title: Plasmodium ovale curtisi and Plasmodium ovale wallikeri circulate simultaneously in African communities.
abstract: It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasite, Plasmodium ovale curtisi and Plasmodium ovale wallikeri. It was recently shown that these two parasite types are sympatric at the country level. However, it remains possible that localised geographic, temporal or ecological barriers exist within endemic countries which prevent recombination between the genomes of the two species. Here, using conventional and real-time quantitative PCR (qPCR) methods specifically designed to discriminate P. o. curtisi and P. o. wallikeri, it is shown that both species are present among clinic attendees in Congo-Brazzaville, and occur simultaneously both in lake-side and inland districts in Uganda and on Bioko Island, Equatorial Guinea. Thus P. o. curtisi and P. o. wallikeri in these localities are exactly sympatric in both time and space. These findings are consistent with the existence of a biological barrier, rather than geographical or ecological factors, preventing recombination between P. o. curtisi and P. o. wallikeri. In cross-sectional surveys carried out in Uganda and Bioko, our results show that infections with P. ovale spp. are more common than previously thought, occurring at a frequency of 1-6% in population samples, with both proposed species contributing to ovale malaria in six sites. Malaria elimination programmes in Africa need to include strategies for control of P. o. curtisi and P. o. wallikeri.
authors.affiliation: Department of Immunology and Infection, Faculty of Infectious & Tropical Diseases, LSHTM, UK.
authors.forename: Mary Chiaka
authors.initials: MC
authors.lastname: Oguike
authors.forename: Martha
authors.initials: M
authors.lastname: Betson
authors.forename: Martina
authors.initials: M
authors.lastname: Burke
authors.forename: Debbie
authors.initials: D
authors.lastname: Nolder
authors.forename: J Russell
authors.initials: JR
authors.lastname: Stothard
authors.forename: Immo
authors.initials: I
authors.lastname: Kleinschmidt
authors.forename: Carla
authors.initials: C
authors.lastname: Proietti
authors.forename: Teun
authors.initials: T
authors.lastname: Bousema
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ndounga
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tanabe
authors.forename: Edward
authors.initials: E
authors.lastname: Ntege
authors.forename: Richard
authors.initials: R
authors.lastname: Culleton
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Sutherland
mesh_terms: D000818:Animals; D003223:Congo / Q000453:epidemiology; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D016701:Guinea / Q000453:epidemiology; D006801:Humans; D008288:Malaria / Q000453:epidemiology* / Q000469:parasitology*; D008969:Molecular Sequence Data; D058974:Phylogeography; D041122:Plasmodium ovale / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D014454:Uganda / Q000453:epidemiology
chemical_list: D016054:DNA, Protozoan; D015800:Protozoan Proteins