Background: In the Greater Mekong Subregion (GMS), situated within Southeast Asia, multidrug-resistant malaria and insecticide resistance have been found, threatening malaria control and elimination. New vector-control tools targeting mosquitoes that bite outside, bite during the daytime, and are resistant to insecticide are needed. The potential of tools likely depends on their modes of action and the bionomics of the local vectors. Previously, vector-control tool selection has been supported by sensitivity analysis of vectorial capacity.
Methods: In this paper, we conducted systematic literature research to generate a bionomic dataset of the main malaria vectors in the GMS, including human blood index (HBI), parity proportion (rate), sac proportion (rate), and the resting period duration. We then used descriptive statistics and inferential statistics to analyze these bionomics. Finally, we performed global sensitivity analyses, Latin hypercube sampling-partial rank correlation coefficients (LHS-PRCC), and Sobol’s method to assess the influence of bionomic and intervention parameters on the relative change of vectorial capacity and intervention effectiveness.
Results: Our review shows that the An. minimus complex, An. sinensis, An. maculatus group, and An. sundaicus complex displays an opportunistic blood-feeding behavior, while An. dirus complex is more anthropophilic. Multivariate regression analysis shows that parity proportion is affected by environmental, climatic, and mosquito sampling factors. The resting duration is 2--3 days in hot rainy seasons and 4--6 days in a cool dry seasons. Global sensitivity analysis demonstrated that HBI and parity proportion are the most influential bionomic parameters, followed by the resting period duration. In a low HBI setting, preprandial killing, disarming, and repelling have similar impacts on model output, and are more influential than postprandial killing. However, preprandial killing has the most decisive impact in a high HBI/parity proportion setting.
Conclusions: HBI, parity proportion, sac proportion, and the resting period duration of the main malaria vectors vary in the GMS, depending on biological, environmental, or measurement differences. Although in general, preprandial killing has the largest community-level effect on reducing transmission, in low HBI settings other modes of action, such as repellency and disarming, can be effective.