Publications by authors named "Zongqiu Chen"

What Is Already Known About This Topic?: 1,4,[5],12:i:- and Rissen are emerging serotypes of that require close monitoring for antimicrobial resistance and containment of their spread.

What Is Added By This Report?: The study aimed to identify antimicrobial resistance genes (ARGs) in 1,4,[5],12:i:- and Rissen strains isolated from environmental sewage in Guangzhou City, Guangdong Province, China. A phylogenetic tree was constructed using single nucleotide polymorphism data to assess genetic relatedness among strains, offering insights for infection outbreak investigations in the future.

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Objective: To monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA contamination in samples linked to imported cold-chain food and assess the situation from the implementation of a centralized supervision warehouse system in Guangzhou, Guangdong Province, China.

Methods: Swabs of workers and frozen-food-related samples were collected between July 2020 and December 2023 in Guangzhou, Guangdong Province. SARS-CoV-2 RNA was extracted and analyzed by a real-time quantitative polymerase chain reaction using the commercially available SARS-CoV-2 nucleic acid test kit.

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The severe acute respiratory syndrome coronavirus 2 has caused a worldwide pandemic. Control measures differ among countries and have a varying degree of effectiveness, which requires assessment. To evaluate the effectiveness of public health interventions of the coronavirus disease 2019 (COVID-19) in Guangzhou by 3 periods according to interventions: January 7 to 22 (no intervention), January 23 to February 23 (implemented intensive interventions), and February 24 to May 17 (the normalization mode of COVID-19 prevention and control).

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Background: The first community transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant of concern (VOC) in Guangzhou, China occurred between May and June 2021. Herein, we describe the epidemiological characteristics of this outbreak and evaluate the implemented containment measures against this outbreak.

Methodology/principal Findings: Guangzhou Center for Disease Control and Prevention provided the data on SARS-CoV-2 infections reported between 21 May and 24 June 2021.

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Background: The quarantine in dedicated hotels has become an inevitable safety measure due to the frequent cross-border travel since the outbreak of COVID-19. The aim of the present study was to explore the trends in the psychological status of individuals entering from high-risk areas of COVID-19 coronavirus while quarantining in dedicated hotels.

Methods: A total of 591 individuals who isolated in dedicated hotels were recruited between March and June 2020.

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Some patients retested positive for SARS-CoV-2 following negative testing results and discharge. However, the potential risk factors associated with redetectable positive testing results in a large sample of patients who recovered from COVID-19 have not been well-estimated. A total of 745 discharged patients were enrolled between January 30, 2020, and September 9, 2020, in Guangzhou, China.

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Background: Sewage transmission of SARS-CoV-2 has never been demonstrated. During a COVID-19 outbreak in Guangzhou, China in April 2020, we investigated the mode of transmission.

Methods: We collected clinical and environmental samples from quarantined residents and their environment for RT-PCR testing and genome sequencing.

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Little is known about the SARS-CoV-2 contamination of environmental surfaces and air in non-health care settings among COVID-19 cases. We explored the SARS-CoV-2 contamination of environmental surfaces and air by collecting air and swabbing environmental surfaces among 39 COVID-19 cases in Guangzhou, China. The specimens were tested on RT-PCR.

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Guangzhou is believed to be the most important epicenter of dengue outbreaks in southern China. In this study, a longitudinal serological investigation of previous cases of dengue fever in Guangzhou was conducted to explore the persistence of IgG antibodies and related factors affecting the changes of antibody level. We recruited 70 dengue virus type 1 (DENV-1) primary infection cases at two years post infection for serological investigation and conducted a second follow-up in the 5th year of prognosis.

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Background: Dengue is the most prevalent mosquito-borne disease in the world, with China affected seriously in recent years. 65.8% of dengue cases identified in mainland China since 2005 were reported from the city of Guangzhou.

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The incidence of dengue is increasing in Guangdong, China, with the largest outbreak to date in 2014. Widespread awareness of epidemiological and molecular characteristics of the dengue virus (DENV) is required. In 2014, we isolated the virus from patients and sequenced its genome.

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Objective: Dengue has become a serious public health problem in southern China particularly with a record-breaking outbreak in 2014. Serological evidence from areas with no known dengue cases reported prior to 2014 could provide information on possible unrecognized circulation of dengue virus (DENV) before this outbreak.

