Olfactory and gustatory dysfunctions of COVID-19 patients in China: A multicenter study.

Introduction: With the spread of the epidemic worldwide, an increasing number of doctors abroad have observed the following atypical symptoms of coronavirus disease 2019 (COVID-19): olfactory or taste disorders. Therefore, clarifying the incidence and clinical characteristics of olfactory and taste disorders in Chinese COVID-19 patients is of great significance and urgency. Materials and Methods: A retrospective study was conducted, which included 229 severe acute respiratory syndrome coronavirus 2 confirmed patients, through face-to-face interviews and telephone follow-up. Following the completion of questionnaires, the patients participating in the study, were categorized according to the degree of olfactory and taste disorders experienced, and the proportion of each clinical type of patient with olfactory and taste disorders and the time when symptoms appeared were recorded. Results: Among the 229 patients, 31 (13.54%) had olfactory dysfunction, and 44 (19.21%) had gustatory dysfunction. For the patients with olfactory dysfunction, 6 (19.35%) developed severe disease and became critically ill. Olfactory dysfunction appeared before the other symptoms in 21.43% of cases. The proportion of females with olfactory and gustatory dysfunction was higher than that of males (P < 0.001). Conclusions: The incidence of olfactory and gustatory dysfunction was much lower than that reported abroad; the prognosis of patients with olfactory dysfunction is relatively favorable; olfactory and gustatory dysfunction can be used as a sign for early screening; females are more prone to olfactory and gustatory dysfunction.

Chinese pregnant women's knowledge, attitude, and practice of self-protection against coronavirus disease 2019 during the post-pandemic period: A structural equation modeling-based survey.

This study aimed to investigate the Chinese pregnant women's levels of knowledge, attitude, and practice (KAP) of self-protection against coronavirus disease 2019 (COVID-19) during the post-pandemic period, to aid the development of targeted health education. An online questionnaire was conducted for 2156 Chinese pregnant women from October 1, 2021, to December 31, 2021, to collect socio-demographic and KAP information. Structural equation modeling (SEM) was used to determine self-protection-related factors. The mean age of the participants was 30 ± 4.1 years. SEM indicated that pregnant women's level of knowledge can directly and indirectly affect the practice of self-protection (r = 0.23) through their belief, with a correlation coefficient of 0.56 and 0.46 between knowledge and belief and belief and practice, respectively. The "basic protection" and "hospital visits after infection" exerted the greatest impact on knowledge formation, with correlation coefficients of 0.85 and 0.89, respectively. Attitude had a direct effect on practice with a correlation coefficient of 0.46. "Awareness of prevention and control" and "family and social support" had the greatest impact on belief formation, with correlation coefficients of 0.77 and 0.73, respectively. Pregnant Chinese women were generally familiar with COVID-19 knowledge, and their levels of knowledge and beliefs particularly affect the practice of self-protection. Health education aimed at improving pregnant women's knowledge and belief toward self-protection against COVID-19 may be an effective way to guide them toward positive practices and promote their health and that of their babies.

Knowledge, attitude and practice regarding occupational protection against COVID-19 among midwives in China: A nationwide cross-sectional study.

Midwives assume the roles in protecting perinatal women and newborns, meanwhile defending their own safety during the epidemic of COVID-19. Since there is currently no specific treatment available that targets the disease, strictly compliance with various infection prevention and control measures appears utmost important to achieve their occupational safety. We then explored the status quo and influencing factors of the knowledge, attitude and practice (KAP) of occupational protection against the COVID-19 among midwives in China. This online cross-sectional survey was conducted on 2663 midwives across the China during the early stages of the pandemic with a self-reported structured questionnaire. 97.4% and 92.9% of them were identified with positive attitude and appropriate practice, respectively, whereas only 6.4% showed good level of knowledge about the occupational protection toward the COVID-19. Midwives with older age, keeping on working during the breakout period, completing the training programs, caring the confirmed COVID-19 cases and having family members with cold-like symptoms were significantly associated with their KAP status. This study could provide valuable information not only for policy makers and administrators to optimize resource allocation and design education programs on targeted midwives, but also serve as a baseline for measuring changes in subsequent, post-intervention KAP studies.

