Articles: sars-cov-2.
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Emerg Microbes Infect · Dec 2021
Serological investigation of asymptomatic cases of SARS-CoV-2 infection reveals weak and declining antibody responses.
Without an effective vaccine against SARS-CoV-2, the build-up of herd immunity through natural infection has been suggested as a means to control COVID-19. Although population immunity is typically estimated by the serological investigation of recovered patients, humoral immunity in asymptomatic subjects has not been well studied, although they represent a large proportion of all SARS-CoV-2 infection cases. In this study, we conducted a serosurvey of asymptomatic infections among food workers and performed serological and cellular response analyses of asymptomatic subjects in Wuhan, the original epicenter of the COVID-19 outbreak. ⋯ Furthermore, the asymptomatic subjects showed lymphopenia and a prominent decrease in the B-cell population, as well as a low frequency of antibody-secreting cells and a low cytokine response. These factors probably contributed to the low and unsustained antibody levels in asymptomatic subjects. Our results show that asymptomatic subjects are likely to be vulnerable to SARS-CoV-2 reinfection, and neither the proportion of population immunity nor the breadth of immune responses is sufficient for herd immunity.
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Comparative Study
CPMPARISON between COVID-19 and MERS demographic data in Saudi Arabia: a retrospective study.
The outbreak of corona virus disease (COVID-19) caused by the new severe acute respiratory syndrome corona virus 2 began in Wuhan, China, resulting in respiratory disorders. In January of 2020, the World Health Organization declared the outbreak a pandemic owing to its global spread. Because no studies have investigated COVID-19 in Saudi Arabia, this study investigated similarities and differences between demographic data during the COVID-19 and Middle East respiratory syndrome (MERS) outbreaks in Saudi Arabia. ⋯ Targeted prevention of and interventions against MERS should be allocated populations according to the areas where they inhabit. However, much more information regarding the dynamics and epidemiology of COVID-19 in Saudi Arabia is needed. Abbrevation : MERS: Middle East Respiratory syndrome; COVID-19: Corona Virus Disease 2019.
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Journal of women's health · Dec 2021
Sex and Gender-Related Differences in COVID-19 Diagnoses and SARS-CoV-2 Testing Practices During the First Wave of the Pandemic: The Dutch Lifelines COVID-19 Cohort Study.
Background: Although sex differences are described in Coronavirus Disease 2019 (COVID-19) diagnoses and testing, many studies neglect possible gender-related influences. Additionally, research is often performed in clinical populations, while most COVID-19 patients are not hospitalized. Therefore, we investigated associations between sex and gender-related variables, and COVID-19 diagnoses and testing practices in a large general population cohort during the first wave of the pandemic when testing capacity was limited. ⋯ Conclusions: We found no sex differences in COVID-19 diagnoses and testing in the general population. Among health care workers, a male preponderance in COVID-19 diagnoses and testing was observed. This could be explained by more pronounced COVID-19 symptoms in males or by gender inequities.
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An estimated 10 million people in the USA are immunocompromised, a risk factor for severe COVID-19. Data informing whether immune-mediated medications lead to more severe infection are sparse. ⋯ Outpatient use of prednisone is associated with severe illness after diagnosis of SARS-CoV-2. Immunomodulator and biologic/small-molecule therapy were not associated, but different risk subgroups were identified. Our findings can inform risk-benefit discussions in the clinic and risk-based recommendations for patients on these therapies.
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Methacholine bronchoprovocation or challenge testing (MCT) is commonly performed to assess airway hyper-responsiveness in the setting of suspected asthma. Nebulization is an aerosol-generating procedure, but little is known about the risks of MCT in the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic. We aimed to quantify and characterize aerosol generation during MCT by using different delivery methods and to assess the impact of adding a viral filter. ⋯ The high particle concentrations generated during MCT pose significant infection control concerns during the COVID-19 pandemic. Particle generation during MCT was significantly reduced by using breath-actuated delivery and a viral filter, which offers an effective mitigation strategy.