Method: Between March and May 2015, we performed a cross-sectional serosurvey using a stratified random sampling method among individuals aged 1-84 years-old in 7 communities in Guangzhou with no reported dengue cases before 2014.

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Objective: To explore the relationship between meteorological factors and scarlet fever incidence from 2006 to 2017 in Guangzhou, the largest subtropical city of Southern China, and assist public health prevention and control measures.

Methods: Data for weekly scarlet fever incidence and meteorological variables from 2006 to 2017 in Guangzhou were collected from the National Notifiable Disease Report System (NNDRS) and the Guangzhou Meteorological Bureau (GZMB). Distributed lag nonlinear models (DLNMs) were conducted to estimate the effect of meteorological factors on weekly scarlet fever incidence in Guangzhou.

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Hand, foot and mouth disease (HFMD) primarily affects children younger than 5 years of age. Recently, HFMD has ranked as the top notifiable infectious disease in China. In December 2015, China approved two novel inactivated enterovirus 71 vaccines (EV71 vaccines) for HFMD.

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Background: Guangzhou reported its first laboratory-confirmed case of influenza A (H7N9) on January 10, 2014. A total of 25 cases were reported from the first wave of the epidemic until April 8, 2014. The fatality rate was much higher than in previous reports.

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Objective: To analyze the results of nine-round environmental specimen surveillance programs in five live poultry markets pre-, during and post the 'closing days' and to evaluate the effects of 'closing days' on live poultry markets regarding the control against avian influenza pollution.

Methods: In January 2014, control measures including culling poultry, completely cleaning and disinfecting and a 'three-day-closing' measure were conducted in five live poultry markets which were found positive for H7N9 nucleic acid in the 1(st) round environmental specimen surveillance program. Second surveillance program was conducted after a thorough disinfection campaign was launched.

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Purpose: A virologic surveillance program for A(H7N9) virus was conducted from April 15, 2013 to February 14, 2014 in Guangzhou, aiming to clarify the geographical distribution of A(H7N9) viruses among live poultry markets (LPMs) and poultry farms in Guangzhou. Virological and serological surveys of poultry workers were also conducted to evaluate the risk of poultry-to-human transmission of the A(H7N9) virus.

Methods: 36 retail LPMs, 6 wholesale LPMs and 8 poultry farms were involved in our surveillance program.

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Targeted surveillance for influenza A(H7N9) identified 24 cases of infection with this virus in Guangzhou, China, during April 1, 2013-March 7, 2014. The spectrum of illness ranged from severe pneumonia to asymptomatic infection. Epidemiologic findings for 2 family clusters of infection highlight the importance of rigorous close contact monitoring.

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Objective: To investigate the epidemic characteristics and pathogenic spectrum of community acquired pneumonia (CAP) in Guangzhou from 2009 to 2012.

Method: 14 major comprehensive hospitals were selected from 11 districts as sentinel hospitals for CAP cases surveillance, including 18 982 223 in total during the 4 years. The characteristics of pathogenic spectrum of CAP were stratified and analyzed by year, age and season.

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Objective: To analyze the results of avian influenza surveillance program in Guangzhou from 2006 to 2012 and to evaluate the risk of infections with H5, H7 and H9 subtypes avian influenza viruses.

Methods: Avian influenza surveillance system in Guangzhou consisted five components:serum surveillance on occupational population, environmental specimen surveillance of avian influenza virus, avian flu emergency surveillance, influenza viruses surveillance on ILI patient and surveillance on pneumonia of unknown causes. Hemagglutination inhibition test was conducted to detect the antibodies against H5, H7 and H9 while RT-PCR was used to test the nucleic acid of H5, H7 and H9 viruses.

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Objective: To assess the relationship between cardiovascular risk factors and osteoporosis.

Methods: 2202 women aged 50 - 73 years were included in this cross-sectional study from the communities in Guangzhou, from July 2008 to January 2010. Cardiovascular risk factors including age, years since menopause, physical activity, anthropometrics, body composition, blood pressure, fasting serum lipids, glucose and uric acid, intima-media thickness (IMT) of carotid artery were assessed.

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Objective: This study assessed the effect of food preference and dietary behaviors on the risk of overweight or obesity in school children and adolescents aged 6 - 19 years.

Methods: All overweight or obese students, with age- and school-matched controls were recruited for this case-control study from 28 elementary and secondary schools in Guangzhou urban districts from October 2006 to April 2007. Weight and height were measured, and body mass index was calculated for the classification of obesity, overweight and underweight.

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