Health officials release warning about West Nile virus

State health officials have released their annual warning about mosquito bite prevention, now that the West Nile virus has been detected in parts of Connecticut.
Officials say infected mosquitoes have been trapped in Darien, Stamford, New Haven and Fairfield.
They say it's just a matter of time before all towns that trap mosquitoes return positive results.
So far, there have been no human cases reported.