Mosquito monitoring expanded after troubling find

The state Department of Health has doubled the number of mosquito traps it has at Honolulu International Airport from twenty to forty after a rare species, efficient at spreading disease, was found there early this year.

Every week state vector control entomologist Jeomhee Hasty checks mosquito traps at the airport. She collected eggs on January 9 and took them back to the lab where they hatched and matured. Her trained eye quickly identified them as a species called aedes aegypti.

"This species, aedes aegypti has not been found since 1949 on Oahu, so that's why it was kind of striking to me," Hasty said Wednesday.

The aedes aegypti has been on the Big Island for more than a century, mostly on the Kona side and near South Point. It is somewhat troubling to find the species on Oahu because the aegypti does a better job of spreading dengue fever and yellow fever than other mosquitoes found on Oahu including the aedes albopictus.

"It may have something to do with the feeding habits of the mosquito itself. This aegypti tends to take a little bite out of a lot of people where as the albopictus will take one blood meal per bite and it won't fly around and bite as many people within a single

meal," explained Gary Gill, Deputy Director for the Department of Health in charge of environmental health.

The airport is the only place on Oahu where the state traps mosquitoes to be tested. It used to collect samples at sites all over the island, but the program was slashed because of budged cuts in 2009. Oahu had 24 vector control specialists. Now it has five.

Troubling maybe, but consider this. There has not been a case of yellow fever in Hawaii in more than 100 years. And in 2011 there were just six cases of dengue fever.

For the disease to spread an infected person must be bitten by a mosquito, then that mosquito must bite someone else.

Despite the long odds of being infected the state is serious about preventing an epidemic of dengue fever. It is urging people to minimize risk by getting rid of standing water where mosquitoes breed.

The DOH plans to test the DNA from the mosquitoes found at the airport to see if they match the DNA from the aedes aegypti on the Big Island. A positive match would indicate the mosquito that laid the eggs at the airport likely hitched a ride from on a flight from Kona. A negative test would indicate the mosquito came from elsewhere.

No new aedes aegypti mosquitoes or eggs have been found on Oahu since the batch of eggs collected January 9.