Field Evaluation of Dried Blood Spots for HIV-1 Viral Load Monitoring in Adults and Children Receiving Antiretroviral Treatment in Kenya: Implications for Scale-up in Resource-Limited Settings.

BACKGROUND: The World Health Organization recommends viral load (VL) as the preferred method for diagnosing antiretroviral therapy failure; however, operational challenges have hampered the implementation of VL monitoring in most resource-limited settings. This study evaluated the accuracy of dried blood spot (DBS) VL testing under field conditions as a practical alternative to plasma in determining virologic failure (VF). METHODS: From May to December 2013, paired plasma and DBS specimens were collected from 416 adults and 377 children on antiretroviral therapy for ≥6 months at 12 clinics in Kenya. DBSs were prepared from venous blood (V-DBS) using disposable transfer pipettes and from finger-prick capillary blood using microcapillary tubes (M-DBS) and directly spotting (D-DBS). All samples were tested on the Abbott m2000 platform; V-DBS was also tested on the Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) version 2.0 platform. VF results were compared at 3 DBS thresholds (≥1000, ≥3000, and ≥5000 copies/mL) and a constant plasma threshold of ≥1000 copies/mL. RESULTS: On the Abbott platform, at ≥1000-copies/mL threshold, sensitivities, specificities, and kappa values for VF determination were ≥88.1%, ≥93.1%, and ≥0.82%, respectively, for all DBS methods, and it had the lowest percentage of downward misclassification compared with higher thresholds. V-DBS performance on CAP/CTM had significantly poorer specificity at all thresholds (1000%-33.0%, 3000%-60.9%, and 5000%-77.0%). No significant differences were found between adults and children. CONCLUSIONS: VL results from V-DBS, M-DBS, and D-DBS were comparable with those from plasma for determining VF using the Abbott platform but not with CAP/CTM. A 1000-copies/mL threshold was optimal and should be considered for VF determination using DBS in adults and children.

The relationship between adherence to clinic appointments and year-one mortality for newly enrolled HIV infected patients at a regional referral hospital in Western Kenya, January 2011-December 2012.

This retrospective cohort analysis was conducted to describe the association between adherence to clinic appointments and mortality, one year after enrollment into HIV care. We examined appointment-adherence for newly enrolled patients between January 2011 and December 2012 at a regional referral hospital in western Kenya. The outcomes of interest were patient default, risk factors for repeat default, and year-one risk of death. Of 582 enrolled patients, 258 (44%) were defaulters. GEE revealed that once having been defaulters, patients were significantly more likely to repeatedly default (OR 1.4; 95% CI 1.12-1.77), especially the unemployed (OR 1.43; 95% CI 1.07-1.91), smokers (OR 2.22; 95% CI 1.31-3.76), and those with no known disclosure (OR 2.17; 95% CI 1.42-3.3). Nineteen patients (3%) died during the follow-up period. Cox proportional hazards revealed that the risk of death was significantly higher among defaulters (HR 3.12; 95% CI 1.2-8.0) and increased proportionally to the rate of patient default; HR was 4.05 (95% CI1.38-11.81) and 4.98 (95% CI 1.45-17.09) for a cumulative of 4-60 and ≥60 days elapsed between all scheduled and actual clinic appointment dates, respectively. Risk factors for repeat default suggest a need to deliver targeted adherence programs.