In fact, to our knowledge, a standard test for outward leakage does not exist. The European Committee for Standardisation Workshop Agreement (CWA) 17553 for face coverings also has no quantitative fit test. While inward leakage testing is part of the requirements for personal protective equipment (PPE) masks in European Standard (EN) 149, the standard for medical masks, EN 14683, does not have any requirement for a leakage test – neither inward nor outward. Particles can escape from the mask in two ways- either direct penetration of the fabric, or leakage around the sides. One approach is to refine and improve face masks, both in terms of fabric and fit.įace masks worn in a pandemic function more effectively as source control rather than protection. However, as the world now faces an inevitable ‘second wave’, it is essential that we redouble our efforts to halt the spread of the virus. The scientific evidence appears to support this, with several reports outlining the role of face coverings in stemming the spread of SARS-CoV-2. Previously we suggested that, in the absence of an effective vaccine, ‘do-it-yourself’ (DIY) face masks were likely to play an important role in stemming the spread of SARS-CoV-2. At the time of writing, 216 countries & territories and two international conveyances have reported cases of COVID-19, with the total number approaching 64 million and over 1.4 million associated deaths. On 11 March 2020, the WHO declared the COVID-19 outbreak a global pandemic. As with SARS, COVID-19 spread rapidly from its Chinese epicenter, though with a considerably farther reach and impact. While SARS-CoV originated from bats, with human transmission occurring via an intermediate host, the true origins of SARS-CoV-2 remain unknown (though bats, pangolins and snakes have all been suggested ). The first CoV to achieve international notoriety was SARS-CoV linked to clusters of ‘atypical pneumonia’ (later named SARS severe acute respiratory syndrome) initially presenting in the Chinese Province of Guangdong, in 2003, before spreading first to Hong Kong and then to some 26 countries infecting more than 8000 people.
SARS-CoV-2 is the seventh member of the Coronaviridae known to infect humans. Metagenomic analysis of a sample of the patient’s bronchoalveolar lavage fluid revealed that the causative agent of COVID-19 is a coronavirus (CoV) named SARS-CoV-2, owing to its phylogenetic relatedness to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus). The patient, a worker at a seafood market in Wuhan, was one of the first reported cases of a newly emerging severe respiratory disease, which we now know as COVID-19. On 26 December 2019, a 41-year-old male was admitted to the Central Hospital of Wuhan, presenting with fever, dizziness and an unproductive cough.
0 kommentar(er)
