Summit County public health officials said Tuesday that they are investigating a cluster of chickenpox cases among middle- and elementary-aged school children.

The local health agency has recorded 10 cases of varicella, which is often referred to as chickenpox, since August. Most of the cases occurred among children who attend school in Summit County and have not received the varicella vaccine, according to a news release.

“We are sorry to report these cases among these young members of our school district,” said Lauren Gilbert, nurse manager with Summit County Public Health, in a statement. “We are working closely with Summit School District to ensure students receive the appropriate care and to minimize further spread of the disease.”

The varicella vaccine, which requires two doses, is one of the shots required to attend Colorado schools unless there is an exemption, such as for medical or religious reasons.

Symptoms of varicella include an itchy, blister-like rash; fever; tiredness and loss of appetite. Chickenpox can appear in people who are immunized, but health officials said vaccination is the best way to limit the spread of the disease. It is usually not serious but can cause severe illness in some people, including infants, pregnant people and those with weakened immune systems, according to the news release.

The Summit School District has notified the parents of students who may have been exposed at Summit Middle School and Dillon Valley Elementary School. The district and public health officials have also contacted parents of other unvaccinated children who were potentially exposed, according to the news release.

More than 90% of all students at both Summit Middle School and Dillon Valley Elementary are fully inoculated against varicella, according to the health department.

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