Lab culture of human norovirus called an important first

first_imgFeb 13, 2007 (CIDRAP News) – A team of researchers has achieved what has been until now a frustratingly elusive goal: a tissue-culture model that allows natural growth in the lab of norovirus, one of the most common and least understood causes of gastrointestinal illness worldwide.Though it causes up to 23 million cases of illness each year, according to the Centers for Disease Control and Prevention (CDC), surprisingly little is known about how the virus attaches to and replicates within cells. The new work by Timothy Straub of the Pacific Northwest National Laboratory and collaborators from Tulane University, the University of Arizona, and Arizona State University should change that: They produced a three-dimensional culture of multiple cell types that mimics the epithelium of the human small intestine, and induced norovirus samples isolated from patients to grow and replicate in it.”This is an important result,” said Craig Hedberg, PhD, associate professor of environmental health sciences at the University of Minnesota School of Public Health. “Up until this point, we have never had a direct measure that would allow us to know how effective any of our environmental prevention measures are against norovirus. There have been a lot of studies looking at things that might be able to kill norovirus and render foods and environmental surfaces safe from contamination, but they have always used surrogates.”Norovirus has been a difficult organism to study because, like other viruses but unlike bacteria, it will not reproduce in a simple growth medium. Instead, it requires a tissue culture resembling cells in the organisms it infects.That lack of a lab model for studying the virus has kept testing protocols, effective sanitizing and control measures, and even newer diagnostic tests out of reach. Those are important because norovirus causes such a high disease burden: It is thought to be responsible for at least half of all foodborne outbreaks of gastroenteritis every year, according to the CDC.”Nobody knows what the incidence of this disease is in the population because it is not easy to diagnose—it is just one of the range of ‘stomach flus’ that people get,” said David Ozonoff, PhD, emeritus chair of the department of environmental health at Boston University School of Public Health. “But it causes very substantial economic loss, because so many people stay home from work because they are sick or their kids are.”To create the model, Straub and collaborators grew human intestinal epithelial cells on collagen-coated microbeads that were tumbled in a rotating reactor vessel. They used the resulting tissues for five passages of two genotypes of norovirus that were originally isolated from patients during outbreaks on a cruise ship and in a nursing home, and proved the presence of norovirus by multiple assays following each passage.The work, which will be published in the March edition of Emerging Infectious Diseases and was posted online ahead of print, represents the first lab model of human norovirus infection; previous models used mouse noroviruses or a related feline virus. Scientists not involved in the research said it could point the way to a better understanding of an under-appreciated pathogen.The authors write that developing a method for culturing human norovirus in the lab was a necessary first step in the effort to understand the virus’s pathogenesis. In future research with the model, they hope to identify protective immune responses and learn more about how the virus replicates, with the aim of devising better prevention measures.Norovirus spreads through the fecal-oral route, via both food and water, but there are also indications that it can spread via environmental contamination and direct person-to-person transmission, according to the CDC.It is fiercely contagious: Ingesting as few as 10 virus particles can cause infection, and infected persons can shed virus for up to two weeks after symptoms end, the CDC says. The illness is miserable, with nausea, diarrhea and vomiting multiple times per day. Symptoms usually last from 24 to 60 hours.”Beyond the nuisance value to the individual, it is such a widespread illness and so persistent in institutional settings where you’re dealing with immune-compromised populations that it becomes an important public health problem,” Hedberg said.The CDC does not conduct routine surveillance for norovirus, so there is no way to confirm how commonly the bug occurs. So far this year, however, large outbreaks have been reported at the Scripps Research Institute in California, at Radford University in Virginia, among customers of a south Florida restaurant, in hospitals in Saskatchewan, Massachusetts, and North Carolina, and among hundreds of passengers on the ocean liner Queen Elizabeth 2.The Hilton Hotel near Dulles International Airport outside Washington, D.C. was hit so hard in mid-January, with 120 guests and staff sick, that it was forced to close for a floor-to-ceiling sanitizing. Some norovirus outbreaks, such as on cruise ships, have recurred despite repeated rounds of aggressive cleaning.Straub TM, zu Bentrup KH, Coghlan PO, et al. In vitro cell culture infectivity assay for human noroviruses. Emerg Infect Dis 2007 Mar; 13(3) (early online publication) [Full text]See also:CDC information on norovirushttp://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-factsheet.htmlast_img read more

LaLiga denounces the RFEF for the audio and will not go to more meetings

first_img• The Action Protocol has been studied, reviewed and approved for the return to training of the LaLiga teams. This protocol will be informed and explained to all the Clubs and SADs affiliated with LaLiga in the next Division Boards that will be held next Thursday, and will be made available to the Higher Sports Council (CSD) and the competent health authorities.• It has been reiterated within the Executive Committee that before any decision on the return to the competition will be to what the health authorities have.LaLiga and AFE meet tomorrow after their fightsLaLiga and the Association of Spanish Soccer Players will meet again. It will be online tomorrow afternoon to continue addressing the solutions that clubs and players demand to alleviate the effects of the coronavirus crisis. Thebes, the president of the employers’ association, and David Aganzo, the maximum manager of the union, will face each other again after a little respite during this Holy Week and after the ‘Audios Case’ whereby its two institutions have denounced the Federation on the understanding that they recorded the last meeting of the Monitoring Commission without permission.The new meeting between LaLiga and AFE, to which Luis Gil and Diego Rivas will also join, It also comes after the disagreements between Thebes and Aganzo, which ended up breaking the economic negotiations on the ERTE (something that about 20% of the 42 professional entities have done so far) and the salary reductions to be applied in the event of losses (Thebes asked for 47% responsibility for the players and they 20% at the most and recovering 10% in the future). For this reason, at this Tuesday’s meeting It will only and exclusively discuss sanitary measures to apply, the return to training and the various calendars that LaLiga manages. in coordination with UEFA in order to restart the competition. LaLiga took a step forward this Monday after the meeting of the Executive Committee, by videoconference, in which Javier Tebas has agreed on his position on the latest events related to the return to training, the ERTE, the negotiation of the player’s salary reduction as well as the controversial meetings with the Federation and AFE. Six First Division clubs (Madrid, Seville, Betis, Valencia, Villarreal and Levante) and another six Second Clubs (Deportivo, Cádiz, Las Palmas, Alcorcón, Almería and Lugo) were summoned to this meeting.At the end of the summit, the employers has made an official statement in which it is recorded that He has denounced the RFEF for allegedly recording him without consent at a meeting, he has assured that he will not go to more meetings with Rubiales for COVID-19 and, in addition, he has announced that he already has a new health protocol ready for the return to training.Official statement from the LaLiga Delegate Commission“The LaLiga Executive Committee held today, has adopted the following agreements:• He remembers not attend the next meetings called by the RFEF of the “COVID-19 Monitoring Commission, after analyzing what happened regarding the biased and interested leak of the audios of said commission to the media.• Contact will be maintained with the RFEF, through the “Monitoring Commission” that is contemplated in the current Coordination Agreement signed last July 3, 2019 between LaLiga and the RFEF.• In view of such facts from LaLiga will adopt the appropriate legal measures, among which are both the filing of a complaint before the Higher Sports Council against the President and the Secretary of the RFEF for the commission of infractions of abuse of authority and carrying out acts that threaten the dignity and decorum of sports, as the complaint by the affected people of a claim before the Spanish Agency for Data Protection for violation of various provisions of the General Data Protection Regulation.last_img read more