Estimating dispersal, survival and population size of wild Aedes aegypti in Dar es Salaam, Tanzania using self-mark-release-recapture method

Abstract Aedes -borne arboviral diseases represent a major global public health challenge, with vector control remaining the primary preventive strategy because there are no available antivirals or universal vaccines for most of these infections. This study quantified dispersal, survival time and population size of Aedes aegypti using a mosquito mark-release-recapture (MMRR) approach to generate ecological parameters required in implementing a release-based approaches for Ae. aegypti control. Wild Ae. aegypti pupae were placed beneath a marking unit covered with fluorescent dust-coated cloth-grids. Marked mosquitoes were recaptured within a 250m radius using BG-sentinel traps, prokopack aspirators, resting buckets and gravid traps. The overall mean distance travelled (MDT) was 94.5m(95%CI:83.4-105.7) and the maximum distance travelled was 156m. The average life expectancy (ALE) was 13.5 days(95%CI:12.2–14.8), with an average probability of daily survival (PDS) of 0.93(95%CI:0.92–0.94). Survival analysis showed that approximately 80% of male and female Ae. aegypti survived up to 10days. The estimated population size was 26,325 individuals within 200m radius of the marking device. These findings demonstrate that, Ae. aegypti exhibit limited dispersal and survive beyond dengue virus’ average extrinsic incubation period (EIP) of 7-12days, providing ecological conditions conducive to sustain arboviral transmission. The results also provide critical parameters for optimizing release-based control strategies.