A fourth Hudson Valley resident contracted the Zika virus while traveling and has since recovered, health officials say.

The Centers for Disease Control and Prevention says the mosquito-borne illness is widening across Central and South America, the Caribbean and Africa.

Westchester County Health Commissioner Dr. Sherlita Amler tells News 12 that officials are primarily concerned about pregnant women contracting the disease because it could cause neurological birth disorders. She says those most at risk should avoid travel to impacted areas.

She also says that while the mosquito carrying the virus has not been found in the Hudson Valley, people need to take precaution.

"Residents need to police their own property," she says.

This includes keeping grass trimmed and limiting standing water.

Putnam, Rockland and Orange counties have each reported one case.

There is no commercial testing for the Zika virus, but News 12 has been told that the state Health Department is offering tests for pregnant women who traveled to impacted areas.