Written by Hester Phillips
More than 10% of sex workers, people in prison and men who have sex with men who are living with HIV are drug-resistant when starting antiretroviral treatment (ART), a global evidence review suggests.
These figures relate to global prevalence â the regional picture is more varied. Data on sex workers, for instance, suggests as many as half in Europe and a third in Africa beginning first-line ART may be drug-resistant.
If someone is found to have HIV drug resistance when they begin treatment it may be because they acquired a drug-resistant strain of HIV or they may have taken ARVs before. If drug resistance is detected, moving to an alternative ARV regimen is required.
A 2019 report from the World Health Organization (WHO) found high levels of pre-treatment drug resistance among people beginning ART in lowâ and middleâincome countries. But the global picture on key populations has been lacking.
Researchers analysed around 330 data sets from 220 eligible studies from around the world, collected between 1988 and 2019, to examine pre-treatment drug resistance among 63,100 people. Participants were a mix of key populations and the general population for comparison. Data relating to prisoners and transgender people, and from low-income countries, was lacking.
Global levels of pre-treatment drug resistance were 18% among people in prison, 17% among people who sell sex, 13% among men who have sex with men and 7% among people who inject drugs. Data on transgender people were not reported.
Regional analysis for sex workers found pre-treatment drug resistance to be as high as 50% in Europe, 33% in Africa and 27% in the Americas.
Just under a third (28%) of people who inject drugs beginning treatment in Africa were drug-resistant, as were 15% in the Americas and 13% in the Eastern Mediterranean. Levels were similarly high among prisoners in Africa at 29%, 14% in the Western Pacific and 11% in Europe.
Around 15% of men who have sex with men starting treatment in the Americas and Europe were drug-resistant, as were 13% in South East Asia.
Sex workers and people who inject drugs were equally as likely to have pre-treatment drug resistance as the general population.
But men who have sex with men in highâincome countries were slightly more likely than other people to be drugâresistant. This is linked to relatively high HIV treatment coverage among men who have sex with men in Europe and the Americas. In other regions, access to treatment for this group is so poor drug resistance is less of an issue.
The study also analysed which class of ARV drugs are driving resistance. This differed between key population and regions, and findings overall were inconclusive. But low levels of resistance to nucleotide reverse transcriptase inhibitors (NRTI) was observed.
This provides further evidence that NRTI-based PrEP, which is recommended by WHO for people at higher risk of HIV, does not result in drug resistance and should be scaled up.
The lack of data shows the need for more studies on pre-treatment drug resistance, particularly among transgender people, and from low- and middle-income countries.
Given the high levels of resistance found, attention should be paid to strengthening viral load monitoring and early detection of treatment failure in key populations, and rapid switching to secondâline ART when necessary.
