Mechanical transmission of Dengue Virus by Aedes aegypti may influence disease transmission dynamics during outbreaks data

Summary
Background: Dengue virus outbreaks are increasing in number and severity worldwide. Viral transmission is assumed to require a minimum time period of viral replication within the mosquito midgut. It is unknown if alternative transmission periods not requiring replication are possible.
Methods: We used a mouse model of dengue virus transmission to investigate the potential of mechanical transmission of dengue virus. We investigated minimal viral titres necessary for development of symptoms in bitten mice and used resulting parameters to inform a new model of dengue virus transmission within a susceptible population.
Findings: Naïve mice bitten by mosquitoes immediately after they took partial blood meals from dengue infected mice showed symptoms of dengue virus, followed by mortality. Incorporation of mechanical transmission into mathematical models of dengue virus transmission suggests that this supplemental transmission route could result in larger outbreaks which peak sooner.
..., Virus and cell maintenance
The clinical isolate 2015 DENV-2 (TW2015; GenBank: KU365901)(19) was propagated in Ae. aegypti mosquitoes and Vero 76 cells (RRID: CVCL_0603). The viral titre was determined via plaque-formation assay using BHK-21 clone 13 cells (RRID: CVCL_1915). Vero cells were grown at 37°C, 5% CO2 in 1× Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 5% foetal bovine serum (FBS), 1× MEM nonessential amino acid solution, and 1× antibiotic-antimycotic solution. BHK-21 clone 13 cells were grown in 1× DMEM supplemented with 2% FBS and 1× antibiotic-antimycotic solution at 37°C, 5% CO2. All reagents were purchased from Thermo Fisher Scientific. All experiments were conducted using viral samples obtained following four passages of the original virus. All cell lines were purchased from the Food Industry Research and Development Institute, Taiwan. For mycoplasma testing: after thawing cells and culturing for at least 48 hours, 1 ml of medium was centrifuged at high spe...,