Population Structure and Transmission Dynamics of Plasmodium vivax in the Republic of Korea Based on Microsatellite DNA Analysis

Abstract

BackgroundIn order to control malaria, it is important to understand the genetic structure of the parasites in each endemic area. Plasmodium vivax is widely distributed in the tropical to temperate regions of Asia and South America, but effective strategies for its elimination have yet to be designed. In South Korea, for example, indigenous vivax malaria was eliminated by the late 1970s, but re-emerged from 1993. We estimated the population structure and temporal dynamics of transmission of P. vivax in South Korea using microsatellite DNA markers.Methodology/Principal FindingsWe analyzed 255 South Korean P. vivax isolates collected from 1994 to 2008, based on 10 highly polymorphic microsatellite DNA loci of the P. vivax genome. Allelic data were obtained for the 87 isolates and their microsatellite haplotypes were determined based on a combination of allelic data of the loci. In total, 40 haplotypes were observed. There were two predominant haplotypes: H16 and H25. H16 was observed in 9 isolates (10%) from 1996 to 2005, and H25 in 27 (31%) from 1995 to 2003. These results suggested that the recombination rate of P. vivax in South Korea, a temperate country, was lower than in tropical areas where identical haplotypes were rarely seen in the following year. Next, we estimated the relationships among the 40 haplotypes by eBURST analysis. Two major groups were found: one composed of 36 isolates (41%) including H25; the other of 20 isolates (23%) including H16. Despite the low recombination rate, other new haplotypes that are genetically distinct from the 2 groups have also been observed since 1997 (H27).Conclusions/SignificanceThese results suggested a continual introduction of P. vivax from other population sources, probably North Korea. Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and transmission dynamics of the parasites - information that can assist in the elimination of vivax malaria in endemic areas.

Is Predominant Clonal Evolution a Common Evolutionary Adaptation to Parasitism in Pathogenic Parasitic Protozoa, Fungi, Bacteria, and Viruses?

“…As in P. falciparum, labile near-clades are observed in P. vivax. In South Korea, two dominant groups persist in spite of high variability and a high rate of MCIs (Iwagami et al, 2012), which is at odds with the starving sex hypothesis (see further). In India, 3 clusters, not linked to geographical distance, are corroborated by Neighbour Joining (NJ), STRUCTURE, and PCA (Gupta et al, 2012).…”

“…b Griffing et al (2011) b,c Guttman and Stavrinides (2010) b,e Grigg and Sundar (2009) c Hanage et al (2006) a,b Heitman (2006) b,c Henriques-Normark et al (2008) b,e Herges et al (2012) e Kurtenbach et al (2010) b Iwagami et al (2012) e Maiden (2006Maiden ( a , 2008 b Karunaweera et al (2008) e Martin et al (2010) e Khan et al (2011) b,e Leblois et al (2011) b Prasad Narra & Ochman (2006) a,b Lehmann et al (2004) c,e…”

“…The parasite therefore undergoes selfing, which leads to clonality (Anderson et al, 2000). Many authors explain clonality in Plasmodium by this hypothesis (see, for example, Branch et al, 2011;Conway, 2007;Falk et al, 2015;Iwagami et al, 2012;Miotto et al, 2013;Neafsey et al, 2008;Weedall and Hall, 2014). We have called this situation the 'starving sex hypothesis', or 'passive clonality' (Tibayrenc and Ayala, 2014a).…”

New Insights into Clonality and Panmixia in Plasmodium and Toxoplasma

“…However, (i) it is the very and only statistic appropriate for testing rarity or absence of recombination, on which the definition of PCE is based; (ii) when enough loci are surveyed, its power of resolution is high (Tibayrenc and Ayala, 2012;Tibayrenc et al, 1990); and (iii) it is widely used as a circumstantial evidence for clonality by many authors working on Plasmodium (Anderson et al, 2000;Arnott et al, 2012;Branch et al, 2011;Chenet et al, 2012;Conway, 2007;Ferreira et al, 2007;Imwong et al, 2007;Iwagami et al, 2009Iwagami et al, , 2012Karunaweera et al, 2008;Mu et al, 2005;Nkhoma et al, 2013;Orjuela-Sánchez et al, 2010;Rezende et al, 2010;Volkman et al, 2007Volkman et al, , 2012a and Toxoplasma (Khan et al, 2011;Lehman et al, 2004;Rajendran et al, 2012;Su et al, 2006), as well as on other pathogens (Tibayrenc and Ayala, 2012). As asserted here, only the LD approach has been able to refute the panmictic prejudice in Plasmodium and Toxoplasma (Tibayrenc et al, 1990(Tibayrenc et al, , 1991.…”

“…Many studies have ascertained evidence for clonality and restrained recombination, based on the analysis of LD in many populations of P. falciparum (Annan et al, 2007;Branch et al, 2011;Chenet et al, 2012;Griffing et al, 2011;Iwagami et al, 2009;Manske et al, 2012;Nkhoma et al, 2013;Razakandrainibe et al, 2005;Volkman et al, 2007Volkman et al, , 2012a and P. vivax (Chenet et al, 2012;Imwong et al, 2007;Iwagami et al, 2012;Karunaweera et al, 2008;Rezende et al, 2010). Consequently, the panmictic model was considered to be "oversimplified" in Plasmodium (Heitman, 2006).…”