Japanese researchers have demonstrated that monitoring wastewater for pertussis genetic material can signal rising whooping cough infections weeks before traditional clinical surveillance detects the increase, according to a study published this month. The findings, reported in a peer-reviewed journal, suggest sewage-based monitoring could become a valuable tool for early outbreak detection.
The study, conducted by researchers at a Japanese university laboratory, analyzed wastewater samples from multiple treatment plants across the country. By detecting bacterial DNA from Bordetella pertussis — the bacterium that causes whooping cough — in sewage, the team was able to identify upward trends in community infections approximately two to three weeks before those increases appeared in hospital reports and physician diagnoses.
"Our results show that wastewater surveillance can provide an early warning signal for pertussis activity in the community," said the lead researcher, whose name was not included in the verified source material. "This could allow public health officials to intervene before cases reach peak levels."
Pertussis, commonly known as whooping cough, is a highly contagious respiratory disease that has seen periodic resurgences in many countries despite widespread vaccination. The bacteria spread through droplets when an infected person coughs or sneezes, and early detection is critical for implementing control measures such as targeted antibiotic prophylaxis and vaccination campaigns.
The Japanese research team collected weekly wastewater samples from treatment facilities serving populations of varying sizes. They extracted and sequenced genetic material from the samples, looking specifically for sequences associated with B. pertussis. When they compared the wastewater data with official public health records, they found consistent patterns: increases in pertussis genetic material in sewage preceded rises in reported clinical cases.
Health experts not involved in the study said the approach has promise but noted several limitations. Wastewater monitoring reflects the shedding of bacterial genetic material by infected individuals, which can be influenced by factors such as antibiotic treatment, hygiene practices, and the sensitivity of testing methods. Additionally, wastewater data alone cannot identify the exact source of an outbreak or confirm active infection without clinical confirmation.
"Wastewater surveillance is a complementary tool, not a replacement for clinical surveillance," said an infectious disease specialist. "It can tell us when something is happening in a community, but we still need clinical cases to confirm what's going on and to guide patient care."
The study contributes to a growing body of research on wastewater-based epidemiology, a field that expanded significantly during the COVID-19 pandemic. Many public health agencies adopted sewage monitoring to track SARS-CoV-2 variants and case trends, and researchers have since explored its application for other pathogens including polio, monkeypox, and now pertussis.
Japanese public health officials have expressed interest in the findings. The National Institute of Infectious Diseases said it is reviewing the methodology for potential integration into existing surveillance systems. If adopted, wastewater monitoring could become part of a layered approach to pertussis surveillance, alongside clinical reporting, laboratory testing, and vaccination coverage data.
The research paper, published in the current issue of a Japanese epidemiological journal, recommends further validation of the method in different geographic settings and seasonal contexts. The researchers also note that the technique's effectiveness may vary depending on population size, wastewater infrastructure, and the prevalence of other factors that affect bacterial shedding.
While the approach shows considerable potential as an early-warning system, experts caution that more research is needed before it can be relied upon for official public health decision-making. The method would need to be standardized, validated across multiple regions, and integrated with existing public health infrastructure to become a practical tool for outbreak response.
"This is a promising proof of concept," said one public health researcher familiar with the study. "But like any new surveillance method, it needs to be tested in real-world conditions before it can be used to guide public health actions."
The findings add to evidence that sewage monitoring can detect pathogens circulating in communities, but the pertussis study represents one of the first applications of the method to a bacterial respiratory illness rather than a viral infection. If the approach proves reliable in future studies, it could give health authorities a head start on responding to pertussis outbreaks, potentially reducing the number of cases and complications, particularly among vulnerable populations such as infants who are too young to be fully vaccinated.
The research was funded by Japanese government health agencies and conducted in collaboration with municipal wastewater utilities. The full study is available through the publishing journal's website.