Epidemiological characteristics and the effectiveness of countermeasures to control coronavirus disease 2019 in Ningbo City, China

Abstract Background: A novel coronavirus (SARS-CoV-2) has spread widely and led to high disease burden around the world. This study aimed to explore key parameters of SARS-CoV-2 infection and to assess the effectiveness of interventions to control the coronavirus disease 2019 (COVID-19).Methods: A susceptible – exposed – infectious – asymptomatic – recovered (SEIAR) model was developed for the assessment. Data of symptomatic and asymptomatic infection of SARS-CoV-2 were collected to calculate the key parameters of the model in Ningbo City, China.Results: A total of 157 confirmed COVID-19 cases (including 51 imported cases and 106 secondary cases) and 30 asymptomatic infections were reported in Ningbo City. The proportion of asymptomatic has an increasing trend. The proportion of asymptomatic of elder people was lower than younger people, and the difference was statistical significant (Fisher’s Exact Test, P = 0.034). There were 22 clusters associated with 167 SARS-CoV-2 infections, among which 29 cases were asymptomatic, with a proportion of 17.37%. We found that the secondary attack rate of asymptomatic was almost the same as that of symptomatic cases, and no significance was observed (χ2 = 1.350, P = 0.245) by Kruskal-Wallis test. The effective reproduction number (Reff) was 1.43 which revealed that the transmissibility of SARS-CoV-2 was moderate. If the interventions were not strengthened, the duration of the outbreak would last about 16 months with a simulated attack rate of 44.15%. The total attack rate and duration of the outbreak would increase along with the increasing delay of intervention.Conclusions: SARS-CoV-2 had moderate transmissibility in Ningbo City, China. Asymptomatic infection has the same transmissibility as symptomatic. The integrated interventions were implemented at different stages during the outbreak, which found to be exceedingly effective in China.

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Lockdown Contained the Spread of 2019 Novel Coronavirus Disease in Huangshi City, China: Early Epidemiological Findings

Clinical Infectious Diseases ◽

10.1093/cid/ciaa390 ◽

2020 ◽

Vol 71 (6) ◽

pp. 1454-1460 ◽

Cited By ~ 14

Author(s):

Tuo Ji ◽

Hai-Lian Chen ◽

Jing Xu ◽

Ling-Ning Wu ◽

Jie-Jia Li ◽

...

Keyword(s):

Temporal Dynamics ◽

Public Health Intervention ◽

Epidemiological Data ◽

Field Investigation ◽

Epidemic Curve ◽

Adults And Children ◽

Asymptomatic Infections ◽

Novel Coronavirus ◽

Nonpharmaceutical Interventions ◽

Epidemiological Characteristics

Abstract Background To control the spread of 2019 novel coronavirus disease (COVID-19), China sealed Wuhan on 23 January 2020 and soon expanded lockdown to 12 other cities in Hubei province. We aimed to describe the epidemiological characteristics in one of the cities and highlight the effect of current implemented lockdown and nonpharmaceutical interventions. Methods We retrieved data of reported cases in Huangshi and Wuhan from publicly available disease databases. Local epidemiological data on suspected or confirmed cases in Huangshi were collected through field investigation. Epidemic curves were constructed with data on reported and observed cases. Results The accumulated confirmed COVID-19 cases and fatality in Huangshi were reported to be 1015 and 3.74%, respectively, compared with 50006 and 5.08% in Wuhan until 27 March 2020. Right after 24 January, the epidemic curve based on observed cases in Huangshi became flattened. And 1 February 2020 was identified as the “turning point” as the epidemic in Huangshi faded soon afterward. COVID-19 epidemic was characterized by mild cases in Huangshi, accounting for 82.66% of total cases. Moreover, 50 asymptomatic infections were identified in adults and children. In addition, we found confirmed cases in 19 familial clusters and 21 healthcare workers, supporting interhuman transmission. Conclusions Our study reported the temporal dynamics and characteristics of the COVID-19 epidemic in Huangshi city, China, across the unprecedented intervention. Such new epidemiological inference might provide further guidance on current lockdown measures in high-risk cities and, subsequently, help improve public health intervention strategies against the pandemic on the country and global levels.

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Basic epidemiological parameter values from data of real-world in mega-cities: the characteristics of COVID-19 in Beijing, China

10.21203/rs.3.rs-23937/v2 ◽

2020 ◽

Author(s):

Xiaoli Wang ◽

Yang Pan ◽

Daitao Zhang ◽

Lijuan Chen ◽

Lei Jia ◽

...

