Putnam County officials are on high alert after cases of the measles have been confirmed in three of its four surrounding counties.

Putnam County Executive MaryEllen Odell is highly encouraging those who have not received the MMR vaccine to schedule an appointment, after cases of the measles have been confirmed in Rockland, Orange and now Westchester counties.

"We're very concerned of course, with any illness that can be contagious and of course be deadly or compromise someone's health in an extreme manner," Odell says.

The Putnam Department of Health is asking everyone to err on the side of caution if someone thinks they have the virus.

Odell says if you think you may have the measles, to call your doctor and they will refer the proper protocol.

"It's really the public, right now, that has to be responsible and we're counting on them to do the responsible thing for their neighbors, for their friends, and the community," says Odell.

The measles virus is especially dangerous to children, pregnant women, and those with compromised immune systems.