Can a mosquito transmit more than one disease?

Online Q&A
September 2016

Q: We know that the same mosquito species can carry many diseases (such as dengue, Zika, chikungunya, and yellow fever). Can a mosquito carry more than one disease at the same time? If so, could someone get more than one disease from a single bite?

The mosquito species Aedes aegypti and Aedes albopictus carry dengue, chikungunya and Zika virus. In addition, Aedes aegypti also transmits yellow fever.

Studies done in Gabon and India show that humans can be infected with chikungunya and dengue at the same time.

Entomological studies confirming coinfection in mosquitoes are rare. The Gabon study found one mosquito specimen that was positive for both viruses, meaning that it is possible that the bite of a single mosquito could infect a person with 2 viruses at the same time.

Coinfection poses a challenge for accurate diagnosis and treatment, particularly when symptoms such as fever and aches can be similar for many diseases.