Comparing malaria risk exposure in rural Cambodia population using GPS tracking and questionnaires

Area of Science:

• Epidemiology
• Parasitology
• Public Health

Background:

• Residual malaria transmission persists in the Great Mekong Subregion, particularly among forest workers and migrant populations.
• Understanding the mobility patterns of high-risk groups is crucial for controlling malaria hotspots.

Purpose of the Study:

• To characterize the fine-scale mobility of forest-goers and its link to malaria transmission.
• To evaluate the accuracy of Global Positioning System (GPS) data loggers and questionnaires in assessing mobility.
• To detect malaria parasites using real-time polymerase chain reaction (RT PCR) and assess exposure to Anopheles bites via antibody quantification.

Main Methods:

• Two 28-day follow-ups were conducted during dry and rainy seasons on male forest goers.
• Methods included GPS tracking, questionnaires, health examinations, RT PCR for parasite detection, and enzyme-linked immunosorbent assay for anti-Anopheles antibodies.
• Analysis focused on time spent in different land use categories and demographic data to identify malaria risk factors.

Main Results:

• Malaria prevalence was highest in participants from villages outside the forest, not associated with time spent in forests.
• Antibody response to Anopheles salivary peptides was higher in the rainy season, correlating with mosquito density but not mobility factors.
• Agreement between GPS and self-reported mobility data was only 61.9%.

Conclusions:

• Questionnaires, GPS, and antibody quantification were insufficient to detect malaria risk factors associated with mobility behaviors in this high-risk group.
• Combined use of GPS and questionnaires revealed limitations of individual methods and benefits of integrated approaches.
• New strategies for malaria detection and follow-up are needed to address residual transmission.