The reliability of malaria rapid diagnostic test kit for detecting P. falciparum PfHRP2 in dried blood spot samples preserved under different conditions and durations

Sixty whole blood samples (approx. 750 mL), which contained the PfHRP2 protein, were collected from patients with uncomplicated malaria. Fifteen dried blood samples (DBS) were made from each sample, making a total of 900 DBS. A set of five DBS each were stored at room temperature (25 °C), 6 °C and - 60 °C, for 30, 60, 90, 120 and 150 days. PfHRP2 was detected in each stored DBS sample. Irrespective of sample storage conditions, PfHRP2 was reproducible from day 30 to 120. However, after storage for 150 days, the positivity rate reduced to 90%, 88.3% and 80% (p = 0.236) when samples were stored at room temperature, 6 °C and - 60 °C, respectively. Although the positivity rates were statistically similar, room temperature offers a cost-effective, equipment-free, and reliable method for preserving PfHRP2 for up to 120 days.