Zika-carrying mosquitoes can pass the virus on to their offspring, scientists have reported in a study published yesterday in the American Journal of Tropical Medicine and Hygiene. Called vertical transmission, this ability may help the Zika virus survive the winter in the insects’ eggs.
Researchers at the University of Texas Medical Branch in Galveston infected groups of Aedes aegypti, the mosquito mainly responsible for spreading Zika. They also infected populations of Aedes albopictus, which can transmit the virus as well. The team gathered the mosquitoes’ eggs, and once they hatched and grew into adulthood, tested the offspring for Zika. They found the virus in a few of the Aedes aegypti mosquitoes (about one in every 290 tested positive).
The new findings indicate that killing adult mosquitoes may not be enough to reign in the Zika virus. “The ratio may sound low,” coauthor Robert Tesh told Reuters, “but when you consider the number of Aedes aegypti in a tropical urban community, it is likely high enough to allow some virus to persist.”