CDC Identifies Most Serious Norovirus Strains

MedicalResearch.com Interview with:
"Day 19: Norovirus (stomach flu) visits our home." by Loren Kerns is licensed under CC BY 2.0Rachel M. Burke, PhD, MPH
Epidemiologist, Viral Gastroenteritis Branch
Centers for Disease Control and Prevention
Atlanta, GA 30329

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Noroviruses are the leading cause of vomiting and diarrhea from acute gastroenteritis (inflammation of the stomach or intestines) among people of all ages in the United States. Each year in the United States, norovirus illness is responsible for an estimated 19 to 21 million cases of acute gastroenteritis, and contributes to 56,000 to 71,000 hospitalizations and 570 to 800 deaths, mostly among children and the elderly.

CDC linked information from two different surveillance systems to analyze 3,747 norovirus outbreaks reported by health departments from 2009 to 2016. Our study provides a comprehensive description of norovirus outbreaks from the epidemiology and laboratory perspectives, using the National Outbreak Reporting System (NORS) and CaliciNet, respectively. 

Norovirus outbreaks caused by GII.4 strains occurred more often in healthcare settings, affected older adults, and caused more severe illness, leading to hospitalization or death.

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Baylor Scientists Grow Noroviruses In Lab For First Time

MedicalResearch.com Interview with:

Mary K. Estes, Ph.D. Distinguished Service Professor Cullen Endowed Chair of Human and Molecular Virology Department of Molecular Virology and Microbiology Baylor College of Medicine Houston, TX 77030

Dr. Mary Estes

Mary K. Estes, Ph.D.
Distinguished Service Professor
Cullen Endowed Chair of Human and Molecular Virology
Department of Molecular Virology and Microbiology
Baylor College of Medicine
Houston, TX 77030

MedicalResearch.com: What is the background for this study?

Response: Noroviruses are the most common cause of acute gastroenteritis (vomiting and diarrhea) worldwide and the leading cause of food-borne gastroenteritis. They also can cause chronic (long-lasting) illness in immunocompromised patients. These viruses are highly contagious and spread rapidly among people. The first report of an outbreak caused by a norovirus was in an elementary school in Norwalk, Ohio in 1968. Since that time, it became known that the virus damaged cells in the small intestine of infected people but attempts by many research groups to grow human noroviruses in the laboratory in a variety of intestinal cancer cells lines failed. This inability to grow human norovirus has been considered the single greatest barrier to norovirus research because it limited studies to understand how the virus makes people sick and how to inactivate the virus to prevent infection.

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Norovirus Highly Prevalent In and Transmitted By Raw Oysters

MedicalResearch.com Interview with:
Yongjie Wang PhD

College of Food Science and Technology
Shanghai Ocean University
Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage & Preservation Ministry of Agriculture
Shanghai China

Medical Research: What is the background for this study?

Dr Wang: Norovirus (NoVs) are recognized as the most important food-borne viruses. They cause acute gastroenteritis in humans and infect people of all ages across the world. In our previous study, we found that approximate 90% of human norovirus sequences were discovered in the coastal regions in China, which likely result from the consumption of NoV-contaminated oysters. Oysters are well recognized as the main vectors of environmentally transmitted noroviruses, and disease outbreaks linked to oyster consumption have been commonly observed.

In order to gain a better understanding of how noroviruses are transmitted via oysters in the environment, we examined the genetic variants associated with oyster-related NoV outbreaks.

Medical Research: What are the main findings?

Dr Wang: A high degree of genetic diversity was observed for oyster-related noroviruses, and almost all the human norovirus genotypes were found in oyster-related norovirus sequences. These sequences were widely but unevenly distributed geographically, and most of them were detected in coastal regions. A higher frequency of GI strains was found in oyster-related than in human-related NoV sequences, while the yearly distributions of oyster-related sequences and human outbreak sequences were similar, indicating that oysters may act as a reservoir of noroviruses in the environment.

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Nanobody May Make Noroviruses Self Destruct

Dr. Grant Hansman CHS Research Group at CellNetworks Heidelberg University and DKFZ Deutsches Krebsforschungszentrum Heidelberg GermanyMedicalResearch.com Interview with:
Dr. Grant Hansman

CHS Research Group at CellNetworks Heidelberg University and DKFZ
Deutsches Krebsforschungszentrum
Heidelberg Germany

Medical Research: What is the background for this study? What are the main findings?

Dr. Hansman: Human noroviruses are the major cause of outbreaks of acute gastroenteritis. There are several promising vaccine candidates. Vaccines may offer some protection, but the fact that the virus changes every other year produces a challenge. Therefore, my research group investigates the possibility to produce universal antivirals targeting conserved regions on the virus capsid.

We found that a Nanobody was able to bind with a high affinity, and broad reactivity to diverse norovirus types. The Nanobody binding on the virus capsid caused the virus particles to disassemble. The disassembly of the particles may render the virus non-infectious and block viral infections.

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