Experimental miniature piglet model for the infection of human norovirus GII

Human norovirus is a leading cause of non-bacterial acute gastroenteritis, which affects all age groups and are found globally. Infections are highly contagious and often occur as outbreaks. Periodic emergence of new strains are not uncommon and novel variants are named after the place of first reported nucleotide sequence. Here, we identified human norovirus GII.4 Hong Kong variant in stool samples from Thai patients presented with acute gastroenteritis. Comparison of amino acid residues deduced from the viral nucleotide sequence with those of historical and contemporary norovirus GII.4 strains revealed notable differences, which mapped to the defined antigenic sites of the viral major capsid protein. Time-scaled phylogenetic analysis suggests that GII.4 Hong Kong shared common ancestry with GII.4 Osaka first reported in 2007, and more importantly, did not evolve from the now-prevalent GII.4 Sydney lineage. As circulation of norovirus minor variants can lead to eventual widespread transmission in susceptible population, this study underscores the potential emergence of the GII.4 Hong Kong variant, which warrants vigilant molecular epidemiological surveillance.

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Molecular Evolution of Human Norovirus GII.2 Clusters

Frontiers in Microbiology ◽

10.3389/fmicb.2021.655567 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xingguang Li ◽

Haizhou Liu ◽

Brittany Rife Magalis ◽

Sergei L. Kosakovsky Pond ◽

Erik M. Volz

Keyword(s):

Population Dynamics ◽

Selection Pressure ◽

Evolutionary Rate ◽

Winter Season ◽

Viral Population ◽

Evolutionary Adaptation ◽

Effective Population ◽

Human Norovirus ◽

The Past ◽

Norovirus Gii

BackgroundThe human norovirus GII.2 outbreak during the 2016–2017 winter season was of unprecedented scale and geographic distribution.MethodsWe analyzed 519 complete VP1 gene sequences of the human norovirus GII.2 genotype sampled during the 2016–2017 winter season, as well as prior (dating back to 1976) from 7 countries. Phylodynamic analyses of these sequences were performed using maximum likelihood and Bayesian statistical frameworks in order to estimate viral evolutionary and population dynamics associated with the outbreak.ResultsOur results revealed an increase in the genetic diversity of human norovirus GII.2 during the recent Asian outbreak and diversification was characterized by at least eight distinct clusters. Bayesian estimation of viral population dynamics revealed a highly fluctuating effective population size, increasing in frequency during the past 15 years.ConclusionDespite an increasing viral diversity, we found no evidence of an elevated evolutionary rate or significant selection pressure in human norovirus GII.2, indicating viral evolutionary adaptation was not responsible for the volatility of or spread of the virus during this time.

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Evaluation of a New Environmental Sampling Protocol for Detection of Human Norovirus on Inanimate Surfaces

Applied and Environmental Microbiology ◽

10.1128/aem.01657-15 ◽

2015 ◽

Vol 81 (17) ◽

pp. 5987-5992 ◽

Cited By ~ 22

Author(s):

Geun Woo Park ◽

David Lee ◽

Aimee Treffiletti ◽

Mario Hrsak ◽

Jill Shugart ◽

...

Keyword(s):

Stainless Steel ◽

Clinical Samples ◽

Environmental Sampling ◽

Viral Gastroenteritis ◽

Human Norovirus ◽

Drying Time ◽

Viral Loads ◽

Toilet Seat ◽

Outbreak Investigations ◽

Norovirus Gii

ABSTRACTInanimate surfaces are regarded as key vehicles for the spread of human norovirus during outbreaks. ISO method 15216 involves the use of cotton swabs for environmental sampling from food surfaces and fomites for the detection of norovirus genogroup I (GI) and GII. We evaluated the effects of the virus drying time (1, 8, 24, or 48 h), swab material (cotton, polyester, rayon, macrofoam, or an antistatic wipe), surface (stainless steel or a toilet seat), and area of the swabbed surface (25.8 cm2to 645.0 cm2) on the recovery of human norovirus. Macrofoam swabs produced the highest rate of recovery of norovirus from surfaces as large as 645 cm2. The rates of recovery ranged from 2.2 to 36.0% for virus seeded on stainless-steel coupons (645.0 cm2) to 1.2 to 33.6% for toilet seat surfaces (700 cm2), with detection limits of 3.5 log10and 4.0 log10RNA copies. We used macrofoam swabs to collect environmental samples from several case cabins and common areas of a cruise ship where passengers had reported viral gastroenteritis symptoms. Seventeen (18.5%) of 92 samples tested positive for norovirus GII, and 4 samples could be sequenced and had identical GII.1 sequences. The viral loads of the swab samples from the cabins of the sick passengers ranged from 80 to 31,217 RNA copies, compared with 16 to 113 RNA copies for swab samples from public spaces. In conclusion, our swab protocol for norovirus may be a useful tool for outbreak investigations when no clinical samples are available to confirm the etiology.

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