As a precaution, the Department of Health contacted all non-immunized students -- there were four of them. Those students have been told not to return to school until Feb.13.

Public Health officials are working with Spencerport Central School District to determine whether other students at Canal View Elementary are at risk of infection. Precautionary guidelines already have been sent to concerned parents.

Measles is a highly contagious respiratory disease caused by a virus spread by nasal and throat secretions of infected people.

Health officials say the problem is not everyone is getting their required vaccines.

A person is considered unlikely to contract the disease if born before January 1, 1957, or have received two doses of MMR (Measles, Mumps and Rubella) vaccine, or a lab test confirming immunity.

"We know that this community is one that's very proactive about health, and at the same time we know that there are a small minority of people who are choosing not to vaccinate their kids," explained Commissioner of Public Health in Monroe County, Dr. Michael Mendoza. "Unfortunately, this is the outcome when you don't vaccinate your kids. You're susceptible to vaccine-preventable illnesses, and unfortunately, today's situation is a good example of that."

Lanette Cypher, a spokesperson for the Spencerport Central School District, said the Department of Public Health is the lead agency in handling this situation and will provide updates on its website.

Canal View Elementary School will be in session Monday morning.

Parents are asked to contact the Monroe County Department of Public Health at 585-753-5164 with their concerns.