Field investigation of the heat stress in outdoor of healthcare workers wearing personal protective equipment in South China.

Since the advent of coronavirus disease 2019 (COVID-19), healthcare workers (HCWs) wearing personal protective equipment (PPE) has become a common phenomenon. COVID-19 outbreaks overlap with heat waves, and healthcare workers must unfortunately wear PPE during hot weather and experience excessive heat stress. Healthcare workers are at risk of developing heat-related health problems during hot periods in South China. The investigation of thermal response to heat stress among HCWs when they do not wear PPE and when they finish work wearing PPE, and the impact of PPE use on HCWs' physical health were conducted. The field survey were conducted in Guangzhou, including 11 districts. In this survey, HCWs were invited to answer a questionnaire about their heat perception in the thermal environment around them. Most HCWs experienced discomfort in their back, head, face, etc., and nearly 80% of HCWs experienced "profuse sweating." Up to 96.81% of HCWs felt "hot" or "very hot." The air temperature had a significant impact on thermal comfort. Healthcare workers' whole thermal sensation and local thermal sensation were increased significantly by wearing PPE and their thermal sensation vote (TSV) tended towards "very hot." The adaptive ability of the healthcare workers would decreased while wearing PPE. In addition, the accept range of the air temperature (T a) were determined in this investigation. Graphical Abstract.

Knowledge, Attitudes, and Practices Towards COVID-19 Among Rural Residents of Hebei Province: A Cross-sectional Survey.

OBJECTIVE: COVID-19 has spread worldwide due to high infectivity. The social sexual environment in rural areas of China and the weak basic medical facilities, may affect the treatment and transmission of the disease. The aim of this study was to understand the knowledge, attitude and practice (KAP) related to COVID-19 among residents in rural areas experiencing the epidemic and the factors, to provide a basis for further epidemic prevention and control. METHODS: The COVID-19 KAP of rural residents in Hebei Province was collected by the snowball sampling method. The COVID-19 KAP questionnaire was distributed on social platforms such as WeChat and QQ through a network questionnaire. RESULTS: The overall level of COVID-19 KAP in rural residents was good, but in terms of knowledge, the correct rate of isolation was 73.2%, the correct rate of two disinfection items were 72.3% and 77.4%, and the correct rate about hand washing was 70.7%. 54.5% residents feel panic. 81.0% disinfected household items, and 84.9% washed hands correctly. Residents still needed to strengthen these aspects. Binary logistic analysis showed that age, education and whether to participated in training were factors affecting the level of COVID-19 KAP. CONCLUSIONS: This study found that rural residents had good levels of COVID-19 KAP, but there were gaps in specific issues that warrant attention. We advocate training on COVID-19 for rural residents.

Epidemiological investigation on a cluster epidemic of COVID-19 in a school in Longchuan County, Yunnan Province

Objective: To investigate a cluster epidemic of coronavirus disease 2019 (COVID-19) infections in a school in Longchuan County, Yunnan Province, and further guide the prevention and control of COVID-19 in the border area. Methods: According to the Protocol on Prevention and Control of Novel Coronavirus Pneumonia (8th Edition), an epidemiological investigation was performed on all COVID-19 cases to collect the information on demographics, onset, diagnosis and treatment, prognosis, and epidemiological history. Close contacts were also tracked to determine the transmission chains. Results: In this cluster epidemic, a total of 37 COVID-19 cases were identified, including 32 females and 5 males aged from 13 to 25 years, who were 35 students and 2 teachers. The student cases were found in four classes of two grades. Furthermore, gene sequencing showed that all cases had been infected with delta variants, belonging to the same transmission chain that was not related to the previous epidemics in Dehong Prefecture. In additionally, a total of 2 127 close contacts were found. After 21 days of centralized quarantine for medical observation, all close contacts tested negative for SARS-CoV-2. In the COVID-19 cases, only one case remained positive for SARS-CoV-2, while the other 36 cases were successfully treated and became negative. Conclusion: This school cluster is caused by the border villagers who contacted the water polluted with SARS-CoV-2. It warrants more strict management of students from border villages and their belongings to prevent similar epidemics in school settings.

Netizens' risk perception in new coronary pneumonia public health events: an analysis of spatiotemporal distribution and influencing factors.

