Dried Blood Spots for Viral Load Monitoring in Malawi: Feasible and Effective

Abstract

ObjectivesTo evaluate the feasibility and effectiveness of dried blood spots (DBS) use for viral load (VL) monitoring, describing patient outcomes and programmatic challenges that are relevant for DBS implementation in sub-Saharan Africa.MethodsWe recruited adult antiretroviral therapy (ART) patients from five district hospitals in Malawi. Eligibility reflected anticipated Ministry of Health VL monitoring criteria. Testing was conducted at a central laboratory. Virological failure was defined as >5000 copies/ml. Primary outcomes were program feasibility (timely result availability and patient receipt) and effectiveness (second-line therapy initiation).ResultsWe enrolled 1,498 participants; 5.9% were failing at baseline. Median time from enrollment to receipt of results was 42 days; 79.6% of participants received results within 3 months. Among participants with confirmed elevated VL, 92.6% initiated second-line therapy; 90.7% were switched within 365 days of VL testing. Nearly one-third (30.8%) of participants with elevated baseline VL had suppressed (<5,000 copies/ml) on confirmatory testing. Median period between enrollment and specimen testing was 23 days. Adjusting for relevant covariates, participants on ART >4 years were more likely to be failing than participants on therapy 1–4 years (RR 1.7, 95% CI 1.0-2.8); older participants were less likely to be failing (RR 0.95, 95% CI 0.92-0.98). There was no difference in likelihood of failure based on clinical symptoms (RR 1.17, 95% CI 0.65-2.11).ConclusionsDBS for VL monitoring is feasible and effective in real-world clinical settings. Centralized DBS testing may increase access to VL monitoring in remote settings. Programmatic outcomes are encouraging, especially proportion of eligible participants switched to second-line therapy.

On the front line of HIV virological monitoring: barriers and facilitators from a provider perspective in resource-limited settings

“…The parent study was a public health evaluation of DBS for VL monitoring at five ART clinics located in district hospitals in central and southern Malawi (Rutstein, et al, 2015). None of the enrolling clinics had access to VL monitoring outside of enrollment in the DBS study; all clinics relied on clinical staging for ART monitoring as CD4-based criteria was not recommended per Malawi guidelines in place during the period of data collection (2013-2014) (“Clinical Management of HIV In Children and Adults,” 2014).…”

“…Dried blood spots (DBS) have emerged as an alternative to plasma-based VL testing for resource-limited settings by simplifying specimen collection and storage; centralizing laboratory testing; and reducing the need for extensive clinic-level laboratory infrastructure. DBS collection by ART providers at outlying clinics and a centralized laboratory for specimen testing may increase access to VL monitoring in remote clinics (Johannessen, 2010; Johannessen, Troseid, & Calmy, 2009; Rutstein et al, 2015). The WHO and national ART management guidelines in many resource-limited settings advocate use of DBS as the preferred monitoring model when traditional VL testing is not feasible (“Clinical Management of HIV In Children and Adults,” 2014; WHO, 2013, 2014).…”

“…These interviews were conducted in the context of a parent study in which we evaluated the feasibility and effectiveness of DBS for VL monitoring in ART clinics in central and southern Malawi (Rutstein, et al, 2015). Less than 1% of Malawian ART patients are on second-line regimens, likely a reflection of providers’ reliance on clinical staging to identify first-line treatment failure (“Integrated HIV Program Report July - September 2013,” 2013).…”

Sustainable HIV treatment in Africa through viral-load-informed differentiated care

“…Quantification of HIV RNA requires sophisticated facilities and skilled staff and costs have been high, although they have decreased substantially recently (5, 6). While modelling studies have indicated there is a benefit of viral load monitoring over monitoring strategies based on the CD4 count or clinical observation (7–16) viral load monitoring has not been found to be cost-effective (7, 10–14), due to the cost of viral load tests and second-line regimens. Currently, the most feasible approach in most countries to begin to measure viral load is to collect samples as dried blood spots (DBS).…”

“…Using existing networks for early infant HIV diagnosis, they can be transported to a regional or national laboratory with results subsequently returned to the clinic by means such as SMS. However, presence of cells and low sample volume in DBS specimens mean that sensitivity and specificity for detecting whether the level is above the 1000 cps/mL threshold used to define viral suppression are imperfect and it is unclear if the approach is adequate (5, 16–27). Looking to the future, it is anticipated that “point-of-care” (POC) tests - i.e.…”