Public health officials are warning that more measles cases are likely after five infants who attend a suburban day care center were diagnosed with the highly infectious disease.
The outbreak at a KinderCare Learning Center in Palatine marks the second appearance of the measles in Illinois within the last month. Officials last week said a suburban Cook County adult had contracted the disease and visited a Palatine grocery store and health clinic while possibly contagious.
Though it's not clear whether that case is connected with the day care cluster, officials said Thursday the public should expect additional diagnoses to emerge.
"There will be more cases. We shouldn't be surprised about that," said Dr. Terry Mason, chief operating officer of the Cook County Department of Public Health. "The cat is out of the bag."
Measles is a respiratory disease that can cause severe health complications, including pneumonia, encephalitis and in rare cases death. The virus is transmitted by contact with an infected person through coughing or sneezing and can remain alive in the air and on surfaces for up to two hours.
Infected people are contagious from four days before their rash starts through four days afterward, state and county health officials said.
A December outbreak at Disneyland in California has grown to more than 100 cases and brought new attention to a movement that has seen some parents - often because of health concerns experts call baseless - deciding not to vaccinate their children.
But officials said the KinderCare children were all under a year old, meaning they were too young to get the vaccine that guards against measles, mumps and rubella.
"Their immune response doesn't last," said Dr. Wendell Wheeler of Ingalls Memorial Hospital in south suburban Harvey. "It's a temporary response, which is why we wait until 12 months."
The Centers for Disease Control and Prevention, the American Academy of Pediatrics and the American Academy of Family Physicians all recommend that children get their first dose of the vaccine at 12 to 15 months, and a second shot at 4 to 6 years.
Mason said Cook County health officials received calls Sunday about two infants with a fever and a rash receiving treatment at Northwest Community Hospital in Arlington Heights. Lab samples were collected, and the following day, it was determined that both infants were in a common room at KinderCare.
On Tuesday, the day care staff notified the county of three other children with symptoms. By late afternoon, the first infant had a positive blood test for measles, and unvaccinated children were told to stay at home.
Late Wednesday, the Illinois Department of Public Health confirmed a second case. County officials then told KinderCare to exclude unvaccinated children for 21 days - or until Feb. 24.
Officials said they expect to get lab results for the three other suspected measles cases by early Friday. All of the KinderCare babies are being cared for at home, they said.
KinderCare runs 1,500 learning centers in the U.S. that offer care and schooling for children ranging from infants to 12-year-olds. Spokeswoman Colleen Moran said the Palatine day care received a precautionary "deep clean" Wednesday night.
"We just want everyone to recover quickly and to stay safe," she said.
Palatine-based Community Consolidated School District 15, which has two schools across the street from the KinderCare, is taking similar steps, including washing school buses and some classrooms with a bleach solution.
Superintendent Scott Thompson said some students attend programs at the KinderCare. If it's determined that they are among the 200 or so children in the 12,500-student district who have not been vaccinated, they'll have to stay home for 21 days, he said.
Children who attend public schools or state-licensed day cares are required to get vaccinations unless they cite medical or religious reasons for abstaining, officials said. Statewide, about 98 percent of schoolchildren have complied with vaccination rules, according to the Illinois State Board of Education, which collects data from public and nonpublic schools. That percentage includes those who got the vaccine and those who officially opted out of vaccinations for religious or medical reasons, according to the agency.
But 1 in 12 children in the United States are not receiving the first dose of the vaccine on time. That underscores considerable measles susceptibility across the country, according to the CDC.
Unvaccinated children are among the most vulnerable to measles, which is one of the most contagious diseases, Wheeler said.
"The very young have small airways," he said. "The disease has thick mucus, and the two don't go together. They are not moving air well and they get into trouble."
Pneumonia is often a complication in such cases, he said.
Children who receive only the first dose of the measles vaccine may not be fully protected. About 5 to 10 percent do not develop an adequate immune response after one shot, which is why the second is necessary, said Dr. Tina Tan, an infectious disease specialist at Lurie Children's Hospital in Chicago.
"If given at the appropriate interval and age, after two doses of measles vaccine a person is considered protected for life," she said.
Those who are too young to get vaccinated are protected by the majority who are inoculated, called herd immunity.
However, when the vaccination rate drops below 95 percent, a community loses its herd immunity to highly contagious diseases such as measles, Tan said.
"(Herd immunity) matters because the virus has no place to go," Wheeler said. "If it hits person one and they're immune and person two and they're immune But if it hits person one who is not immune, well, it can increase exponentially."
Television crews and news reporters flanked KinderCare's small parking lot for hours Thursday afternoon, seeking comment from parents picking up their children. Most parents appeared overwhelmed by the media attention and would not stop to talk.
Heather Robinson, of Homewood, takes care of her 15-month-old daughter at home, but she knows the anxiety measles can provoke. When she took the child for her vaccine shot last month, the girl broke out into a rash that covered every inch of her body, even the inside of her ears.
"I was totally freaking out," she said. "I thought it was measles."
It turned out to be a reaction to the shot. Still, Robinson said she was glad she had been proactive.
"I have friends who don't vaccinate," she said. "They admit that they're depending on others to be responsible, which is kind of hypocritical."
Some child care centers say they're taking extra steps to ward off measles as its national presence widens.
At Blocks Infant Toddler Child care in the South Loop, officials are having a pediatric nurse who normally visits the facility once a month come in twice to ensure staff are following best practices, said program director Aishah Fields.
The nurse also led a workshop with staff about recognizing the signs of measles and other information so all would be educated on the topic, Fields said.
"It takes the fear out and we feel equipped to handle it if something like that arises," she said. "We know what to look for."
Tribune reporter Greg Trotter contributed.
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