A field evaluation in rural Malawi found malaria rapid diagnostic tests varied substantially by patient subgroup, with sensitivity dropping markedly in adults aged 25 to 40 years and in infants younger than one year. Across 1,108 patient visits, investigators reported overall sensitivity of 67% for rapid tests among qPCR-confirmed positives, with specificity at 91%. The results also linked most false negatives to low parasite densities below 200 parasites per microliter. Authors reported that symptoms such as fever and vomiting reduced the likelihood of false negatives but increased the probability of false positives, underscoring the need for targeted diagnostic strategies at the point of care.