Combating HIV drug resistance

With the rapid scale up of access to ART and with countries working towards the 90-90-90 and 2030 targets, this session seemed very pertinent in addressing the final tier of the cascade – that 90% of those on treatment should have an undetectable viral load. Meg Doherty from WHO discussed that this is particularly important in settings where access to viral load and drug resistance testing is limited.

Several low and middle income countries have reported levels of HIVDR at or above 10% in ART naive patients and up to 37% in those restarting ART with prior exposure to ART. *

The WHO speaker cautioned that a “one size fits all approach” would be a mistake and this was certainly evidence by presentations from certain countries with varying resistance rates. However access to viral load, not to mind genotypic resistance testing is lacking in many low and middle income resource countries and each country needs to collect this data to guide and tailor its own response.

Modeling suggests that the cost of inaction is a costly price to pay with increased morbidity and mortality, increased transmitted resistance, increased program costs with second and third line ARVs and increases in new infection rates.

WHO recommends that each country should have a HIVDR surveillance strategy that is based on 1) Early Warning Indicators which essentially reflect the quality of care of the program and include data on prescribing practices, loss to follow-up, ARV supply continuity, viral load etc, 2) National surveys of pre-treatment resistance, 3) National surveys of acquired drug resistance, and 4) Nationally representative surveys that measure drug resistance in <18month olds.

Other interesting comments from panel members at the session emphasised the importance of monitoring drug resistance in pregnant women returning to care with PMTCT option B+ and also in children and adolescents who have lower viral load suppression rates than with adults.

The Global Fund panelist talked about the important implications of HIVDR rates in reaching other targets such as 90% of people who have need of PrEP having access to it, and HIVDR rates being important for effective PrEP.

Dr Anna Flavia presented some of the drug resistant data from Brazil where pre-treatment Efavirenz resistance rates are 7%. This has prompted discussions about whether the national program should recommend routine resistance testing prior to ART initiation, or whether the country simply switch to including Dolutegravir in the first line regimen. All cost benefit analyses favour the switch to Dolutegravir rather than performing resistance testing on all commencing treatment.

The take home message from this presentation was that drug resistance is rising and if the target of ending AIDS by 2030 is to be achieved, then monitoring and responding to HIVDR will be a critical element and that each country is called to act and collect more and better data in order to tailor their response in terms of thinking about switching ART regimens and quality improvements to their HIV programs.

*The WHO draft of the Global Action Plan on Drug Resistance (2017-2021)