similar to small pox