Health officials have declared an end to the state of Minnesota's worst measles outbreak in years because it has been six weeks since the last measles case was reported.
"The measles outbreak in Hennepin County is considered over," the Minnesota Department of Health announced Thursday on its website.
There were 23 cases in total, with 14 children hospitalized and no deaths reported, according to the Star Tribune. The outbreak, which was the largest in the country so far this year, began in February when a Minneapolis baby was hospitalized with the disease. More cases later began to pop up, many among unvaccinated children in the Somali community.
"We all have June 9th (marked) on our calendar to sort of exhale," Patty Stinchfield, director of infectious disease at Children's Hospitals and Clinics of Minnesota, said, according the Star Tribune.
The Health Department waited six weeks after the last reported case, twice the normal incubation period for the measles virus, to be certain. Many health officials recalled a 1990 outbreak in St. Paul, Minn., in which three children were killed and hundreds more were sickened by a measles outbreak.
"This particular outbreak is sort of officially over, but I have a big asterisk on that," Dr. Ruth Lynfield, the state epidemiologist, said, according to the Star Tribune. "Unless we continue to keep our immunization rates high, we will see this again."
Investigation by the health department found that many families in the Somali community have avoided vaccination because of fears of a link to autism that officials tried to allay. Lynfield said that many parents don't realize how dangerous measles can be due to its effective eradication in the United States years ago. In the early 1960s, over 500,000 Americans got measles every year and hundreds died.
"What happened this year is, it came into a population that was vulnerable, that did not have a high level of immunity, and so it did spread," Lynfield said, according to the Star Tribune.