HIV getting resistant to antiretroviral drugs : study

At least one in 10 people in Homa Bay County who is HIV-positive has an HIV strain that is resistant to at least one of the available antiretrovirals, even when he or she has never been put on any HIV/Aids treatment.

This means they were infected by strains or types of HIV that are resistant to at least one of the available antiretroviral (ARV) drugs. The consequence of these changes in the virus is ARV treatment failure and, hence, further spread of drug-resistant HIV.

FYI: There are two main ways to test if a person has resistance (ADR or TDR). One is the Phenotypic resistance test, which measures the concentration of drugs required to inhibit 50 per cent of the growth of HIV. This costs between Sh70,000 and Sh100,000, is time consuming, and takes up to two months to give the results. The other is the Genotypic resistance test, which looks for the presence of specific mutations (errors) in the HIV gene that cause ARV drug resistance. It is available at the Kenya Medical Research Institute and at the Walter Reed Project in Kericho. The results are out within one to two weeks and it costs between Sh9,000 to 18,000 per test, depending on the institute it is done in.

The findings are in a study published in the research journal PloS One on February 8, 2017.

This transmitted drug-resistant (TDR) HIV is passed on in the same ways as ‘normal HIV’, such as having unprotected sex with an HIV-positive partner who has TDR, sharing contaminated needles or blades, from a mother with TDR to her child, or through transfusion with infected blood.

Lead author Harris Onywera told HealthyNation that the study surveyed people who were infected with the virus within one and a half years.

“Our study means that for every 100 of the recorded new infections in rural western Kenya, about nine have strains of HIV-1 already resistant to the ARV regimens. But, from what we observed, 9.2 per cent was moderate as per the World Health Organisation’s TDR surveillance classification scale,” said the PhD candidate in Medical Virology at the Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa.

In severe cases, the patient will require to move to either the second or third-line treatment regimens, which are three times and 18 times more expensive, respectively, than first-line drugs, says the WHO. Further, these treatments are limited.

But the peer-reviewed study says the first-line ARV regimens in Kenya are still safe to be used.

Currently, it costs the government Sh20, 000 annually to put one HIV patient on treatment. There are over 1.6 million Kenyans living with the virus and about one million on treatment.

Of these, it is not clear how many have Transmitted Drug Resistant HIV, but there are regional rates which range between one to 13 per cent over the last decade, in Nairobi (4.5 per cent), Kilifi (1.1 per cent), and Mombasa (13.2 per cent).

“At the moment, our results show that the TDR level in rural western Kenya is relatively higher than for most regions (including urban settings) documented in Kenya. We suggest that the survey be repeated in order to confirm these findings, to further understand the scale of the problem and access the potential sources of HIV drug resistance,” says Mr Onywera.

In addition, he says, there is also need for continuous monitoring to prevent further rise of HIV TDR as well as surveillance of acquired drug resistance (ADR) — resistance in HIV-infected persons who are on, or have been exposed to, treatment.

This is particularly important because all Kenyans who test positive for HIV are put on ARV immediately under a programme called Anza Sasa. It also means that the greater use of ART is expected to further increase ART resistance in all regions of the world.