Abstract:

To assess the laboratory capabilities in two genetic types of imported Plasmodium ovale in Hubei Province. Blood samples were collected from imported malaria cases in the province during 2015—2018. All cases were rechecked and genotyped by the Hubei Provincial Diagnostic Reference Laboratory (Hubei DRL) using microscopy and nested polymerase chain reaction (nested PCR). The detection accuracy of importedP. ovale by microscopy and malaria rapid diagnostic test (RDT) were compared with the nested PCR, which was used as positive reference. During 2015—2018, a total of 494 malaria cases were confirmed in Hubei Province, of them 76 cases (15.38%) were identified ofP. ovale infection by nested PCR, including 50 (65.79%) P. ovale curtisi, a subspecies,and 26 (34.21%) P. ovale wallikeri, a mutated subspecies. In examining the P. ovale curtisi, the Hubei DRL detected 48 cases by microscopy with a coincidence rate of microscopy and RDT was 96.00% and 64.00%, respectively. In examining the P. ovale wallikeri, the Hubei DRL detected 23 cases by microscopy with coincidence rate of microscopy and RDT was 88.46% and 80.77%, respectively. The microscopic examination in the city-level Center for Disease Control and Prevention (CDC) detected 37 cases ofP. ovale, with an accuracy of only 48.68%. Overall, 97.36% (74/76) of the P. ovale cases were from Africa. The results suggested that microscope operation training should be strengthened in city-level CDCs to improve the identification capability for P. ovale identification, and that the combined use of microscopy and RDT should be promoted for diagnosis of imported P. ovale malaria cases.

Key words: Imported cases, Ovale malaria, Nested PCR, Diagnostic Reference Laboratory