State laboratories around the country are testing mosquitoes to warn people about the presence of the West Nile virus, but federal and state budget cuts are threatening some of those labs.

Abbott Brush collects mosquitoes for observation at the Connecticut Agricultural Experiment Station. One mosquito trap — a bucket of smelly water — is in a wooded area of New Haven near a pond.

“It attracts them because they want to come there and lay the eggs,” he says.

A fan sucks them up into a mesh net, which has about 100 mosquitoes stuck in it. Brush visits four sites and brings his mosquito catch back to the lab.

Since West Nile was first found in the U.S. in 1999, the virus has spread and established itself as an annual concern. Last year, 57 people in the U.S. died of the virus. It causes a mild illness in most healthy adults, but the elderly are particularly vulnerable. So far this year, three people have died.

In the Connecticut state lab, undergraduate student Tara Hannon and other seasonal workers stare at the mosquitoes through microscopes, identifying the subtle traits that distinguish the 30 or so different species in the state.

“My supervisor warned me that we’d be looking at mosquitoes so often that they’d be in your dreams, and they are,” Hannon says.

DNA tests confirm whether or not the mosquitoes have West Nile. They also test for Eastern equine encephalitis, a rarer, but more dangerous virus. The head of the program, state entomologist Theodore Andreadis, says the operation costs about $400,000 to $500,000 a year.

“The only thing that’s allowed us to expand this program,” he says, “has been this federal [Centers for Disease Control and Prevention] funds that were made available to all states throughout the country in an attempt to enhance surveillance to build up capacity to deal with this newly emerging virus.”

Connecticut, like the rest of country, has seen that federal funding significantly cut over the past five years or so. Roger Nasci of the CDC says cutting the federal funding was always their plan.

“The program was never intended to be a long-term, high-level maintenance,” he says, “but to provide the core capacity to the states, with the hope and the assumption that they would pick up the components that were required for their particular jurisdictions.”

However, it’s not a great time for state budgets. In North Carolina, the state cut funding for its mosquito-surveillance program earlier this summer, putting Bruce Harrison out of a job.

“Instead of us finding that West Nile is prevalent and warning people to take precautions and use repellent and stay indoors if the mosquitoes are bad, there’s not going to be anybody to do that here in the state,” he says, “and any program across the United States that’s had cuts is in the same pickle.”

In 2002, there were nearly five times as many deaths from the virus as there were in 2010. Harrison says that means they’ve done a good job preventing human cases, but he says it also means West Nile is off the radar of those who provide the funding.