BACKGROUND: Internet search volume reflects the level of Internet users' risk perception during public health events. The Internet search volume index model, an algorithm of concentration of Internet users, and statistical analysis of popular topics on Weibo are used to analyze the effects of time, space, and space-time interaction. We conducted in-depth research on the characteristics of the spatial and temporal distribution of Internet users' risk perceptions of public health events and the associated influential factors. METHODS: We analyzed the spatiotemporal distribution characteristics of Internet users' risk perception after the Wuhan "city closing" order during the coronavirus disease 2019 (COVID-19) pandemic. We established five linear regression models according to different time periods and analyzed factors influencing Internet users' risk perception by employing a Poisson and spatial distribution and topic modeling analysis. RESULTS: Economy, education, health, and the degree of information disclosure affect Internet users' risk perception significantly. Internet users' risk perception conforms to the exponential distribution law in time and has periodic characteristics and stability trends. Additionally, Internet users' average arrival rate dropped from week 1 to week 8 after the "city closing." Internet users' risk perception has a uniform distribution in space, economic and social development level distribution consistency, spatial agglomeration, and other characteristics. The results of the time-space interaction show that after 8 weeks of COVID-19, Internet search hot topics have become more stable, and Internet users' information demand structure has become more rational. CONCLUSIONS: The Internet search cycle of the COVID-19 event is synchronized with the evolution cycle of the epidemic. The physical risk of Internet users is at the top of the risk structure, focusing on the strong concern about the government's ability to control COVID-19 and its future trend. The government should strengthen network management; seize the risk control focus of key time nodes, regional locations, and information content of online communication; actively adjust the information content supply; effectively control the rebound of Internet users' risk perception; establish a data-driven, risk-aware intelligence system for internet users; and guide people to actively face and overcome the potential risks and threats of COVID-19.

Thermal discomfort caused by personal protective equipment in healthcare workers during the delta COVID-19 pandemic in Guangzhou, China: A case study

Background In contrast to the previous COVID-19 pandemic, most frontline healthcare workers (HCWs) worked on residents’ nucleic acid tests in outdoor environments, instead of taking care of COVID-19 patients in hospitals during the hot summer of 2021. Therefore, it is necessary to investigate the prevalence and characteristics of thermal discomfort caused by personal protective equipment (PPE). Methods A cross-sectional survey was conducted online at hospitals from 11 administrative regions of Guangzhou for the assessment of thermal discomfort among HCWs from June 12–16, 2021. Univariate and logistic regression analyses were used to explore the risk factors associated with thermal discomfort. Results A total of 3658 valid responses were collected. The thermal discomfort and humid discomfort levels increased from 2.91 ± 1.19 to 3.61 ± 0.72 and from 0.98 ± 1.36 to 3.06 ± 1.1 after wearing PPE, respectively (p < 0.01). Feelings of being “very hot” and “uncomfortably humid” were the most influenced by wearing PPE, increasing from 31% to 69.1% and from 9.1% to 45.7%, respectively. There were significant increases in the thermal discomfort level (3.75 ± 0.57 vs. 3.33 ± 0.89, p < 0.01) and the humid discomfort level (3.33 ± 0.95 vs. 2.54 ± 1.19, p < 0.01) between the comfortable group and uncomfortable group, accompanied by similar patterns in the feelings of being “very hot” and “uncomfortably humid.” For general thermal-related symptoms, the most common new-onset symptom was profuse sweating (80%) followed by labored breathing (55.2%) and excessive dehydration (46.8%), while facial swelling (74%) was associated with local thermal-related symptoms, followed by hand maceration erosion (56.7%) and visual impairment (49.3%). In the multivariate analysis, the apparent temperature of the environment (≥35 °C), working in negative-pressure ambulances and outdoors, continuing to wear PPE for 1–3 days during this period, being aged >40 years, and previous experiences fighting the pandemic were independently associated with thermal discomfort (p < 0.01). Immediately after PPE removal, 32.3% of respondents considered drinking ice water/another drink, followed by 25% shortening the duration of wearing PPE and 19.1% going to the toilet. A large proportion of the participants looked forward to modifications to the material of the suit (72.9%) and mask (53.4%) for heat dissipation and dehumidification, as well as anti-fogging goggles (60.2%), adding hydration equipment to PPE (53.4%), and using soft materials to reduce pressure (40%). Conclusions Thermal discomfort is common and degrades health physiology related to PPE in summer environments. This suggests that modifications to the current working practices are urgently required to improve the resilience of HCWs and enhance their services during pandemics.

Exploration of the Mechanism of Lianhua Qingwen in Treating Influenza Virus Pneumonia and New Coronavirus Pneumonia with the Concept of "Different Diseases with the Same Treatment" Based on Network Pharmacology.

The 31 main components of Lianhua Qingwen (LHQW) were obtained through a literature and database search; the components included glycyrrhizic acid, emodin, chlorogenic acid, isophoroside A, forsythia, menthol, luteolin, quercetin, and rutin. Sixty-eight common targets for the treatment of novel coronavirus pneumonia (NCP) and influenza virus pneumonia (IVP) were also obtained. A "component-target-disease" network was constructed with Cytoscape 3.2.1 software, and 20 key targets, such as cyclooxygenase2 (COX2), interleukin-6 (IL-6), mitogen-activated protein kinase14 (Mapk14), and tumor necrosis factor (TNF), were screened from the network. The David database was used to perform a Kyoto Encyclopedia of Genes and Genomes (KEGG) signal pathway enrichment analysis and gene ontology (GO) biological process enrichment. Results showed that the key targets of LHQW in the treatment of NCP and IVP mainly involved biological processes, such as immune system process intervention, cell proliferation, apoptosis and invasion, toxic metabolism, cytokine activity, and regulation of the synthesis process. KEGG enrichment analysis revealed that 115 signalling pathways were related to the treatment of LHQW. Amongst them, IL-17, T cell receptor, Th17 cell differentiation, TNF, toll-like receptor, MAPK, apoptosis, and seven other signalling pathways were closely related to the occurrence and development of NCP and IVP. Molecular docking showed that each component had different degrees of binding with six targets, namely, 3C-like protease (3CL), angiotensin-converting enzyme 2 (ACE2), COX2, hemagglutinin (HA), IL-6, and neuraminidase (NA). Rutin, isoforsythiaside A, hesperidin and isochlorogenic acid B were the best components for docking with the six core targets. The first five components with the best docking results were isoforsythiaside, hesperidin, isochlorogenic acid B, forsythin E, and quercetin. In conclusion, LHQW has many components, targets, and pathways. The findings of this work can provide an important theoretical basis for determining the mechanism of LHQW in treating NCP and IVP.

