The city of Plano has been informed one of its residents has contracted the city's first human case of West Nile virus this year, a city spokesperson confirmed Friday.

Plano Director of Media Relations Steve Stoler said the Collin County Health Department informed the city on Thursday about the case, which took officials by surprise after the city's regular mosquito testing turned up no indications of a threat.

"We haven't had a single mosquito test positive for West Nile" this year in Plano, Stoler said.

The city on Monday plans to spray the area immediately around Hickey Elementary School near the city's eastern border, even though it is unclear whether the patient contracted the disease within city limits, Stoler said.

At least six other human cases of West Nile virus have been reported in Texas since the start of 2017, according to the Texas Department of State Health Services. None of those previous cases were in Collin County.

A spokesperson for Collin County did not immediately reply to a request for comment Friday afternoon.