Instances of the Aedes aegypti mosquito carrying both dengue and chikungunya viruses at the same time during vector-borne transmission this season have been discovered by the Post-Graduate Institute of Medical Education and Researchs (PGI) Virology Department. 101 instances of chikungunya and 839 cases of dengue have been reported in the Union Territory (UT) to date. The chikungunya and dengue viruses are co-infecting the human host due to a common vector.

When two mosquitoes, each carrying a different virus, bite a human, it might result in a concurrent viral infection. These viruses are dengue virus (DENV) and chikungunya virus (CHIKV).

The same Aedes mosquito species spreads both viruses. These viruses can reproduce simultaneously in the mosquito, transmitting concurrently contagious dengue and chikungunya virus particles through saliva in a single bite.

Mosquitoes with a primary dengue virus infection can develop a subsequent chikungunya virus infection.

Prof RK Ratho, Head of the Virology Department, says: "It has been seen Aedes aegypti happens to be the primary vector species for the transmission of dengue disease. Similarly, the same mosquito also possesses the capacity to transmit chikungunya virus. Sometimes, the mosquito is found harboring both infections simultaneously. This mosquito is a day bitter, more so in the morning and evening hours, and prefers to breed around the human dwellings."

Common clinical manifestations of dengue and chikungunya viral infections include high-grade fever, headache, nausea, rashes, and bodily pain. Therefore, a disease with overlapping symptoms could develop due to co-infection with the two viruses.

(Source: https://www.tribuneindia.com/news/chandigarh/mosquitoes-carrying-twin-viruses-causing-co-infection-454825)