Annual viral load monitoring is a safe option for children with HIV in resource-poor settings
Less frequent viral load monitoring for children living with HIV was not associated with treatment failure, however, age and sickness at treatment initiation were.
Annual viral load monitoring of stable children living with HIV in Asia did not result in any increased likelihood of treatment failure compared to children who were monitored every six months. The results provide evidence that less frequent viral load monitoring is still a safe and effective strategy for managing antiretroviral treatment (ART) in resource-poor settings with limited access to viral load monitoring.
The study found 25% of children who received annual viral load monitoring developed treatment failure compared to 23% of children who had received viral load monitoring every six months.
Frequency of viral load monitoring was not associated with treatment failure, instead, children being older, entering treatment at an already late stage of infection, and shorter time on ART were significantly associated with treatment failure in this cohort.
The analysis included 2,413 children perinatally infected with HIV from the TREAT Asia Pediatric HIV Observational Database (TApHOD) – a multinational, longitudinal cohort of children living with HIV in Asia-Pacific. Sites could be included if they provided at least annual viral load monitoring, which left 1,200 (46.7%) children from Cambodia, Malaysia and Thailand that were included in the study. All children were under the age of 18, virally suppressed and on first-line ART with a non-nucleoside reverse transcriptase inhibitor-based regime (NNRTI).
At the start of the study the median age of the children was 9.2 years and most (64.6%) were on nevirapine-based regimes. 581 (47.6%) of the participants were male and prior to starting ART 55.3% were at clinical stage 3 or 4 by World Health Organization (WHO) classification, both of which are points at which HIV infection is either moderately of severely symptomatic, with stage 4 being where the patient has AIDS defining illnesses. At the end of the study 20 children were lost to follow-up.
Of all eligible children, 1,042 (85.4%) were from six sites which performed annual viral load monitoring while 178 (14.6%) were from four sites which performed semi-annual viral load monitoring. The criteria for treatment failure was either two consecutive viral load readings of over 1,000 copies per mL while on ART, a change in drug class to a protease inhibitor-based (PI) regime, or death. There were 77 failures of the first category (5.9%), 211 of the second (17.3%) and 10 of the third (0.8%).
Around the world, guidelines for viral load monitoring are inconsistent. The World Health Organization (WHO) suggests annual viral load monitoring for children who are stable and on first-line ART, but other treatment bodies, predominantly in high-resourced contexts, recommend plasma viral load (pVL) testing every three to four months.
While viral load monitoring should remain the gold standard for assessing treatment effectiveness for people living with HIV, it can be expensive to conduct with prices ranging from USD $10 to $85 for the per-test cost of the reagent. Reducing the number of tests needed among certain sub-populations, including stable children on treatment, could provide an opportunity to lessen the resource burden on the health system.
The authors stressed that regular viral load monitoring should remain the gold standard for measuring treatment success, as it can alert clinicians to treatment adherence issues or the onset of possible HIV drug resistance, but resources saved from semi-annual viral load monitoring could be used instead to provide more comprehensive care for children living with HIV, including adherence support for those who are not stable and on treatment.
The study also found an increased likelihood of treatment failure among older children and adolescents, which is not surprising. This can be partly explained by the fact that these children will have been on treatment longer if infected via mother-to-child transmission. It also highlights some of the behavioural and social challenges around adherence that we know exist for older children and adolescents.
“Annual pVL monitoring was not associated with an increased risk of treatment failure compared with semi-annual monitoring,” concluded the authors. “Taking into consideration patient-level factors when determining pVL monitoring frequency may help balance clinical needs and program costs.”