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Microsatellite DNA analysis revealed a drastic genetic change of Plasmodium vivax population in the Republic of Korea during 2002 and 2003.

Iwagami M, Hwang SY, Kim SH, Park SJ, Lee GY, Matsumoto-Takahashi EL, Kho WG, Kano S - PLoS Negl Trop Dis (2013)

Bottom Line: Vivax malaria was successfully eliminated in the Republic of Korea (South Korea) in the late 1970s, but it was found to have re-emerged from 1993.The LD analysis showed a gradual decrease in LD levels, while the levels of genetic differentiation between successive years and analysis of the population structure based on the Bayesian approach suggested that a drastic genetic change occurred in the South Korean population during 2002 and 2003.Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and temporal dynamics of parasite transmission; information that can assist in the elimination of vivax malaria in endemic areas.

View Article: PubMed Central - PubMed

Affiliation: Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan.

ABSTRACT

Background: Vivax malaria was successfully eliminated in the Republic of Korea (South Korea) in the late 1970s, but it was found to have re-emerged from 1993. In order to control malaria and evaluate the effectiveness of malaria controls, it is important to develop a spatiotemporal understanding of the genetic structure of the parasite population. Here, we estimated the population structure and temporal dynamics of the transmission of Plasmodium vivax in South Korea by analyzing microsatellite DNA markers of the parasite.

Methodology/principal findings: We analyzed 14 microsatellite DNA loci of the P. vivax genome from 163 South Korean isolates collected from 1994 to 2008. Allelic data were used to analyze linkage disequilibrium (LD), genetic differentiation and population structure, in order to make a detailed estimate of temporal change in the parasite population. The LD analysis showed a gradual decrease in LD levels, while the levels of genetic differentiation between successive years and analysis of the population structure based on the Bayesian approach suggested that a drastic genetic change occurred in the South Korean population during 2002 and 2003.

Conclusions/significance: Although relapse and asymptomatic parasite carriage might influence the population structure to some extent, our results suggested the continual introduction of P. vivax into South Korea through other parasite population sources. One possible source, particularly during 2002 and 2003, is North Korea. Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and temporal dynamics of parasite transmission; information that can assist in the elimination of vivax malaria in endemic areas.

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Proportion of ancestral populations among the South Korean P. vivax populations from 1994 to 2008.The colors represent the different ancestral populations of the South Korean P. vivax population (163 isolates) for K = 2, 3 and 5, estimated by STRUCTURE version 2.3.4 software [43]. These circular graphs were made based on results of the STRUCTURE analysis shown in Figure 1. The colors of the graphs correspond to those of Figure 1.
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pntd-0002522-g003: Proportion of ancestral populations among the South Korean P. vivax populations from 1994 to 2008.The colors represent the different ancestral populations of the South Korean P. vivax population (163 isolates) for K = 2, 3 and 5, estimated by STRUCTURE version 2.3.4 software [43]. These circular graphs were made based on results of the STRUCTURE analysis shown in Figure 1. The colors of the graphs correspond to those of Figure 1.

Mentions: The results of STRUCTURE analysis using an independent allele frequency model are shown in Figures 1 and 3. The highest value of Ln P(D) was observed at K = 5 (Fig. 4 A). This result suggested that the most appropriate population number (K) of P. vivax in South Korea is 5. However, the differences between Ln P(D) values of each K (3–10) were very small. In order to make the break in slope of the distribution of Ln P(D) salient at true K, we calculated value of ΔK using the method described by Evanno et al. [44]. The highest value of ΔK was observed at K = 2, and the second highest was observed at K = 3 (Fig. 4 B). These three K values (K = 2, 3 and 5) were thus adopted (Fig. 1 and 3). For K = 5, two genotypes (light green, yellow) were predominant from 1994 to 2002. Five genotypes (light green, blue, purple, red, yellow) coexisted from 2003 to 2008 (Fig. 1 and 3). For K = 2, two genotypes (light green, yellow) coexisted from 1994 to 2008. The light green genotype was predominant from 1994 to 2000, whereas the yellow genotype was predominant from 2001 to 2008 (Fig. 1 and 3). For K = 3, two genotypes (light green, yellow) coexisted from 1994 to 2001, while three genotypes (blue, light green, yellow) coexisted from 2002 to 2008 (Fig. 1 and 3). For all K values greater than 2, there was a drastic genetic change in the population structure of P. vivax in South Korea during 2002 and 2003. The results of STRUCTURE analysis, which used a model of correlated allele frequency among population, were almost the same as those of the analysis using the independent allele frequency model.


