Intra-Host Evolution of Norovirus GII.4 in a Chronic Infected Patient With Hematopoietic Stem Cell Transplantation

Human noroviruses (NVs) are the leading cause of acute gastroenteritis outbreaks worldwide. The majority of outbreaks are caused by genogroup II.4 (GII.4), with new variants emerging every 2 to 4 years. Immunocompromised patients are hypothesized to be important reservoirs where new NV variants emerge. Here, we examined intra-host NV variants and assessed immune-driven NV evolution in chronically infected immunocompromised hosts. Three NV GII.4-positive samples were collected from the same patient in different clinical phases following allogeneic hematopoietic stem cell transplantation, and had viral RNA concentrations of 2.46 × 106, 1.47 × 106, and 2.26 × 106 genome copies/mL. The non-synonymous (dN) and synonymous (dS) substitution ratio of the sequences in the partial P domain were>1, indicating strong positive selection in the patient. Both the number and the frequency of the single nucleotide variants increased over time in the patient. Also, the majority of capsid amino acid changes were located at blocking epitopes and histo-blood group antigen (HBGA)-binding sites, and 11 positive selection sites were found in the capsid region, of which 8 sites were presented in blocking epitopes or HBGA-binding sites. Homodimeric P-domain capsid models also suggested a structural change in the epitopes and HBGA-binding sites. The results suggested that novel variants of NV GII.4 with HBGA and antigenic site changes were produced in the immunocompromised patient....
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

Related Links:

a D, Lewis L Abstract The Camp Fire, California's deadliest wildfire, began November 8, 2018, and was extinguished November 25 (1). Approximately 1,100 evacuees from the fire sought emergency shelter. On November 10, acute gastroenteritis (AGE) was reported in two evacuation shelters; norovirus illness was suspected, because it is commonly detected in shelter-associated AGE outbreaks. Norovirus is highly contagious and resistant to several disinfectants. Butte County Public Health Department (BCPHD), assisted by the California Department of Public Health (CDPH), initiated active surveillance to identify cases, con...
Source: MMWR Morb Mortal Wkl... - Category: Epidemiology Authors: Tags: MMWR Morb Mortal Wkly Rep Source Type: research
ConclusionsEmployees in hospitals and community facilities seem quantitatively to be most vulnerable towards NoV epidemics. Therefore, high quality of prevention measures in these settings, respective compliance with prevention strategies should have the highest priority. The disease can be considered as an occupational disease, even regularly without long-term consequences. Following work safety rules, a vaccination for vulnerable groups should be recommended if the vaccine development turns out to be successful.
Source: International Archives of Occupational and Environmental Health - Category: Occupational Health Source Type: research
This investigation highlights the importance of acute gastroenteritis (AGE) surveillance at sea to identify contaminated foods at sea not yet implicated on land and to prevent transmission of AGE illness through U.S. ports.
Source: CDC Morbidity and Mortality Weekly Report - Category: American Health Tags: Foodborne Disease MMWR Morbidity & Mortality Weekly Report Norovirus Infection Source Type: news
This study investigated the incidence, clinical picture, treatment and resource use of norovirus gastroenteritis in l...
Source: BMC Geriatrics - Category: Geriatrics Authors: Tags: Research article Source Type: research
This study evaluated the impact of common chemical and physical properties of surface water on the stability of murine norovirus and examined the effect of food-safe chitosan microparticles on infectivity of two human norovirus surrogates. While chemical additives had a minor impact on virus survival, chitosan microparticles significantly reduced infectious titers of both murine norovirus and MS2 bacteriophage.
Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
A leading cause of acute gastroenteritis, norovirus can be transmitted by infected food handlers but norovirus outbreaks are not routinely investigated in Kenya. We estimated norovirus prevalence and associate...
Source: BMC Public Health - Category: Consumer Health News Authors: Tags: Research article Source Type: research
In this study, we analyzed the epidemiological and genetic features of NoV outbreaks from July 2014 to June 2018 in Huzhou, China. A total of 450 stool samples collected from 51 AGE outbreaks were tested for NoVs by real-time RT PCR. Partial polymerase and capsid sequences of NoV-positive samples were amplified and sequenced for phylogenetic analysis. NoVs were found to be responsible of 84.3% of AGE outbreaks in Huzhou over the past 5 years. Most NoV outbreaks were reported in the cool months (November-March) and occurred in primary schools and kindergartens. Changes in the diversity of genotypes and the distribution of p...
Source: Archives of Virology - Category: Virology Source Type: research
Authors: Hanisch FG, Aydogan C Abstract Norovirus infections belong to the most common causes of human gastroenteritis worldwide, and epidemic outbreaks are responsible for hundreds of thousands deaths annually. Strikingly, no antiviral treatment is available due to the difficulty in cultivating virions or in generating a vaccine, and due to the fact that their infection mechanisms are poorly understood. However, there is consent that noroviruses bind to histo-blood group antigens (HBGAs) on their way through the digestive tract. The HBGA profiles vary individually, making people more or less susceptible to differe...
Source: Nestlee Nutrition Institute Workshop Series - Category: Nutrition Tags: Nestle Nutr Inst Workshop Ser Source Type: research
ConclusionThe probability of virus detection is independent of the time between notification of the outbreak or symptom onset and sample collection. Our results suggest possible defects in cleaning protocols and disinfection in closed and semi-closed settings.
Source: Journal of Hospital Infection - Category: Infectious Diseases Source Type: research
Human noroviruses (HuNoVs) cause sporadic and epidemic outbreaks of gastroenteritis in all age groups worldwide. We previously reported that stem cell-derived human intestinal enteroid (HIE) cultures support replication of multiple HuNoV strains and that some strains (e.g., GII.3) replicate only in the presence of bile. Heat- and trypsin-treatment of bile...
Source: Proceedings of the National Academy of Sciences - Category: Science Authors: Tags: Biological Sciences Source Type: research
More News: Epidemiology | Gastroenteritis | Gastroenterology | International Medicine & Public Health | Microbiology | Norovirus | Outbreaks | Stem Cell Therapy | Stem Cells | Study | Transplants