CHRISTIAN BEURET, DOROTHE KOHLER, and THOMAS LÜTHI
Cantonal Food Laboratory of Solothurn, CH-4500 Solothurn, Switzerland
Abstract—
Norwalk-like viruses (NLVs) is a genus belonging to the Caliciviridae. NLVs are transmitted by the fecal-oral and the aerosol route and are the most common cause of outbreaks of nonbacterial gastroenteritis. NLVs are responsible for an estimated 67% of all illnesses caused by known foodborne pathogens and for 96% of nonbacterial gastroenteritis in the United States. Many outbreaks could be associated with the consumption of primarily or secondarily contaminated foods. To our knowledge, no epidemic arising from contaminated mineral water has been reported. We investigated the presence of NLV sequences in 63 mineral waters of 29 different brands that were imported into or bottled in Switzerland. NLV sequences were detected in 21 mineral waters by reverse transcription-seminested polymerase chain reaction. Specimens of two NLV genogroups (gg), gg I and gg II, were randomly present in the contaminated samples. The presence of NLV sequences could not be correlated either with bottle characteristics or with chemical properties like mineralization, pH, or the presence of carbonic acid. Nucleotide sequence analysis of 12 NLV-positive samples revealed several point mutations. All isolated NLV gg I strains have a similarity of 70 to 87% with the common Desert Shield virus (UO4469), and all isolated NLV gg II strains have a similarity of 89 to 93% with the Camberwell virus (U46500). Possible reasons for the presence of NLV sequences in mineral waters are discussed.
Beuret, C., Kohler, D., Baumgartner, A. & Luthi, T.M. Norwalk-like virus (NVL)-sequences in mineral waters: One year monitering of three brands.
Applied and Environmental Microbiology,
68, 1925 - 1931, (2002).
Mineral water contamination claim
Signs of virus from human faeces found in bottled water.
in Nature
ICTV (International Committee on Taxonomy of Viruses)dB /The Universal Virus Database
Index of Viruses /ICTV Index to Virus Classification and Nomenclature
Taxonomic lists and Catalogue of viruses
Norwalk-like Virus Infection
For information only
Source : The Government of the Hong Kong Special Administrative Region of the People's Republic of China
Causative agent
The infection is caused by a group of viruses known as Norwalk-like viruses, also known as small round structured viruses (SRSVs).
Clinical features
The disease is usually self-limiting with symptoms of nausea, vomiting, diarrhoea, abdominal pain, low-grade fever and malaise. The symptoms usually last 24 to 48 hours. The Norwalk-like viruses often cause food poisoning or outbreaks of gastroenteritis especially in elderly homes and schools. Isolated cases of the disease also occur among people of all age groups.
Mode of transmission
The infection can be transmitted via the following ways:
1. by food or water contaminated with the virus;
2. by contact with vomitus or faeces from infected persons;
3. by contact with contaminated objects; or
4. by aerosol spread.
Incubation period
The incubation period is usually 24 to 48 hours.
Management
The patient is given fluid replacement. Antibiotics are of no value in treatment.
Prevention
- Maintain high standard of personal, food and environmental hygiene.
- Wash hands thoroughly before handling food and eating and after going to toilets and handling vomitus or faecal matter.
- Wear gloves while disposing of vomitus and faeces, and wash hands afterwards.
- Clean and disinfect soiled linens, clothes and surfaces promptly and thoroughly with household bleach (5.85%) diluted in a ratio 1 in 49 units of water.
- Food handlers and caretakers developing vomiting or diarrhoea should refrain from work and seek medical advice.
- No vaccine is available for Norwalk-like virus infection.
