One in six South Africans has potential viral resistance to ART

At the Conference on Retroviruses and Opportunistic Infections (CROI2019), it was announced that up to 17% of South African people who had not previously been treated and who had evaded HIV testing may have a drug-resistant strain of the virus, and more than half of those who passed therapy, have resistance to at least one drug (ART).

A new assessment of the degree of resistance (LU) of the South African population to antiretroviral drugs revealed that it is necessary to change the priority of using an integrase inhibitor in South Africa in first-line regimens and strengthen support for the commitment of people receiving ART. Also, to prevent the development of drug resistance, emphasis should be placed on the earliest possible transfer of patients from unsuccessful to effective regimens.

South Africa’s HIV treatment program, with more than 4.4 million people already involved, is the largest in the world. By the end of 2020, South Africa plans to reach another two million people with therapy, and by the end of this year, introduce a dolutegravir-based regimen as a first-line treatment priority. This decision is based on the fact that the medication has the highest barrier to HIV resistance compared to other ART.

Like other countries, South Africa is also considering how to deal with potential fetal neural tube defects in mothers exposed to dolutegravir during conception. Some countries have decided not to prescribe the drug to women of childbearing age, but now they are urgently faced with the need to balance this refusal with the need to prescribe the most effective treatment regimen.

As part of the fifth South African national study on the prevalence of HIV-related morbidity and behavior, in 2017, specialists first tested for drug resistance to the virus. According to the authors of the work, the survey could include people who had not previously sought medical help or refused it.

The study identified 2294 people with HIV, of which 1107 had an undetectable viral load. Drug resistance testing was successful in 697 cases (in the rest, the samples were either insufficient or the viral loads were too low for testing).

LN mutations were detected in 200 people (27.4% of those tested for resistance). The most common form of LN was the class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) (18.9% of all tested samples), 7.8% of the sample had resistance to both NNRTIs and at least one drug in the class of NRTIs, and 0, 5% - to NNRTIs, NRTIs and protease inhibitors.

More than half of all those who tested positive for traces of antiretroviral drugs in the blood (checked to confirm treatment status, as the population was not associated with clinical records) had at least one drug resistance mutation (55.7%), most often with drugs, both in the NNRTI class and in the NRTI class (40.4%).

Among people who reported that they had never taken antiretroviral drugs and had negative ART results when taking samples, 15.3% had drug resistance, all to the class of NNRTIs (viruses with resistance to NNRTIs are more likely to be transmitted than viruses with other LU mutations).

Among those who reported that they had received antiretroviral treatment but who had negative ART testing, 75.9% had drug resistance, mainly to NNRTIs (56.4%) or NNRTIs and NRTIs (14.3%).