Health officials are monitoring clusters of highly contagious whooping cough cases in teens across Los Angeles County, including at a San Fernando Valley private school.
According to the Los Angeles County Department of Public Health, the number of cases overall has not increased over the last five years, but three clusters of cases among 11- to 18-year-olds who share classrooms and carpools prompted DPH to issue a health alert to pediatricians and other health care providers last week.
Harvard-Westlake School has had 30 cases since November and recently sent a notice to parents about the outbreak, according to The Hollywood Reporter.
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The public health agency said there were three clusters in different areas of the county, with a median 17 cases per cluster, but did not specify locations.
Harvard-Westlake's community health officer has been coordinating directly with the Department of Public Health and that agency is confident about the steps being taken to prevent further spread of the illness, according to a school spokesman.
"We have gone above and beyond," spokesman Ari Engelberg told City News Service. "We've been doing everything that we possibly can...we're as upset and concerned about our kids getting whooping cough as anyone else would be."
Those extra measures include sending students home when they exhibit any symptoms of the illness -- which can resemble the flu -- and directing parents to test their children for whooping cough before allowing them to return to school.
The illness, also known as pertussis, gets its name from a distinctive cough that sounds like a whoop, but it may present like an ordinary respiratory infection in those who have been vaccinated. And while vaccination is the best defense, immunity wanes in five to 10 years after the last vaccine dose.
Public health officials have advised health care providers to consider pertussis in anyone who has a persistent cough and to report suspected cases within one day without waiting for laboratory confirmation.
Asked about vaccine policies, Engelberg said only 18 of Harvard-Westlake's roughly 1,600 students have medical exemptions allowing them to opt out of immunizations. None of those children have contracted pertussis, he said.
Personal belief and religious exemptions were eliminated under a state law passed in 2015. A few upper school students are grandfathered under previous exemptions, Engelberg said.
The illness can be treated with antibiotics and contagion typically ends five days after starting antibiotic treatment.
It is particularly dangerous and even deadly for infants, who end up in the hospital about 50 percent of the time after contracting the illness, according to the DPH.