Rabbit haemorrhagic disease, caused by rabbit hemorrhagic disease virus (RHDV), results in the death of millions of adult rabbits worldwide, with a mortality rate that exceeds 90%. The sole capsid ...protein, VP60, is divided into shell (S) and protruding (P) domains, and the more exposed P domain likely contains determinants for cell attachment and antigenic diversity. Nine mAbs against VP60 were screened and identified. To map antigenic epitopes, a set of partially overlapping and consecutive truncated proteins spanning VP60 were expressed. The minimal determinants of the linear B-cell epitopes of VP60 in the P domain, N super(326) PISQV super(331), D super(338) MSFV super(342) and K super(562) STLVFNL super(569), were recognized by one (5H3), four (1B8, 3D11, 4C2 and 4G2) and four mAbs (1D4, 3F7, 5G2 and 6B2), respectively. Sequence alignment showed epitope D super(338) MSFV super(342) was conserved among all RHDV isolates. Epitopes N super(326) PISQV super(331) and K super(562) STLVFNL super(569) were highly conserved among RHDV G1-G6 and variable in RHDV2 strains. Previous studies demonstrated that native viral particles and virus-like particles (VLPs) of RHDV specifically bound to synthetic blood group H type 2 oligosaccharides. We established an oligosaccharide-based assay to analyse the binding of VP60 and epitopes to histo-blood group antigens (HBGAs). Results showed VP60 and its epitopes (aa 326-331 and 338-342) in the P2 subdomain could significantly bind to blood group H type 2. Furthermore, mAbs 1B8 and 5H3 could block RHDV VLP binding to synthetic H type 2. Collectively, these two epitopes might play a key role in the antigenic structure of VP60 and interaction of RHDV and HBGA.
The family
includes viruses with single-stranded, positive-sense RNA genomes of 7.4-8.3 kb. The most clinically important representatives are human noroviruses, which are a leading cause of acute ...gastroenteritis in humans. Virions are non-enveloped with icosahedral symmetry. Members of seven genera infect mammals (
,
,
,
,
,
and
), members of two genera infect birds (
and
), and members of two genera infect fish (
and
). This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family
, which is available at ictv.global/report/caliciviridae.
Norovirus Robilotti, Elizabeth; Deresinski, Stan; Pinsky, Benjamin A
Clinical microbiology reviews
28, Issue:
1
Journal Article
Peer reviewed
Open access
Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the ...transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management.
Globally, norovirus is associated with approximately one-fifth of all diarrhea cases, with similar prevalence in both children and adults, and is estimated to cause over 200,000 deaths annually in ...developing countries. Norovirus is an important pathogen in a number of high-priority domains: it is the most common cause of diarrheal episodes globally, the principal cause of foodborne disease outbreaks in the United States, a key health care-acquired infection, a common cause of travel-associated diarrhea, and a bane for deployed military troops. Partly as a result of this ubiquity and burden across a range of different populations, identifying target groups and strategies for intervention has been challenging. And, on top of the breadth of this public health problem, there remain important gaps in scientific knowledge regarding norovirus, especially with respect to disease in low-income settings. Many pathogens can cause acute gastroenteritis. Historically, rotavirus was the most common cause of severe disease in young children globally. Now, vaccines are available for rotavirus and are universally recommended by the World Health Organization. In countries with effective rotavirus vaccination programs, disease due to that pathogen has decreased markedly, but norovirus persists and is now the most common cause of pediatric gastroenteritis requiring medical attention. However, the data supporting the precise role of norovirus in low- and middle-income settings are sparse. With vaccines in the pipeline, addressing these and other important knowledge gaps is increasingly pressing. We assembled an expert group to assess the evidence for the global burden of norovirus and to consider the prospects for norovirus vaccine development. The group assessed the evidence in the areas of burden of disease, epidemiology, diagnostics, disease attribution, acquired immunity, and innate susceptibility, and the group considered how to bring norovirus vaccines from their current state of development to a viable product that will benefit global health.
Norovirus infections are a major cause of gastroenteritis, and outbreaks occur frequently. Several factors are currently increasing the challenge posed by norovirus infections to global health, ...notably the increasing number of infections in immunocompromised individuals, who are more susceptible to disease, and the globalization of the food industry, which enables large norovirus outbreaks to occur on an international scale. Furthermore, the rapid rate of the genetic and antigenic evolution of circulating noroviruses complicates the development of vaccines and therapies that are required to counter these challenges. In this Review, we describe recent advances in the study of the transmission, pathogenesis and evolution of human noroviruses, and consider the ongoing risk of norovirus outbreaks, together with the future prospects for therapeutics, in a rapidly changing world.
