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This article is part of the supplement: Challenges in malaria research

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Microsatellite characterization of Plasmodium vivax in pregnant women on the Thai–Myanmar border

Supinya Thanapongpichat1, Mallika Imwong2*, Rose McGready3, Nicholas PJ Day45, Francois Nosten3, Georges Snounou67 and Nicholas J White45

  • * Corresponding author: Mallika Imwong

Author Affiliations

1 Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand

2 Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand

3 Shoklo Malaria Research Unit, Mae Sot, Tak, Thailand

4 Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand

5 Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital University of Oxford, Oxford, UK

6 Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S 945,Paris, France

7 Université Pierre & Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris, France

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Malaria Journal 2012, 11(Suppl 1):P137  doi:10.1186/1475-2875-11-S1-P137

The electronic version of this article is the complete one and can be found online at:

Published:9 November 2012

© 2012 Thanapongpichat et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Plasmodium vivax infections in pregnant women are associated with low birth weight and anemia. Genotyping of P.vivax is useful to study P. vivax in pregnancy, though it is still remains challenging to distinguish between relapse from hypnozoite stage and recrudescence from blood stage following treatment. A genetic investigation of P.vivax in pregnancy on the Thai-Burmese border, comparing the genotype between at follow up with the day of admission for pregnant patients and non pregnant patients was undertaken in this study.

Materials and methods

One hundred and sixteen blood samples infected with P.vivax were isolated from 18 pregnant women with ≥2 episodes obtained from whole blood (12 women had 2 reappearances, 4 and 2 women had 3 and 4 reappearances, respectively) and 18 non-pregnant women with 2 consecutive episodes collected on dried blood spot. All samples were genotyped with eight microsatellite markers. Analyses were performed for genetic diversity, multiplicity of infection (MOI), and comparison of genotypes for individual episodes detected in samples.


Eight microsatellite loci, 6 to 15 alleles were found at each locus. The mean number of alleles per locus was 1.40 and 1.17 (p<0.001) for pregnant and non-pregnant patients, respectively. The overall mean expected heterogygosity (He) was 0.845 in both groups. In pregnant patients, the multiplicity of infection (MOI) was 1.85 while it was 1.44 (p=0.028) in non-pregnant patients.

The greater number of minor alleles in pregnant patients may either the nature of the sample.

Combined genetic data from days of follow and day of admission showed that genotypes were different 57 % (25/44) of those pregnant patients and 58 % (21/36) of non-pregnant patients (p=0.891).


This study confirmed that different P.vivax genotypes were found during follow up when compared to day of admission in both groups.


Supported by grant from under the program "Strategic Scholarships for Frontier Research Network for the Ph.D." Program Thai Doctoral degree from the Office of the Higher Education Commission, Thailand and the Wellcome Trust of Great Britain.