Objectives: An increasing prevalence of HIV pretreatment drug resistance (PDR) has been observed in Africa, which could decrease the effectiveness of antiretroviral therapy (ART) programs. We describe our experiences, the costs and challenges of implementing an oligonucleotide ligation assay (OLA) for management of PDR in Nairobi, Kenya.
Design: An observational report of the implementation of OLA in a Kenyan laboratory for a randomized clinical trial evaluating whether onsite use of OLA in individuals initiating ART would decrease rates of virologic failure.
Methods: Compared detection of mutations and proportion of mutants in participants' viral quasispecies by OLA in Kenya vs. Seattle. Reviewed records of laboratory workflow and performance of OLA. Calculated the costs of laboratory set-up and of performing the OLA based on equipment purchase receipts and supplies and labor utilization, respectively.
Results: OLA was performed on 492 trial participants. Weekly batch-testing of median of seven (range: 2-13) specimens provided test results to Kenyan clinicians within 10-14 days of sample collection at a cost of US$ 42 per person tested. Cost of laboratory setup was US$ 32 594. Challenges included an unreliable local supply chain for reagents and the need for an experienced molecular biologist to supervise OLA performance.
Conclusion: OLA was successfully implemented in a Kenyan research laboratory. Cost was twice that projected because of fewer than predicted specimens per batch because of slow enrollment. OLA is a potential simple, low-cost method for PDR testing in resource-limited settings (RLS). Ongoing work to develop a simplified kit could improve future implementation of OLA in RLS.