 Hvad er meningen? Orakeludsagn, morsomme indslag, videnskabelige observationer og er håndvask det eneste saliggørende, eller er det blot Søren Brostrøms forsøg på at vaske hænder. Pludselig er en meter nok – Hvor lang er en meter i øvrigt i praksis …sådan cirka? Anbefalinger fra Sundhedsstyrelsen 10. maj 2020: Hold mindst 1 meters afstand mellem personer i det offentlige rum Hold dog mindst 2 meters afstand i situationer, hvor der kan være øget risikofor dråbesmitte, eller hvor et forsigtighedsprincip tilsiger et særligt hensyn, som f.x.: Hvis der er tvivl om luftvejssymptomer hos enselv eller den anden, f.eks. hvis man på vej hjem fra arbejde føler sig sløj, hvis man synes den anden ser forkølet ud osv. Ved besøg på plejecentre, sygehuse, hos personer med særlig risiko mv. jfr. Sundhedsstyrelsens anbefalinger af 4. maj 2020 Vedaktiviteter med kraftig udånding, hvor dråber dannes og slynges længere væk fra personen end ved normal tale, f.eks. sang, råb, foredrag, skuespil, fysisk anstrengelse m.v. Ved aktiviteter i bevægelse f.eks. rutsjebane. Ved ophold i lukkede rum med begrænset bevægelsesrum, dårlig udluftning m.v. f.eks. kælderlokaler, skakter m.v. Konkret vil det f.eks. betyde, at der bør sikres 2 meters afstand mellem underviser/fore-dragsholder og forreste række i klasselokale/auditorium, mens det er tilstrækkeligt med 1 meters afstand mellem elever/tilhørere. Ved f.eks. gudstjenester bør der sikres 2 meters afstand mellem kirkegængere hvis der synges, mens 1 meter ertilstrækkeligt hvis sang undlades. Afstanden vurderes ’fra næsetip til næsetip’, således at der f.eks. ved siddende indretning skal måles fra midtenaf stolesæder, ikke fra armlæn til armlæn.I mange situationer kan det være lettere at sikre afstandskrav ved siddende indretning. Ved regulering af stående og gående personer kan afstand markeres på væg, bord, gulv eller lignende, f.eks. ved serveringsdisk, indgangspartier, steder med kødannelse m.v. I situationer hvor det er vanskeligt eller umuligt at overholde afstandsanbefalinger eller regulere afstand til andre, er det vigtigt at reducere antallet og varigheden af kontakter, særligt ift. ansigt-til-ansigt kontakter. (Sundhedsstyrelsen, d. 10. maj 2020). Se fremad! Face forward! Gesicht nach vorn!… Sundhedsstyrelsen er den 10. maj kommet med nye sundhedsfaglige anbefalinger om forebyggelse af smittespredning. Anbefalingerne betyder, at afstandskravet sænkes, og der er større fokus på god hygiejne. Sundhedsstyrelsen anbefaler, at man holder fysisk afstand på 1 meter og især undgår at være tæt, hvis man er ansigt-til-ansigt. Der kan være en række situationer, hvor det – også over længere tidsrum – ikke er muligt at sikre mindst 1 meters afstand mellem personer. Det kan f.eks. være siddende transport over længere afstande i bus, tog eller fly, hvor sædeindretningen ikke muliggør at 1 meters afstand overholdes. I sådanne situationer anbefaler Sundhedsstyrelsen, at passagererne sidder med ansigtet i samme retning, og uden ansigt-til-ansigt kontakt under 1 meter. (min fremhævelse) Sundhedsstyrelsen anbefaler desuden, at man medbringer hånddesinfektion eller vådservietter, når man færdes blandt mange mennesker og på steder med mange kontaktpunkter, fx i den kollektive transport. (Flere rejsende i den kollektive transport, Transport- og boligministeriet) https://www.trm.dk/nyheder/2020/flere-rejsende-i-den-kollektive-transport/  See You in the next aerosol … 2 meters enough for social distancing? MIT researcher says droplets carrying coronavirus can travel up to 8 meters (Jordan Culver, USA Today)  Multiphase Turbulent Gas Cloud From a Human Sneeze. Credit: JAMA (2020). DOI: 10.1001/jama.2020.4756 Moist Breath Zone – The funny song version from New Zealand  https://www.youtube.com/watch?v=yZvtoVrykb8 https://parents.education.govt.nz/essential-information/news-stories/covid-19-preparing-for-alert-level-2/ In crowded places distance rules don’t work – but face masks might EU on Collective transport: “Passengers should wear face masks in transport hubs and vehicles used for collective transport, especially where physical distancing measures cannot be fully observed at all times.” COVID-19: Guidelines on the progressive restoration of transport services and connectivity (EU Commission 13.5.2020). EU on Tourism industry: “The use of medical or improvised non-medical face masks by staff and guests in the tourism facilities can be considered as a means of source control (i.e. to prevent the spreading of droplets from infected people with or without symptoms). The use of face masks should be considered only as a complementary measure, not replacing core preventive measures. Appropriate use of face masks is important. The face mask should completely cover the face from the bridge of the nose down to the chin. Information about the proper use of face masks should be available, highlighting the importance of cleaning hands with soap and water or alcohol-based hand rub solutions before wearing and after removing the face mask.” COVID-19: EU Guidance for the progressive resumption of tourism services and for health protocols in hospitality establishments. (EU Commission 13.5.2020) Medical and non-medical face masks are acceptable in community settings, taking into account issues of availability and ensuring that medical face masks are prioritised for use in healthcare settings. The use of filtering face piece (FFP) respirators is not recommended in community settings as these must be prioritised for use in healthcare settings. Not only when “the fat lady” sings Communication in i ”naturemedicine” fra 3. april 2020 indicates that face masks might be important:  https://www.nature.com/articles/s41591-020-0843-2
