Lake County health officials report an increase in the number of mumps cases but don't consider the situation to require special action.
Authorities said four probable and one suspected case of the contagious viral illness have been reported this year, compared to one confirmed case last year. The isolated cases involved three adults and two children, including a 12-year-old student at Fremont Middle School in Mundelein.
"It's not that significant because it's not a cluster," said Leslie Piotrowski, health department spokeswoman. She added there was heightened awareness, but no health department alerts or actions were being taken.
There were no confirmed cases, and none of those who contracted it were hospitalized, Piotrowski said. All had been vaccinated.
"It's not 100 percent effective so from time to time you'll see people who were vaccinated come down with mumps," she said. The MMR or MMRV vaccines are the best protection, she added.
Swelling or pain close to the jaw on one or both sides of the face is a hallmark symptom of mumps. Other common symptoms include fever, headache, muscle aches, tiredness or loss of appetite, according to the health department. Symptoms typically appear 16 to 18 days after infection, but up to half of those who get the mumps have very mild or no symptoms, according to Piotrowski.
Complications can develop that affect the thyroid gland, kidneys, heart, joints, pancreas, ovaries and testes, the brain and central nervous system and hearing. The disease is rarely fatal.
Fremont District 79 was notified of the case there May 1. The student returned to school May 5 after it was shown he was no longer a threat to staff or students, according to Margaret Van Duch, communications coordinator.
There were no other reported cases in the district and no calls from parents with concerns, she added. The student with the suspected case and those he came in contact with had been immunized.
A letter with information from the health department regarding mumps was sent to district parents.
As of Wednesday, 88 cases had been reported to the Illinois Department of Public Health compared with 26 for all of 2013. Most of the cases were in downstate Morgan, Sangamon and Champaign counties.
The state agency is working with local health departments to investigate cases and implement control measures, such as conducting surveillance in affected communities for at least a month.