A person infected with measles visited southeastern Minnesota, Wisconsin and Iowa and exposed the public to the highly contagious disease at various restaurants and other public places during a four-day stretch this month, health officials said Wednesday.

The infected individual was from Missouri, a state "currently reporting several cases of measles," said Minnesota Department of Health spokesman Doug Schultz.

None of these states has reported any infections attributed to these exposures yet. The window for symptoms to arise runs from roughly April 23 to May 7, Schultz added.

As of late last week, there have been more than 20 reported cases of measles in the Kansas City, Mo., metro area and elsewhere in Kansas near the Missouri border.

Coincidentally, these infections and exposures in the Midwest are being reported during National Infant Immunization Week, a campaign spearheaded by the federal Centers for Disease Control and Prevention. The measles vaccine is 93 percent effective after one dose and becomes 97 percent effective after two doses, according to the CDC.

Minnesota health officials said the exposures occurred April 13 at a McDonald's on Main Street in Winona and April 16 at the Freeborn County Co-op gas station on Margaretha Avenue in Albert Lea.

In Wisconsin, the La Crosse and Trempealeau county health departments listed the following times and places where exposure occurred: the evening of April 13 at Beedle's Bar and Restaurant in Galesville, April 13-16 at the Comfort Inn in Onalaska, April 14 at the Dollar Tree in Onalaska, the evening of April 14 at Fairfield Inn & Suites in La Crosse, 10 a.m. to 1:30 p.m. on April 15 at St. Mary's Catholic Church in Galesville, the afternoon of April 15 at Champions Riverside Resort in Galesville, and the evening of April 15 at the Texas Roadhouse in La Crosse.

The exposures in Iowa occurred at two locations: the morning of April 13 at a Hardee's on Merle Hay Road in Des Moines, and during the afternoon of April 16 at the Panera Bread on Delaware Avenue in Ankeny.

"If someone has been exposed and has signs consistent with measles, it is important that they stay isolated from others to prevent spreading the disease and call their health care provider," Kris Ehresmann, director of infectious disease for the Minnesota Department of Health, said in a statement.

In two counties across the border from southeastern Minnesota, health departments there say they were alerted by Missouri officials to the contagious visitor's presence in many locations.

"Measles is extremely contagious, and you can have very severe outcomes," said Jennifer Rombalski, director of the La Crosse County Health Department. "For every 1,000 children who get measles, one or two will die from it."

Measles symptoms include high fever, coughing, runny nose, red and watery eyes, and a rash. It spreads when an infected person coughs or sneezes.

Rombalski said this person could well have been unaware he or she was infected while traveling with others first in Iowa, then Minnesota and Wisconsin and back again in Iowa.

"It just depends on the onset of symptoms with this particular individual," Rombalski said.

"You can start out with fever, a runny nose and watery eyes, and it's not until the rash appears" that having the measles becomes obvious, she said.