(Updates with doctor's quote, KinderCare comment, background on U.S. measles cases)
By Mary Wisniewski
CHICAGO, Feb 5 (Reuters) - Five babies at a suburban Chicago daycare center have been diagnosed with measles, adding to a growing outbreak of the disease across the United States, Illinois health officials said on Thursday.
Officials are investigating the cluster of measles cases at KinderCare Learning Center in Palatine, said a statement from the Illinois and Cook County health departments. All the children are under 1 year old and would not have been subject to routine measles vaccination, which begins at 12 months.
The source of the infection was not immediately known.
Public health officials have reported that more than 100 people across the United States have been infected with measles, many of them traced to an outbreak that began at the Disneyland theme park in Anaheim, California, in December.
"These cases underscore the need for everyone who is eligible for the vaccine to ensure that they have been vaccinated," Dr. Nirav Shah, director of the Illinois Department of Public Health, said in a statement. "There are certain individuals who, because of their age or clinical condition, cannot be vaccinated."
One adult in Illinois was recently diagnosed with measles. The diagnoses for the adult and two of the babies have been confirmed through laboratory testing, health officials said.
Test results for the other three cases are still pending, but they have been diagnosed based on clinical and epidemiological criteria, officials said.
On the advice of health officials, the KinderCare center is excluding until Feb. 24 unvaccinated children and staff who may have been exposed to the virus, according to a statement from Knowledge Universe, KinderCare's parent company. The center was given a "deep clean" on Wednesday night, the statement said.
Measles is a highly contagious respiratory disease that causes fever, red and sore eyes, runny nose, cough and a rash. It can be fatal in some cases.
Measles was declared eliminated in the United States in 2000 after decades of intensive childhood vaccine efforts.
The measles outbreak has renewed a debate over the so-called anti-vaccination movement in which fears about potential side effects of vaccines, fueled by now-debunked research suggesting a link to autism, have led a minority of parents to not have their children inoculated.
Last year, the United States had 644 cases from 27 states, the most since 2000, according to the U.S. Centers for Disease Control and Prevention. (Reporting by Mary Wisniewski; Editing by Will Dunham and Peter Cooney)