World Health Organization Guidelines Is Associated With High Misclassification Rates and Drug Resistance Among HIV-Infected

Background. Antiretroviral therapy (ART) in resource-limited settings (RLSs) is monitored clinically and im-munologically, according to World Health Organization (WHO) or national guidelines. Revised WHO pediatric guidelines were published in 2010, but their ability to accurately identify virological failure is unclear. Methods. We evaluated performance of WHO 2010 guidelines and compared them with WHO 2006 and Cambodia 2011 guidelines among children on ≥6 months of first-line ART at Angkor Hospital for Children between January 2005 and September 2010. We determined sensitivity, specificity, positive and negative predictive values, and accuracy using bootstrap resampling to account for multiple tests per child. Human immunodeficiency virus (HIV) resistance was compared between those correctly and incorrectly identified by each guideline. Results. Among 457 children with 1079 viral loads (VLs), 20 % had>400 copies/mL. For children with WHO stage 1/2 HIV, misclassification as failure (met CD4 failure criteria, but VL undetectable) was 64 % for WHO 200