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

Abstract

Title

PLASMODIUM KNOWLESI SUB-POPULATIONS: TEMPORAL VARIATIONS AND CLINICAL MANIFESTATIONS AMONG PATIENTS AT KAPIT HOSPITAL, SARAWAK, MALAYSIAN BORNEO

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

Authors

Main Author
Ting Huey Hu1
Presenting Author
Ting Huey Hu1
Co-Author
Nawal Rosli1
Dayang A. Mohamad1
Khamisah A. Kadir1
Zhen Hao Ching2
Yaw Hung Chai2
Nur Naqibah Ideris2
Linda S.C Ting2
Adeline A. Dihom2
Sing Ling Kong2
Edmund K.Y Wong2
Jenny E.H. Sia2
Tiana Ti2
Irene P.F. Chai2
Wei Yieng Tang2
King Ching Hii2
Paul C.S. Divis1
Cyrus Daneshvar3
Balbir Singh1

Authors' Institution

Department / Institution / Country
Faculty of Health Sciences and Medicine / Universiti Malaysia Sarawak / Malaysia1
Kapit Hospital / Kapit Hospital / Malaysia2
Department of Thoracic Medicine / Univerity Hospitals Plymouth NHS Trust / United Kingdom3
Content
Abstract Content

Plasmodium knowlesi, a malaria parasite typically found in nature in long-tailed and pig-tailed macaques, causes malaria in humans which can be severe and fatal. There has been a recent increase in the number of knowlesi malaria cases in Malaysian Borneo and in the past 2 years (2017-2018), 99.7% (6697/6716) of indigenous malaria cases in Sabah and Sarawak were due to P. knowelsi. Population genetic studies on P. knowlesi infections in macaques and humans from the Kapit Division in Sarawak, Malaysian Borneo, identified two divergent sub-populations, associated with long-tailed (termed Cluster 1) and pig-tailed macaques (Cluster 2) respectively. To determine whether distinct clinical and laboratory features were associated with each sub-population and whether any temporal variations in P. knowlesi clinical manifestations have occurred, a prospective study was conducted at Kapit Hospital from September 2016 to October 2018, and compared with clinical data from a study conducted at Kapit Hospital 10 years ago. The initial study recruited 107 patients with 10 (9.35%) diagnosed as severe knowlesi malaria and there were two fatalities, while 418 patients were recruited for the recent study with 45 (10.8%) diagnosed as severe and no casualties. Cluster 1 was the dominant P. knowlesi subpopulation in both studies, accounting for 74/107(69.2%) and 286/418 (68.4%) of cases in the previous and current study respectively (p=0.54). There were no statistically significant differences observed in the prevalence of severe malaria when the 2006 cohort was compared with the recent cohort for both Cluster 1 patients [ 6/74(8.11%) versus 33/286 (11.5%); p=0.53] and Cluster 2 patients [4/32 (12.5%) versus 7/105 (6.6%); p=0.272] respectively. Additional analyses are being undertaken to determine if any significant differences in laboratory findings between the 2 cohorts. Further studies are also required to determine factors behind increase in human knowlesi malaria cases over the recent years in Malaysian Borneo.

Keywords: malaria; Plasmodium knowlesi; zoonosis; Kapit; knowlesi sub-populations
Requires Audio or Video system for Presentation?: Yes