Dengue virus transovarial transmission detection in Aedes aegypti from dengue hemorrhagic fever patients' residences in Denpasar, Bali

Abstract

Background and Aim: To effectively control dengue hemorrhagic fever (DHF), it is necessary to assess the risk of vertical virus transmission in Aedes aegypti mosquitoes. This study aimed to detect dengue virus (DENV) transovarial transmission in A. aegypti collected from DHF patients' residences in Denpasar, Bali. Materials and Methods: A. aegypti samples were acquired by rearing A. aegypti eggs collected from ovitraps placed in the homes of DHF patients. Ovitraps were installed for 7 days and viewed using a loupe to determine whether there were Aedes spp. eggs present. An immunocytochemical method was utilized with 200 samples, and virus detection was performed using a reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Of the 10 DHF patient houses fitted with ovitraps, four produced positive ovitraps from which larvae developed (house index=40%). Of the 50 ovitraps mounted in the 10 homes, 14 ovitraps were positive and contained A. aegypti eggs (ovitrap index=28%). Of these 14 positive ovitraps containing A. aegypti eggs, 10 ovitraps produced larvae. Immunocytochemical tests were conducted on A. aegypti eggs from the four houses under study. It was found that from the 200 samples collected, 197 samples could be observed, and 11 samples (5.6%) were positive for DENV antigen. RT-PCR examination conducted on mosquitoes reared from the four houses studied obtained a negative virus content result. Conclusion: This study found the presence of DENV antigen to be as high as 5.6%. This means that potential for transovarial transmission exists within DHF patients' homes in Denpasar, Bali. Aedes control strategy in Denpasar should address this finding, in addition to the current approaches which have focused primarily on the elimination of larval breeding habitats and control of adults using insecticidal fogging during outbreaks.

Study of Dengue Virus Transovarial Transmission in Aedes spp. in Ternate City Using Streptavidin-Biotin-Peroxidase Complex Immunohistochemistry

“…With 78,300 inhabitants, this district is the most populous in the city [ 10 ]. The finding of transovarial transmission in this study confirms the previous opinion which stated that female mosquitoes infected with dengue virus in their ovaries can transmit the virus to their offspring transovarially [ 7 , 11 ]. However, only a small number of studies have used transovarial transmission and monitoring of viral vectors as tools for control and surveillance.…”

“…aegypti contributes to the spread and maintenance of the dengue epidemic [ 6 ]. Immunocytochemical techniques can be used to determine whether or not transovarial transmission is present [ 7 ]. Dengue virus can also be detected using other methods, including immunofluorescence, immune-peroxidase, and polymerase chain reaction (PCR) [ 8 , 9 ].…”

Prevalence of anti-DENV IgG among routine Bangladeshi blood donors, and strategies for the future

“…The dengue virus is expected to be included to the serology of blood banks in tropical and subtropical countries in the near future. This is owing to the fact that 40% of dengue fever patients display no symptoms and so are not detected or reported to the health authorities 11 .…”

Analysis of the spread of dengue hemorrhagic fever with the moran index (Case study of Sukoharjo Regency in 2019)

“…Dengue Hemorrhagic Fever (DHF) is one of the endemic diseases that can be found in tropical areas [1]. Dengue fever is caused by the dengue virus, which is transmitted to humans primarily through the bites of infected female mosquitoes, mainly the Aedes aegypti mosquito [2].The dengue virus does not develop at the base of the mosquito's proboscis [3]. Instead, the virus replicates and multiplies in the mosquito's midgut after it feeds on the blood of an infected person [4].…”