Malaria in non-endemic Kuwait:: Detection of very low level Plasmodium falciparum infections using polymerase chain reaction

Objective: Imported malaria continues to be a problem in Kuwait since most patients present with very low levels of parasitaemia. The diagnosis is often delayed or missed because of the low sensitivity of the standard stained blood smear test used for the identification of malarial parasites. In this study, we standardized a highly sensitive polymerase chain reaction (PCR) to detect malarial parasites. Methods: A total of 100 individuals presenting with various forms of infection were screened with the standard Giemsa-stained smears and were compared with the PCR for diagnosis and the sensitivity of the two methods. Results: Our results show that PCR is a highly sensitive and specific technique to detect low levels of Plasmodium falciparum parasites in clinical samples, and at least 6 cases (12%) who were microscopically negative had PCR-detectable parasitaemia. Conclusion: The PCR is a highly sensitive assay which can detect very low levels of malarial parasites and thus is of great value to obtain accurate detection of chronic, residual and sub-patent infections in Kuwait.