As news of a measles outbreak spread across the nation last week, data indicated that the vaccination rate for Colorado pre-kindergarten and kindergartners was the lowest in the U.S., at 81.4 percent.

Vaccination rates for pre-kindergarten and kindergarten students in Montezuma-Cortez School District Re-1 are slightly higher than the state average, at 90 percent, according to data collected by the school district. Still, that's lower than federal recommendations.

Measles, nearly eradicated 15 years ago, made a comeback in the past year. The Centers for Disease Control and Prevention says a measles, mumps and rubella (MMR) vaccination rate of at least 95 percent is needed to prevent the spread of the highly contagious disease.

Colorado's MMR vaccination rate could be low because it's one of 20 states that allow parents to claim medical, religious and personal-belief exemptions from vaccines. A medical exemption needs a doctor's clearance, while religious and personal-belief exemptions need just a parent's signature.

Vaccinations have come under intense public scrutiny in the past few years, after two studies linked the measles vaccine to autism. Both studies, one published in the British Medical Journal in 1998 and one in a smaller U.S. medical journal last summer, have been debunked and retracted.

Dolores RE-4 school district nurse Denise Brisbin said that of the 726 enrolled elementary to high school in the district, 628 students or 86 percent of the district is compliant with the MMR vaccination. 37 students, or 5.09 percent, have signed exemptions.

On Feb. 5, the well-known autism advocate Autism Speaks released a statement emphasizing that vaccinations don't cause autism and urging parents to get their children vaccinated amid the outbreak.

Susan Ciccia, director of health services for Re-1, says the school district is required to tell parents they may exempt their child from vaccinations if the reason is medical, religious or personal. District employees also tell parents of the possible consequences.

"The problem with these preventable diseases, they're a lot more dangerous to little children, so if school-age kids pick this up and take it back home where there's an infant or toddler, the results could be quite tragic," Ciccia said. "Should the outbreak be upgraded to an epidemic and the health department has to require us to exclude unvaccinated children, it also could affect their education."

The Re-1 Health Services department keeps records of vaccination rates, as well as exemption and non-compliance rates. The exemption rate is 7.5 percent; the non-compliance rate is 2 percent.

Mesa Elementary has the lowest vaccination rate - 85 percent vaccinated, 6 percent exempted and 8.6 non-compliant. Kemper Elementary has the highest vaccination rate, with 95 percent vaccinated, 4.3 percent exempt and 0.3 non-compliant.

The only MMR vaccination data available from the Montezuma County Department of Public Health were for the 19-to-35-month age group, which covers the first of two MMR vaccine rounds recommended for young children entering school. As of 2014, the county's rate for that age range was 80.38 percent, and the state rate for that age range was 86 percent.

County public health nurse Lauri Wood said the data is from the Colorado Immunization Information System. Because the records submitted and analyzed by the CIIS are submitted voluntarily by patients, the percentage could be higher.

Only one Colorado case of the measles has been confirmed since the outbreak began at Disneyland and spread to 19 states since December, but officials are still urging the public to take precaution and get vaccinated.

"If you or your children haven't had the measles vaccine - or don't know whether you have been vaccinated - the best thing you can do to protect yourselves and those around you is to contact your health-care provider and get vaccinated," Dr. Larry Wolk, chief medical officer at the Colorado Department of Public Health and Environment, said.

There were 102 cases of measles reported in 14 states during the first two weeks of 2015, according to the CDC. Colorado's one confirmed case was reported Jan. 5.