Resistance to HIV drugs is closing in on and rising above 10% in infected people who are about to initiate or reinitiate first-line antiretroviral therapy, according to an study led by researchers at University College London and the World Health Organization.
The study found that resistance — particularly to one of the main types of first-line drug, non-nucleoside reverse transcriptase inhibitors, or NNRTI — is increasing and those showing resistance were more likely to have previously been exposed to antiretroviral drugs, often during pregnancy.
Data included in the research came from 56,044 adults across 63 low- and middle-income countries who were beginning first-line therapy for HIV from 1996 and 2016.
According to the study, from 2001-2016, the odds of drug resistance in low- and middle-income countries across Sub-Saharan Africa, Latin America and Asia were increasing. The yearly incremental increase in NNRTI resistance was 29% in eastern Africa, 23% in southern Africa and 11% in Asia.
The study did not focus on high-income countries, but other studies have found that levels of drug resistance to NNRTIs in high-income countries were either plateauing or declining.
Researchers found drug resistance to be highest in southern Africa, where 11.1% of people beginning first-line therapy had a virus with NNRTI drug-resistant mutations, compared to 10.1% in eastern Africa, 7.2% in western/central Africa and 9.4% in Latin America.
In addition, the study found that people starting therapy who self-report previous use of antiretroviral drugs are more likely to carry a resistant virus, and are at greater risk of virological failure, which means a risk that the virus will not be adequately kept under control by the HIV treatment. Data suggests that in some areas, 10%-30% of people presenting for antiretroviral therapy have previously been exposed to antiretroviral drugs.
According to the researchers, drug resistance to NNRTIs exceeding 10% in people starting therapy could result in 890,000 more AIDS deaths and 450,000 more infections in sub-Saharan Africa before 2030 if no action is taken.
"If we are to combat HIV drug resistance, we must ensure countries can do a good job in monitoring and responding to it when needed," said co-author Silvia Bertagnolio of the World Health Organization. "New WHO guidelines and a global action plan aim to help make this happen."
A previous WHO report based on surveys from 11 countries in Africa, Asia and Latin America found that in six of the 11 countries surveyed, over 10% of people starting antiretroviral therapy had a strain of HIV that was resistant to some of the most widely used treatments.
The organization recommended transitioning patients to ViiV Healthcare Ltd.'s Tivicay, also known by its generic name dolutegravir. The company has been investigating the drug's use in a two-tablet regimen with a drug from Johnson & Johnson's Janssen unit.
The WHO's guidelines on pre-treatment HIV drug resistance recommend that countries switch to more robust first-line treatment when levels of resistance reach 10%.
Also, a five-year global action plan urges all countries and partners to join efforts to prevent, monitor and respond to HIV drug resistance and to protect the ongoing progress toward the sustainable development goal of ending the AIDS epidemic by 2030.
