State health officials have confirmed a case of measles in a 19-month-old Hennepin County child, prompting them to notify other Twin Cities families that they could be at risk amid an unusual measles outbreak that is crisscrossing the country.

The case is the first in Minnesota so far this year.

Nationally, 129 cases and 13 outbreaks have been reported by the U.S. Centers for Disease Control and Prevention for the first four months of 2014 — the highest in that period for the past 18 years.

The Minnesota Department of Health has alerted health care providers about the case and is working with Hennepin County to notify people who might have been exposed, according to Kris Ehresmann, the department’s infectious disease director. The health agencies are also offering immune globulin with antibodies against the measles virus to anyone who might have been exposed.

Ehresmann said any cases to result from the Hennepin County child are likely to emerge between now and May 12.

Measles, which has nearly been eliminated in the United States, produces a telltale blotchy red rash, along with cold-like symptoms including fever, runny nose, cough and watery eyes. People infected with measles are contagious during the four days before they develop a rash and four days after.

The virus is highly contagious and spreads through inhaling particles from the sneeze, cough or breath of an infected person — even up to two hours after they have left the room.

Ehresmann said the baby caught measles when traveling internationally, so “thankfully” there weren’t many exposures in Minnesota.

The CDC declared measles eliminated from the United States in 2000, but it’s still prevalent around the world. The Philippines is undergoing a measles outbreak with more than 20,000 cases.

“It’s important for people to remember that with the exception of the smallpox virus, these diseases have not been eradicated,” Ehresmann said. “They really are just a plane ride away.”

The CDC recommends that children receive a first dose of measles vaccine when they’re 12 to 15 months old and a second dose before starting kindergarten.

The Hennepin County child had received the first dose of the measles vaccine. But Ehresmann said the first dose doesn’t always prevent the disease.

Adults born after 1956 should get at least one dose and two if they are at risk as college students, health care workers, international travelers or women who could become pregnant. Before 1957, measles was so widespread that anyone born before then has natural immunity to the virus.

Hennepin County had a measles outbreak in 2011, when a 1-year-old caught the disease while traveling and then infected 20 people. Seven of the patients were too young to get the vaccine and seven weren’t vaccinated because their parents were concerned about the safety of the vaccine.

As the most deadly rash or fever illness children can catch, measles is best prevented by getting vaccinated, the CDC recommends. The vaccine has been in use since 1963.

If families suspect their child has measles, Ehresmann said, they should call the hospital before they go in so health care providers can take precautions to prevent the spread of the virus.

Rebecca Harrington is a University of Minnesota student reporter on assignment for the Star Tribune.