Current Surge In Norovirus Outbreaks In Various Geolocations Across The World Possibly Driven By New Norovirus Variant Called San Francisco GII.4
Nikhil Prasad Fact checked by:Thailand Medical News Team Apr 01, 2024 8 months, 3 weeks, 4 hours, 39 minutes ago
Medical News: Norovirus outbreaks are currently on the rise globally, with a notable surge being attributed to a new variant of norovirus called San Francisco GII.4 This variant, identified with an amino acid insertion at the beginning of epitope A in viral protein 1, has been detected in multiple countries including the United States, Gabon, South Africa, and the United Kingdom around late 2017 to 2022. The early identification of such variants holds significant importance in evaluating their pandemic potential and informing strategies for vaccine development.
Surge In Norovirus Outbreaks In Various Geolocations Across The
World Possibly Driven By New Norovirus Variant Called GII.4
Recent
Medical News reports and coverages have shown a rise of norovirus outbreaks in various geolocations.
https://wlos.com/news/local/norovirus-outbreak-alert-appalachian-trail-nc-tennessee-georgia-hikers-urged-take-precautions-gastrointestinal-illness-highly-infectious-national-park-service
https://www.yahoo.com/news/ready-norovirus-2024-stomach-bug-030441791.html
https://globalnews.ca/news/10389335/norovirus-cases-canada-us/
https://www.dcnewsnow.com/whats-going-around/norovirus-spreading-in-the-dmv/
https://health.wusf.usf.edu/health-news-florida/2024-03-18/four-florida-distributors-are-affected-by-an-oyster-recall-due-to-norovirus-fears
https://www.star-telegram.com/news/local/article286732495.html
https://www.bristolpost.co.uk/news/health/nhs-advice-norovirus-symptoms-treatment-9165818
https://www.youtube.com/watch?v=Hw8cTNBQQTA
https://www.columbian.com/news/2024/mar/13/clark-county-health-officials-say-that-stomach-flu-could-be-norovirus/
Researchers believe that a newly emerged Norovirus variant called San Francsico GII.4 is behind all these new outbreaks.
Introduction to No
rovirus and Its Genetic Diversity
Norovirus stands as the leading cause of acute gastroenteritis (AGE) worldwide, characterized by its ≈7.7 kb positive-sense single-stranded RNA genome organized into three open reading frames (ORFs). Among the various genogroups, Genogroup II genotype 4 (GII.4) viruses are responsible for the majority of illnesses globally. Over the years, different GII.4 variants have emerged, each with distinct characteristics affecting their interaction with host cells.
The Emergence of GII.4 Variants
Historically, GII.4 variants such as US95-96, Farmington Hills_2002, Asia_2003, and others have been associated with changes in epitopes on the surface of VP1, influencing their binding with histo-blood group antigens (HBGA) on host cells. Since 2012, the GII.4 Sydney variant has been prevalent globally, showcasing the dynamic nature of norovirus evolution.
Investigating the New GII.4 San Francisco Variant
A recent study delved into the genomic characteristics of the novel GII.4 San Francisco variant, which has been identified in outbreaks across multiple continents. The study involved sequencing complete genomes or VP1 of GII.4 viruses from various locations and comparing them with existing GII.4 sequences. The investigation utilized advanced molecular techniques to analyze the genetic makeup and structural changes of the GII.4 San Francisco variant.
https://wwwnc.cdc.gov/eid/article/30/1/23-1003_article
Methodology and Analysis
Researchers employed techniques such as reverse transcription PCR (RT-PCR) and phylogenetic analysis to study the genetic similarities and differences among GII.4 variants. By aligning amino acid sequences and conducting structural modeling, they were able to identify key mutations and structural changes in the GII.4 San Francisco variant, particularly in epitopes A and D of VP1.
Characteristics of GII.4 San Francisco Variant
The GII.4 San Francisco variant exhibited unique features, including an alanine insertion at the beginning of epitope A and mutations in various regions of VP1. Structural modeling revealed significant changes in the viral protein, potentially affecting its interaction with host cells and immune responses. Despite these alterations, the variant maintained ligand binding capabilities, indicating its potential for increased spread and impact.
Implications for Vaccine Development and Public Health
The emergence of the GII.4 San Francisco variant underscores the ongoing evolution of norovirus and the challenges it presents in terms of vaccine development and public health strategies. Understanding the antigenic and structural changes in this variant is crucial for designing effective vaccines and implementing targeted control measures to curb norovirus outbreaks.
Conclusion
In conclusion, the detection of the GII.4 San Francisco variant highlights the dynamic nature of norovirus evolution and the need for continuous surveillance and research efforts. Early identification and characterization of novel variants are essential in assessing their pandemic potential and implementing timely interventions to mitigate their impact on public health. Collaborative global efforts in monitoring and studying norovirus variants are paramount for effective disease control and management.
Thailand
Medical News would however like to add that besides the GII.4 San Francisco variant, there are strong suspicions that a new sub-lineage of the G11.4 variant and also other genotypes of the norovirus have possibly emerged in Europe and also the United States sometime in 2023 and investigations and studies are currently under way.
For the latest on Norovirus, keep on logging to Thailand
Medical News.
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