BACKGROUND: Six epidemic waves of human infection with avian influenza A (H7N9) virus have emerged in China with high mortality. However, study on quantitative relationship between clinical indices in ill persons and H7N9 outcome (fatal and non-fatal) is still unclear. A retrospective cohort study was conducted to collect laboratory-confirmed cases with H7N9 viral infection from 2013 to 2015 in 23 hospitals across 13 cities in Guangdong Province, China. METHODS: Multivariable logistic regression model and classification tree model analyses were used to detect the threshold of selected clinical indices and risk factors for H7N9 death. The receiver operating characteristic curve (ROC) and analyses were used to compare survival and death distributions and differences between indices. A total of 143 cases with 90 survivors and 53 deaths were investigated. RESULTS: Average age (Odds Ratio (OR) = 1.036, 95% Confidence Interval (CI) = 1.016-1.057), interval days between dates of onset and confirmation (OR = 1.078, 95% CI = 1.004-1.157), interval days between onset and oseltamivir treatment (OR = 5.923, 95% CI = 1.877-18.687), body temperature (BT) (OR = 3.612, 95% CI = 1.914-6.815), white blood cell count (WBC) (OR = 1.212, 95% CI = 1.092-1.346) were significantly associated with H7N9 death after adjusting for confounders. The chance of death from H7N9 infection was 80.0% if BT was over 38.1 °C, and chance of death is 67.4% if WBC count was higher than 9.5 (10/L). Only 27.1% of patients who began oseltamivir treatment less than 9.5 days after disease onset died, compared to 68.8% of those who started treatment more than 15.5 days after onset. CONCLUSIONS The intervals between date of onset and confirmation of diagnosis, between date of onset to oseltamivir treatment, age, BT and WBC are found to be the best predictors of H7N9 mortality.
Adult ; Aged ; China ; epidemiology ; Confidence Intervals ; Female ; Hospitalization ; statistics & numerical data ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza, Human ; epidemiology ; mortality ; virology ; Logistic Models ; Male ; Middle Aged ; ROC Curve ; Retrospective Studies ; Risk Factors ; Young Adult

Adolescent ; Humans ; Influenza A Virus, H7N9 Subtype ; immunology ; pathogenicity ; Lymphopenia ; immunology ; microbiology ; Male ; T-Lymphocytes ; metabolism

Objective: To investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza A (H7N9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. Methods: Epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. Samples collected from the patient, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (RT-PCR). Virus isolation, genome sequencing and phylogenetic analysis were conducted for positive samples. Results: The case had no live poultry contact history, but had a history of pulled chicken processing without taking protection measure in an unventilated kitchen before the onset. Samples collected from the patient's lower respiratory tract, the remaining frozen chicken meat and the live poultry market were all influenza A (H7N9) virus positive. The isolated viruses from these positive samples were highly homogenous. An insertion which lead to the addition of multiple basic amino acid residues (PEVPKRKRTAR/GL) was found at the HA cleavage site, suggesting that this virus might be highly pathogenic. Conclusions: Live poultry processing without protection measure is an important infection mode of "poultry to human" transmission of avian influenza viruses. Due to the limitation of protection measures in live poultry markets in Guangzhou, it is necessary to promote the standardized large scale poultry farming, the complete restriction of live poultry sales and centralized poultry slaughtering as well as ice fresh sale.
Animals ; Chickens ; China ; Commerce ; Humans ; Influenza A Virus, H7N9 Subtype/pathogenicity* ; Influenza in Birds/virology* ; Influenza, Human/virology* ; Phylogeny ; Poultry/virology* ; Real-Time Polymerase Chain Reaction ; Zoonoses

Aged ; Animals ; Female ; Follow-Up Studies ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza, Human ; pathology ; virology ; Male ; Middle Aged ; Tomography, X-Ray Computed

Herpes Zoster Oticus ; diagnosis ; virology ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Magnetic Resonance Imaging ; Male ; Middle Aged

China ; epidemiology ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza, Human ; epidemiology ; virology

Antiviral Agents ; therapeutic use ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza, Human ; diagnosis ; diet therapy ; Middle Aged

BACKGROUNDIn March 2013, human cases of infection with a novel A (H7N9) influenza virus emerged in China. The epidemic spread quickly and as of 6 May 2013, there were 129 confirmed cases. The purpose of this study was to analyze the epidemiology of the confirmed cases, determine the impacts of bird migration and temperature changes on the H7N9 epidemic, predict the future trends of the epidemic, explore the response patterns of the government and propose preventive suggestions.

METHODSThe geographic, temporal and population distribution of all cases reported up to 6 May 2013 were described from available records. Risk assessment standard was established by analysing the temperature and relative humidity records during the period of extensive outbreak in three epidemic regions in eastern China, including Shanghai, Zhejiang and Jiangsu provinces. Risk assessment maps were created by combining the bird migration routes in eastern China with the monthly average temperatures from May 1993 to December 2012 nationwide.

RESULTSAmong the confirmed cases, there were more men than women, and 50.4% were elderly adults (age >61 years). The major demographic groups were retirees and farmers. The temperature on the days of disease onset was concentrated in the range of 9°C-19°C; we defined 9°C-19°C as the high-risk temperature range, 0°C-9°C or 19°C-25°C as medium risk and <0°C or >25°C as low risk. The relative humidity on the days of disease onset ranged widely from 25% to 99%, but did not correlate with the incidence of infection. Based on the temperature analysis and the eastern bird migration routes, we predicted that after May, the high-risk region would move to the northeast and inland, while after September, it would move back to north China.

CONCLUSIONSTemperature and bird migration strongly influence the spread of the H7N9 virus. In order to control the H7N9 epidemic effectively, Chinese authorities should strengthen the surveillance of migrating birds, increase poultry and environmental sampling, improve live poultry selling and husbandry patterns and move from a "passive response pattern" to an "active response pattern" in focused preventive measures.

Antiviral Agents ; therapeutic use ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza, Human ; drug therapy ; epidemiology ; virology

Animals ; Birds ; China ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza in Birds ; epidemiology ; virology ; Influenza, Human ; epidemiology ; virology