Spatial analyses of Plasmodium knowlesi vectors with reference to control interventions in Malaysia

Area of Science:

• Medical Entomology
• Spatial Epidemiology
• Vector-borne Diseases

Background:

• The Leucosphyrus Group of Anopheles mosquitoes transmits malaria parasites like Plasmodium knowlesi from macaques to humans.
• Plasmodium knowlesi is the most common zoonotic malaria parasite in Malaysia, necessitating vector distribution knowledge for control.

Purpose of the Study:

• To map the distribution of the Leucosphyrus Group of Anopheles mosquitoes in Malaysia.
• To correlate vector distribution with Plasmodium knowlesi malaria cases for targeted interventions.

Main Methods:

• Utilized historical vector data (1957-2021) and created distribution maps.
• Developed a predictive logistic regression model incorporating significant environmental factors.
• Employed Inverse Distance Weighting (IDW) for interpolation and overlaid with environmental variables.

Main Results:

• High vector abundances identified in specific regions of Sarawak, Pahang, and Sabah.
• Anopheles mosquitoes predominantly found in Peninsular Malaysia, Sabah, and Sarawak, with lower densities in southern Peninsular Malaysia and western Sarawak.
• The predictive model achieved 75.3% overall accuracy, with water bodies, elevation, temperature, forest loss, and cover as significant factors.

Conclusions:

• Provides crucial insights into the spatial distribution of Anopheles mosquitoes in Malaysia.
• The predictive vector map aligns with P. knowlesi malaria occurrences.
• Informs public health strategies for effective malaria control and elimination.