Splitting the sample size roughly into two groups the study found that in Africa 60% of patients were resistant to Tenofovir, whereas in Europe the figure was only 20%.
The paper, which has been published in The Lancet Infectious Diseases journal,
said poor administration of the drug, in terms of regularly taking the right levels of Tenofovir could be explanation for the discrepancy.
"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 Gupta told the BBC News website.
"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," he added.
The paper also suggested that Tenofovir-resistant strains of HIV could be passed on from person to person.
"We certainly cannot dismiss the possibility that resistant strains can spread between people and should not be complacent. We are now conducting further studies to get a more detailed picture of how Tenofovir-resistant viruses develop and spread," Dr Gupta said.
Friday, January 29, 2016
Bad HIV news
HIV becoming resistant to key drug, study finds - BBC News