There have been more than 100 cases of whooping cough reported in just three Brooklyn neighborhoods within the past year, according to officials.
Although the sickness can be avoided with proper vaccinations, the Health Department is advising caution and reaching out to the public to help people catch signs of the symptoms.
About 109 cases of pertussis have been reported in Borough Park, Crown Heights and Williamsburg.
All three neighborhoods have large Orthodox Jewish communities, where officials say they've seen the most cases.
Health officials say about 90 percent of the cases have affected children, and more than a third of those cases have been in infants. More than half of the patients were unvaccinated or had fallen behind on vaccine schedules.
Symptoms include a respiratory infection that lasts for about a week to 10 days, followed by a cough and sometimes vomiting.
State Assemblyman Dov Hikind is urging residents in those communities to be mindful of vaccination deadlines.
"It isn't one single vaccination that deals with the problem," Hikind says. "There are five over a period of time from when the baby is a couple months old to four months and into the first couple of years."
To control the outbreak, the Health Department is asking doctors to recall patients who are not up to date on vaccines, vaccinate pregnant women, report suspicious cases, obtain cultures for analysis and provide antibiotics promptly.
Officials say antibiotics are effective treatment when provided early.