Whooping Cough Spreads Through Pasadena Schools, Hitting a Third Campus With Six New Cases

The Pasadena Public Health Department is investigating an outbreak of six confirmed pertussis cases at Sequoyah School’s high school campus, the third school cluster of whooping cough confirmed in the city since late April.

The Sequoyah outbreak extends a citywide pertussis surge, with the department reporting 17 confirmed cases identified in Pasadena since the start of 2026, compared with an annual average of about three.

“Pertussis is a serious and highly contagious illness,” said Manuel Carmona, director of public health. “Staying home when sick is the key to stopping the spread of this preventable illness in our community. Parents should be on the alert for persistent or unusual coughs and seek medical care promptly if symptoms arise.”

Health Officer Parveen Kaur urged clinicians to confirm suspected cases with laboratory testing.

“Timely testing and treatment is essential for stopping the spread of pertussis,” Kaur said. “Healthcare providers who suspect pertussis should conduct confirmatory testing using a nasal swab for a PCR test and follow proper treatment guidelines. Children who are suspected with pertussis should not be allowed to return to school until they have met recommended clearance criteria.”

The department said it is continuing to collaborate closely with schools and community partners to monitor for additional cases, and that all identified close contacts have received guidance, including instructions on testing, treatment, and staying home if symptoms develop.

The Sequoyah cluster follows two earlier outbreaks.

On April 29, the department announced four confirmed cases at Don Benito Fundamental School at 3700 Denair St., and on May 19 it announced three confirmed cases at Blair Middle School. On May 11, the department issued a Pertussis Health Advisory to local clinicians citing a “significant increase” in pertussis activity in the community and directing providers to suspect, test, treat and report cases.

Whooping cough spreads through coughing or close contact with an infected person, with symptoms usually appearing five to 21 days after exposure, the department said. Early symptoms resemble a cold — sneezing, runny nose, mild cough and low-grade fever — but the cough typically worsens over one to two weeks.

Severe coughing fits may cause gasping (“whooping”), vomiting, or difficulty breathing. Infants may not cough but may gag, turn red or blue, or briefly stop breathing. A nasal swab is used to confirm infection.

The department recommends that people who have been exposed to pertussis monitor for symptoms for 21 days, contact a healthcare provider if symptoms develop, and keep sick individuals home until cleared by a provider or after five days of appropriate antibiotics. A five-day course of azithromycin is the appropriate first-line choice for treatment. High-risk contacts, including infants under one year, pregnant people, and caregivers of infants, may need preventive antibiotics even without symptoms, the department said. The release also advises preventing contact between sick individuals and infants or pregnant people.

Staying up to date on vaccines is the best way to significantly decrease the likelihood of infection, severe illness, and further complications, the department said. It recommends that children be up to date on their Diphtheria, Tetanus, and Pertussis (DTaP) vaccine, that children ages 11 or 12 receive the Tetanus, Diphtheria, and Pertussis (Tdap) booster, and that adults — especially pregnant people and caregivers of young children — also receive a Tdap booster.

The Pasadena Public Health Department offers the Tdap vaccine on Monday and Wednesday from 8:30 a.m. to 11:30 a.m. and 1:30 p.m. to 4:30 p.m. by appointment and walk-in. Most private health insurance plans cover the DTaP/Tdap vaccines, and the federal Vaccines for Children program provides vaccines to children whose parents or guardians may not be able to afford them.

The local rise in pertussis comes against a backdrop of declining national activity. According to the U.S. Centers for Disease Control and Prevention, preliminary data show fewer pertussis cases reported nationally in 2026 than in the same period in 2025, with reported cases having last peaked in November 2024. The CDC describes pertussis as a cyclical disease, with peaks every few years. The California Department of Public Health reported more than 2,000 pertussis cases and one infant death in the state between January and October 2024.

For more information on testing and treatment, the department directed clinicians and the public to the California Department of Public Health’s Pertussis website.