MSPTM 2019 Annual Scientific Conference
13 - 14 March 2019
InterContinental Kuala Lumpur

Abstract

Title

PREDOMINANT PLASMODIUM KNOWLESI SUBPOPULATION ASSOCIATED WITH LONG-TAILED MACAQUES INFECTING HUMAN KNOWLESI MALARIA PATIENTS IN KAPIT DIVISION, MALAYSIAN BORNEO

Type
Oral Presentation
Theme
Scaling Up Efforts in Tropical Disease and Vector Control through Evidence-Based Research
Topic
Malaria

Authors

Main Author
Paul CS Divis1
Presenting Author
Paul CS Divis1
Co-Author
Ting Huey Hu1
Nur Emyliana Yunos1
Khamisah A Kadir1
Dayang SA Mohamad1
King Ching Hii2
David J Conway3
Balbir Singh1

Authors' Institution

Department / Institution / Country
Malaria Research Centre, Faculty of Medicine and Health Sciences / Universiti Malaysia Sarawak / Malaysia1
Sarawak State Health Department / Kapit Hospital / Malaysia2
Department of Pathogen Molecular Biology / London School of Hygiene and Tropical Medicine / United Kingdom3
Content
Abstract Content
Plasmodium knowlesi parasite is the main cause of malaria in humans across Malaysian Borneo. Previous population genetic surveys using multi-locus microsatellite assays indicated the existence of two divergent P. knowlesi subpopulations associated with forest dwelling long-tailed macaques (Cluster 1) and pig-tailed macaques (Cluster 2) in Sarawak. Human-animal-environment interactions potentially affect the distribution of P. knowlesi infections, and this could result in changes in the frequency of each P. knowlesi subpopulation. Using a simple genotyping PCR assay to distinguish the dimorphic P. knowlesi parasites, we monitored the variations in the proportion of these two subpopulations in 1204 clinical isolates from Kapit Division, Sarawak over different timeframes. Overall, two thirds of the total infections were accounted as Cluster 1, indicating that the majority of human P. knowlesi infections were acquired from long-tailed macaques. One-third of human P. knowlesi infections were of the type associated with pig-tailed macaques (Cluster 2) while only a small proportion (5%) contained both parasite types. Over three time periods of 2000–2002 (n = 110), 2006–2008 (n=176), and 2013–2018 (n = 918), the proportion of Cluster 1 and Cluster 2 subpopulations showed similar patterns of distribution, with the Cluster 1 subpopulation being the predominant one. Similarly, comprehensive monitoring the distribution patterns from June 2013 until May 2018 showed heterogeneity despite Cluster 1 still being the major subpopulation. Continued monitoring of the frequency of the two subpopulations together with environmental alterations are necessary to determine whether there are changes in the epidemiology of knowlesi malaria in future.
Keywords: zoonotic malaria; Plasmodium knowlesi; epidemiology
Requires Audio or Video system for Presentation?: No