Arizona logged nearly 1,000 whooping cough cases in 2025, the state's highest tally in more than a decade, and health officials say new infections are already being reported this year. Local hospitals and public health leaders largely point to slipping childhood vaccination rates and growing use of personal belief exemptions as key drivers of the spike.
State data and trends
State surveillance tracked a sharp rise in pertussis cases last year, pushing totals well beyond recent norms. According to KJZZ, public records and state messaging show case counts steadily climbed through 2025, and the Arizona Department of Health Services has been issuing guidance to clinicians and schools as the outbreak unfolded.
Doctors point to vaccination gaps
At Phoenix Children's Hospital, pediatric hospitalist Dr. Vasu Bhavaraju reports seeing whooping cough numbers that exceed what has been typical in recent years, even though pertussis is preventable with a long-studied vaccine. Citing state data, ABC15 noted that Arizona recorded 992 pertussis cases in 2025, roughly double the five-year average, with 43 additional cases already reported in 2026. The outlet also reported that kindergarten personal belief exemption rates rose from about 5.9% in 2018-19 to 9% in 2024-25.
Schools and county protocols
School districts say they are following county notification rules and helping with contact tracing whenever a student tests positive. As ABC15 reported, Deer Valley Unified School District nurse coordinator Jackie Duarte said Maricopa County notifies schools about which students have tested positive and typically supplies guidance letters for districts to send home to families. State communicable disease rules also require local health agencies to investigate reported pertussis cases and identify close contacts, according to the Arizona Administrative Code.
National picture and what families can do
Pertussis activity is elevated across the country as well. The Associated Press reported that preliminary federal counts from the Centers for Disease Control and Prevention show thousands of whooping cough cases in 2025, an increase compared with recent years, based on coverage from the AP. As outlined by the CDC, vaccination remains the best protection, with a DTaP series recommended for infants and young children and Tdap booster shots for adolescents and adults, including one dose during each pregnancy to help protect newborns. Health officials advise parents to review their children's immunization records, talk with pediatricians about any needed catch-up shots, practice regular handwashing and keep sick children home while seeking medical care if a cough is persistent or severe.
