Detection of avian influenza A(H7N9) virus from live poultry markets in Guangzhou, China: a surveillance report.

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.

Influenza associated mortality in Southern China, 2010-2012.

Objective: Influenza caused substantial morbidity and mortality worldwide. The mortality burden caused by influenza has been under evaluation; however, data assessing this burden have been relatively sparse in tropical or subtropical regions. We estimated influenza-associated mortality in Guangzhou, China and assessed the excess mortality due to different influenza virus subtypes.

[Evaluation on the risks of H5, H7 and H9 avian influenza infections in Guangzhou: using data from the 2006-2012 avian influenza surveillance program].

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.

A two-year surveillance of 2009 pandemic influenza A (H1N1) in Guangzhou, China: from pandemic to seasonal influenza?

In this two-years surveillance of 2009 pandemic influenza A (H1N1) (pH1N1) in Guangzhou, China, we reported here that the scale and duration of pH1N1 outbreaks, severe disease and fatality rates of pH1N1 patients were significantly lower or shorter in the second epidemic year (May 2010-April 2011) than those in the first epidemic year (May 2009-April 2010) (P<0.05), but similar to those of seasonal influenza (P>0.05).

Antibody dynamics of 2009 influenza A (H1N1) virus in infected patients and vaccinated people in China.

Background: To evaluate the risk of the recurrence and the efficiency of the vaccination, we followed-up antibody responses in patients with the 2009 pandemic H1N1 influenza and persons who received the pandemic H1N1 vaccine in Guangzhou China.

Methods: We collected serum samples from 129 patients and 86 vaccinated persons at day 0, 15, 30, 180 after the disease onset or the vaccination, respectively. Antibody titers in these serum samples were determined by haemagglutination inhibition (HI) assay using a local isolated virus strain A/Guangdong Liwan/SWL1538/2009(H1N1).

Epidemiological investigation of an outbreak of pandemic influenza A (H1N1) 2009 in a boarding school: serological analysis of 1570 cases.

Background: A large number of 2009 pandemic influenza A (H1N1) infections were localized in school populations.

Objectives: To describe the epidemiology, clinical features and risk factors associated with an outbreak that occurred at a vocational boarding school in Guangzhou, P.R.

Immunogenicity associated with the routine use of an influenza A H1N1 vaccine in health care personnel in Guangzhou, China.

We present immunogenicity data on the routine vaccination of 103 health care personnel during the 2009 H1N1 national vaccination campaign. The seroprotection rate (percentage of samples with hemagglutination inhibition titers of > or =1:40) was 83.2% at 30 days postvaccination, lower than those obtained in previously published controlled trials.

[Avian influenza virus infection in people occupied in poultry fields in Guangzhou city].

Objective: To conduct serological investigation on H5N1/H9N2/H7N7 infection among people occupied in poultry fields.

Methods: Serum samples were collected from people working in live poultry and none-poultry retailing food markets, poultry wholesaling, large-scale poultry breading factories and in small-scale farms, wide birds breeding, swine slaughtering houses and from normal population. Antibodies of H5, H9 and H7 with hemagglutination inhibition and neutralization tests were tested and analyzed.

Food markets with live birds as source of avian influenza.

A patient may have been infected with highly pathogenic avian influenza virus H5N1 in Guangzhou, People's Republic of China, at a food market that had live birds. Virus genes were detected in 1 of 79 wire cages for birds at 9 markets. One of 110 persons in the poultry business at markets had neutralizing antibody against H5N1.

Monoclonal antibody-based antigen capture enzyme-linked immunosorbent assay reveals high sensitivity of the nucleocapsid protein in acute-phase sera of severe acute respiratory syndrome patients.

Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients.

[Analysis on the risk factors of severe acute respiratory syndromes coronavirus infection in workers from animal markets].

Objective: To investigate the possible risk factors of severe acute respiratory syndromes coronavirus (SARS-CoV) infection in workers from animal markets.

Methods: Self-designed questionnaires were used and serum samples were tested. Logistic regression analysis was used to analyze the data.

[An epidemiologic investigation on infection with severe acute respiratory syndrome coronavirus in wild animals traders in Guangzhou].

Objective: To investigate status of infection with severe acute respiratory syndrome coronovirus (SARS-CoV) in traders of wild animals wholesale markets in Guangzhou.

Methods: Serum antibody against SARS-CoV IgG was determined cross-sectionally and symptoms of respiratory infection were investigated retrospectively for part of traders of three wholesale markets for wild animals in Guangzhou.

Results: Overall rate of infection with SARS-CoV in 635 traders was 16.