Active Public Health Outbreaks in Hawaii
Surveillance Report • November 30, 2025
Critical Alert
Pertussis Surge
Whooping Cough
vs. 84 total cases in 2024
Monitoring
Avian Influenza
H5N1 Strain
No human cases confirmed in HI
Travel Advisory
Dengue Fever
Imported Cases
0 confirmed local transmission
Pertussis (Whooping Cough): A "Worrying Rise"
The most significant active public health concern in Hawaii for late 2025 is the resurgence of Pertussis. Data from the Hawaii Department of Health (DoH) indicates a sharp deviation from post-pandemic trends. As of July 31, 2025, the state recorded 203 confirmed cases, a figure that more than doubles the total case count for the entire year of 2024 (84 cases).
Contrast in Vulnerability: While cases have been reported across all counties, the demographic impact is uneven. Infants under one year of age—who are too young to be fully vaccinated—face the highest incidence rates and risk of severe complications. This contrasts with the adult population, where incidence remains substantially lower, highlighting a critical gap in "cocooning" vaccination strategies for families.
Incidence Hotspots
- Kaua?i High Incidence
- Hawai?i Island High Incidence
- Maui Elevated
- O?ahu Moderate
Avian Influenza (H5N1): Environmental Presence
Hawaii lost its status as the only U.S. state free of H5N1 Avian Influenza in late 2024. The virus was first detected in a backyard flock in Central O?ahu in November 2024, followed swiftly by wastewater detections in Hilo on the Big Island in December 2024.
Wastewater Surveillance
Wastewater testing has proven to be a leading indicator, detecting viral fragments before clinical cases in animals are confirmed. This method provides an early warning system that contrasts with traditional reliance on reporting sick livestock.
Human Risk Assessment
Despite the presence of the virus in local bird populations and wastewater, the CDC and Hawaii DoH maintain that the risk to the general public remains low. No human cases have been confirmed in Hawaii to date, distinguishing the state from mainland outbreaks involving dairy and poultry workers.
Vector-Borne Diseases: The "Traveler" Distinction
| Disease | 2025 Status | Transmission Source |
|---|---|---|
| Dengue Fever | ~12 Cases (Aug 2025) | Travel-Related Only |
| Oropouche Virus | Monitoring | Travel Advisory |
Note on Data Discrepancy: While news outlets occasionally report "suspected" local spread, official DoH data strictly categorizes current Dengue cases as travel-associated (imported), emphasizing that the disease is not currently endemic in Hawaii despite the presence of the Aedes mosquito vector.
Respiratory Virus Season (2025-2026)
As of November 2025, Hawaii is entering its respiratory virus season. The Department of Health has issued updated immunization recommendations for COVID-19, Influenza, and RSV. While activity levels for COVID-19 were classified as "medium" earlier in the year (May 2024), current surveillance focuses on the co-circulation of these three viruses. The state advises residents, particularly those in congregate settings or with high-risk conditions, to adhere to the 2025-2026 vaccination guidance to mitigate hospital strain.