Research on Influencing Factors and Classification of Patients With Mild and Severe COVID-19 Symptoms.

Objective: To analyze the epidemiological history, clinical symptoms, laboratory testing parameters of patients with mild and severe COVID-19 infection, and provide a reference for timely judgment of changes in the patients' conditions and the formulation of epidemic prevention and control strategies. Methods: A retrospective study was conducted in this research, a total of 90 patients with COVID-19 infection who received treatment from January 21 to March 31, 2020 in the Ninth People's Hospital of Dongguan City were selected as study subject. We analyzed the clinical characteristics of laboratory-confirmed patients with COVID-19, used the oversampling method (SMOTE) to solve the imbalance of categories, and established Lasso-logistic regression and random forest models. Results: Among the 90 confirmed COVID-19 cases, 79 were mild and 11 were severe. The average age of the patients was 36.1 years old, including 49 males and 41 females. The average age of severe patients is significantly older than that of mild patients (53.2 years old vs 33.7 years old). The average time from illness onset to hospital admission was 4.1 days and the average actual hospital stay was 18.7 days, both of these time actors were longer for severe patients than for mild patients. Forty-eight of the 90 patients (53.3%) had family cluster infections, which was similar among mild and severe patients. Comorbidities of underlying diseases were more common in severe patients, including hypertension, diabetes and other diseases. The most common symptom was cough [45 (50%)], followed by fever [43 (47.8%)], headache [7 (7.8%)], vomiting [3 (3.3%)], diarrhea [3 (3.3%)], and dyspnea [1 (1.1%)]. The laboratory findings of patients also included leukopenia [13(14.4%)] and lymphopenia (17.8%). Severe patients had a low level of creatine kinase (median 40.9) and a high level of D-dimer. The median NLR of severe patients was 2.82, which was higher than that of mild patients. Logistic regression showed that age, phosphocreatine kinase, procalcitonin, the lymphocyte count of the patient on admission, cough, fatigue, and pharynx dryness were independent predictors of COVID-19 severity. The classification of random forest was predicted and the importance of each variable was displayed. The variable importance of random forest indicates that age, D-dimer, NLR (neutrophil to lymphocyte ratio) and other top-ranked variables are risk factors. Conclusion: The clinical symptoms of COVID-19 patients are non-specific and complicated. Age and the time from onset to admission are important factors that determine the severity of the patient's condition. Patients with mild illness should be closely monitored to identify those who may become severe. Variables such as age and creatine phosphate kinase selected by logistic regression can be used as important indicators to assess the disease severity of COVID-19 patients. The importance of variables in the random forest further complements the variable feature information.

Rapid isolation and immune profiling of SARS-CoV-2 specific memory B cell in convalescent COVID-19 patients via LIBRA-seq.

B cell response plays a critical role against SARS-CoV-2 infection. However, little is known about the diversity and frequency of the paired SARS-CoV-2 antigen-specific BCR repertoire after SARS-CoV-2 infection. Here, we performed single-cell RNA sequencing and VDJ sequencing using the memory and plasma B cells isolated from five convalescent COVID-19 patients, and analyzed the spectrum and transcriptional heterogeneity of antibody immune responses. Via linking BCR to antigen specificity through sequencing (LIBRA-seq), we identified a distinct activated memory B cell subgroup (CD11chigh CD95high) had a higher proportion of SARS-CoV-2 antigen-labeled cells compared with memory B cells. Our results revealed the diversity of paired BCR repertoire and the non-stochastic pairing of SARS-CoV-2 antigen-specific immunoglobulin heavy and light chains after SARS-CoV-2 infection. The public antibody clonotypes were shared by distinct convalescent individuals. Moreover, several antibodies isolated by LIBRA-seq showed high binding affinity against SARS-CoV-2 receptor-binding domain (RBD) or nucleoprotein (NP) via ELISA assay. Two RBD-reactive antibodies C14646P3S and C2767P3S isolated by LIBRA-seq exhibited high neutralizing activities against both pseudotyped and authentic SARS-CoV-2 viruses in vitro. Our study provides fundamental insights into B cell response following SARS-CoV-2 infection at the single-cell level.