HIV is spread most commonly by having unprotected sex with an infected partner. The virus can enter the body through the lining of the vagina, vulva, penis, rectum, or mouth during sex.
HIV is also spread by sharing needles and/or syringes (primarily for drug injection) with someone who is infected. Babies born to HIV-infected women may become infected before or during birth or through breast-feeding after birth. In the health care setting, workers have been infected with HIV after being stuck with needles containing HIV-infected blood or, less frequently, after infected blood gets into a worker’s open cut or a mucous membrane.
The blood antibody testing is a two-step process: first, an enzyme-linked immunoassay (ELISA) is usually performed as a screening test. This is a highly sensitive though not very specific test that must be confirmed by a Western blot. The Western blot is an interpretive test, which requires the services of a skilled pathologist and is highly specific and sensitive for HIV. There are two different tests available, HIV-1 and HIV-2, though HIV-2 infection is rare in the United States. Most laboratories automatically perform a Western blot when a repeatedly reactive ELISA is found, and these do not have to be ordered separately.
Recently oral fluid and rapid HIV testing has become available. This service is provided to our patients through NAP (Nebraska AIDS Project) at the same time as the regular clinic. In addition to providing immediate results, NAP also provides anonymous testing.
Reporting of HIV infection is also state-specific. Most states now classify HIV infection as a reportable disease, including Nebraska. Laboratories report HIV positive tests to the Department of Health who then contacts the ordering provider for demographic information about the patient. If the patient has no known risk factor for HIV infection, the Department of Health may conduct an investigation, which involves contacting the patient for an interview; otherwise, the patient is not contacted. Recent federal legislation now mandates spousal notification, which is also performed by the Department of Health. A good “faith" effort must be made by the Department to notify any spouse of married patients who test positive for HIV.
It is generally good medical practice to confirm a diagnosis of HIV infection by repeating the test. Further testing, including CD4 cell count and viral load, would determine whether or not a patient has AIDS and could help to answer questions about prognosis.
Without treatment, life expectancy of a person with HIV infection is about 12 years, and the long term on successful therapy is unknown but may be as long as 30 years.
The only way to prevent infection by the virus is to avoid behaviors that put one at risk of infection, such as sharing needles and having unprotected sex. One should either abstain from having sex or use male latex condoms or female polyurethane condoms, which may offer partial protection, during oral, anal, or vaginal sex. Only water-based lubricants should be used with male latex condoms.
Much of the above information was provided by Susan Swindells, MD or dapted from CDC/NIH. For more information go to the NIH: HIV Infection and AIDS: An Overview