Rapid, sensitive, and convenient detection of Plasmodium falciparum infection based on CRISPR and its application in detection of asymptomatic infection

Rapid and convenient detection of the Plasmodium in clinically diagnosed individuals and asymptomatically infected populations is essential for global malaria eradication, especially in malaria-endemic African countries where medical equipment and professionals are relatively deficient. Here, we described a CRISPR-based diag-nostic for the detection of Plasmodium falciparum, the deadliest and most prevalent species of malaria parasite in Africa, via lateral flow strip readout without the need of nucleic acid extraction. The assay exhibited 100% sensitivity on clinical samples (5 P falciparum) and significant consistency with qPCR test on asymptomatic infection samples (49 P falciparum and 51 non -P. falciparum, Kappa=0.839). An artemisinin-resistant P. falciparum strain and 4 other laboratory-cultured strains can also be detected through this assay, whereas no cross-reactivity with Plasmodium vivaz was observed. A 0.001% parasitaemia (corresponding to -60 para-sites/mu L) below the low parasite density test threshold (200 parasites/mu L) is detectable. Our study demon-strated that direct malaria detection using whole blood on the spot and the detection of both clinical and asymptomatic infections of P. falciparum are feasible. This method is expected to be employed for clinical testing and large-scale community screening in Africa and possibly other places, contributing to the accurate diagnosis and control of malaria.

Automated summary

Rapid and convenient detection of Plasmodium falciparum, the deadliest malaria parasite in Africa, is crucial for malaria eradication efforts in medical resource-limited settings. A CRISPR-based diagnostic method that can detect P. falciparum without nucleic acid extraction was developed and showed high sensitivity and consistency with qPCR test. It can also detect artemisinin-resistant strains and other laboratory-cultured strains. This method has great potential for clinical testing and large-scale community screening in Africa and other regions.