Abstract:
Background: Access to routine virologic monitoring, critical to ensuring treatment
success, remains limited in low- and middle-income countries. We report on
implementation of routine viral load (VL) monitoring and risk factors for virologic
failure among HIV-infected children on antiretroviral treatment (ART) in Western
Kenya.
Methods: Routine VL testing was introduced in western Kenya in November 2013. We
performed a case-control study among 1190 HIV-infected children ≤15 years on ART
who underwent routine VL testing June 2014-May 2015. A random sample of 98 cases
(virologic failure define as VL >1000 cps/mL) and 201 controls (VL <1000 cps/mL)
from five facilities in three high HIV prevalence counties in Kenya were followed for a
minimum of 12 months. Data from patient charts were analyzed using logistic regression
to determine factors associated with failure to attain virologic suppression at initial
routine and subsequent VL testing among cases.
Results: Overall, 1190 (94%) children with a median age of 8 years underwent routine
VL testing of whom (37%) had virological failure. Among the 299 cases and controls,
WHO stage, baseline CD4 count and time since ART initiation were not associated with
virologic failure during the follow-up period. In multivariable analysis, unsuppressed
children at initial test were more likely to be male (adjusted Odds Ratio (aOR) 2.1, 95%
Confidence Interval (CI) 2.1-3.6) and have had an ART regimen change (aOR 2.0, CI
1.0-3.7) than controls. Of the two-thirds of children 201/299 who had a subsequent VL
performed, VL suppression was greater among those suppressed at initial test 126/135
(93.3%) compared to children with virologic failure 15/66 (22.7%, p<0.0001). Among
those failing at first test who achieved viral suppression in follow up, 12/15 (80%) were
on a protease inhibitor (PI)-based regimen. In the multivariable analysis of children with
subsequent VL testing, children on PI-based 2nd line regimens were 10-fold more likely
to achieve viral suppression than children on first-line NNRTI-based ART (adjusted
Odds Ratio [aOR] 0.1; 95%CI 0.0-0.4).
Conclusion: Coverage of initial routine viral load testing among children on ART in
western Kenya is high. However, subsequent testing and virologic suppression are low in
children with virologic failure on initial routine viral load test. There is an urgent need to
improve management and viral load monitoring of children living with HIV experiencing
treatment failure to ensure improved long-term outcomes.