i-Base

Glossary

Selected words and phrases

wild-type virus – HIV that has no drug resistance mutations.

This is usually the virus that you were first infected with. However, approximately 10% of people who are diagnosed with HIV in the UK are likely to already have resistance to one or more HIV drugs.

This is called transmitted drug resistance. This is also why everyone diagnosed with HIV should also have a resistance tests.

Rates of transmitted drug resistance vary in different countries.

frequency – how often.

specificity – when referring to the accuracy of a test result, specificity refers to the proportion of people who do not have an illness or disease who have a negative test result.

If a test has low specificity, the concern is over false-positive results – where people who to not have a condition are wrongly diagnosed as having it.

If a test has high specificity, then people who to not have a condition are correctly ruled out from the condition.

For a serious condition, high specificity is essential to prevent people being unnecessarily treated.

Online calculator.

See sensitivity.

combination therapy – using three or more drugs together to treat HIV. It is also called triple therapy, cART (combination antiretroviral therapy)  or HAART (highly active antiretroviral therapy).

RNA – an abbreviation for the scientific word for genetic material found in some types of viruses. It is the abbreviation for ribonucleic acid. It is very similar to DNA but is single-strand rather than the double-strand in DNA. See DNA.