Unvaccinated Pregnant Women Should Avoid Hawaiʻi's Pertussis Outbreak

The Hawaiʻi Department of Health (DOH) continues to respond to a significant increase in pertussis (whooping cough) cases this year.

As of July 31, 2025, DOH has identified 203 cases of pertussis, more than double the 84 cases identified in all of 2024. 

According to the DOH's media release on August 11, 2025, cases have been reported in every county, with the highest rates on Kaua‘i, Maui, and Hawai‘i Island.

The DOH says pertussis is a highly contagious respiratory disease spread through the air via coughs or sneezes of an infected person. Initially, the symptoms resemble a cold, but can progress to intense coughing fits.

In children, coughing fits can be followed by a deep breath that makes a "whooping" sound. Health complications can be severe and even life-threatening, especially for infants and young children who are not fully vaccinated. 

The most effective way to reduce the risk and severity of pertussis is through vaccination, says the DOH.

The Tdap vaccine has been available for nearly 20 years and is recommended for pregnant women, which helps protect their newborns from this severe disease.

"The high number of cases means there's a greater risk of getting exposed to pertussis in the community. If you have not yet vaccinated your infant, please consider doing so to reduce the risk of hospitalization or even death," commented Dr. Kenneth Fink, DOH director.

"Like with other vaccine-preventable diseases, we continue to strongly encourage all individuals to remain up to date on recommended vaccinations to help protect both the person vaccinated and those in our families and communities who are most vulnerable."

For more information about pertussis and how to protect yourself and your loved ones, visit the Department of Health website. 

The U.S. CDC recently stated that in 2024, reported cases of pertussis increased across the United States. Preliminary data show that more than six times as many cases were reported in 2024 compared to 2023. 

Furthermore, preliminary case reports remain elevated in 2025.

Across the Pacific Ocean from Hawai'i, Japan has been battling a multi-year pertussis outbreak.

As of August 2025, Japan has surpassed 50,000 cases for the first time since comparable data became available in 2018.