Viral gastroenteritis Bányai, Krisztián; Estes, Mary K; Martella, Vito ...
The Lancet,
07/2018, Volume:
392, Issue:
10142
Journal Article
Peer reviewed
Open access
Enteric viruses, particularly rotaviruses and noroviruses, are a leading cause of gastroenteritis worldwide. Rotaviruses primarily affect young children, accounting for almost 40% of hospital ...admissions for diarrhoea and 200 000 deaths worldwide, with the majority of deaths occurring in developing countries. Two vaccines against rotavirus were licensed in 2006 and have been implemented in 95 countries as of April, 2018. Data from eight high-income and middle-income countries showed a 49–89% decline in rotavirus-associated hospital admissions and a 17–55% decline in all-cause gastroenteritis-associated hospital admissions among children younger than 5 years, within 2 years of vaccine introduction. Noroviruses affect people of all ages, and are a leading cause of foodborne disease and outbreaks of gastroenteritis worldwide. Prevention of norovirus infection relies on frequent hand hygiene, limiting contact with people who are infected with the virus, and disinfection of contaminated environmental surfaces. Norovirus vaccine candidates are in clinical trials; whether vaccines will provide durable protection against the range of genetically and antigenically diverse norovirus strains remains unknown. Treatment of viral gastroenteritis is based primarily on replacement of fluid and electrolytes.
The capacity of human norovirus (NoV), which causes >90% of global epidemic nonbacterial gastroenteritis, to infect a subset of people persistently may contribute to its spread. How such enteric ...viruses establish persistent infections is not well understood. We found that antibiotics prevented persistent murine norovirus (MNoV) infection, an effect that was reversed by replenishment of the bacterial microbiota. Antibiotics did not prevent tissue infection or affect systemic viral replication but acted specifically in the intestine. The receptor for the antiviral cytokine interferon-λ, Ifnlr1, as well as the transcription factors Stat1 and Irf3, were required for antibiotics to prevent viral persistence. Thus, the bacterial microbiome fosters enteric viral persistence in a manner counteracted by specific components of the innate immune system.
Norovirus Gastroenteritis Glass, Roger I; Parashar, Umesh D; Estes, Mary K
The New England journal of medicine,
10/2009, Volume:
361, Issue:
18
Journal Article
Peer reviewed
Open access
Noroviruses are now recognized as the leading cause of epidemics of gastroenteritis and an important cause of sporadic gastroenteritis among both children and adults. In the United States, more than ...90% of the outbreaks of gastroenteritis for which the cause could not previously be identified can now be attributed to this virus. Understanding the nature of immunity to the norovirus is a key determinant for future improvements in the control and prevention of this viral infection.
Noroviruses are now recognized as the leading cause of epidemics of gastroenteritis. Understanding the nature of immunity to the norovirus is a key determinant for future improvements in the control and prevention of this viral infection.
The Norwalk agent was the first virus that was identified as causing gastroenteritis in humans, but recognition of its importance as a pathogen has been limited because of the lack of available, sensitive, and routine diagnostic methods. Recent advances in understanding the molecular biology of the noroviruses, coupled with applications of novel diagnostic techniques, have radically altered our appreciation of their impact. Noroviruses are now recognized as being the leading cause of epidemics of gastroenteritis and an important cause of sporadic gastroenteritis in both children and adults. Although norovirus gastroenteritis is generally mild and of short duration, new evidence suggests . . .
Worldwide, noroviruses are a leading cause of gastroenteritis. They can be transmitted from person to person directly or indirectly through contaminated food, water, or environments. To estimate the ...proportion of foodborne infections caused by noroviruses on a global scale, we used norovirus transmission and genotyping information from multiple international outbreak surveillance systems (Noronet, CaliciNet, EpiSurv) and from a systematic review of peer-reviewed literature. The proportion of outbreaks caused by food was determined by genotype and/or genogroup. Analysis resulted in the following final global profiles: foodborne transmission is attributed to 10% (range 9%%-11%) of all genotype GII.4 outbreaks, 27% (25%-30%) of outbreaks caused by all other single genotypes, and 37% (24%%-52%) of outbreaks caused by mixtures of GII.4 and other noroviruses. When these profiles are applied to global outbreak surveillance data, results indicate that ≈14% of all norovirus outbreaks are attributed to food.
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