Eurosurveillance - Volume 31, Issue 5, 05 February 2026

Public Health Intelligence (PHI) aims to detect health threats early for a timely and effective response. The PHI team at the Robert Koch Institute (RKI) uses the Epidemic Intelligence from Open Sources (EIOS) system in combination with other sources for detecting signals of international public health threats relevant to Germany. However, while EIOS is increasingly used for PHI worldwide, it is rarely evaluated.

We designed and conducted an attribute-based evaluation to assess EIOS’s performance for international PHI in 2023 and to identify areas for improvement.

We adapted surveillance system attributes and designed attribute-specific data collection methods. We conducted a mixed-method evaluation combining prospective and retrospective operational data collection with feedback from PHI officers.

During 2 weeks in July 2023, the PHI team reported 20 signals: 16 detected using EIOS and four from other sources. Increasing the number of EIOS sources increased timeliness and sensitivity slightly but caused a 35-fold increase in articles to screen (35,546 vs 1,138). The team found EIOS flexible and simple for signal detection but identified challenges in simplicity of signal documenting and reporting and in completeness of EIOS sources screened by the team.

The current use of EIOS proved sensitive and timely. However, PHI must balance sensitivity, timeliness and resource requirements. To maintain this balance, we strongly recommend regular evaluations of the use of EIOS for PHI. Our evaluation offers practical guidance for other PHI teams. We recommend integrating EIOS with an event management system to facilitate signal documentation and reporting.

Aeromonas, Campylobacter and Salmonella species can cause gastrointestinal infections in humans. Information on the performance of detection methods is relevant to assess the impact of changes on surveillance.

We aimed to assess detection of Aeromonas, Campylobacter and Salmonella by culture and Seegene multiplex real-time PCR in faecal samples from patients with gastrointestinal symptoms.

In 2023, all faecal samples submitted to a clinical microbiology laboratory in Sydney, Australia, were tested for Aeromonas, Campylobacter and Salmonella species by culture and Seegene PCR, both detecting at the genus level. The results were analysed descriptively and with binomial generalised linear model, quantile regression, censored regression model and Wald tests.

Of the 90,291 samples tested, more samples were positive with PCR than with culture for Aeromonas (PCR: 2.9%; culture: 0.5%) and Campylobacter (PCR: 4.2%; culture: 3.1%), but fewer for Salmonella species (PCR: 0.7%; culture: 0.8%). Of the culture-positive samples, 19.2% were negative for Aeromonas by PCR, 3.6% for Campylobacter and 23.0% for Salmonella. Of the PCR-positive samples, 81.9% were negative for Aeromonas by culture, 25.6% for Campylobacter and 14.2% for Salmonella. Quantification cycle (Cq) values were negatively associated with patient age for Aeromonas, indicating higher bacterial loads in older patients and positively associated with age for Campylobacter, indicating lower bacterial loads in older patients (p < 0.001). Also, Cq values were negatively associated with detection by culture and faecal calprotectin levels (p < 0.001).

These findings highlight the importance of pathogen- and method-specific interpretation of PCR and culture results in diagnostic testing and surveillance.