Abstract
In Korea, the majority of imported malaria cases are Plasmodium vivax and P. falciparum, but Plasmodium ovale cases are rarely reported. We describe an imported case of P. ovale that was confirmed by peripheral blood smear and nested PCR targeting the small subunit ribosomal RNA (SSU rRNA) gene. A 37-yr-old male had visited the Republic of Ghana in tropical West Africa 3 months ago, and suffered from fever and headache since 2 weeks after his return to Korea. The results of rapid malaria test using SD Malaria Antigen/Antibody Kit (Standard Diagnostics, Korea) were negative, but Plasmodium species was observed in Wright-Giemsa-stained peripheral blood smear. For the evaluation of possible mixed infection and identification of species, we performed a nested PCR targeting the SSU rRNA gene. P. ovale single infection was confirmed by PCR. The sequence analysis of the P. ovale SSU rRNA gene showed that our isolate was P. ovale classic type. We should confirm P. ovale infection for an accurate diagnosis and treatment of imported malaria cases in Korea because the number of travelers to P. ovale-endemic regions has recently increased.
Figures and Tables
Fig. 1
Wright-Giemsa-stained peripheral blood smear (magnification, ×1,000). A ring form of malaria trophozoite in an enlarged red blood cell with fimbriated margin is observed in each of the two pictures.
![lmo-2-51-g001](/upload/SynapseData/ArticleImage/0192lmo/lmo-2-51-g001.jpg)
Fig. 2
Plasmodium species-specific nested PCR. The Plasmodium genus can be identified from the presence of first-round amplification product (1,000 bp). Plasmodium species can be identified from the presence of second-round amplification products specific for P. vivax (144 bp), P. falciparum (205 bp), and P. ovale (788 bp) respectively. Only P. ovale DNA was detected from the patient's blood. (P, positive control; N, negative control; Pt., Patient's peripheral blood sample; M, DNA ladder marker).
![lmo-2-51-g002](/upload/SynapseData/ArticleImage/0192lmo/lmo-2-51-g002.jpg)
Fig. 3
Phylogenetic tree based on the small subunit ribosomal RNA genes of Plasmodium species including eight registered P. ovale isolates (Nigerian I/CDC, Papua New Guinea, MAL/MAI, CAG/Cameroon, classic types, and variant types) and P. ovale isolate (SM10-201) of this study. SM10-201 is more similar to the isolates of P. ovale classic type1 than other isolates.
![lmo-2-51-g003](/upload/SynapseData/ArticleImage/0192lmo/lmo-2-51-g003.jpg)
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