Keyword(s):

Real World ◽

Attack Rate ◽

Real World Data ◽

Serial Interval ◽

Imported Cases ◽

Asymptomatic Infections ◽

And Control ◽

Parameter Values ◽

Beijing China ◽

Mega Cities

Abstract Background. With the spread of SARS-CoV-2 worldwide, understanding the basic epidemiological parameter values of COVID-19 from real-world data in mega-cities is essential for disease prevention and control. Methods. To investigate the epidemiological parameters in SARS-CoV-2 infected cases in Beijing, we studied all confirmed cases and close contacts in Beijing from Jan 1st to Apr 3rd 2020. The epidemiological and virological characteristics of SARS-CoV-2 were analyzed.Results. A total of 602 cases were positive for SARS-CoV-2, including 585 confirmed patients and 17 asymptomatic infections. The imported cases were mainly from Wuhan initially and then from abroad. Among 585 confirmed case-patients, the median age was 39 years old. The mean incubation period was 6.3 days. The secondary attack rate among households was higher than social contacts (15.6 vs 4.6%). The secondary attack rate of healthcare workers (HCWs) was higher than non-HCWs’ (7.3 vs 4.2%). The basic reproduction number was 2.0, and the average serial interval was 7.6 days. No significant genetic variant was identified.Conclusions. The transmissibility of SARS-CoV-2 was relatively high, especially among households and from HCWs, which draws specific public health attention. So far, no evidence of widespread circulation of SARS-CoV-2 in communities in Beijing was found.

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Leukopenia of Asymptomatic COVID-19 Infections under 18 Years Old in Recovery Stage

10.21203/rs.3.rs-29855/v1 ◽

2020 ◽

Author(s):

Wei Zhang ◽

Youshu Yuan ◽

Zhengqiao Yang ◽

Jinxia Fu ◽

Yun Zhang ◽

...

Keyword(s):

Treatment Period ◽

Clinical Characteristics ◽

Clinical Laboratory ◽

World Health ◽

Recovery Stage ◽

Familial Cluster ◽

Asymptomatic Infections ◽

The Difference ◽

Novel Coronavirus ◽

Health Organization

Abstract Background In December, 2019, a type of novel coronavirus which was designated novel coronavirus 2019 (2019-nCoV) by World Health Organization (WHO) occurred in Wuhan, Hubei, China. The epidemiological and clinical characteristics of those patients under 18 years old in the recovery stage are limited. To compare the difference of epidemiological and clinical characteristics of COVID-19 involving 25 patients under 18 years old in recovery stage between confirmed and asymptomatic infections.Methods Retrospective, single-center cohort study of COVID-19 involving 25 patients under 18 years old in the recovery stage at Guizhou Provincial Staff Hospital in Guiyang, China, from January 29, to March 31, 2020; final date of follow-up was April 22. Epidemiological, demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Epidemiological and clinical characteristics of confirmed COVID-19 infections and asymptomatic infections were compared.Results Among the 25 COVID infections under 18 years old, 16 (64%) were mild or moderate confirmed cases, and 9 (36%) were asymptomatic. The shortest treatment period was 6 days, the longest 26 days, and the average treatment period 14 days. Four cases (44.4%) had visited Wuhan or had a living story in the city. There were 9 (100%) asymptomatic cases were familial cluster outbreak, with an average infection number was 6 cases among all families. The number of asymptomatic COVID-19 infections’ Leukopenia were significantly more than confirmed cases (p = 0.04).Conclusions Leukopenia mostly occurred in asymptomatic COVID-19 infections under 18 years old compared with the confirmed patients.

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The differences of clinical characteristics and outcomes between imported and local patients of COVID-19 in Hunan: A two-center retrospective study

10.21203/rs.3.rs-23247/v3 ◽

2020 ◽

Author(s):

Chang Wang ◽

Lizhi Zhou ◽

Juan Chen ◽

Yong Yang ◽

Tianlong Huang ◽

...

