Characterization of Anopheles mosquito breeding habitats for malaria vector control in Mazowe and Shamva districts, Zimbabwe.

Abstract

Background objectives: Area-specific identification and studies of Anopheles breeding habitat diversity, distribution, and productivity in different seasons are important in designing and advancing effective malaria vector control according to the local context and needs. This study identified and characterized Anopheles breeding habitats for targeted control of malaria vectors in Mazowe and Shamva districts.

Methods: Repeated cross-sectional surveys were conducted in Mazowe and Shamva districts between April and December 2023. Habitat productivity and physicochemical parameters were measured. Anopheles larvae were collected, reared to adults, and identified using morphological keys. SPSS software was used for data analysis. One-way ANOVA, Fisher's exact, Pearson's correlation, and simple linear regression tests were conducted.

Results: Seven different types of Anopheles breeding habitats were identified from 56 sites. The highest mean density of larvae was recorded in stream edge pools during the post-rainfall period. Anophelespretoriensis (67.4%), An. gambiae s.l. (23.1%), An. rufipes (9.2%) and An. coustani (0.38%) were breeding in the study area. Anopheles pretoriensis bred in all habitat types, An. coustani in swamps only while An. gambiae s.l. and An. rufipes preferred stream edge pools, roadside pools, and hoof prints. There was a significant positive correlation between larval density and dissolved oxygen (r = 0.535; p < 0.001) and conductivity (r = 0.288; p = 0.032).

Interpretation conclusion: Size, origin, and type of breeding habitat were positive indicators for different Anopheles species in the study area. Potential malaria vector breeding habitats should be targeted for larval control under the current malaria control and elimination phases in the two districts.