Stanford-led study finds limited mutations involved in transmission of drug-resistant HIV
In the largest study of its kind to date, researchers at Stanford University School of Medicine and their colleagues have found that worldwide only a limited number of mutations are responsible for most cases of transmission of drug-resistant HIV. HIV, the virus that causes AIDS, can mutate in the presence of antiviral drugs, and these mutations can be transmitted from one person to the next.
In the new study of more than 50,000 patients in 111 countries, the researchers found a small group of mutations accounted for a majority of the cases of transmission-related resistance to the HIV drugs used to treat infections in resource-limited settings. The results suggest the levels of transmission of drug-resistant strains have not increased globally as much as once feared, said Robert Shafer, MD, professor of medicine at Stanford and principal investigator for the study.
"What we are showing is that the rates of transmitted drug-resistant HIV in the low- and middle-income countries most affected by HIV have increased modestly. The rate of increase in sub-Saharan Africa has been low, and an increase has not been detected in south Asia and Southeast Asia. That's good news," Shafer said.
However, there continues to be an increase in drug resistance because the regimens used by HIV patients in lower-income countries are often not as robust as those used in upper-income countries, and strict adherence to a daily, lifetime regimen of taking the pills is challenging, particularly for people in the poorest parts of the world, he noted.
"It is inevitable that transmitted drug resistance will increase further, so we need to continue ongoing monitoring to ensure successful, long-term treatment outcomes for the millions of people on therapy worldwide," Shafer said.
He said the findings could have important implications for treatment in these hard-hit regions, leading to the possible development of an inexpensive test for key mutations to help determine which drugs should be given to previously untreated patients.
The study will be published 7 in PLOS Medicine.
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