Denton officials confirmed the city's second positive sample of West Nile virus Wednesday, triggering Denton's second-highest risk level, which it classifies as a public health warning.
The sample, collected Monday, came from a trap at the city's service center on Texas Street, officials said.
The public health warning means Denton will continue to conduct routine surveys of adult mosquitoes and the amounts of biological agents applied to kill larva will be increased.
"Mosquito control efforts in past seasons have been successful, which would not have been possible without the source reduction and larviciding efforts of Denton citizens," said Deborah Viera, Denton assistant director of environmental services.
The city asked people to help eliminate breeding grounds for mosquitoes by removing standing water from their property.
