The Florida Department of Health said it investigating after a Broward County elementary school confirmed a fifth case of the measles on Monday.
The Broward school district said it conducted a deep cleaning of Manatee Bay Elementary in Weston over the weekend and replaced its air filters.
Measles is a highly contagious virus that can lead to complications including brain damage, deafness and, in rare cases, death, according to health officials.
Health department officials said anyone who has received the full series of MMR shots (measles, mumps, rubella) is 98% protected. People who are unvaccinated or have compromised immune systems are most at risk.
The Broward health department said it was working with the school district and local hospitals, to identify contacts that are at risk of transmission. Those people may be candidates for post-exposure treatments.
Health care providers in the area have been notified," the agency said in a press release.
The first case at Manatee Bay Elementary in Weston was reported on Friday.
The most prominent symptom of measles is a rash on the face and neck that can spread to the rest of the body. Prior to the rash, symptoms can include high fever, cough, runny nose and red, watery eyes.
If you notice any of symptoms, contact your health care provider to receive instructions on how to safely seek medical attention without exposing other patients, health officials said. Do not abruptly visit a provider without contacting them ahead of time.
Health News Florida's Rick Mayer contributed to this report.