‘Norwalk‐like viruses’ as a cause of foodborne disease outbreaks

  title={‘Norwalk‐like viruses’ as a cause of foodborne disease outbreaks},
  author={Umesh D. Parashar and Stephan S. Monroe},
  journal={Reviews in Medical Virology},
While outbreaks of foodborne disease remain an important public health concern, their aetiology is not identified in a majority of instances. In targeted studies, the application of newly developed molecular assays has demonstrated that a large proportion of these outbreaks may be caused by the ‘Norwalk‐like viruses’ (NLV), a genus of genetically related viruses belonging to the family Caliciviridae. NLV outbreaks associated with consumption of faecally contaminated oysters are frequently… 

Detection of multiple enteric virus strains within a foodborne outbreak of gastroenteritis: an indication of the source of contamination

Faecal contamination of the salad at source was the most probable explanation for the diversity of viruses detected and characterized in the British Royal Fleet Auxillary ship Argus outbreak of acute gastroenteritis.

Unravelling the epidemiology of norovirus outbreaks in hospitals

There is a demonstrable association with mortality in older people, and around 3,000 norovirus admissions to hospital each year, and a strategy of prompt closure is beneficial, particularly in larger wards and during winter time.

The Application of New Molecular Methods in the Investigation of a Waterborne Outbreak of Norovirus in Denmark, 2012

The combined microbiological, epidemiological and environmental investigations strongly indicates the outbreak was caused by norovirus contamination of the water supply system.

Statistical analysis of attack rate in norovirus foodborne outbreaks.

Foodborne enteric infections.

Methods for decreasing the disease burden are discussed, including education of health care professionals and the public, modification of food-handling behaviors, the use of food irradiation, and the application of probiotics to foods.

Norovirus pathogenesis: mechanisms of persistence and immune evasion in human populations

Observations suggest that the norovirus capsid evolves to evade the memory immune response while retaining its ability to bind any of several HBGAs, which allows escape from herd immunity.

Shellfish-Borne Viral Outbreaks: A Systematic Review

A systematic review of shellfish-borne viral outbreaks found the majority of reported outbreaks were located in East Asia, followed by Europe, America, Oceania, Australia and Africa, and differences in reporting of outbreaks were seen.

Emergence of a New Norovirus Genotype II.4 Variant Associated with Global Outbreaks of Gastroenteritis

A nested reverse transcriptase PCR (nRT-PCR) that was designed to amplify the highly conserved 3′ end of the polymerase region and the 5′End of the capsid gene of NoV genogroup II (GII) was validated with strains isolated from sporadic and outbreak cases between 1997 and 2004 in Australia.

Detection of Multiple Genotypes of Calicivirus Infection in Asymptomatic Swine in Taiwan

The study demonstrated the presence of multiple genotypes of both human and porcine NoVs infecting swine of various ages asymptomatically and revealed the importance of monitoring emerging strains in swine to mitigate the potential impact of recombinant NoVsinfecting the human population.



Molecular epidemiology of "Norwalk-like viruses" in outbreaks of gastroenteritis in the United States.

Improved molecular techniques to detect NLVs demonstrate that most outbreaks of nonbacterial gastroenteritis in the United States appear to be associated with these viruses and that sequence analysis is a robust tool to help link or differentiate these outbreaks.

Widespread outbreaks of clam- and oyster-associated gastroenteritis. Role of Norwalk virus.

The magnitude, persistence, and widespread nature of these outbreaks raise further questions about the safety of consuming raw shellfish.

An outbreak of Norwalk virus gastroenteritis associated with eating raw oysters. Implications for maintaining safe oyster beds.

This outbreak was caused by contamination of oysters in the oyster bed, probably by stool from one or more ill harvesters, and education of oysterHarvesters and enforcement of regulations governing waste disposal by oyster harvesting boats might prevent similar outbreaks.

Detection of norwalk-like virus in shellfish implicated in illness.

Using a newly developed and sensitive method, an NLV G2 strain was identified in 2 oyster samples implicated in a 1998 California outbreak involving 171 cases, and capsid primers demonstrated a greater specificity of PCR detection than did polymerase primers.

An outbreak of viral gastroenteritis associated with consumption of sandwiches: implications for the control of transmission by food handlers

Current recommendations to exclude food handlers from work for 48–72 h after recovery from illness may not always prevent transmission of Norwalk-like viruses because virus can be shed up to 10 days after illness or while exhibiting no symptoms.

Development of Methods To Detect “Norwalk-Like Viruses” (NLVs) and Hepatitis A Virus in Delicatessen Foods: Application to a Food-Borne NLV Outbreak

A method to detect NLVs and HAV recovered from food samples that was applied to food samples implicated in an NLV-associated outbreak at a university cafeteria and indicated that the sequence was identical to the sequence from virus detected in the stools of ill students.

Outbreak of viral gastroenteritis due to drinking water contaminated by Norwalk-like viruses.

Fifteen of 27 patient stool samples had NLV GGII, with an identical amplification product to that found in the water samples, indicating that the outbreak was caused by this virus.

A large nontypical outbreak of Norwalk virus. Gastroenteritis associated with exposing celery to nonpotable water and with Citrobacter freundii.

Serum samples implicated Norwalk virus as the most probable cause of this outbreak, and all outbreaks of gastroenteritis associated with nonpotable water should be investigated for evidence of viral cause.

Widespread environmental contamination with Norwalk-like viruses (NLV) detected in a prolonged hotel outbreak of gastroenteritis

The extent of environmental contamination that may occur during a large NLV outbreak is demonstrated for the first time in a large hotel in North-West England.

Outbreak of viral gastroenteritis due to a contaminated well. International consequences.

The investigation documented SRSVs in a vehicle epidemiologically linked to a gastroenteritis outbreak, demonstrating the power of molecular detection and identification and underscore the importance of fundamental public health practices such as restaurant inspection, assurance of a safe water supply, and disease surveillance.