Whooping Cough Cases Continue in Multiple States Amid National Decline
Pertussis, commonly known as whooping cough, remains a notable public health concern in the United States in 2026 even as overall case numbers trend downward from the elevated levels seen in prior years. According to preliminary data from the Centers for Disease Control and Prevention, fewer cases have been reported in 2026 compared to the same period in 2025. As of late May 2026, approximately 4,598 cases have been documented nationwide, with several states accounting for a disproportionate share of the reports.
California leads with nearly 700 cases so far this year. Washington state follows with more than 328 cases, while Ohio reports over 280 and Florida more than 262. These figures come against a backdrop of 28,783 total cases recorded for all of 2025 and 43,321 in 2024, numbers that marked the highest totals in more than a decade before the current moderation.
Understanding Pertussis: The Disease and Its Transmission
Pertussis is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis. It spreads through respiratory droplets when an infected person coughs or sneezes. The illness often begins with cold-like symptoms such as runny nose, mild cough, and low-grade fever, progressing after one to two weeks into intense coughing fits that can end with a characteristic high-pitched "whoop" sound as the person gasps for air. In infants and young children, these fits may lead to vomiting, exhaustion, or pauses in breathing known as apnea.
The disease follows a cyclical pattern, with peaks typically occurring every few years. National surveillance data indicate that reported cases peaked in November 2024 before beginning a decline, consistent with the expected post-peak reduction in this cyclical illness. Despite the downturn, activity remains above pre-pandemic baselines in many areas.
Historical Context and Recent Trends
Pertussis was once a leading cause of childhood illness and death in the United States before widespread vaccination dramatically reduced incidence. Routine immunization programs introduced in the 1940s led to sharp drops, yet the disease has never been fully eliminated. Annual cases typically ranged between 10,000 and 20,000 in the years leading up to the COVID-19 pandemic, with a notable high of 48,277 in 2012.
The COVID-19 period brought unusually low numbers due to masking, distancing, and reduced social mixing, with only 7,063 cases reported in 2023. The rebound began in 2024 and continued into 2025 before easing in 2026. Pan American Health Organization data for the Americas region similarly show a significant increase from 2023 to 2024, followed by a moderate decline in 2025 and further reduction into 2026.
State-Level Reports Highlight Geographic Variation
While national totals have moderated, certain states continue to report elevated activity. In addition to the leading states mentioned, Texas and Oregon have historically contributed high numbers in recent cycles. Public health departments in affected areas monitor clusters, particularly in schools and childcare settings where close contact facilitates spread.
Enhanced surveillance through the CDC's Emerging Infections Program network in seven participating states provides more detailed tracking, helping identify patterns and inform responses. These efforts complement standard national notifiable disease reporting.
Photo by Erik Mclean on Unsplash
Vulnerable Populations and Health Impacts
Infants under one year of age face the greatest risk of severe complications and death from pertussis. Their immune systems are immature, and they may not yet have completed the primary vaccination series. Data from recent years show that the majority of pertussis-related deaths occur in this age group. Adolescents and young adults also experience notable infection rates, often due to waning immunity from earlier vaccinations.
Complications can include pneumonia, seizures, encephalopathy, and prolonged hospitalization. Even in milder cases, the characteristic cough can last for weeks or months, disrupting daily life, work, and school attendance. In 2025, 16 deaths were reported nationally, underscoring the ongoing threat despite overall declines.
Vaccination Coverage and Immunity Challenges
Vaccination remains the primary defense against pertussis. The diphtheria, tetanus, and acellular pertussis (DTaP) vaccine is recommended for infants and young children in a five-dose series, while the tetanus, diphtheria, and acellular pertussis (Tdap) booster is advised for adolescents, adults, and pregnant individuals. Maternal Tdap vaccination during pregnancy provides passive protection to newborns.
Declining or incomplete vaccination coverage, combined with naturally waning immunity over time, contributes to periodic resurgences. Only about one in five children under six who contracted pertussis in 2025 had completed their primary DTaP series. Public awareness of current recommendations varies, with polls indicating confusion among some adults about booster needs.
Public Health Responses and Prevention Strategies
Health authorities emphasize timely vaccination, prompt testing and treatment with antibiotics when appropriate, and isolation of confirmed cases to limit spread. Post-exposure prophylaxis may be recommended for close contacts, especially those at high risk. Schools and childcare facilities often implement exclusion policies during outbreaks.
Broader measures include ongoing surveillance, public education campaigns, and collaboration between federal, state, and local agencies. The cyclical nature of the disease means continued vigilance is essential even during periods of lower reported incidence.
Expert Perspectives on the Current Situation
Infectious disease specialists note that while 2026 numbers are lower than the 2025 peak, the persistence of cases across multiple states signals the need for sustained prevention efforts. Factors such as reduced vaccine uptake in some communities and the time required for immunity to build after vaccination play roles in transmission dynamics.
Clinicians highlight the importance of considering pertussis in differential diagnoses for patients with prolonged cough, particularly in high-activity regions. Early recognition allows for effective antibiotic treatment that shortens contagiousness and may reduce severity.
Looking Ahead: Outlook and Recommendations
With pertussis being an endemic and cyclical disease, periodic increases remain likely. Continued monitoring by the CDC and state health departments will track whether the current downward trend holds through the remainder of 2026. Maintaining high vaccination rates, especially among pregnant people, infants, and adolescents, offers the best protection against future surges.
Individuals are encouraged to review their vaccination status with healthcare providers and ensure eligible family members receive recommended doses. Staying informed through official public health channels helps communities respond effectively to evolving patterns.
For more information on national trends, visit the CDC Pertussis Surveillance page. Additional regional data appear in reports from the Pan American Health Organization. Recent state-specific updates are available via outlets such as U.S. News & World Report.