Massive outbreak of viral gastroenteritis associated with consumption of municipal drinking water in a European capital city

Abstract

SUMMARYOn 24 August 2008, an outbreak alert regarding cases of acute gastroenteritis in Podgorica triggered investigations to guide control measures. From 23 August to 7 September, 1699 cases were reported in Podgorica (population 136 000) and we estimated the total size of the outbreak to be 10 000-15 000 corresponding to an attack rate of y10 %. We conducted an age-and neighbourhood-matched case-control study, microbiologically analysed faecal and municipal water samples and assessed the water distribution system. All cases (83/83) and 90 % (89/90) of controls drank unboiled chlorinated municipal water [matched odds ratio (mOR) 11 . 2, 95 % confidence interval (CI), 1 . 6-O]. Consumption of bottled water was inversely associated with illness (mOR 0 . 3, 95 % CI 0 . 1-0 . 8). Analyses of faecal samples identified six norovirus genotypes (21/38 samples) and occasionally other viruses. Multiple defects in the water distribution system were noted. These results suggest that the outbreak was caused by faecally contaminated municipal water. It is unusual to have such a large outbreak in a European city especially when the municipal water supply is chlorinated. Therefore, it is important to establish effective multiple-barrier water-treatment systems whenever possible, but even with an established chlorinated supply, sustained vigilance is central to public health.

Efficacy and Mechanisms of Murine Norovirus Inhibition by Pulsed-Light Technology

“…Our results showed that water hardness up to 400 mg liter Ϫ1 CaCO 3 equivalent (686 S cm Ϫ1 ), mineral water, or with conductivities up to 14.3 mS cm Ϫ1 did not interfere with viral inactivation with pulsed light, suggesting a high potential of the technology for treating municipal drinking water, which has been a vehicle for the spread of norovirus infection (37,38). In contrast, turbidity did have a negative impact on treatment efficacy.…”

Critical Review on the Public Health Impact of Norovirus Contamination in Shellfish and the Environment: A UK Perspective

“…Vulnerable people such as the elderly, immunocompromised or the very young can require additional care (Harris et al 2008). Outbreaks of NoV frequently occur in high-density settings such as care homes, hospitals, and cruise ships; however, outbreaks in restaurants, hotels, holiday camps and through consumption of contaminated drinking water are also commonplace (Heijne et al 2009; Werber et al 2009). …”

Molecular Characterization of Noroviruses and Rotaviruses Involved in a Large Outbreak of Gastroenteritis in Northern Italy

“…No virus was detected in water from a home swimming pool, indicating that the viral concentration was below detection limits, at least during sampling. However, the association of norovirus with waterborne outbreaks (4,5,12,17,32) is undisputed, and acceptable hyperchlorination limits may be insufficient in cases of abnormal viral contamination (16,27). …”