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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330164

ABSTRACT

Objectives: Since the outbreak of coronavirus disease 2019 (COVID-19), it has caused serious casualties worldwide. In recent months, the virus has mutated into an increasingly infectious form (Delta variant) and spread rapidly. Methods In the current study, we analyzed the clinical, epidemiological and viral genetic characteristics of the first four imported Delta cases in Anhui Province, China. Results The four imported Delta cases developed chest inflammation, tissue damage and recovered after admission, the serum high-sensitivity C-reactive protein (hs-CRP) and CRP levels showed a first increasing and then decreasing trend. The changes of hs-CRP /CRP and serum neutralizing antibodies (Nab) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) levels were associated with the regression of chest lesions. The combination of genetic sequencing and epidemiological analysis suggested that the SARS-CoV-2 delta variant infection of these four patients may originate from Russia. Conclusions Our study found the certain correlations of serum hs-CRP/CRP and Nab levels with the occurrence, development and outcome of COVID-19 delta variant, suggesting that monitoring hs-CRP/CRP and Nab levels of COVID-19 delta variant patients at hospital admission may be useful for understanding the severity of patients’ current conditions.

2.
Front Med (Lausanne) ; 9: 829273, 2022.
Article in English | MEDLINE | ID: covidwho-1715010

ABSTRACT

Detection of serum-specific SARS-CoV-2 antibody has become a complementary means for the identification of coronavirus disease 2019 (COVID-19). As we already know, the neutralizing antibody titers in patients with COVID-19 decrease during the course of time after convalescence, whereas the duration of antibody responses in the convalescent patients has not been defined clearly. In the current study, we collected 148 serum samples from 37 confirmed COVID-19 cases with different disease severities. The neutralizing antibodies (Nabs), IgM and IgG against COVID-19 were determined by CLIA Microparticle and microneutralization assay, respectively. The time duration of serum titers of SARS-CoV-2 antibodies were recorded. Our results indicate that IgG (94.44%) and Nabs (89.19%) can be detected at low levels within 190-266 days of disease onset. The findings can advance knowledge regarding the antibody detection results for COVID-19 patients and provide a method for evaluating the immune response after vaccination.

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324820

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.

4.
Research Evaluation ; 31(1):132-144, 2022.
Article in English | Academic Search Complete | ID: covidwho-1621673

ABSTRACT

The technological innovation of wind power is crucial to energy security and energy structure transformation. The Chinese government has been committed to improving the innovation of the wind power industry for decades. Although academic researchers and wind power policymakers have been widely concerned about the absolute score of innovation output, concentrating on innovation output in isolation is ultimately insufficient. This article goes beyond bean counting and evaluates the innovation of the Chinese wind power industry from the perspective of relative efficiency, and then assesses the efforts of the government to improve innovation efficiency (IE). The study uses the data of 105 wind power listed enterprises in China over the period 2008–2019. According to the recommendation made by the existing papers, IE is defined as the capability to generate innovation outputs per unit of R&D investment. Regression analysis is applied to test the policy effect. During 2008–2019, the average value of IE of Chinese wind power industry is 0.196. The IE of wind power enterprises in eastern China (0.265) is higher than that in central and western China (0.169). Besides, the regression results indicate that all categories of wind power innovation policies contribute to the IE of wind power industry in China. Furthermore, the innovation policies issued by the departments of the State Council significantly improve the IE of wind power industry, but the innovation policies from the National People's Congress and the State Council have no significant impacts on IE. [ FROM AUTHOR] Copyright of Research Evaluation is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

5.
J Med Virol ; 93(10): 5998-6007, 2021 10.
Article in English | MEDLINE | ID: covidwho-1432442

ABSTRACT

In the context of the coronavirus disease 2019 pandemic, we investigated the epidemiological and clinical characteristics of a young patient infected by avian influenza A (H5N6) virus in Anhui Province, East China, and analyzed genomic features of the pathogen in 2020. Through the cross-sectional investigation of external environment monitoring (December 29-31, 2020), 1909 samples were collected from Fuyang City. It was found that the positive rate of H5N6 was higher than other areas obviously in Tianma poultry market, where the case appeared. In addition, dual coinfections were detected with a 0.057% polymerase chain reaction positive rate the surveillance years. The virus was the clade 2.3.4.4, which was most likely formed by genetic reassortment between H5N6 and H9N2 viruses. This study found that the evolution rates of the hemagglutinin and neuraminidase genes of the virus were higher than those of common seasonal influenza viruses. The virus was still highly pathogenic to poultry and had a preference for avian receptor binding.


