Current Tools to Combat Malaria, special Focus on Plasmodium knowlesi workshop – 2019: Day 5

MESA Correspondents bring you cutting-edge coverage from the Current Tools to Combat Malaria-with Special Focus on Plasmodium knowlesi workshop.

Day 5: 8^th March 2019

Session 1. Phylogenetics and molecular epidemiology of Plasmodium knowlesi

Prof Dr Fong Mun Yik shared his research findings on phylogenetics and molecular epidemiology of P. knowlesi in Malaysia. Based on the evidence from various genetic markers, two distinct P. knowlesi types were found in Borneo and Peninsular Malaysia, which seem a result of having evolved following the sea-level rise at the end of the last ice age (15,000 years ago), which separated Borneo from Peninsular Malaysia. The populations were isolated, along with their monkey and vector hosts. Strikingly, two distinct genetic lineages were also found in the long-tailed macaques which correspond to the populations from Borneo and Peninsular Malaysia, respectively. The incriminated vector species P. knowlesi were also found to be different in both regions. Their evolution and distribution were likely shaped by past and recent events and independently became human zoonosis, according to Dr Fong Mun Yik.

Dr Fong Mun Yik emphasized the importance of molecular epidemiology in tracing back the origin of P. knowlesi infection

Session 2. Spatial distribution, epidemiology, and genotyping of Plasmodium knowlesi among primates in Peninsular Malaysia

This lecture was given by Dr Reuben Sunil Kumar Sharma, veterinarian and veterinary parasitologist from the University Putra Malaysia. In the initial session, Dr Reuben Sunil Kumar Sharma pointed out that forest destruction is a major threat to wildlife in Southeast Asia, which includes the long-tailed macaques. The macaques are being displaced from their natural habitats, being forced to encroach into urban and suburban areas. Subsequently, they have started to colonise and reproduce due to the availability of food resources and shelter. This situation narrows the gap between the human-wildlife interface, and therefore, the zoonotic wildlife diseases are more common due to increased proximity between the infectious agent, host, environment and vector.

The main host of P. knowlesi, Macaca fascicularis, is the most abundant and widespread non-human primate in a broad range of habitats in Southeast Asia. Its distribution ranges from coastal mangroves to inland hill forest, as well as recreational parks, suburban areas and agricultural areas. A high prevalence of P. knowlesi-infected macaques has been observed in Malaysia, but most of the times, these infections are with low parasitaemia, making them an excellent reservoir for this malaria parasite. Therefore, the macaques will be a constant source of human infection as long as the mosquito vector is present. This situation poses a serious challenge to malaria elimination in Malaysia and the Southeast Asian region where the disease is endemic.

Forest destruction is a major threat to wildlife in Southeast Asia, including the long-tailed macaques, according to Dr Reuben Sunil Kumar Sharma

Session 3. The clinical features and management of knowlesi malaria

The participants were delighted to have Dr Timothy William, an infectious disease physician from the Gleneagles Kota Kinabalu Hospital, Sabah, as the speaker for the clinical features and management of knowlesi malaria session. Dr William mentioned that distinguishing among P. falciparum, P. vivax and P. knowlesi in places where all three species frequently occur is challenging. Misdiagnosis can potentially lead to inappropriate treatment, including chloroquine therapy for P. falciparum and a lack of anti-relapse therapy for P. vivax.

Plasmodium knowlesi has been microscopically misidentified as P. malariae, P. falciparum and P. vivax and often associated with case fatalities due to the lack of severe disease recognition and delayed parenteral artesunate. Dr William also shared his knowledge on the drug treatments for the cases of uncomplicated and severe knowlesi malaria. Other supportive therapies such as fluid management, renal replacement therapy, inotropes, respiration ventilation, and blood transfusion were also briefly explained to the participants. The issue of drug resistance was also discussed.

Dr William sharing his experience in treating malaria-infected patients

Session 4. Quiz and end-of-course certificate

At the end of the workshop, the participants took a quiz related to the lectures and practical classes that they attended in this 5-day workshop. A certificate was given to each participant upon completion of the workshop.

Gifts were given to the top three winners of the quiz contest

Closing ceremony

The closing ceremony of the “Current Tools to Combat Malaria-with Special Focus on Plasmodium knowlesi” workshop was officiated by the Head of Department of Parasitology, Prof Dr Suresh Kumar A/L P Govind. He congratulated the organizing committee members and participants on such a successful event and stressed that collaboration should be initiated, being the way forward to reaching greater heights.

This blog was written by Dr Lucas Low Van Lun (Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya) as part of the MESA Correspondents program. Editorial support has been provided by Dr Indra Vythilingam.