Plasmodium Knowlesi Malaria Ecology and Control

Plasmodium knowlesi is a zoonotic malaria parasite maintained in macaque populations across Southeast Asia and transmitted to humans by Anopheles mosquitoes. Its ecology is shaped by interactions among non-human primate reservoir hosts, vector species, and human activities at forest interfaces. Land-use change, in particular deforestation and forest fragmentation, alters macaque habitats and vector breeding sites, increasing spillover risk along forest edges. Human cases often occur among adult men engaged in forest-based occupations or residing near fragmented woodland, though peri-domestic transmission has also been documented. Control strategies must therefore integrate vector control, landscape management and enhanced surveillance. Novel diagnostic tools targeting parasite biomarkers, together with ecological and epidemiological modelling, support risk mapping and guide targeted interventions within a One Health framework to reduce human exposure and interrupt transmission at the animal–human interface.

Research from Nature Portfolio

Recent studies have refined our understanding of transmission dynamics and vector ecology. Model-based analyses of human case surveillance in Malaysia estimate individual reproductive numbers consistently below unity, confirming that P. knowlesi remains primarily zoonotic rather than sustaining onward human-to-human spread. This finding underscores the importance of minimising macaque-to-human spillover rather than focusing solely on human transmission chains. In southern Thailand, field surveys combining morphological and molecular identification have revealed that multiple Anopheles species—especially An. latens and An. introlatus—harbour P. knowlesi sporozoites, with peak infection rates during the rainy season and early night-time biting. These results highlight the need for season- and species-specific vector control measures in areas of human–macaque overlap.

Plasmodium Knowlesi Malaria Ecology and Control publication trend

The graph below shows the total number of articles in plasmodium knowlesi malaria ecology and control across all publications each year (not limited to Nature Index journals).

Technical terms

Zoonosis: An infection naturally transmitted between vertebrate animals and humans.

Reservoir host: A species that harbours a pathogen long-term, serving as a source of infection for other hosts.

Subcritical transmission: A situation in which the individual reproductive number (R_C) of an infection is below one, indicating that each case generates fewer than one secondary case on average.

Ecological niche modelling: A computational approach that predicts the geographic distribution of species or disease risk by relating occurrence data to environmental variables.

Forest fragmentation: The breaking up of continuous forest into smaller, isolated patches, often increasing edges where humans, vectors and wildlife interact.

References

1. No evidence of sustained nonzoonotic Plasmodium knowlesi transmission in Malaysia from modelling malaria case data. Nature Communications (2023).
2. Landscape drives zoonotic malaria prevalence in non-human primates. eLife (2024).
3. Predicting Plasmodium knowlesi transmission risk across Peninsular Malaysia using machine learning-based ecological niche modeling approaches. Frontiers in Microbiology (2023).
4. Natural vectors of Plasmodium knowlesi and other primate, avian and ungulate malaria parasites in Narathiwat Province, Southern Thailand. Scientific Reports (2023).
5. Individual-level factors associated with the risk of acquiring human Plasmodium knowlesi malaria in Malaysia: a case-control study. The Lancet Planetary Health (2017).
6. Plasmodium knowlesi: Reservoir Hosts and Tracking the Emergence in Humans and Macaques. PLOS Pathogens (2011).