In resource-limited settings, there is increased demand for human immunodeficiency virus type 1 drug resistance testing. Because preservation of plasma specimens is often not feasible in resource-limited settings, use of dried blood spots (DBSs) is being adopted. We used 2 panels of DBSs for genotyping assay validation and proficiency testing in selected laboratories in the World Health Organization laboratory network in 14 countries. An amplification sensitivity of 1000 copies/mL was achieved by 2 laboratories. Reproducibility and accuracy of nucleotide sequence determination and resistance-associated mutation identification from DBSs was similar to that previously determined for plasma. International shipping at ambient temperature had no significant effect on amplification success. These studies indicate that DBS-based genotyping is equally reproducible and reliable, although slightly less sensitive, compared with plasma.
Bibliographical noteFunding Information:
Financial support. This work was supported by The Bill & Melinda Gates Foundation (to the WHO) and the National Institutes of Health, National Institute of Allergy and Infectious Disease, Division of AIDS (NO1-AI-5004 to the Virology Quality Assurance program. Grant no. NIAID K23 AI074423-05 to MRJ).