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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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Estimated population structure of the South Korean P. vivax populations from 1994 to 2008.The population structure of the South Korean P. vivax population (163 isolates) from 1994 to 2008 was estimated by Bayesian approach using STRUCTURE software version 2.3.4, under the assumption of uncorrelated allele frequencies model [43]. Each isolate was represented by a vertical line partitioned into colored segments in proportion to the estimated membership (ancestral population). Different colors represent different genotypes (ancestral population). If one bar has more than two colors, it indicates that the genotype of the isolate is admixed with more than two ancestral populations. Results shown were for K = 2, 3 and 5. The numbers in parentheses after collection year represent the number of isolates for each year.
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pntd-0002522-g001: Estimated population structure of the South Korean P. vivax populations from 1994 to 2008.The population structure of the South Korean P. vivax population (163 isolates) from 1994 to 2008 was estimated by Bayesian approach using STRUCTURE software version 2.3.4, under the assumption of uncorrelated allele frequencies model [43]. Each isolate was represented by a vertical line partitioned into colored segments in proportion to the estimated membership (ancestral population). Different colors represent different genotypes (ancestral population). If one bar has more than two colors, it indicates that the genotype of the isolate is admixed with more than two ancestral populations. Results shown were for K = 2, 3 and 5. The numbers in parentheses after collection year represent the number of isolates for each year.

Mentions: Figure 1 shows the number of isolates found in samples from each year (Fig. 1). In total, 71 unique haplotypes were observed in the 163 isolates (Table 1). The allelic composition of each haplotype is shown in Table S2. There were 2 major haplotypes: H35 and H43. H35 was observed in 22 (13.5%) of the 163 isolates in samples collected from 1995 to 2001. H43 was observed in 58 (35.6%) of the 163 isolates in samples collected from 1994 to 2001, 2003 and 2007. By increasing the number of loci (from 10 to 14) and isolates (from 87 to 163), the number of unique haplotypes was increased from 40 to 71 [33], which enabled us to perform a more precise estimation of the transmission dynamics of the South Korean P. vivax population over the study period. When compared to the previous study, however, the changes in the levels of genetic diversity (heterozygosity) observed in the present study were relatively minor (Table S1, Fig. S1 and S2) [33].


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)

Estimated population structure of the South Korean P. vivax populations from 1994 to 2008.The population structure of the South Korean P. vivax population (163 isolates) from 1994 to 2008 was estimated by Bayesian approach using STRUCTURE software version 2.3.4, under the assumption of uncorrelated allele frequencies model [43]. Each isolate was represented by a vertical line partitioned into colored segments in proportion to the estimated membership (ancestral population). Different colors represent different genotypes (ancestral population). If one bar has more than two colors, it indicates that the genotype of the isolate is admixed with more than two ancestral populations. Results shown were for K = 2, 3 and 5. The numbers in parentheses after collection year represent the number of isolates for each year.
© Copyright Policy
Related In: Results  -  Collection

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

pntd-0002522-g001: Estimated population structure of the South Korean P. vivax populations from 1994 to 2008.The population structure of the South Korean P. vivax population (163 isolates) from 1994 to 2008 was estimated by Bayesian approach using STRUCTURE software version 2.3.4, under the assumption of uncorrelated allele frequencies model [43]. Each isolate was represented by a vertical line partitioned into colored segments in proportion to the estimated membership (ancestral population). Different colors represent different genotypes (ancestral population). If one bar has more than two colors, it indicates that the genotype of the isolate is admixed with more than two ancestral populations. Results shown were for K = 2, 3 and 5. The numbers in parentheses after collection year represent the number of isolates for each year.
Mentions: Figure 1 shows the number of isolates found in samples from each year (Fig. 1). In total, 71 unique haplotypes were observed in the 163 isolates (Table 1). The allelic composition of each haplotype is shown in Table S2. There were 2 major haplotypes: H35 and H43. H35 was observed in 22 (13.5%) of the 163 isolates in samples collected from 1995 to 2001. H43 was observed in 58 (35.6%) of the 163 isolates in samples collected from 1994 to 2001, 2003 and 2007. By increasing the number of loci (from 10 to 14) and isolates (from 87 to 163), the number of unique haplotypes was increased from 40 to 71 [33], which enabled us to perform a more precise estimation of the transmission dynamics of the South Korean P. vivax population over the study period. When compared to the previous study, however, the changes in the levels of genetic diversity (heterozygosity) observed in the present study were relatively minor (Table S1, Fig. S1 and S2) [33].

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