HIV drug resistance is approaching and exceeding 10% in people living with HIV who are about to initiate or reinitiate first-line antiretroviral therapy, according to the largest meta-analysis to date on HIV drug resistance, led by researchers at UCL and the World Health Organization (WHO) and funded by the Bill & Melinda Gates Foundation and the WHO.

The study, published today in The Lancet Infectious Diseases, looked at data for people who were beginning antiretroviral therapy, and found that resistance - particularly to one of the main types of first-line drug, NNRTIs - is increasing and those who exhibited drug resistance were more likely to have previously been exposed to antiretroviral drugs, often during pregnancy.

"Treatments for HIV have improved immensely in recent years, and close to 21 million people worldwide are now being treated with antiretroviral therapy. Yet to end the AIDS epidemic as a public health threat, minimising drug resistance will be one part of the response. Our findings show the importance of improving how we monitor drug resistance, and suggest we should review which drugs are included in first-line therapies,” said the study’s lead author, Professor Ravindra Gupta (UCL Infection & Immunity).

The researchers pulled together 358 datasets, including data from 56,044 adults across 63 low- to middle-income countries who were beginning first-line therapy for HIV from 1996 and 2016. The research was conducted by a team of 33 authors on five continents.

Current WHO treatment guidelines for first-line therapy recommend non-nucleoside reverse transcriptase inhibitors (NNRTI) in combination with nucleoside reverse transcription inhibitors (NRTI). The research team focused on studies that included data on the presence of drug-resistant mutations in the virus, most commonly resistant to NNRTI drugs.

The research team found that, from 2001-2016, the odds of drug resistance in low- to middle-income countries across Sub-Saharan Africa, Latin America and Asia were increasing. In particular, the yearly incremental increase in NNRTI resistance was greatest in Eastern Africa (29% annual increase) and in Southern Africa (23% annual increase, with an absolute increase of 1.8 percentage points from 2015 to 2016) and was the smallest in Asia (11% annual increase).

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.

The study authors 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.

Agencies