Background: In August 2022, the Hellenic National Public Health Organisation was notified about a gastroenteritis outbreak in town A in Southern Greece. Investigations aimed to identify the source and implement control measures. Methods: Case definition categories were used in a 1:3 case–control study. Cases and controls were interviewed about various exposures. Cases’ stool samples were cultured on agar plates and characterised by serotyping, antimicrobial susceptibility testing and Pulse Field Gel Electrophoresis (PFGE). Environmental investigations included tap water sampling for microbiological and chemical analysis in town A and inspection of the water supply system. Results: We identified 33 cases (median age: 17 years). Tap water consumption was the only significant risk factor for gastroenteritis (OR = 5.46, 95% CI = 1.02–53.95). Salmonella (S.) Bovismorbificans isolated from eight stool and one tap water samples had identical PFGE profiles. No resistant isolates were identified. Residual chlorine levels were lower than the acceptable limits before and during the outbreak. We advised consumption of bottled water and adherence to strict hand hygiene rules until tap water was declared suitable for drinking. Conclusions: Epidemiological and molecular data revealed a waterborne S. Bovismorbificans outbreak in town A. We recommend local water safety authorities to ensure that residual chlorine levels comply with the legislation towards water safety planning, to mitigate risks.

Background: waterborne disease outbreaks (WGDOs) following the contamination of drinking water remain a public health concern. Methods: The current study aims to assess the occurrence and identify gaps in the notification and investigation of WGDOs in Greece. Data for 2004–2023 were retrieved and summarized. Results: Thirty-five outbreaks with 6128 recorded cases were identified. The median time from the date of onset in the first cases to reporting was 7 days (range: 1–26 days). Authorities were informed by health care services in thirty (85.7%) outbreaks and by the media in five (14.3%). The investigation methods used varied. An analytical study was conducted in nine (25.7%) outbreaks and the testing of clinical samples in twenty-seven (77.1%). In three (11.1%) outbreaks, clinical samples were simultaneously tested for multiple bacteria, viruses, and parasites. Water samples were collected in nineteen (54.3%) outbreaks (in three after chlorination) with a mean time lag of 5 days (range: 1–20 days) from the first cases. A pathogen in clinical samples was identified in 20 (57.1%) outbreaks and, in 1 (6.25%), the same microorganism was isolated in both clinical and water samples. Conclusions: delays in reporting and the heterogeneity of investigations depict that the surveillance of WGDOs and response practices should be strengthened, and operational procedures should be standardised.

Foodborne diseases remain a major public health challenge. Among them, salmonellosis is one of the most frequently reported illnesses, associated with clusters and outbreaks and with considerable morbidity, potentially severe in vulnerable populations. Children are more susceptible due to biological, behavioral, and dietary factors. This study aimed to summarize and describe national surveillance data from the Mandatory Notification System, combined with serotyping data, on reported salmonellosis cases in Greece during the period 2005–2024, with a focus on children aged 0–14 years. During the study period, a total of 7340 salmonellosis cases were reported among children aged 0–14 years. Notification rates declined gradually until 2021, followed by an increase through 2024. The mean annual notification rate was 23.0 cases per 100,000 population, with the highest incidence observed among children aged 0–4 years. A clear seasonal pattern was observed, with a peak during summer months, alongside notable geographical variation. The most frequently identified serovars were Salmonella Enteritidis and Salmonella Typhimurium. These findings indicate that salmonellosis remains a public health concern in the pediatric population, highlighting the need for enhanced surveillance, improved food hygiene practices, and targeted prevention strategies to reduce disease burden.