Reuters reports that in some parts of the world, more than half of people continue to have uncontrolled HIV despite treatment turned out to have a form of the virus, which is resistant to the drug tenofovir, “researchers report in The Lancet Infectious Diseases.”
According to the new sturdy, treatment and monitoring of HIV persists around the world has to be improved, while surveillance also needs to be stepped up, Reuters quotes senior author Dr. Ravi Gupta, of University College London.
Tenofovir is the well-known drug for treating and preventing the human immunodeficiency virus (HIV), a drug that can also be used for treating hepatitis B.
“If you develop resistance to that, it’s a very large loss,” said study author Dr. Robert Shafer, of Stanford University in California.
“The availability of second-line drugs is increasing, but they’re quite a bit more expensive and have more side effects associated with them,” Gupta told Reuters Health.
People acquire HIV resistance to tenofovir in one of two ways, Shafer said. It is either they don’t take the drug as directed and the virus mutates, or they are infected by someone with a resistant form of the virus.
In the new study, researchers used data from 1,926 people in 36 countries who continues to have uncontrolled HIV despite simultaneous treatment with an assortment of drugs, which included tenofovir. The result shows that the proportion of people with tenofovir-resistant HIV ranged from 20 percent in Europe to over 50 percent in sub-Saharan Africa.
Despite not being able to tell what causes tenofovir-resistant HIV, the sturdy was able to discover that the health of the immune system when treatment starts and the other drugs in the treatment regimen, are linked to the risk resistance.
Individuals who started treatment with a low CD4-cell count, which is a measure of the immune system’s health, were about 50 percent more likely to have resistance than those with healthier immune systems.
“We think that part of the reason is that the immune system helps the drugs,” said Gupta.
Unlike studies carried out in the past, Gupta said, the new research found tenofovir-resistant HIV reproduces itself just as much as non-resistant HIV does, which means that resistance can be passed on to other individuals.
“I think that if these trends continued . . . and you found a lot of HIV infections had resistance, then you would find the efficacy of PrEP is compromised,” said Gupta, while referring to pre-exposure prophylaxis, which is the practice of having uninfected people take anti-HIV drugs to try to avoid getting the virus.
The researchers say they can’t predict how many people with the virus will have resistance, since their research only included individuals who failed treatment.
The researchers’ estimates however, suggest that under current circumstances, about 8 percent to 18 percent of patients in sub-Saharan Africa who receive tenofovir plus efavirenz will develop resistance in the first year of treatment.