Skeeter Monitoring Is All in Day’s Work

DIAS CREEK — The Cape May County Department of Mosquito Control daily collects mosquitoes from around the county in traps, but what does it do with those pesky varmints it brings back to its laboratory?
Chief Microbiologist Karen Hedstrom operates from a lab with two sealed doors bearing a sign warning of potential biohazards. It looks like a scene from the movie “The Andromeda Strain.” While she may encounter mosquitoes carrying West Nile Virus or Eastern Equine Encephalitis, she does not handle extraterrestrial organisms as in the sci-fi movie.
Hedstrom’s mission is to detect mosquito-borne viruses that could make residents ill. She said West Nile Virus appeared in the U.S. in 1999 and swept across the country to California.
While West Nile Virus has waned in the past year or two, Hedstrom said the public still needs to report dead birds, such as crows and blue jays. Birds provide an early indicator of the virus, she said.
Eastern Equine Encephalitis is rare in humans in this state but the department continues to test for the virus.
The mosquitoes Hedstrom works with come from traps set in areas where it is predicted certain species of mosquitoes live.
“Certain species carry certain viruses,” she said.
When samples of mosquitoes arrive at the Mosquito Control lab, they are ground up and the essence of their genetic material is extracted. Hedstrom said there are specific tests to detect RNA from the viruses they are seeking.
The lab also tests for St. Louis and La Crosse encephalitis, both are fairly uncommon in New Jersey.
Hedstrom said the testing process takes about three to four hours from the time a sample of mosquitoes arrives in the building. Results from a large batch of mosquitoes may take one day to complete.
The department also checks mosquito samples for other counties.
“If we repeatedly get mosquitoes positive for a virus, the kind that bites people, then it’s the time for us to get in gear for some kind of spraying,” she said.
Hedstrom places the mosquito samples — and her hands — in a biological safety cabinet equipped with a HEPA filter, which keeps any viruses contained, away from the air in the lab. When something infectious is found, she renders it non-infectious with hot water or steam.
She encourages those experiencing a lot of the pesky insects to report them to Mosquito Control so staff can sample their area such as drainage ditches. The department gives 24 hours notice of spraying an area.
Department of Mosquito Control Director Peter Bosak showed the Herald the mosquito surveillance laboratory where Identification Specialist Diane McNelly looks at every mosquito and enters them into a database.
McNelly was sorting through a box of dead mosquitoes, which can sometimes number in the thousands. The department has 24 traps countywide.
She said she hates mosquitoes but finds them very interesting.
“Some are actually very pretty,” said McNelly, noting some appear to be painted.
Some mosquitoes have blue and green reflective qualities, said Bosak.
The department has a hot, humid room where some mosquitoes are bred for test purposes such Asian Tiger and Culex mosquitoes.
“The warmer it is, the faster they go through their life cycle,” said Bosak.