Whooping cough found at S.F. high school
Small clusters of pertussis, or whooping cough, have been found among students at Sacred Heart Cathedral Preparatory, a Catholic high school at Ellis and Franklin streets, according to the public health department.
Since January, 13 cases of pertussis have been confirmed in San Francisco — two in January, five in February and six in March, said the San Francisco Department of Public Health.
Most of the cases were among vaccinated high school students and their close contacts, and there have been no reports of serious illness, hospitalizations or deaths. There is no evidence of widespread community transmission in San Francisco.
“We have been working closely with the school’s administrators to notify, inform and educate the campus community about pertussis,” the health department said in a statement.
Whooping cough, a highly contagious respiratory disease caused by the bacterium Bordetella pertussis, can be fatal in infants, the group that doctors worry most about since they are too young to be vaccinated. It can cause fits of violent coughing in older children, teens and adults that can last for months.
The San Francisco cases coincide with a recent outbreak in Marin County, which has reported about 100 cases since December, most of them among high school students at Tamalpais High in Mill Valley.
Infectious disease experts say it is not unheard of for vaccinated teens to contract pertussis because protection from the Tdap (tetanus, diphtheria and pertussis) vaccine fades over time. Most U.S. children get their most recent Tdap shot around age 11, so some of the immunity has waned by the time they enter high school. At the same time, teens tend to spend time together in close proximity, which makes transmission more likely.
“Pertussis immunity is relative, not absolute,” said Dr. Paul Katz, a pediatrician at Kaiser Permanente in San Rafael. “So if you’re exposed a lot, you’re more likely to get pertussis even though you have some immunity. If one kid, say, on a sports team has it, it will spread throughout the group.”
Older children, teens and adults who have been vaccinated usually get a milder version of whooping cough than infants, but it “is a miserable disease to have as an adult and it can persist for quite a while,” said Dr. George Rutherford, a UCSF pediatrician and epidemiologist who called the recent clusters “the edge of worrisome.”
Historically, there have been small surges of pertussis every three or four years, and the most recent one of note in California was in 2018 and 2019, when about 2,300 and 3,200 cases were reported in California, respectively, according to state data. In 2023 there were 640 cases in California; so far in 2024, there have been 180.
Because most Bay Area students were sheltering in place or in virtual learning in 2020 and 2021 at the height of the COVID-19 pandemic, there weren’t major upticks in the region in those years, and the current swell could simply be that surge happening now, only delayed.
“You can’t have spread if you’re not together,” Katz said. “Shelter in place blunted what we would’ve expected.”
“We have been working closely with the school’s administrators to notify and educate the campus community about pertussis.” S.F. Department of Public Health