Subject(s)
COVID-19/epidemiology , Influenza A virus/isolation & purification , Influenza in Birds/virology , Influenza, Human/virology , Animals , Child, Preschool , China , Female , Genome, Viral/genetics , Humans , Influenza A virus/classification , Influenza A virus/genetics , Influenza, Human/diagnosis , Mutation , Phylogeny , Poultry/virology , Reassortant Viruses/classification , Reassortant Viruses/genetics , Reassortant Viruses/isolation & purification , SARS-CoV-2 , Viral Proteins/genetics
6.
J Med Virol ; 93(10): 5998-6007, 2021 10.
Article in English | MEDLINE | ID: covidwho-1298504

ABSTRACT

In the context of the coronavirus disease 2019 pandemic, we investigated the epidemiological and clinical characteristics of a young patient infected by avian influenza A (H5N6) virus in Anhui Province, East China, and analyzed genomic features of the pathogen in 2020. Through the cross-sectional investigation of external environment monitoring (December 29-31, 2020), 1909 samples were collected from Fuyang City. It was found that the positive rate of H5N6 was higher than other areas obviously in Tianma poultry market, where the case appeared. In addition, dual coinfections were detected with a 0.057% polymerase chain reaction positive rate the surveillance years. The virus was the clade 2.3.4.4, which was most likely formed by genetic reassortment between H5N6 and H9N2 viruses. This study found that the evolution rates of the hemagglutinin and neuraminidase genes of the virus were higher than those of common seasonal influenza viruses. The virus was still highly pathogenic to poultry and had a preference for avian receptor binding.


Subject(s)
COVID-19/epidemiology , Influenza A virus/isolation & purification , Influenza in Birds/virology , Influenza, Human/virology , Animals , Child, Preschool , China , Female , Genome, Viral/genetics , Humans , Influenza A virus/classification , Influenza A virus/genetics , Influenza, Human/diagnosis , Mutation , Phylogeny , Poultry/virology , Reassortant Viruses/classification , Reassortant Viruses/genetics , Reassortant Viruses/isolation & purification , SARS-CoV-2 , Viral Proteins/genetics
7.
Int J Infect Dis ; 117: 372-377, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1225254

ABSTRACT

BACKGROUND: COVID-19 has spread worldwide and become a pandemic. We report the epidemiological and clinical characteristics of cluster infections. METHODS: Data of clustered cases were retrieved from the public health emergency monitoring information system of China. We analyzed the incubation period, generation gap, secondary attack rate, and viral load in various grouped cases. RESULTS: A total of 60 COVID-19 infection clusters including 226 patients and 19 asymptomatic cases involving four generations were analyzed. With the increase of transmission generations, secondary attack rate decreased (P<0.001) and severity alleviated (P = 0.008). The median incubation period and intergenerational interval were 9 and 6 days, respectively. The secondary attack rate was 7.1% in the index cases, 5.0% in the first generation, 1.0% in the second generation, and 4.7% overall. Severe cases were seen more in the index (13, 65%) and first generation (7, 35%) ones, who had a significantly higher viral load than the mild and moderate ones. CONCLUSIONS: With the increase of transmission generation, secondary infection rate and severity decreased. Severe patients had a higher virus load. Patients in the incubation period and asymptomatic carriers were potential infection sources who might play an important role in transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , China/epidemiology , Humans , Incidence , Pandemics
9.
BMC Infect Dis ; 20(1): 930, 2020 Dec 07.
Article in English | MEDLINE | ID: covidwho-962806

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.


Subject(s)
Asymptomatic Infections/epidemiology , COVID-19/epidemiology , COVID-19/virology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , COVID-19/transmission , China/epidemiology , Contact Tracing , Disease Hotspot , Disease Outbreaks , Female , Humans , Male , Molecular Epidemiology , Pandemics , Phylogeny , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, RNA
10.
SSRN; 2020.
Preprint | SSRN | ID: ppcovidwho-691

ABSTRACT

Background: SARS-CoV-2 has caused a huge outbreak in China and multiple countries since it emerged in Wuhan, China in December, 2019. The virus caused diseases

11.
Int J Infect Dis ; 99: 325-327, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-597916

ABSTRACT

Few studies have focused on the transmission efficiency of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Our follow-up study was performed on 147 asymptomatic carriers in Anhui Province. Of these, 50.0% were male, 50.3% were older than 40 years, 43.8% were farmers, and 68.7% were from the north of Anhui Province. 16 of the 147 asymptomatic carriers developed symptoms in the following 14 days of isolated observation, and were subsequently diagnosed as confirmed cases. The possible latent infection period was found to range from 1-5 days before onset, with a median time of 2 days. The second attack rate for the 16 confirmed cases who had transferred from being asymptomatic carriers was 9.7% (23/236 close contacts), while for the 131 asymptomatic carriers the rate was 2.6% (24/914 close contacts), showing a significant difference in second attack rate between the two groups (p<0.001). Our study indicated that COVID-19 cases are contagious during the incubation period, and that close contact screening should be extended to include the incubation period. Our results also showed that the transmission efficiency for asymptomatic carriers was lower than that for confirmed case.


Subject(s)
Betacoronavirus/physiology , Communicable Diseases, Emerging/transmission , Coronavirus Infections/transmission , Pandemics/prevention & control , Pneumonia, Viral/transmission , Adult , Asymptomatic Diseases , COVID-19 , China/epidemiology , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/prevention & control , Communicable Diseases, Emerging/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Female , Follow-Up Studies , Humans , Incidence , Male , Mass Screening , Middle Aged , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Pneumonia, Viral/virology , SARS-CoV-2 , Young Adult
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