Density of Dengue Vector in Hodeidah, Yemen 2017

Abstract

Background: Dengue fever is a significant vector-borne disease in tropical and subtropical regions, with Aedes aegypti and Aedes albopictus being the primary vectors. Hodeidah, Yemen, has witnessed increasing dengue cases, necessitated an in-depth analysis of vector density. Objective: This report aimed to investigate the density of dengue vector (Aedes aegypti) in Hodeidah in 2017. Methods: The entomological survey was conducted in Hodeidah Governorate, Yemen in  2017. Data were collected across four seasons—winter, spring, summer, and autumn—through field inspections of mosquito breeding sites. Standard indices, including the House Index (HI), Container Index (CI), and Breteau Index (BI), were calculated based on larval and pupal presence. Environmental parameters such as temperature, humidity, and rainfall were also recorded to assess their correlation with vector density. Results: The entomological survey revealed notable differences in the density of Aedes aegypti between urban and rural districts in Hodeidah Governorate. In urban districts, including Al Hali, Al Hawak, and Al Mina, the mean House Index (HI) was 33.3%, the Container Index (CI) was 17.2%, and the Breteau Index (BI) was 57.23. These levels, while concerning, were significantly lower than those observed in rural districts. In contrast, rural areas showed a higher risk of dengue transmission, with a mean HI of 52.3%, CI of 23.4%, and an alarming BI of 139.9. Several districts such as As Salif, Az Zaydiyah, and Al Qanawis reported BI values exceeding the World Health Organization (WHO) epidemic threshold of 50, reaching up to 330.0 in As Salif.  Conclusion : The study revealed a seasonally dynamic trend, with peak infestation observed particularly in autumn and spring. These high values suggest intense but uneven breeding activity across rural settings. The variation in vector indices across districts indicates that while urban areas face persistent risk due to population density and poor sanitation, rural districts may act as hotspots for outbreak initiation due to weak surveillance and inadequate vector control. Coordinated public health action, tailored to local epidemiological and environmental conditions, remains essential to curbing dengue transmission.