DNA, Bacterial / DNA Transposable Elements · Journal article

Early detection of pertussis related activity by wastewater surveillance of Bordetella pertussis- and Bordetella parapertussis-associated DNA concentrations in Osaka, Japan.

Emerging Microbes & Infections · August 19, 2026

Promising Why this matters to you Expert discussion

Encouraging direction, but not yet definitive.

AI Summary

This observational study demonstrates that quantitative PCR detection of B. pertussis IS481 DNA in wastewater from four Osaka treatment plants preceded clinical case reports by one to several months between April 2023 and July 2025. The finding suggests wastewater surveillance may complement clinical surveillance for early warning of pertussis activity, but requires prospective validation and multi-site replication before implementation.

What was studied

Prospective observational surveillance study. Wastewater from four treatment plants serving Osaka Prefecture, Japan. No individual-level clinical data; population-level surveillance.. Intervention: Wastewater surveillance via quantitative PCR detection of B. pertussis IS481 and B. parapertussis IS1001 DNA. Compared with: Reported clinical pertussis cases from regional public health surveillance systems. Four wastewater treatment plants in Osaka Prefecture, Japan.

Key findings

B. pertussis-associated IS481 DNA concentration increased markedly from 2024 onwards Wastewater IS481 DNA concentration preceded reported cases by one to several months B. parapertussis-associated IS1001 DNA showed transient peak in 2023, aligned with contemporaneous clinical reports, remained low thereafter

Safety

Safety was not reported in the material analysed. Check the source before drawing any conclusion about harm.

Who this may help

Public health officials monitoring respiratory disease trends may consider wastewater surveillance as an adjunct tool for early detection of pertussis resurgence, particularly useful when clinical diagnostic delays or healthcare-seeking behaviour obscure case trends. However, this single-region study does not yet justify standalone implementation; prospective validation and multi-centre replication are needed.

Plain-language summary

A single-centre observational study of wastewater surveillance showing earlier detection of pertussis DNA than clinical reporting, but lacking formal validation against a prospective clinical gold standard or multi-site confirmation.

Study design

As stated by the source record.

MethodsWeekly wastewater samples were collected from four treatment plants in Osaka Prefecture between April 2023 and July 2025. IS481- and IS1001-associated DNA concentrations were quantified using quantitative PCR. Threshold-based onset detection and cross-correlation analysis were applied to compare wastewater DNA trends with reported clinical cases.

DesignProspective observational surveillance study

PopulationWastewater from four treatment plants serving Osaka Prefecture, Japan. No individual-level clinical data; population-level surveillance.

InterventionWastewater surveillance via quantitative PCR detection of B. pertussis IS481 and B. parapertussis IS1001 DNA

ComparatorReported clinical pertussis cases from regional public health surveillance systems

SettingFour wastewater treatment plants in Osaka Prefecture, Japan

Reported figures

Quoted from the source exactly as published.

Study durationApril 2023 to July 2025

Number of treatment plants4

Lead time of wastewater detectionone to several months

B. parapertussis prevalence in Tokyo respiratory samples (2023)∼1.0%

Clinical bottom line

Caveats

No prospective comparison of wastewater signals against a pre-specified clinical gold standard (e.g., lab-confirmed case count with known testing rate).
Single prefecture limits generalisability; no data on how findings apply outside Osaka or in settings with different vaccination coverage or healthcare-seeking patterns.
No quantification of predictive value, sensitivity, specificity, or positive/negative predictive value of wastewater DNA thresholds for clinical cases.
Mechanism for early detection not established: cannot distinguish whether wastewater signal reflects asymptomatic shedding, pre-symptomatic cases, or delays in clinical reporting.

Evidence assessment

Graded across the dimensions that decide whether you should act, each from what the source actually supports. There is no single score, and where a dimension was not assessed it says so.

Study design

moderate

Prospective weekly wastewater sampling with quantitative PCR; observational, not experimental design.

Directness

moderate

DNA concentrations used as surrogate for case activity; not direct clinical outcome measurement.

Consistency

limited

B. parapertussis signal aligned with clinical reports; B. pertussis signal preceded cases, but single region.

Risk of bias

moderate

No blinding mentioned; potential for selection or temporal bias in comparing wastewater to clinical reporting.

Sample adequacy

moderate

Four treatment plants over 27 months; adequate duration but single prefecture limits generalisability.

Source abstract

Pertussis causes recurrent outbreaks worldwide. Clinical surveillance can be affected by healthcare-seeking behaviour, diagnostic practices, testing sensitivity, and reporting delays. This study evaluated the utility of wastewater surveillance (WWS) by quantifying Bordetella-associated IS481 and IS1001 DNA concentrations. Weekly wastewater samples were collected from four treatment plants in Osaka Prefecture, Japan, between April 2023 and July 2025, and IS481- and IS1001-associated DNA concentrations were measured using quantitative PCR. The putative B. pertussis-associated IS481 DNA concentration increased markedly from 2024 onwards. Both threshold-based onset detection and cross-correlation analysis indicated that the wastewater IS481 DNA concentration preceded reported cases by one to several months. In contrast, the B. parapertussis-associated IS1001 DNA concentration exhibited a transient peak in 2023, which aligned with contemporaneous clinical reports but remained at low levels thereafter. These findings suggest that WWS may detect increases in pertussis-related activity earlier than clinical reporting and highlight the potential of WWS as a complementary tool to clinical surveillance for monitoring respiratory infectious diseases.

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Kazunori TomonoNaomi SakonKoichiro SuzukiDNA, BacterialDNA Transposable ElementsDaisuke Motooka