PITTSBURGH _ Mosquito tests underway at Penn State University should begin revealing within weeks whether species native to North America could spread the feared Zika virus.
A research team in State College plans to study as many as 20 mosquito species over the next couple of years, helped along by a $432,000 grant from the National Institutes of Health, lead researcher Jason Rasgon said Tuesday.
Test results could help government agencies better target their insect-control strategies to prevent people from picking up the mosquito-borne virus, said Rasgon, an associate professor of entomology and disease epidemiology. He said many species targeted in the research live in Pennsylvania, where some Culex mosquitoes already carry West Nile Virus.
"You need to know what's transmitting so you can do the right kind of mosquito control," said Rasgon, whose team began feeding Zika-infected blood to laboratory-kept mosquitoes last month. He declined to say which mosquito type his group is checking first, although he said testing each species can take about a month.
Disease experts have blamed two kinds of Aedes mosquitoes _ the yellow fever and the Asian tiger _ for much of the Zika illness that's swept through Central America, South America and the Caribbean since early 2015. Those species have only a limited presence in the United States, tending to turn up in tropical and subtropical climates, according to the Centers for Disease Control and Prevention.
It wasn't until late last month that health authorities found Zika cases that likely originated from infectious mosquito bites on the U.S. mainland. The CDC is reviewing 14 such cases in Miami, a habitat for the yellow fever species thought to be most responsible for transmitting Zika in the epidemic abroad. No other signs of Zika-infected mosquitoes have been announced in the continental U.S.
Pennsylvania last had a confirmed sighting of a yellow fever mosquito, or Aedes aegypti, in 2002, according to the state Department of Environmental Protection. The Asian tiger species, or Aedes albopictus, appears more in the commonwealth and first landed in the Pittsburgh area about a decade ago.
"It's been a very small nuisance in some areas, more of a nuisance in the eastern part" of Pennsylvania, said Bill Todaro, a medical entomologist at the Allegheny County Health Department.
While scholars have said it's unlikely that any mosquitoes as far north as Pennsylvania could carry Zika, Rasgon's findings may have international implications. He said his team's research will include Culex mosquitoes, which also appear in South America, and the Anopheles species. The latter is often linked to malaria.
"It's not hard to do, but it's kind of nit-picky," Rasgon said of the testing process.
After giving the mosquitoes some infected blood, researchers run a series of checks to see whether the virus infects the gut or emerges in the saliva, where it could infect humans. A Penn State containment lab seals off the tested insects from public exposure.
Rasgon said he may introduce initial findings within the next couple of months, or "definitely by the end of the year." His group may release additional results in waves from their work, which he expects will complement similar studies at other institutions.
"I assume more groups are doing this. The more, the merrier," he said.
Researchers in Brazil said last month that they found Zika in a type of Culex mosquito there. But Rasgon said the presence of the virus doesn't necessarily mean an insect can spread Zika. The virus also may travel through sexual contact and blood transfusions.
At the University of Pittsburgh, an international research alliance known as "Cura Zika" recently picked six proposals for pilot grant funding, spokeswoman Allison Hydzik said. The effort received 15 pitches from scientists in Pittsburgh and Brazil.
"The funded studies include probing Zika's impact on the placenta immune response in the first trimester of pregnancy, developing high-performance tests to better detect Zika exposure in pregnant women and the general population, and engineering and evaluating a vaccine against Zika, among others," Hydzik wrote in an email.
The virus has raised alarms especially for pregnant women, who can see elevated rates of birth defects such as microcephaly from the infection.
Most infected people don't show any symptoms, which can include a fever, rash and joint pain that may last about a week.
