If Zika reaches Missouri, these MSU researchers will be the first to know

The disturbing news out of Miami, Florida, that 14 people have contracted the Zika virus from local mosquitoes makes David Claborn's work at Missouri State University even more urgent.

Claborn is leading a team of researchers who are fanning out across Missouri to trap and identify mosquitoes. They hope to find out if Missouri harbors the kinds of mosquitoes that can carry the Zika virus. Their traps might serve as an early warning picket line to identify when — or if — Zika virus makes its way to the state.

"The yellow fever mosquito is the primary vector for Zika, and has existed in Missouri before," said Claborn at his lab on the MSU campus. "The question we're trying to answer is if it's still in Missouri. We're going on seven weeks with this study and we still haven't found one yet. We have no reason to believe Zika is in the mosquito population in Missouri at this time."

Yellow fever mosquitoes are plentiful in southern states, especially along the gulf coast, but are less common farther inland. However, another species — the Asian tiger mosquito — is also known to carry Zika virus in other parts of the world, though it does not appear to be as efficient at passing the disease to humans as yellow fever mosquitoes.

Claborn said his Missouri traps have caught thousands of Asian tiger mosquitoes, though none were infected with Zika.

The Centers for Disease Control and Prevention says Zika virus can cause babies to be born with abnormally small heads and brains. It also might trigger Guillain-Barre syndrome, an uncommon sickness of the nervous system, in a small number of cases.

According to CDC's Zika virus web site, once someone has been infected with Zika, it’s very likely they’ll be protected from future infections. There is no evidence that past Zika infection poses an increased risk of birth defects in future pregnancies.

Claborn's staff has trapped mosquitoes across the state, most recently in an area southwest of Springfield and as far south as Lampe. They use a special trap baited with dry ice to draw them in.

"Mosquitoes are drawn to carbon dioxide in your breath, so that's what the dry ice imitates," Claborn said. "The trap has a small fan that sucks them into a net on the bottom. We collect the mosquitoes, freeze them in the lab to kill them, and then we put them under a microscope to sort them by species and by sex — male or female."

The researchers are particularly looking for female mosquitoes because they are the ones that bite people, not the males.

"Females are the ones that take the blood meal and transmit the disease," said Madison Poiry, a student researcher helping Claborn run the mosquito traps. "Females don't eat the blood. They use it to make egg yolks for the eggs they lay. Adult mosquitoes actually get most of their nutrition from plant nectar."

In the lab, some of the mosquito larvae — wrigglers collected from standing water in old tires for example — are allowed to hatch into adult mosquitoes, dining on fish food dropped into their glass containers. Those adults are cataloged by species and sex.

"We feed them raisins and apples in the lab. They love it," Poiry said.

Every trapping site is logged by GPS coordinates that also describe the kind of environment in which the mosquitoes were found. At a heavily overgrown location on the edge of the Republic Library, the trap caught dozens of mosquitoes likely breeding in a swampy area not far from the library.

The data they collect is shared with the Missouri Department of Health and Human Services, which then shares the findings with the CDC. So far, Claborn and his staff have identified and cataloged more than 10,000 mosquitoes.

"The state wants to know what's here and have a plan for how to deal with it if Zika does reach Missouri," Claborn said. "I think it's wise for our state health department to get ahead of this before it happens."

Missourians can help reduce mosquito populations by taking some very basic steps around their property. Mosquitoes breed prolifically in pools of stagnant water, so Claborn said removing those sources should be the first step.

Debris-filled gutters, for example, allow water to back up and provide a perfect breeding ground for mosquitoes. Clean out those gutters, Claborn recommends.

Look for other places where water collects, like flower vases, old tires, plastic cups, kids' pools and pickup truck beds. Outdoor pet water bowls and birdbaths should be emptied regularly, and rain barrels should be covered in a way that prevents mosquitoes from reaching the stored water.

According to the CDC, larvicide briquettes are available that can be tossed in stagnant pools of water. The product kills the wrigglers that feed on it. Learn more about mosquito control around the home at CDC's web site -  http://www.cdc.gov/zika/prevention/controlling-mosquitoes-at-home.html.