Steve Moberly, a student intern with the County Health Department, examines a mosquito under a microscope to determine its species during a sorting process. Moberly and a recent IU Southeast graduate Molly McDonough are certified to test mosquitoes for the West Nile virus and St. Louis encephalitis. Holly Moberly of Crestwood, Ky., examines a mosquito to determine its species as part of a sorting process.

A type of mosquito that can carry West Nile virus but not seen before in Indiana was identified in Clark County earlier this summer by IU Southeast students. The students also captured Floyd County’s first batch of mosquitoes to test positive for the illness.

Claude Baker, a biology professor on the New Albany campus, arranged for his biology students to trap, sort and test the insects for West Nile virus, as well as for St. Louis encephalitis, in collaboration with the health departments in Clark, Floyd and Harrison counties.

On July 19, local health officials reported that the IU Southeast biology students found a new interloper in the state—an Asian species known as Ochlerotatus japonicus—in four Clark County locations—downtown Jeffersonville, the corridor of Ind. 60 and Ind. 111 near Borden, and two sites on Ind. 3 near Otisco.

“I have never seen a bunch of students more excited that those working on the WNV project,” said Baker. “They took their own initiative and called the Smithsonian (Institution), found the correct person and are now collaborating with a top expert on the new mosquito. They will be shipping the mosquitoes to the Smithsonian for DNA testing.”

Biology student Steve Moberly said that while he was viewing the mosquito under a microscope, he could not determine its type.

“I sent it to the state as an unknown species,” he said. Moberly worked as a paid intern for the Clark County Health Department as part of the collaborative effort between Baker’s class and local health agencies. Clark County, in turn, has provided test equipment and mosquito traps for surveillance.

The Centers for Disease Control (CDC) in Atlanta reported that the Ochlerotatus japonicus was first identified in 1998 in New York and New Jersey. The mosquito prefers to breed in artificial containers, including rock holes and used tires. Other likely breeding sites are unattended pools, fountains, birdbaths, flowerpots, clogged gutters and other similar containers.

While the CDC reports that this breed primarily bites during daylight hours, Douglas Bentfield, registered environmental health specialist for Clark County, noted that the mosquitoes captured by IU Southeast students were trapped at night.

"There is no human vaccine and no treatment for the West Nile virus," said James Howell, a veterinary epidemiologist with the Indiana State Department of Health. "But it is preventable."

State health officials urged individuals who spend time outdoors to use insect repellent with DEET and wear long sleeves and pants, whenever possible.

"It's difficult to predict how many human cases we might have this year, as it can depend a lot on the weather," Howell said. "However, we know that West Nile virus is present in Indiana, and we urge Hoosiers to take personal precautions to avoid infection."

"Hundreds of mosquitoes can come from a fairly small amount of water, as would be found in a discarded tire or an unattended flowerpot," said Howell. "After a rain is a great time to check for and remove standing water on your property."

To curb mosquito population and the spread of West Nile virus, the average person can:

• Wear protective clothing during active mosquito hours (dusk to dawn);

• Use insect repellants that contain DEET;

• Free property of any standing water, which serve as breeding grounds for mosquitoes. Ways to do this include:

• Repair failed septic systems;

• Drill holes in the bottom of recycling containers that are left out of doors;

• Dispose of old tires, tin cans, plastic containers, ceramic pots or other unused containers that can hold water;

• Clean clogged roof gutters, particularly if leaves tend to plug up the drains;

• Aerate ornamental pools, or stock them with predatory fish.

http://www.cdc.gov

http://www.IN.gov/isdh/