Human Immunodeficiency Virus (HIV) Infection and Acquired Immune Deficiency Syndrome (AIDS)
Acquired immune deficiency syndrome (AIDS) is an infectious disease of the immune system and is considered to be the last phase of the clinical spectrum of infection by the human immunodeficiency virus (HIV). HIV is a retrovirus that affects the cells in the body that have a CD4 receptor on their surface. The types of cells that have the CD4 receptor and can be infected by the virus include lymphocytes, monocytes, macrophages, glial cells, bone marrow progenitors, and gut-associated lymphoid tissue. The CD4 T lymphocytes (also called T4 or T-helper cells) have the greatest number of CD4 receptors and are consequently the major target of HIV. These lymphocytes are ultimately destroyed by HIV, which results in severely impaired cell-mediated immunity in the host. Humoral immune function is also impaired because the B lymphocytes are unable to respond appropriately to the presence of a new antigen without the help of normal CD4 T lymphocytes. The effect of HIV on the monocyte and macro phage further depresses immune system function.
HIV has been isolated from all body fluids but at this point, transmission has been associated only with blood, semen, amniotic fluid, vaginal secretions, and breast milk. The known routes of transmission are by intimate sexual contact, mucous membrane or percutaneous exposure to infected blood or blood products, and perinatal transmission from mother to child. The four high-risk groups for acquiring HIV infection are heterosexuals with multiple sexual partners, men who have sex with men, intravenous drug users, and recipients of blood/blood products. Treating HIV-infected women during pregnancy with an antiretroviral agent (e.g., zidovudine) has significantly reduced the transmission of HIV from mother to child.
Infection with HIV tends to follow a particular course, with the clinical expression being attributed to either the effects of the virus itself or the consequences of CD4 T lymphocyte depletion. The initial event in the course of the disease is acute retroviral infection, which occurs about 1-6 weeks after exposure to HIV. The person experiences symptoms such as fever, headache, myalgias, lymph adenopathy, rash, fatigue, and sore throat that may persist for a week or longer. Then, the HIV-infected person enters the chronic infection stage. In the early period of chronic infection, the person may be asymptomatic or continue to experience mild symptoms such as fatigue, headache, and lymphadenopathy. This early period often lasts as long as 10-12 years, depending on the rate of viral replication and the rapidity of CD4 T lymphocyte destruction. The symptomatic stage of HIV infection develops when the CD4 T lymphocyte count drops below 500 cells/mm3 and the HIV viral load rises above 10,000 copies/ml. In the early symptomatic stage, the person has various nonspecific symptoms (e.g., unexplained fever and weight loss, fatigue, night sweats, peripheral neuropathy, persistent diarrhea) and persistent localized viral or fungal infections. AIDS is the last stage of HIV infection. In addition to the symptoms experienced in the previous stage, AIDS is heralded by immune suppression (serologically defined as a CD4 T lymphocyte count less than 200 cells/mm3) and the presence of a condition that meets the criteria for definition of an AIDS case as specified by the Centers for Disease Control and Prevention (CDC). These AIDS-indicator conditions include HIV-related encephalopathy, HIV wasting syndrome, opportunistic infections (e.g., Pneumocystis carinii pneumonia [PCP]; candidiasis of esophagus or bronchi, trachea, or lungs; Mycobacterium tuberculosis, Mycobacterium avium complex [MAC]; extrapulmonary cryptococcosis; cytomegalovirus infection; Toxoplasma encephalitis; coccidioidomycosis), and AIDS-related cancers (e.g., Kaposi’s sarcoma, non-Hodgkin’s lymphoma, invasive cervical cancer).
At this time, there is no cure for HIV infection. However, there have been significant advances in antiretroviral therapy and prevention of opportunistic infections that have increased the long-term survival of persons with HIV infection. Earlier treatment and the use of highly active antiretroviral therapy (HAART), which consists of a combination of at least 3 antiretroviral agents, have made significant differences in sustaining viral suppression, slowing disease progression, and reducing drug resistance. Because of the side effects of the antiretroviral agents and lack of adherence to the drug regimen, current federal guidelines suggest that treatment be offered early, but that it can be delayed until higher levels of immune suppression are observed. The antiretroviral agents used to control viral replication of HIV include nucleoside reverse transcriptase inhibitors (e.g., zidovudine, lamivudine, zalcitabine, abacavir, didanosine, stavudine), protease inhibitors (e.g., saquinavir, ritonavir, indinavir, amprenavir, nelfinavir), nonnucleoside reverse transcriptase inhibitors (e.g., nevirapine, delavirdine, efavirenz), and fusion inhibitors (e.g., enfuvirtide). Chemoprophylactic therapy to prevent AIDS-defining opportunistic infections has also led to a significant decline in the incidence of certain diseases such as Pneumocystis carinii pneumonia, Mycobacterium avium complex, tuberculosis, and toxoplasmosis.
Impaired respiratory function
ineffective breathing pattern
ineffective airway clearance
impaired gas exchange
Risk for imbalanced fluid and electrolytes
deficient fluid volume
Imbalanced nutrition: less than body requirements
oral, pharyngeal, and/or esophageal pain
skin and local tissue pain
Impaired oral mucous membrane
Actual/Risk for impaired tissue integrity
Disturbed thought processes
Risk for infection: opportunistic infection or sepsis
Risk for injury
Ineffective coping or Impaired adjustment
Risk for loneliness
Interrupted family processes
Deficient knowledge, Ineffective therapeutic regimen management, or Ineffective health maintenance
Altered comfort: chills and excessive diaphoresis
Altered comfort: pruritus
Disturbed sleep pattern
Ineffective sexuality patterns
Risk for powerlessness