Researchers in Osaka found that pertussis-associated DNA in wastewater rose weeks before reported cases, pointing to a new way to complement clinical surveillance

Osaka, Japan – Pertussis, or whooping cough, continues to cause periodic outbreaks worldwide and can be especially dangerous for infants who have not completed vaccination. Yet conventional surveillance depends on people seeking medical care, being tested, diagnosed, and reported, which can delay recognition of changes in community transmission.

Researchers at the University of Osaka and the Osaka Institute of Public Health have now shown that wastewater surveillance may provide an earlier signal. By monitoring sewage across Osaka Prefecture for more than two years, the team found that increases in pertussis-associated DNA appeared before increases in reported cases.

From April 2023 to July 2025, wastewater was collected weekly from four treatment plants and analyzed for DNA markers associated with Bordetella pertussis, the bacterium that causes pertussis, and Bordetella parapertussis. The concentration of the B. pertussis-associated marker IS481 began increasing in 2024 and showed a temporal pattern similar to reported pertussis cases.

In the main cross-correlation analysis, the wastewater signal preceded reported cases by 10 weeks. Other analyses showed lead times ranging from 4 to 16 weeks, consistently indicating that changes in wastewater appeared earlier.

Wastewater surveillance has an important advantage. It does not depend on whether infected people seek medical care or undergo testing. It may therefore capture broader community-level trends, including mild or asymptomatic infections that are not fully represented in clinical reports.

“By combining wastewater surveillance with clinical surveillance, we hope to detect changes in community transmission earlier,” says Dr. Daisuke Motooka of the Research Institute for Microbial Diseases, the University of Osaka.

The findings suggest that wastewater monitoring could complement clinical surveillance and support earlier public health preparedness, including heightened clinical awareness, expanded testing, and infection-prevention measures. This could support a shift from a reactive to a proactive public health approach. By building a system that detects and responds to early signs of an outbreak, rather than acting only after it has begun, the researchers aim to help limit the spread of infection within communities.
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The article, “Early Detection of Pertussis Related Activity by Wastewater Surveillance of Bordetella pertussis- and Bordetella parapertussis- Associated DNA Concentrations in Osaka, Japan,” was published in Emerging Microbes & Infections at DOI: https://doi.org/10.1080/22221751.2026.2717860

About The University of Osaka
The University of Osaka was founded in 1931 as one of the seven imperial universities of Japan and is now one of Japan's leading comprehensive universities with a broad disciplinary spectrum. This strength is coupled with a singular drive for innovation that extends throughout the scientific process, from fundamental research to the creation of applied technology with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world. Now, The University of Osaka is leveraging its role as a Designated National University Corporation selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for human welfare, sustainable development of society, and social transformation.
Website: https://resou.osaka-u.ac.jp/en