“If the right levels of the drug are not taken, as in they are too low or not regularly maintained, the virus can overcome the drug and become resistant,” Dr. Ravi Gupta, a researchers at University College London, told BBC News. “Tenofovir is a critical part of our armamentarium against HIV, so it is extremely concerning to see such a high level of resistance to this drug.”
The study, published in The Lancet Infectious Diseases, followed more than 2,000 HIV patients in Africa and Europe starting 2012. They found 60 percent of patients in Africa were resistant to tenofovir, compared to just 20 percent of patients in Europe.
Gupta said better administration of HIV and AIDS care for patients, as well as better ways to help people take the drugs properly, could solve the problem but would require funding to build facilities and improve care programs.
Additional studies also are being conducted to determine how the virus has become resistant to tenofovir.