Articles: sars-cov-2.
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Objectives Serological assays for detection of SARS-CoV-2 antibodies are increasingly used during the COVID-19 pandemic caused by the SARS-Coronavirus-2. Here we evaluated the analytical and clinical performance of three commercially available SARS-CoV-2 antibody assays. Methods A total of 186 samples from 58 patients with PCR-confirmed COVID-19 infection were measured using SARS-CoV-2 antibody assays by Siemens Healthineers, Roche Diagnostics and Euroimmun. ⋯ Discordant results were observed in three COVID-19 patients and in one COVID-19 patient none of the investigated assays detected antibodies. Conclusions The investigated assays were highly specific and sensitive in detecting SARS-CoV-2 antibodies in samples obtained ≥14 days after PCR-confirmed infection. Discordant results need to be investigated in further studies.
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Curr Allergy Asthma Rep · Aug 2020
ReviewThe Loss of Smell and Taste in the COVID-19 Outbreak: a Tale of Many Countries.
Olfactory dysfunction in upper airway viral infections (common cold, acute rhinosinusitis) is common (> 60%). During the COVID-19 outbreak, frequency of sensory disorders (smell and/or taste) in affected patients has shown a high variability from 5 to 98%, depending on the methodology, country, and study. ⋯ A sudden, severe, isolated loss of smell and/or taste, in the absence of other upper airway inflammatory diseases (allergic rhinitis, chronic rhinosinusitis, nasal polyposis), should alert individuals and physicians on being potentially affected by COVID-19. The evaluation of smell/taste disorders with a visual analogue scale or an individual olfactory or gustatory test, at the hospital or by telemedicine, to prevent contamination might facilitate an early detection of infected patients and reduce the transmission of SARS-CoV-2. During the COVID-19 outbreak, patients with sudden loss of smell should initiate social distancing and home isolation measures and be tested for SARS-CoV-2 diagnostic test when available. Olfactory training is recommended when smell does not come back after 1 month but can be started earlier.
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J. Korean Med. Sci. · Aug 2020
Clinical Course and Outcomes of 3,060 Patients with Coronavirus Disease 2019 in Korea, January-May 2020.
The fatality rate of patients with coronavirus disease 2019 (COVID-19) varies among countries owing to demographics, patient comorbidities, surge capacity of healthcare systems, and the quality of medical care. We assessed the clinical outcomes of patients with COVID-19 during the first wave of the epidemic in Korea. ⋯ In Korea, almost all patients of < 50 years of age with COVID-19 recovered without supplemental oxygen. In patients of ≥ 50 years of age, the fatality rate increased with age, reaching 14% in patients of ≥ 80 years of age.
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Increased population movements and increased mobility made it possible for severe acute respiratory syndrome coronavirus 2, which is mainly spread by respiratory droplets, to spread faster and more easily. This study tracked and analysed the development of the coronavirus 2019 (COVID-19) outbreak in the top 100 cities that were destinations for people who left Wuhan before the city entered lockdown. Data were collected from the top 100 destination cities for people who travelled from Wuhan before the lockdown, the proportion of people travelling into each city, the intensity of intracity travel and the daily reports of COVID-19. ⋯ The average intensity of intracity travel on the nth day in these cities during the development of the outbreak was positively related to the growth rate of the number of confirmed COVID-19 cases on the n + 5th day in these cities and had a significant linear relationship (P < 0.01). Higher intensities of population movement were associated with a higher incidence of COVID-19 during the pandemic. Restrictions on population movement can effectively curb the development of an outbreak.
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In this review, Wilson, Norton, Young & Collins challenge the overly-simplistic view that SARS-CoV-2 transmission risk can be easily divided between droplet-contact and aerosol precautions.
Why is this important?
Many national societies have policies on Personal Protective Equipment (PPE) guided by classification of COVID exposure into aerosol-generation procedures (AGP) or other exposures. Although founded in some evidence, there are questions as to whether PPE shortage and availability also drives these recommendations. Widespread concern over healthcare worker (HCW) infection is understandable, given that during SARS 20% of infections were among HCWs.
Understanding the science behind respiratory particle generation and transmission helps to inform our understanding of how best to use limited PPE.
On the science of respiratory shedding
Aerosol generation is important because virus inhalation and deposition in small distal airways may be associated with greater infection risk and disease severity. Wilson et al. describe three mechanisms of aerosol generation:
- Laryngeal activity - talking, coughing, sneezing.
- High velocity gas flow - eg. high-flow oxygen
- Cyclical opening & closing of terminal airways.
Notably, the clinically features of COVID itself make all three high-risk mechanisms more likely. Additionally various studies show that even talking and tidal volume breathing produce large numbers and size ranges of respiratory droplets.
Exposure relative risk is primarily about proximity and exposure duration
Further, considering retrospective data form SARS HCW infections involving various procedures (eg. intubation, HCW infection RR 4.2; oxygen mask manipulation RR 9; urinary catheterisation RR 5), Wilson et al. propose that healthcare work risk can be considered:
infection risk ∝ 𝑏 × 𝑣 × 𝑡 / 𝑒
Where: 𝑏 = breathing zone particle viable virion aerosol concentration, 𝑣 = minute volume of healthcare worker, 𝑡 = time exposed , 𝑒 = mask efficiency
And on intubation:
"...[other] healthcare workers should stand over 2 m away and out of the direct exhalation plume. During a rapid sequence intubation muscle relaxation should be protective as coughing will be prevented and high airway gas flow and expiratory output will terminate. When expiratory flow is ended ... aerosol particles should start settling in the airways. The forces generated in gentle laryngoscopy are unlikely to cause aerosol formation."
"...[there is] limited evidence to suggest AGPs cause an increase in airborne healthcare worker transmission as this has not been studied. The few studies to sample pathogenic airborne particles in relation to procedures show no increase with the majority of AGPs."
Bear in mind...
Much of the evidence guiding our understanding of SARS-CoV-2 transmission is founded on understanding and research focusing on the 2003 SARS pandemic (SARS-CoV-1) and influenza research. Although sharing similarities, "...each has its own infective inoculum and aerosol characteristics."
What's the bottom-line?
Transmission of SARS-CoV-2 should be conceptualised as a spectrum of risk where time exposed may be the dominant factor and droplet-airborne spread is a complex continuum of varying probability of infection. Many 'non-AGP' events could in fact be higher risk than those traditionally considered AGP, such as intubation.
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