BinaxNOW vs malaria: A diagnostic showdown: Design and implementation of a verification strategy across 4 academic hospitals in an area with low malaria prevalence.

Objective: Due to low malaria prevalence, implementation of the only US Food and Drug Administration (FDA)-cleared rapid malaria diagnostic, BinaxNOW Malaria, in US clinical laboratories is challenging due to limited clinical specimens for test verification. We describe the initial BinaxNOW evaluation at an academic medical center and its verification across a large health care network with site-based microbiology laboratories, using well-characterized, previously tested blood samples.

Methods: For the initial evaluation, we compared the BinaxNOW Malaria to blood smear examination in 294 whole-blood specimens at the primary evaluation site. For subsequent site-based verification, each site tested 10 previously malaria antigen-positive and 10 previously malaria antigen-negative whole-blood specimens. Positive percent agreement (PPA), negative percent agreement (NPA), concordance, and reproducibility were calculated.

Results: For the initial evaluation, the BinaxNOW Malaria correctly identified Plasmodium species in 100% of specimens positive for Plasmodium falciparum with 96% identified to the species level. Overall BinaxNOW Malaria test sensitivity and specificity were 100%. For the subsequent site-based verification, PPA, NPA, concordance, and reproducibility were 100%.

Conclusions: The approach described provides proof of concept for BinaxNOW Malaria test verification in areas with low malaria prevalence using archived well-characterized blood samples. With this strategy, rapid malaria antigen testing could be expanded, improving diagnostic capabilities across the United States.