Four mosquito samples collected July 9 from areas in East Northport, Northport and Huntington have tested positive for West Nile virus, Suffolk County health officials said Friday.
Also testing positive were two dead crows collected Thursday in Nesconset, according to the county health department.
Nassau County reported its first two positive mosquito samples, collected July 12 in Kings Point and Plandome Manor.
Some mosquitoes' bites transmit West Nile to humans. Mosquitoes pick up the virus through feeding on infected birds. No human cases have been reported so far this year on Long Island.
Nationally, last year ranked as the second-worst in terms of West Nile cases since the disease was first detected in the United States in 1999, the Centers for Disease Control and Prevention said.
Nassau and Suffolk counties reported 14 human cases each last year, including one Nassau death.
The positive samples this year indicate "the virus is actively circulating within the mosquito population," said James L. Tomarken, commissioner of Suffolk County Health Services, in a release. "While there is no cause for alarm, we urge residents to cooperate with us in our efforts to contain the spread of the virus, which can be debilitating to humans."
That means eliminating standing water, which can collect in tin cans, birdbaths and discarded tires and serve as mosquito breeding grounds.
Learn more at suffolkcountyny.gov/health and nassaucountyny.gov/agencies/Health/