Microsatellite DNA analysis revealed a drastic genetic change of Plasmodium vivax population in the Republic of Korea during 2002 and 2003.

Iwagami M, Hwang SY, Kim SH, Park SJ, Lee GY, Matsumoto-Takahashi EL, Kho WG, Kano S - PLoS Negl Trop Dis (2013)

Proportion of ancestral populations among the South Korean P. vivax populations from 1994 to 2008.The colors represent the different ancestral populations of the South Korean P. vivax population (163 isolates) for K = 2, 3 and 5, estimated by STRUCTURE version 2.3.4 software [43]. These circular graphs were made based on results of the STRUCTURE analysis shown in Figure 1. The colors of the graphs correspond to those of Figure 1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814342&req=5

pntd-0002522-g003: Proportion of ancestral populations among the South Korean P. vivax populations from 1994 to 2008.The colors represent the different ancestral populations of the South Korean P. vivax population (163 isolates) for K = 2, 3 and 5, estimated by STRUCTURE version 2.3.4 software [43]. These circular graphs were made based on results of the STRUCTURE analysis shown in Figure 1. The colors of the graphs correspond to those of Figure 1.
Mentions: The results of STRUCTURE analysis using an independent allele frequency model are shown in Figures 1 and 3. The highest value of Ln P(D) was observed at K = 5 (Fig. 4 A). This result suggested that the most appropriate population number (K) of P. vivax in South Korea is 5. However, the differences between Ln P(D) values of each K (3–10) were very small. In order to make the break in slope of the distribution of Ln P(D) salient at true K, we calculated value of ΔK using the method described by Evanno et al. [44]. The highest value of ΔK was observed at K = 2, and the second highest was observed at K = 3 (Fig. 4 B). These three K values (K = 2, 3 and 5) were thus adopted (Fig. 1 and 3). For K = 5, two genotypes (light green, yellow) were predominant from 1994 to 2002. Five genotypes (light green, blue, purple, red, yellow) coexisted from 2003 to 2008 (Fig. 1 and 3). For K = 2, two genotypes (light green, yellow) coexisted from 1994 to 2008. The light green genotype was predominant from 1994 to 2000, whereas the yellow genotype was predominant from 2001 to 2008 (Fig. 1 and 3). For K = 3, two genotypes (light green, yellow) coexisted from 1994 to 2001, while three genotypes (blue, light green, yellow) coexisted from 2002 to 2008 (Fig. 1 and 3). For all K values greater than 2, there was a drastic genetic change in the population structure of P. vivax in South Korea during 2002 and 2003. The results of STRUCTURE analysis, which used a model of correlated allele frequency among population, were almost the same as those of the analysis using the independent allele frequency model.

Bottom Line: Vivax malaria was successfully eliminated in the Republic of Korea (South Korea) in the late 1970s, but it was found to have re-emerged from 1993.The LD analysis showed a gradual decrease in LD levels, while the levels of genetic differentiation between successive years and analysis of the population structure based on the Bayesian approach suggested that a drastic genetic change occurred in the South Korean population during 2002 and 2003.Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and temporal dynamics of parasite transmission; information that can assist in the elimination of vivax malaria in endemic areas.

View Article: PubMed Central - PubMed

Affiliation: Department of Tropical Medicine and Malaria, Research Institute, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan.

ABSTRACT

Background: Vivax malaria was successfully eliminated in the Republic of Korea (South Korea) in the late 1970s, but it was found to have re-emerged from 1993. In order to control malaria and evaluate the effectiveness of malaria controls, it is important to develop a spatiotemporal understanding of the genetic structure of the parasite population. Here, we estimated the population structure and temporal dynamics of the transmission of Plasmodium vivax in South Korea by analyzing microsatellite DNA markers of the parasite.

Methodology/principal findings: We analyzed 14 microsatellite DNA loci of the P. vivax genome from 163 South Korean isolates collected from 1994 to 2008. Allelic data were used to analyze linkage disequilibrium (LD), genetic differentiation and population structure, in order to make a detailed estimate of temporal change in the parasite population. The LD analysis showed a gradual decrease in LD levels, while the levels of genetic differentiation between successive years and analysis of the population structure based on the Bayesian approach suggested that a drastic genetic change occurred in the South Korean population during 2002 and 2003.

Conclusions/significance: Although relapse and asymptomatic parasite carriage might influence the population structure to some extent, our results suggested the continual introduction of P. vivax into South Korea through other parasite population sources. One possible source, particularly during 2002 and 2003, is North Korea. Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and temporal dynamics of parasite transmission; information that can assist in the elimination of vivax malaria in endemic areas.

Show MeSH
Related in: MedlinePlus