When the American Society of Tropical Medicine and Hygiene met for their 2016 annual meeting on November 14, some surprising research was presented: a single mosquito carrying both Zika virus and chikungunya viruses can infect the person it bites with both viruses -- in a single bite.
Zika, chikungunya, and dengue all use the mosquito Aedes aegypti as a host. Zika and dengue are flaviviruses; chikungunya is an alphavirus. All lead to neurologic diseases. Scientists have been investigating interactions between these viruses in their vector because they wonder if one viral infection can affect the severity of a different viral infection. For example, do existing antibodies to dengue affect how someone responds to Zika?
A group at Colorado State University led by Greg Ebel, ScD, is interested in the interactions of Zika and chikungunya. Tests showed that saliva from Aedes mosquitoes tested positive for both Zika and chikungunya, meaning that a person bitten with a mosquito could get both diseases at the same time. Though it is unclear whether a single mosquito can harbor all three viruses simultaneously, some patients in Nicaragua were found to be co-infected with both two or three viruses.
Because each virus is linked to severe neurological problems, it will be important for doctors to be aware of the potential clinical symptoms upon co-infection.
-- Sharon Kam