Kommentar til håndvask: Totalt overdrevet Anmerkungen zum Händewaschen „total übertrieben“ Zu Ansteckungen mit Sars-CoV-2 sagte Drosten, es erscheine ihm „total übertrieben“, wie oft auf das Händewaschen und Desinfizieren von Oberflächen hingewiesen werde: Nach seiner Einschätzung machen Schmierinfektionen, also Ansteckungen etwa über kontaminierte Gegenstände, nur einen kleinen Teil der Infektionen aus. (Interview med Tysklands top Covid-19 rådgiver, Christian Drosten, i Die Welt.: English version Comments on hand washing "totally exaggerated" Regarding infections with Sars-CoV-2, Drosten said it seemed "totally exaggerated" how often hand washing and disinfection of surfaces was mentioned: According to his assessment, smear infections, i.e. infections from contaminated objects, only make up a small part of the infections out. For resten hvor var det nu 1 og 2 meters afstandsanbefalinger kommer fra? Her et bud: “The WHO’s three-foot recommendation originates with work done in the 1930s done by William Wells, a Harvard researcher who studied tuberculosis. He found that droplets— bits of spit, mucus, and sputum (aka phlegm) emitted when we breathe, cough, or sneeze— tend to land within three feet of where they’re expelled... When the SARS pandemic hit in 2003, for example, scientists found some evidence that the three-foot cutoff may not be enough. Researchers looked at the prevalence of SARS infections within a single flight, and concluded that droplets of the virus could actually travel between passengers six feet apart—not three.” (Quartz) https://qz.com/1831100/where-does-the-six-feet-social-distancing-guideline-come-from/ And today we know that aerosols that may contain SARS-CoV-2 virus can reach even farther and linger for some time, meaning that facing forward might not be enough.  On face masks, aerosols, and SARS-CoV-2 stability Apparently, there isn’t much knowledge about the spread of Covid-19 (SARS-CoV-2) virus. Does it happen by touching an infected person or a surface containing the virus, (fomite transmission)? Or are Covid-19 virus also spread through the air, by people inhaling virus contained in aerosols emitted by infected persons just by breathing, talking, and coughing? If transmission only or primarily happens through touch, the often-repeated advice about frequent handwashing will certainly be important in preventing the spread, together with frequent cleaning of surfaces that we touch. But we really don’t know if this is the only or even the primary transmission mechanism. What if the virus also spreads through the air so to speak? By inhaling virus found in aerosols emitted by people just breathing or coughing? Then handwashing may have less of an effect, just allowing us to get rid of the droplets emitted by infected people. It would certainly NOT be very effective against airborne aerosols, with minute particles less than < 5 μm in size. Such particles may linger in the air and spread widely, even after the infected person has left the area. If that is the case then we need some form of protection, apart from handwashing, when moving about in the presence of people who may be infected. This could mean that the use of some form of face masks may be a very important addition to handwashing. One or two other things we don’t seem to know very much about at the moment. What is the stability of the virus on different kinds of surfaces and in aerosols? Will there be a difference in the seriousness of an infection when an infection is a result of hand contact with large droplets found say on a handrail, or inhaling virus in an aerosol? Perhaps the minute particles containing virus in an aerosol may easily penetrate directly into the lungs of people due to their size, leading perhaps to more serious effects? While contact with large droplets may result in less severe cases. The ham-fisted approach to containing the spread of the Covid-19 virus in the absence of knowledge about the mechanisms involved, consists of course in keeping a physical (not necessarily a social) distance of 2 meters or more, together with various forms of self-isolation. This will prevent the spread, but for how long can a ham-fisted approach be used without serious consequences, not the least for the economy? I don’t know the answers to all these