The prevalence of Dengue virus in Aedes mosquito populations and investigation of the density and breeding sites of Aedes mosquitoes in Veterinary and Remount Department, Thong Teekayu Camp, Nakhon Pathom Province

Abstract

Background: Dengue fever is caused by the dengue virus, which is transmitted to humans through the bite of infected Aedes mosquitoes. The disease typically occurs during the rainy season each year and can spread extensively, becoming a public health issue in many countries, particularly in tropical and subtropical regions. Nakhon Pathom Province consistently reports high annual infection rates and ranks among the top provinces in the country for dengue cases.  Therefore, it is interesting to study the prevalence of the dengue virus in Aedes mosquitoes in this area. Methods: This is a survey-based research study conducted by investigating the breeding sites of Aedes mosquitoes and setting up Biogents Sentinel Traps (BGS) with carbon dioxide gas (dry ice). The mosquito traps were placed in the residential areas of personnel from 8:00 AM to 3:00 PM, with a total of 20 traps per day for 2 days, from June 5th to 6th, 2024, to survey and collect adult mosquitoes. The mosquitoes were identified by their morphological characteristics. Their heads and thoraxes were analyzed for the dengue virus using the Multiplex Real-time PCR technique. Results: A total of 338 mosquitoes were collected, divided into four genera: Aedes, Anopheles, Culex, and Mansonia. The majority of the mosquitoes (83.1%) collected around the residential area of the personnel were from the genus Aedes, including 278 Ae. aegypti (162 females and 116 males) and 3 Ae. albopictus (3 females). A total of 165 female Aedes mosquitoes (162 Ae. aegypti and 3 Ae. albopictus) were tested for the dengue virus, and no infections were detected. Among the 19 buildings surveyed, larvae were found in 9, resulting in a House Index (HI) of 47.3, with the highest index observed in residential areas. In the survey of 176 containers, Aedes mosquito larvae were found in 32 containers, resulting in a Container Index (CI) of 18.2. The most common larval habitats were water basins, jars, and water tanks, accounting for 38.1%. Conclusion: This research study indicates that the Veterinary and Remount Department area is currently free from dengue fever. However, there remains a risk and possibility of dengue fever and other mosquito-borne diseases due to the density of Aedes mosquito populations found in breeding sites within the area. Therefore, educational sessions on the prevention and control of dengue fever were provided to military personnel and their families. The inspection report has also been submitted to the Army Veterinary Department Headquarters for further acknowledgment.