Some parents in Southington were notified on Thursday that a reported case of measles has been confirmed.
On Wednesday, officials said they were investigating a possible case of measles at Derynoski Elementary School.
Thursday school officials said the case was confirmed.
The news had parents double-checking their children's vaccination records.
Exposure would have taken place in the school on April 26, 27, or 30.
Anyone who may have been exposed might develop symptoms between May 3 and May 21.
"Parents should consult with their child’s physician for additional information regarding their specific set of circumstances," the letter said.
People who have had measles in the past or who have been vaccinated against measles are considered immune according to the Centers for Disease Control and Prevention (CDC).
Last week, two cases of measles were confirmed in New Haven County.
"Because measles is a highly contagious disease, it can spread quickly among unvaccinated people. However, the majority of people exposed to measles are not at-risk of developing the disease since most people have either been vaccinated or have had measles in the past, before vaccination became routine," officials said in the letter that was sent out on Wednesday.
Measles is spread through the air, so children can catch it from coughs or sneezes.
“In most people, it causes a rash, high fever, conjunctivitis, pink eye, a cough. It’s kind of a respiratory virus," Dr. Nicholas Bennett, division head of Infectious Disease and Immunology at Connecticut Children's Medical Center, said in a previous interview with Channel 3.
Symptoms include a mild-to-moderate fever, a cough, runny nose, red eyes and a sore throat. A short time later, a red or reddish-brown rash appears first on the face at the hairline and spreading downward to the entire body.
When the rash appears, a fever may spike to more than 104 degrees. The rash lasts a few days then disappears in the same order.
People with the disease can be contagious for up to four days.
According to the Department of Health's most recent report, 99 percent of public school children in CT have been vaccinated for measles, but parents of the 1% that aren't, had to show a medical or religious reason for not getting their child the vaccine.
"You look at what's going into their bodies, what's in these vaccinations, are all of them necessary," said Adrienne Durando, a Southington parent.
Parents like Doug Zepka and Durando have doubts. Their children are vaccinated, but they say they are worried about side effects.
"People say they give their child a vaccine and overnight they change. That alone is scary," Zepka said.
Other say what's happening at Derynoski is exactly why they take vaccinations so seriously.
"You never know. For the protection of my son and for the future, I'd like him to stay on track," said Ben Dutkiewicz, a parent.
For more information on measles from the CDC, click here.
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