HIV Drug Resistance Early Warning Indicators in Namibia with Updated World Health Organization Guidance

Abstract

BackgroundIn response to concerns about the emergence of HIV drug resistance (HIVDR), the World Health Organization (WHO) has developed a comprehensive set of early warning indicators (EWIs) to monitor HIV drug resistance and good programme practice at antiretroviral therapy (ART) sites.MethodsIn 2012, Namibia utilized the updated WHO EWI guidance and abstracted data from adult and pediatric patients from 50 ART sites for the following EWIs: 1. On-time Pill Pick-up, 2. Retention in Care, 3. Pharmacy Stock-outs, 4. Dispensing Practices, and 5. Virological Suppression.ResultsData for EWIs one through four were abstracted and validated. EWI 5 – Virological Suppression was not included due to poor data entry at many sites. On-time Pill Pick-up national estimate was 87.9% (87.2–88.7) of patients picking up pills on time for adults and 90.0% (88.9–90.9) picking up pills on time for pediatrics. Retention in Care national estimate was 82% of patients retained on ART after 12 months for adults and 83% for pediatrics. Pharmacy Stock-outs national estimate was 99% of months without a stock-out for adults and 97% for pediatrics. Dispensing Practices national estimate was 0.01% (0.003–0.064) of patients dispensed mono- or dual-therapy for adults and 0.25% (0.092–0.653) for pediatrics.ConclusionsThe successful 2012 EWI exercise provides Namibia a solid evidence base, which can be used to make national statements about programmatic functioning and possible HIVDR. This evidence base will serve to contextualize results from Namibia's surveys of HIVDR, which involves genotype testing. EWI abstraction has prompted the national program and its counterparts to engage sites in dialogue regarding the need to strengthen adherence and retention of patients on ART. The EWI collection process and EWI results will serve to optimize patient care and support Namibia in making evidence-based recommendations and take action to minimize the emergence of preventable HIVDR.

Assessment of the World Health Organization’s HIV Drug Resistance Early Warning Indicators in Main and Decentralized Outreach Antiretroviral Therapy Sites in Namibia

“…Similar to past EWI monitoring rounds in Namibia [15–17], data quality assessments were implemented throughout the EWI process on the data queried centrally from the two national databases. Three elements of data quality were considered in the assessments: data reliability, data completeness, and data consistency.…”

“…The target sample size for each EWI is based on the number of eligible patients according to WHO guidance, and the Namibian methods discussed herein have been previously detailed by Jonas et al [16–17] For On-time pill pick-up and Dispensing practices , the number of eligible patients at each site to be sampled was the number of patients who were “active” on ART at the time of the sample start date (1 January, 2013). All sites began abstraction from the sample start date and abstracted data until the appropriate sample size for each site was reached, and data were oversampled by 20% to account for potential censoring of patients.…”

“…[16] In 2012, Namibia utilized the updated WHO guidelines for EWI data abstraction at 50 ART sites. [17]…”

Population-Based Surveillance of HIV Drug Resistance Emerging on Treatment and Associated Factors at Sentinel Antiretroviral Therapy Sites in Namibia

“…Patients were followed prospectively for 12 months. At endpoint, each individual’s status was classified into one of the following categories: on first-line ART at 12 months, switch to second line ART, lost to follow-up (LTFU), ART stop by physician, or death [10]. For participants who reached the endpoints of on first-line ART at 12 months and switch to second-line ART, a blood draw was collected for VL quantitation; HIVDR genotyping was performed on specimens with VL >1000 copies/ml.…”

“…In 2006 Namibia completed its first survey of transmitted HIVDR (TDR) and documented low levels of TDR in the capital, Windhoek [Namibia MoHSS, unpublished data]. In 2010, 2013 and 2014, national HIVDR Early Warning Indicator (EWI) results highlighted high rates of lost to follow-up 12 months after ART initiation, raising concern about emergence of preventable HIVDR due to treatment interruptions amongst those lost from care [8–10]. …”