Water closets as breeding sites for Aedes mosquitoes in dry seasons

Abstract

The challenges of reducing vectors that transmit diseases such as mosquitoes have been very tasking, especially in dry seasons where there are no visible  breeding habitats. The identification of these breeding habitats and control measures during dry periods are important in the integrated control approach. This study assessed various water closets to ascertain the occurrence and density of mosquitoes and the physicochemical parameters of the water in a University in Southern Nigeria. Water closets in the main campus and its annexes were examined for either the presence or absence of immature stages and adult mosquitoes. Mosquito density in each sampled closet was determined. Water parameters were taken using standard techniques. The association between the density of immature stages and adults with water parameters was equally determined. Mosquitoes were morphologically identified. Hydrogen ion concentration (7.57), electrical conductivity (498.60 μS/cm), and salinity (249.20 ppm) were highest in closets with mosquitoes compared to the closets without mosquitoes. Significant differences were observed between all the sampled water parameters of closets with and without mosquitoes (p< 0.05). Mean larval density (40.77) and occurrence were higher than eggs, pupal and adults. All adult mosquitoes (49) identified was Aedes aegypti. Out of the closets sampled, 48.2% had  mosquitoes. Temperature and Hydrogen ion concentration (pH) positively influenced larval and pupae density while conductivity and salinity showed no correlation to all stages of mosquitoes. This study revealed that closets in this area also serve as reservoir habitats for Aedes aegypti especially when they are not in use during dry seasons and has implications for disease transmission in the region. This requires urgent awareness and prompt public health interventions.