Keyword(s):

Clinical Characteristics ◽

Gamma Globulin ◽

Laboratory Data ◽

Hunan Province ◽

Local Resident ◽

Imported Cases ◽

History Of ◽

The Difference ◽

Novel Coronavirus ◽

Severe Type

Abstract Background: The clinical characteristics and outcomes of the 2019 novel coronavirus (COVID-19) pneumonia are different in Hubei compared to other regions in China. But there are few comparative studies on the differences between imported and local patients which may provide information of the different courses of the virus after transmission. Methods: We investigated 169 cases of COVID-19 pneumonia in two centers in Hunan Province, and divided them into two groups according to epidemiological history, "imported patients" refers to patient with a clear history of travel in Wuhan within 14 days before onset, and " local patients” refers to local resident without a recent history of travel in Wuhan, aiming to analyze the difference in clinical characteristics and outcomes between the two groups. All the epidemiological, clinical, imaging, and laboratory data were analyzed and contrasted. Results: The incidence of fever on admission in imported patients was significantly higher than local patients. There was a significantly higher proportion of abnormal pulmonary signs, hypokalemia, hyponatremia, prolonged PT, elevated D-dimer and elevated blood glucose in imported patients. Compared with local patients, the proportion using antibiotics, glucocorticoids and gamma globulin were significantly higher in imported patients. The moderate type was more common in local patients, and the severe type were more frequent in imported patients. In addition, the median duration of viral clearance was longer in imported patients. Conclusions: In summary, we found that imported cases were more likely to develop into severe cases, compared with local patients and required more powerful treatments.Trial registration: Registered 21st March 2020, and this study has been approved by the Medical Ethics Committee (Approved Number. 2020017).

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Molecular epidemiology of SARS-CoV-2 clusters caused by asymptomatic cases in Anhui Province, China

10.21203/rs.3.rs-29833/v3 ◽

2020 ◽

Author(s):

yuan yuan ◽

Jun He ◽

Lei Gong ◽

Weiwei Li ◽

Liangliang Jiang ◽

...

Keyword(s):

Disease Transmission ◽

Close Contact ◽

Control Strategies ◽

Asymptomatic Infection ◽

Droplet Spreading ◽

Close Link ◽

Spike Gene ◽

Asymptomatic Patients ◽

Asymptomatic Infections ◽

Novel Coronavirus

Abstract Background: COVID-19 is a newly emerging disease caused by a novel coronavirus (SARS-CoV-2), which spread globally in early 2020. Asymptomatic carriers of the virus contribute to the propagation of this disease, and the existence of asymptomatic infection has caused widespread fear and concern in the control of this pandemic.Methods: In this study, we investigated the origin and transmission route of SARS-CoV-2 in Anhui’s two clusters, analyzed the role and infectiousness of asymptomatic patients in disease transmission, and characterized the complete spike gene sequences in the Anhui strains.Results: We conducted an epidemiological investigation of two clusters caused by asymptomatic infections sequenced the spike gene of viruses isolated from 12 patients. All cases of the two clusters we investigated had clear contact histories, both from Wuhan, Hubei province. The viruses isolated from two outbreaks in Anhui were found to show a genetically close link to the virus from Wuhan. In addition, new single nucleotide variations were discovered in the spike gene.Conclusions: Both clusters may have resulted from close contact and droplet-spreading and asymptomatic infections were identified as the initial cause. We also analyzed the infectiousness of asymptomatic cases and the challenges to the current epidemic to provided information for the development of control strategies.

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COVID-19: epidemiology and preventive measures in Jiangsu province, China

10.21203/rs.3.rs-25763/v1 ◽

2020 ◽

Author(s):

Yi Chen ◽

JiaShu Liu ◽

ChangRui Yang ◽

Zi-sheng Ai ◽

AiHong Zhang

Keyword(s):

Preventive Measures ◽

Jiangsu Province ◽

Prevention Measures ◽

Cure Rate ◽

The People ◽

Improve Cure Rate ◽

Imported Cases ◽

Community Transmission ◽

Novel Coronavirus ◽

Epidemiological Characteristics

Abstract Background: To investigate the epidemiological features of coronavirus disease 2019(COVID-19) and the prevention measures in Jiangsu Province. Methods: Information of all novel coronavirus pneumonia conﬁrmed cases in Jiangsu was collected from the oﬃcial website of Jiangsu Commission of Health. All data were entered into Excel and Python3 for statistical analysis. Epidemiological characteristics of novel coronavirus pneumonia conﬁrmed cases from January 10, 2020 to March 18 in Jiangsu province were retrospectively analyzed. Meanwhile, the preventive measures of Jiangsu Commission of Health and the people’s Government of Jiangsu Province were also analyzed. Results: 631 COVID-19 cases were diagnosed in Jiangsu Province, covering 13 cities in Jiangsu. Before February 1, the conﬁrmed cases were mainly imported cases, and after February 1, community transmission cases became main part of conﬁrmed cases. There were more male patients than females, and most patients were in the group of 30-70 years old, 49 patients (7.8%) with mild symptom and 572 patients (90.6%) with common type accounted for the majority. The cumulative mortality rate was 0% and the cure rate was 100%. Reasonable treatments, timely and eﬀective preventive measures were taken to eﬀectively improve cure rate and to prevent the spread of the epidemic, all measures ensure the health and life safety of the people. Conclusion: The preventive measures in Jiangsu Province were timely and eﬀective, the epidemic situation in Jiangsu Province had been well controlled.