questions, but here are some references relating to possible answers: On handwashing methods and effects Hand Hygiene: Why, How & When, WHO https://www.who.int/gpsc/5may/Hand_Hygiene_Why_How_and_When_Brochure.pdf Interim recommendations on obligatory hand hygiene against transmission of COVID-19, WHO https://www.who.int/who-documents-detail/interim-recommendations-on-obligatory-hand-hygiene-against-transmission-of-covid-19 Does hand hygiene reduce SARS-CoV-2 transmission? Chao Yang https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7100395/ The effectiveness of hand hygiene procedures in reducing the risks of infections in home and community settings including handwashing and alcohol-based hand sanitizers, Sally F. Bloomfield et. al. https://www.researchgate.net/publication/237645197_The_Effectiveness_of_Hand_Hygiene_Procedures_in_Reducing_the_Risks_of_Infections_in_Home_and_Community_Settings_Including_Handwashing_and_Alcohol-Based_Hand_Sanitizers Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review, Charlotte Warren-Gash https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5781206/ On face masks and their efficiency Face Masks for the General Public, DELVE https://rs-delve.github.io/reports/2020/05/04/face-masks-for-the-general-public.html Recommendation Regarding the Use of Cloth Face Coverings, Especially in Areas of Significant Community-Based Transmission, CDC https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html Use of Respirators, Facemasks, and Cloth Face Coverings in the Food and Agriculture Sector During Coronavirus Disease (COVID-19) Pandemic, FDA https://www.fda.gov/food/food-safety-during-emergencies/use-respirators-facemasks-and-cloth-face-coverings-food-and-agriculture-sector-during-coronavirus Using face masks in the community – Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks, European Centre for Disease Prevention and Control https://www.ecdc.europa.eu/en/publications-data/using-face-masks-community-reducing-covid-19-transmission Plötzlich ändert das Robert-Koch-Institut seine Einschätzung zum Mundschutz, Die Welt https://www.welt.de/wissenschaft/article206979269/Corona-Robert-Koch-Institut-aendert-Einschaetzung-zu-Mundschutz.html Impact of population mask wearing on Covid-19 post lockdown, Babak Javid and Nathalie Q. Balaban https://www.medrxiv.org/content/10.1101/2020.04.13.20063529v Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households – A Cluster Randomized Trial, Benjamin J. Cowling et.al. https://annals.org/aim/fullarticle/744899/facemasks-hand-hygiene-prevent-influenza-transmission-households-cluster-randomized-trial The role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; Berlin, Germany, 2009-2011, Thorsten Suess et.al. https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-12-26 COMMENTARY: Masks-for-all for COVID-19 not based on sound data, Dr. Brosseau and Dr. Sietsema https://www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data BTW Can face masks be cleaned and re-used? Addressing COVID-19 Face Mask Shortages, Amy Price and Larry Chu https://stanfordmedicine.app.box.com/v/covid19-PPE-1-1 On airborne transmission: Aerosols Could SARS-CoV-2 be transmitted via speech droplets? Philip Anfinrud et.al. https://www.medrxiv.org/content/10.1101/2020.04.02.20051177v1 Airborne transmission of SARS-CoV-2: The world should face the reality, Lidia Morawska and Junji Cao https://www.sciencedirect.com/science/article/pii/S016041202031254X Respiratory virus shedding in exhaled breath and efficacy of face masks, Nancy H. L. Leung et. al. https://www.nature.com/articles/s41591-020-0843-2 Transmission Potential of SARS-CoV-2 in Viral Shedding Observed at the University of Nebraska Medical Center, Joshua L. Santarpia et.al. https://www.medrxiv.org/content/10.1101/2020.03.23.20039446v2 Rapid Expert Consultation on the Possibility of Bioaerosol Spread of SARS-CoV-2 for the COVID-19 Pandemic National Research Council https://www.nap.edu/catalog/25769/rapid-expert-consultation-on-the-possibility-of-bioaerosol-spread-of-sars-cov-2-for-the-covid-19-pandemic-april-1-2020 Aerosol transmission is an important mode of influenza A virus spread, Benjamin J. Cowling et.al. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3682679/ COMMENTARY: COVID-19 transmission messages should hinge on science, Dr. Brosseau https://www.cidrap.umn.edu/news-perspective/2020/03/commentary-covid-19-transmission-messages-should-hinge-science On the stability of SARS-CoV-2 virus in the air and on surfaces Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1 https://www.nejm.org/doi/full/10.1056/NEJMc2004973 Stability of SARS-CoV-2 in different environmental conditions, Alex W. H. Chin et. al. https://www.medrxiv.org/content/10.1101/2020.03.15.20036673v2 Review of data on persistence of SARS-CoV-2 in the environment and potential infection risk, NERVTAG Review https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/882727/30-review-data-persistence-sars-cov-2-in-environment-14022020.pdf |
