BACKGROUND: Changes in vector biology and behaviour resulting from interventions such as indoor residual spraying (IRS), long-lasting insecticidal nets (LLINs), and the use of insecticidal aerosol sprays, coils, and other mosquito control measures underscore the need for strengthened and regular vector surveillance. Understanding vector behaviour and species diversity is crucial for adapting interventions to achieve more effective and sustainable malaria control. This study examined malaria vector biting behaviour and transmission risk in Simiw, a community located in the coastal forest of Ghana's Central Region. METHODS: Adult malaria vectors were collected using human landing catch (HLC) method during the dry and rainy season of 2021. Vector densities, biting patterns and entomological transmission indices of An. gambiae s.l. were evaluated. Molecular techniques were employed to identify vector species, detect Plasmodium falciparum infection, and analyze insecticide resistance genes. RESULTS: A total of 4,173 mosquitoes from four different genera were collected during the sampling period, with a surprising higher abundance recorded in the dry season compared to the rainy season. Indoor collections of An. gambiae s.l. outnumbered outdoor collections in both seasons. An. coluzzii was the most prevalent species, making up 79.0% (678/858), followed by An. gambiae s.s. at 17.6%, hybrids of An. gambiae and An. coluzzii at 1.9% (16/858), and An. melas at 1.5% (13/858). The biting rate for An. gambiae s.l. peaked in the early morning hours between 04:00 and 05:00. The overall entomological inoculation rate (EIR) was calculated at 61.20 infective bites per person per year. CONCLUSION: The study found higher abundance and biting rates of An. gambiae s.l. during the dry season, with both the HBR and EIR being greater indoors than outdoors. The observed species diversity and transmission risk indices emphasize the importance of ongoing vector monitoring.
Obboh et al. (2026) studied this question.