SALT LAKE CITY — Six confirmed cases of measles have been detected and contained to Salt Lake County, health officials announced Friday.

All confirmed cases have passed beyond the infectious period, therefore the patients are no longer under voluntary isolation. However, people who are unvaccinated and were exposed to the six people with measles remain under voluntary quarantine (and excluded from school) because the measles incubation period has not ended and those individuals may still develop and transmit the disease.

Four schools in the Granite School District have been affected by the measles outbreak: Olympus and Skyline high schools, Evergreen Junior High and William Penn Elementary. When the outbreak started, students without the proper vaccinations or proof of immunization were sent home from school. Accommodations have been made to keep them up to date with their school work. However, the school district's spring break week begins Monday, April 18.

The local outbreak likely originated with a Utah family who recently vacationed in Poland to pick up their missionary daughter.

According to the Salt Lake Valley Health Department, 98 percent of school-age children in Salt Lake County are properly vaccinated for measles.

There are no confirmed cases of measles in Davis County health authorities have ruled out two possible cases while two cases with "rash-like symptoms" remain under watch, a spokesman said.

— Marjorie Cortez