SARS-CoV-2 Omicron Variant: Epidemiological Features, Biological Characteristics, and Clinical Significance.

The SARS-CoV-2 Omicron (B.1.1529) variant was designated as a variant of concern (VOC) by the World Health Organization (WHO) on November 26, 2021. Within two months, it had replaced the Delta variant and had become the dominant circulating variant around the world. The Omicron variant possesses an unprecedented number of mutations, especially in the spike protein, which may be influencing its biological and clinical aspects. Preliminary studies have suggested that increased transmissibility and the reduced protective effects of neutralizing antibodies have contributed to the rapid spread of this variant, posing a significant challenge to control the coronavirus disease 2019 (COVID-19) pandemic. There is, however, a silver lining for this wave of the Omicron variant. A lower risk of hospitalization and mortality has been observed in prevailing countries. Booster vaccination also has ameliorated a significant reduction in neutralization. Antiviral drugs are minimally influenced. Moreover, the functions of Fc-mediated and T-cell immunity have been retained to a great extent, both of which play a key role in preventing severe disease.

A cross-sectional study of olfactory and taste disorders among COVID-19 patients in China.

To determine the prevalence and clinical features of olfactory and taste disorders among coronavirus disease 2019 (COVID-19) patients in China. A cross-sectional study was performed in Wuhan from April 3, 2020 to April 15, 2020. A total of 187 patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) completed face-to-face interviews or telephone follow-ups. We found that the prevalence of olfactory and taste disorders was significantly lower in the Chinese cohort than in foreign COVID-19 cohorts. Females were more prone to olfactory and taste disorders. In some patients, olfactory and taste disorders precede other symptoms and can be used as early screening and warning signs.

Proportion of asymptomatic coronavirus disease 2019: A systematic review and meta-analysis.

We aim to systematically review the characteristics of asymptomatic infection in the coronavirus disease 2019 (COVID-19). PubMed and EMBASE were electronically searched to identify original studies containing the rate of asymptomatic infection in COVID-19 patients before 20 May 2020. Then mate-analysis was conducted using R version 3.6.2. A total of 50 155 patients from 41 studies with confirmed COVID-19 were included. The pooled percentage of asymptomatic infection is 15.6% (95% CI, 10.1%-23.0%). Ten included studies contain the number of presymptomatic patients, who were asymptomatic at screening point and developed symptoms during follow-up. The pooled percentage of presymptomatic infection among 180 initially asymptomatic patients is 48.9% (95% CI, 31.6%-66.2%). The pooled proportion of asymptomatic infection among 1152 COVID-19 children from 11 studies is 27.7% (95% CI, 16.4%-42.7%), which is much higher than patients from all aged groups. Abnormal CT features are common in asymptomatic COVID-19 infection. For 36 patients from 4 studies that CT results were available, 15 (41.7%) patients had bilateral involvement and 14 (38.9%) had unilateral involvement in CT results. Reduced white blood cell count, increased lactate dehydrogenase, and increased C-reactive protein were also recorded. About 15.6% of confirmed COVID-19 patients are asymptomatic. Nearly half of the patients with no symptoms at detection time will develop symptoms later. Children are likely to have a higher proportion of asymptomatic infection than adults. Asymptomatic COVID-19 patients could have abnormal laboratory and radiational manifestations, which can be used as screening strategies to identify asymptomatic infection.

COVID-19 immune features revealed by a large-scale single-cell transcriptome atlas.

A dysfunctional immune response in coronavirus disease 2019 (COVID-19) patients is a recurrent theme impacting symptoms and mortality, yet a detailed understanding of pertinent immune cells is not complete. We applied single-cell RNA sequencing to 284 samples from 196 COVID-19 patients and controls and created a comprehensive immune landscape with 1.46 million cells. The large dataset enabled us to identify that different peripheral immune subtype changes are associated with distinct clinical features, including age, sex, severity, and disease stages of COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was found in diverse epithelial and immune cell types, accompanied by dramatic transcriptomic changes within virus-positive cells. Systemic upregulation of S100A8/A9, mainly by megakaryocytes and monocytes in the peripheral blood, may contribute to the cytokine storms frequently observed in severe patients. Our data provide a rich resource for understanding the pathogenesis of and developing effective therapeutic strategies for COVID-19.