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

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

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

Animals ; Antiviral Agents ; therapeutic use ; Birds ; China ; Humans ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza in Birds ; transmission ; Influenza, Human ; drug therapy ; epidemiology ; transmission ; Oseltamivir ; therapeutic use

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 ; drug therapy ; epidemiology ; virology