September 26, 2017
Higgs co-authors commentary in The Lancet
Stephen Higgs, director of the Biosecurity Research Institute and professor of diagnostic medicine and pathobiology in the College of Veterinary Medicine, co-authored "Zika virus and Culex quinquefasciatus mosquitoes: a tenuous link," in the October 2017 issue of The Lancet.
The commentary explains the controversy behind the species that transmit Zika virus. Although researchers know Aedes aegypti and Aedes albopictus mosquitoes transmit the virus, some have also thought Culex quinquefasciatus mosquitoes were involved in outbreaks. More recent studies and reports, however, show that most populations of Cx. quinquefasciatus are resistant to infection with Zika virus. Previous research at the BRI proved that North American Culex were not able to transmit the virus.
Higgs and his co-authors explain why finding these results has been a difficult process.
"Essentially, a number of factors complicate collecting mosquito samples in the field that can make mosquitoes seem to have been infected," Higgs said. "If a mosquito has fed on an infected person shortly before it is collected, then it appears to be infected because it contains infected blood in its gut. But that does not mean that the mosquitos are susceptible vectors capable of transmitting the virus. Highly sensitive laboratory techniques can detect virus at very low levels, below what is actually capable of making mosquitoes infectious."
Identifying the key vectors of Zika virus is important in developing effective responses to the disease.
"Controlling mosquito-borne diseases such as Zika often depends on reducing mosquito populations, and so knowing which species to target is very important," Higgs said.