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Density of surgical specimens and correlation with clinical characteristics of women submitted to mastectomy: the archimedes project

Mastology ◽

10.29289/259453942020v30s1073 ◽

2020 ◽

Vol 30 (Suppl 1) ◽

Author(s):

Cassio Cardoso ◽

Mariana Sousa Sguerra Silva ◽

Ana Gabriela Bicalho Rabelo ◽

Cesar Cabello dos Santos ◽

Giuliano Mendes Duarte

Keyword(s):

Breast Cancer ◽

Prevalence Ratio ◽

Surgical Reconstruction ◽

Age At Menarche ◽

Chi Square ◽

Exact Test ◽

Female Breast ◽

Postural Changes ◽

The Difference ◽

Epidemiological Characteristics

Introduction: Breast cancer is the second most common neoplasm among women, being responsible, per year, for 60 thousand new cases of breast cancer in Brazil. The treatment varies according to staging, and mastectomy is indicated in cases in which conserving surgery it is not possible. Mastectomy patients who do not present with indication for breast surgical reconstruction may have self-esteem problems, and external prostheses are one of the means to recover body image. Despite being an external, relatively simple device, external prosthesis may lead do pruritus, pain, paresthesia and postural changes. Therefore, the objective of this study is to describe the density of the female breast to serve as a base to improve these prostheses, considering that the current literature lacks studies to establish this parameter. Objectives: To determine the density of the female breast and correlate it with the clinical and epidemiological characteristics and the treatment. Subjects and Methods: This is a descriptive study that measured the mass and volume of 100 mastectomy specimens to calculate density, with correlation to factors such as age, parity, menstrual factors. Determination of frequencies, means and standard-deviation of the variables, with risk assessment, was carried out with the chi-square or the Fisher’s exact test for the expected values lower than 5, as well as the log-binomial model between the variables using the prevalence ratio with 95% confidence interval (GraphPad®, available at https://www.graphpad.com/quickcalcs/contingency2/). We considered p<0.05 as significant, and confidence intervals (CI) were established at 95%. Results: Of the 100 women included in this study, 78% were white, mean age was 58 years (300‒94 years), mean age at menarche was 13 years, and mean age at menopause was 49 years. Of the women submitted to mastectomy, 39% were in their reproductive years. Mean density of the mastectomy specimens in this study was 1.23g/cm3. There was statistically significant correlation regarding the difference in the density of the specimens in patients with Body Mass Index (BMI)>30 in relation to the density of the specimens in patients with BMI<30. In this aspect, we found lower density associated with BMI>30 (p=0.0025). Conclusion: unlike what we found in the literature, the mastectomy specimens are approximately 20% denser in relation to water and silicone, which are commonly used materials in internal and external prosthesis. This reference can collaborate with the development of prosthesis that are more similar to the natural breast, better adjusting to the daily life of women, with fewer side effects and better quality of life.

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Molecular epidemiology of SARS-CoV-2 clusters caused by asymptomatic cases in Anhui Province, China

10.21203/rs.3.rs-29833/v2 ◽

2020 ◽

Author(s):

yuan yuan ◽

Jun He ◽

Lei Gong ◽

Weiwei Li ◽

Liangliang Jiang ◽

...

