Background: The aim of this study was to conduct a clinical-epidemiological and microbiological investigation into an outbreak of waterborne disease caused by Campylobacter jejuni due to the consumption of drinking water.
Patients and method: A historical cohort study was carried out among 237 residents of Torres de Segre (Lleida, Spain) who were selected using a systematic sample. We conducted a telephone interview about water consumption, symptoms and the onset of disease. We investigated samples of drinking water and stools from 14 patients. The risk associated with each water source was assessed by applying relative risk (RR) analysis at 95% confidence (CI) intervals.
Results: The overall attack rate was 18.3% (43/237). The symptoms were: diarrhoea, 93.0% (18/43); abdominal pain, 80.9% (34/42); nausea; 56,1% (23/41); vomits, 42.9% (18/42), and fever, 11.9% (5/42). Only 5.8% of patients contact with his physician. The consumption of drinking water was statistically associated with the disease (RR = 3.0; 95% CI, 1.7-5.3), while the consumption of bottled water (RR = 0.6; 95% CI 0.3-1.0) and water from other villages (RR = 0.3; 95% CI, 0.1-1.1) were a protection factor. The day of outbreak notification we did not detect any residual chlorine in the drinking water: it was qualified as no potable and we isolated Campylobacter jejuni in 8 samples stools.
Conclusions: This research highlights the potential importance of waterborne outbreaks of gastroenteritis due to Campylobacter jejuni transmitted through untreated drinking water and suggests to need systematic controls over drinking water and the proper register of their results.