Did malaria rapid tests perform differently in rural clinics and a reference lab?

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Malaria rapid diagnostic tests (RDTs) are widely used as an alternative to microscopy in malaria-endemic countries. Quality control of test performance and execution in the field is important for proper use and diagnosis. The study compared a histidine-rich protein 2-based RDT used under real-life conditions at peripheral health facilities with testing at a central reference laboratory that strictly followed the manufacturer's instructions.

Febrile children attending rural health clinics were tested using an RDT provided by the Burkina Faso Ministry of Health, as recommended by the National Malaria Control Programme. A blood sample was also collected in an EDTA tube from every study participant and retested at the central reference laboratory using the same RDT brand according to the manufacturer's instructions; expert malaria microscopy was the gold standard. The researchers used Fisher's exact test to compare proportions, treating p ≤ 0.05 as statistically significant.

Among 407 febrile children, expert microscopy diagnosed malaria in 59.9% (244/407). Sensitivity was 97.5% for RDTs performed at health facilities and a comparable 98.8% at the laboratory. The difference in false negatives between the two groups was not statistically significant (p = 0.5209). Specificity was lower at health facilities, at 52.8%, than at the laboratory, at 74.2%. The difference in false positives between the two groups was statistically significant (p = 0.0005).

The authors concluded that RDTs performed at the participating rural health facilities produced more false positives than those performed at the central laboratory. They suggested that storage and transportation conditions and health worker training are among the factors most likely to influence test performance. They emphasized appropriate quality control and training programmes to ensure correct RDT performance.