Keyword(s):

Disease Transmission ◽

Close Contact ◽

Control Strategies ◽

Asymptomatic Infection ◽

Droplet Spreading ◽

Close Link ◽

Spike Gene ◽

Asymptomatic Patients ◽

Asymptomatic Infections ◽

Novel Coronavirus

Abstract Background: COVID-19 is a newly emerging disease caused by a novel coronavirus (SARS-CoV-2), which spread globally in early 2020. Asymptomatic carriers of the virus contribute to the propagation of this disease, and the existence of asymptomatic infection has caused widespread fear and concern in the control of this pandemic. Methods: In this study, we investigated the origin and transmission route of SARS-CoV-2 in Anhui’s two clusters, analyzed the role and infectiousness of asymptomatic patients in disease transmission, and characterized the complete spike gene sequences in the Anhui strains. Results: We conducted an epidemiological investigation of two clusters caused by asymptomatic infections sequenced the spike gene of viruses isolated from 12 patients. All cases of the two clusters we investigated had clear contact histories, both from Wuhan, Hubei province. The viruses isolated from two outbreaks in Anhui were found to show a genetically close link to the virus from Wuhan. In addition, new single nucleotide variations were discovered in the spike gene. Conclusions: Both clusters may have resulted from close contact and droplet-spreading and asymptomatic infections were identified as the initial cause. We also analyzed the infectiousness of asymptomatic cases and the challenges to the current epidemic to provided information for the development of control strategies.

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Analysis on the Clinical Characteristics of 10 Cases of Asymptomatic SARS-CoV-2 Novel Coronavirus Infection

Proceedings of Anticancer Research ◽

10.26689/par.v5i1.1877 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Lijun Chen ◽

Xiaoyong Ma ◽

Juanxia Chen ◽

Liting Ma

Keyword(s):

Clinical Features ◽

Asymptomatic Infection ◽

Chest Ct ◽

Clinical Classification ◽

Asymptomatic Group ◽

Ct Examination ◽

Asymptomatic Patients ◽

Significant Difference ◽

The Difference ◽

Novel Coronavirus

Objective: To analyze the clinical features of asymptomatic patients infected with the SARS-CoV-2 novel coronavirus. Methods: The clinical data of 10 asymptomatic cases and 12 symptomatic cases of COVID-19 diagnosed during February 2020 to April 2020 was collected and the clinical features of the two groups of patients were compared. Results: 10 cases of asymptomatic infection and 12 cases of symptomatic patients were tested positive for the novel coronavirus nucleic acid test. There was no significant difference in gender distribution between the two groups (P?0.05); the average age of patients in the asymptomatic group was lower than that of the symptomatic group ( P?0.05), the difference in clinical classification between the two groups was statistically significant (P?0.05); there was no statistically significant difference in the results of chest CT examination involving lung lobes between the two groups (P?0.05), and there was no statistically significant difference in mortality between the two groups (P>0.05). Conclusion: The average age of asymptomatic novel coronavirus infections was lower than that of confirmed cases of COVID-19, mainly among young people. There was no significant difference in clinical classification, mortality and chest CT examination results between symptomatic and asymptomatic cases.

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Epidemiological Analysis of Asymptomatic SARS-CoV-2 Novel Coronavirus Infection Cases in Yinchuan City of Ningxia

Journal of Clinical and Nursing Research ◽

10.26689/jcnr.v5i1.1757 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Lijun Chen ◽

Wang Xu ◽

Juanxia Chen ◽

Chunyan Xia ◽

Liang Xie

Keyword(s):

Close Contact ◽

Asymptomatic Infection ◽

Antibody Detection ◽

Research Subjects ◽

Normal Range ◽

History Of ◽

Coronavirus Infection ◽

Novel Coronavirus ◽

Underlying Diseases ◽

Epidemiological Characteristics

Objective: To analyze the epidemiological characteristics of asymptomatic SARS-CoV-2 novel coronavirus infection cases in Yinchuan City, Ningxia. Methods: Cases of asymptomatic SARS-CoV-2 novel coronavirus infections discovered in Yinchuan City from February 2020 to April 2020 were taken as the research subjects, epidemiological and laboratory examination data were collected, and statistics and analysis were conducted. Results: Among the 10 cases of asymptomatic infection, 6 were males and 4 were females, with an average age of (34.3±2.1) years; 2 cases had a history of living in Hubei, 8 cases had a history of close contact with confirmed cases; 6 cases had no other underlying diseases while the other 4 cases were accompanied by one or more underlying diseases; 6 cases were diagnosed as asymptomatic infection by serum-specific IgM antibody detection; 4 cases were diagnosed as asymptomatic infection by throat swab testing; there were 4 cases with alanine base transferase level higher than the normal range, 2 cases with aspartate aminotransferase level higher than the normal range, and 3 cases with D-dimer level out of the normal range. Conclusion: The asymptomatic SARS-CoV-2 novel coronavirus infection has certain clinical characteristics; it is infectious and has insidious characteristics. Even if medical observation is dismissed, monitoring is still needed to prevent the pandemic from rebounding.

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