Genetic evidence of cross-border plasmodium vivax spread in a malaria pre-elimination region of south Asia

Authors

• Anjana Rai, Menzies School of Health Research and Charles Darwin University, Australia
• Edwin Sutanto, Menzies School of Health Research and Charles Darwin University, Australia
• Prakash Ghimire, Tribhuvan University, Nepal
• Sonam Wangchuk, Ministry of Health, Bhutan
• Tobgyel Drukpa, Ministry of Health, Bhutan
• Mohammad Shafiul Alam, International Centre for Diarrhoeal Disease Research, Bangladesh
• Najia Bano Ghanchi, Aga Khan UniversityFollow
• Awab Gulam Rahim, Afghan International Islamic University, Afghanistan
• Angela Rumaseb, Menzies School of Health Research and Charles Darwin University, Australia
• Bushra Qurashi, Aga Khan UniversityFollow
• Shan-E-Zehra Zaidi, Aga Khan University
• Mohammad Asim Beg

Document Type

Article

Department

Pathology and Laboratory Medicine

Abstract

Background: Plasmodium vivax is the predominant cause of malaria in South Asia. P. vivax cases have fallen over the past decade, but cross-border transmission remains a major challenge to elimination. Genetic data can generate valuable insights into transmission; however, until now, only low-resolution data have been available from Nepal, Bhutan and Bangladesh. We piloted high-resolution genotyping using a new microhaplotype (multiallelic) assay to monitor P. vivax transmission across borders.
Methods: Genotyping was conducted using the 93-microhaplotype vivaxGEN panel on P. vivax parasites collected from patients enrolled in clinical trials in Bangladesh, Bhutan, and Nepal between 2013 and 2023. These data were compared with open-access microhaplotype and genomic data derived from Afghanistan, India, and Pakistan between 2014 and 2024. Complexity and relatedness (identity by descent (IBD)) were determined within and between countries.
Results: High-quality genotyping data were generated for Nepal (n=19), Bhutan (n=27), and Bangladesh (n=35); comparative data were sourced from Afghanistan (n=159), India (n=24), and Pakistan (n=213). High-complexity infections were observed in 27.04% (43/159) of isolates from Afghanistan, 16.43% (35/213) from Pakistan, and 28.57% (10/35) from Bangladesh. Low prevalence of high-complexity infections was observed in Bhutan (3.70%; 1/27) and Nepal (5.26%; 1/19), suggesting lower superinfection or co-infection. Country-wide IBD analyses revealed three genetic clusters partitioning Bangladesh and Bhutan (partial) from the remaining countries. There were two sub-populations in Bhutan, which separated local and cross-border imported cases.
Conclusions: Our results highlight the use of regional high-resolution genetic data to enhance monitoring of transmission intensity and cross-border importations.

Comments

Pagination, volume and issue no are not provided by author/publisher

Publication (Name of Journal)

The Journal of infectious diseases

DOI

10.1093/infdis/jiag268

Recommended Citation

Rai, A., Sutanto, E., Ghimire, P., Wangchuk, S., Drukpa, T., Alam, M., Ghanchi, N., Rahim, A., Rumaseb, A., Qurashi, B., Zaidi, S., Beg, M. (2026). Genetic evidence of cross-border plasmodium vivax spread in a malaria pre-elimination region of south Asia. The Journal of infectious diseases.
Available at: https://ecommons.aku.edu/pakistan_fhs_mc_pathol_microbiol/1770