HIV treatment has become highly effective, but the virus can sometimes develop changes that make particular medicines less effective. HIV resistance testing examines these changes and helps healthcare professionals understand which antiretroviral medicines may be suitable. It is a laboratory-based test and is interpreted alongside a person's treatment history, viral load, and other clinical information.
HIV resistance testing generally looks for genetic changes in HIV that are associated with resistance to specific medicines. The test may involve analyzing a blood sample and examining the virus's genetic material.
There are different approaches to resistance testing, and the choice depends on the clinical situation.
Resistance testing does not diagnose HIV itself. Instead, it provides additional information about the virus after HIV infection has been identified. Results may help healthcare professionals understand whether resistance could be contributing to a high or increasing viral load.
Resistance can develop when HIV medicines do not fully suppress the virus. Missing doses, drug interactions, inadequate treatment combinations, or other factors can sometimes contribute to treatment failure and the development of resistance. However, resistance can also be transmitted from one person to another, meaning someone may have resistant HIV before starting treatment.
Testing can therefore provide useful information in several situations.
The meaning of a resistance test should always be discussed with a qualified healthcare professional. A detected mutation does not necessarily mean that every medicine in a particular drug class will be ineffective. Interpretation depends on the specific mutations, medicines involved, previous treatment, and the overall clinical picture.
Understanding HIV resistance testing can make conversations about treatment clearer and more informed. The test provides valuable laboratory information, but treatment decisions should be individualized and made with appropriate medical guidance.