Releasing Intracellular NS1 from Mosquito Cells for the Detection of Dengue Virus-Infected Mosquitoes

Abstract

Dengue virus (DENV), the pathogen that causes dengue fever, is mainly transmitted by Aedes aegypti. Surveillance of infected mosquitoes is a major component of integrated mosquito control methods for reducing the risk of vector-born disease outbreaks. However, a specialized rapid test for DENV detection in mosquitoes is not currently available. Utilizing immunoblotting, we found that the secretion of NS1 from both a DENV-infected mosquito cell line and mosquito bodies was below the detection threshold. However, when Triton X-100 was used to lyse infected mosquitoes, intracellular NS1 was released, and could then be effectively detected by the NS1 rapid test. The distribution of DENV NS1 in intrathoracically infected mosquitoes was different from that of orally infected mosquitoes. Next, we performed sensitivity tests by bisecting mosquitoes longitudinally; one half of each mosquito was subjected to the NS1 rapid test while the other half was used for qPCR confirmation. This modified test had a sensitivity of nearly 90% from five days post-infection onwards, while DENV had escaped from the midgut barrier. This adapted test offers a valuable, easy-to-use tool for mosquito surveillance, which is a crucial component of DENV disease control.

Transgenic refractory Aedes aegypti lines are resistant to multiple serotypes of dengue virus

“…albopictus species. Once mosquito acquired the DENV, virus would infect midgut in 3–5 days, disseminate into circulatory system to reach salivary glands in 7–10 days, and transmit virus to next host in 10–14 days 6 – 8 . Therefore, blocking virus acquisition or replication in the tissues of the mosquito may be a strategy for reducing the incidence of DENV transmission to humans.…”

Comparison of Fan-Traps and Gravitraps for Aedes Mosquito Surveillance in Taiwan

“…In urban areas, the electricity can be sourced from nearby houses or streetlamps. As an additional measure for mosquito surveillance programs, captured mosquitoes from the fan-traps can be tested for dengue infection with rapid testing methods ( 40 ) to provide more information for dengue disease control, due to correlations previously identified between the number of infected mosquitoes and human dengue fever cases ( 41 , 42 ). As an additional benefit of fan-traps, previous studies have reported that dengue virus non-structural protein 1, a therapeutic target for dengue virus, can be detected from mosquitoes captured by gravid sticky traps ( 43 ).…”

“…In comparison, fan-traps are not hindered by retrieval issues, meaning that mosquito bodies can be obtained via air-dried conditions ( 40 , 44 , 45 ) and tested for biomarkers of dengue virus. Estimating the efficiency of fan-traps in specifically capturing gravid female mosquitoes should therefore be possible but will require further experiments.…”