Greenwich health officials are urging people to adhere to a public health notice that in some cases could mean the difference between life and death.

The town recommended a curfew last week after a batch of mosquitoes from Mianus River Park tested positive for West Nile virus.

The health department is asking that people clear local parks and some outdoor clubs a half-hour before dusk and reopen no earlier than a half-hour after sunrise, to minimize their expose to mosquitoes. The curfew applies to locations in Old Greenwich, Riverside, and North Mianus.

So far this year, there have been two human cases of West Nile virus in Greenwich.