Glossary of Key Concepts and Terms
- Active Infection
An infection that is currently producing symptoms or in which the causative organism of the disease is rapidly reproducing. For example, a person may be infected with the herpes virus yet only when herpes lesions (e.g., cold sores on the mouth or sores on the genitals) are present is it considered an active infection. People may transmit infections even when they are not active.
- Primary Infection
The earliest stage of HIV infection, usually describing the time from initial infection by the virus and the first few months afterward. Beyond this time, HIV disease is thought of as a chronic infection.
- Latent Infection
Describes a time when an infectious organism is present, but not actively reproducing and therefore not causing symptoms or harm to the body and/or immune system. When an infection is persistent without causing damage, obvious or subtle, this is described as a latent infection. People may transmit infections even when they are latent. For long periods during the course of HIV infection, there are often no obvious symptoms or physical signs of disease, even though the virus is present, actively reproducing itself and causing damage to the immune system. In this setting, HIV is not a latent infection.
- Drug Resistance
The ability of a disease-causing organism to continue growing and reproducing despite the presence and activity of drug(s) which suppress that organism's growth. In HIV, this happens when the virus mutates -- or changes in the process of reproduction -- in a way that makes new copies of the virus insensitive or less sensitive to particular anti-HIV drugs. Once resistant mutants are produced, they can grow rapidly despite the continuing presence of the drug. People who have higher HIV levels are more at risk for developing drug resistant HIV, as are people who have developed resistance to drugs that are similar to those they are taking.
- Human Papilloma Virus (HPV) Types
There are more than 70 identified types of human papilloma virus, and approximately 20 of these infect the cervix. HPV-related genital and anal warts are caused by certain HPV types (mostly types 6 and 11) and other HPV types (such as types 16, 18, 31) are strongly associated with dysplasias (a pre-cancerous condition) and cervical cancer. Most people with HPV are infected with a dominant type, however studies have shown that some women living with HIV have multiple HPV types. Some researchers now suggest that HPV DNA testing (which distinguishes HPV types) may be a more effective way of identifying high-risk HPV types before they cause disease, as opposed to relying on standard Pap smears, which only indicates the presence of problems once HPV-related symptoms appear.
- Viral Load
The amount of virus measurable in blood or other fluid or tissue. The viral load number has been shown to be a good predictor of the risk of HIV disease progression, particularly among people with CD4+ cell counts greater than 50.
- "Undetectable" or "Below The Limit Of Detection" Viral Load
A viral load measurement below the lower limit to which a particular form of viral load test can reliably count (for the most standard tests, the lower limit of detection is around 400-500 copies per cubic milliliter per blood). It does not mean the virus is not there, just that it is present in such low numbers, making it impossible to measure with the standard test. "Supersensitive" or ultra-sensitive versions of the viral load tests are also available which can measure accurately down to 20 to 50 copies of virus. Viral load below this limit, however, still does not mean that HIV is gone, but only that it is harder to find. The main benefit identified so far from suppressing viral load below the limit of detection on the supersensitive or ultra sensitive test is that this usually results in the longest possible protection against the development of drug resistant virus.
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