H7N9 avian influenza is the latest subtype of influenza virus to emerge in the world. By April 17, 2013 in Shanghai, a total of 31 confirmed cases were reported, and 11 of these patients died. The epidemiological characteristics and the clinical progress of this new human flu infection are still not clear. Thirteen confirmed patients have now been treated in Shanghai Public Health Clinical Center. Among the first batch of patients, hospitalised at the beginning of April 2013, two who were admitted with the same estimated date of onset of disease had very different outcomes. After active treatment at the Centre, one recovered by April 18, 2013, but one patient entered critical condition and died on April 11, 2013. The clinical and laboratory characteristics in hospital are here analysed and compared to learn more about H7N9 avian influenza. Confirmation that the observed differences are valuable for prognosis and treatment decisions for H7N9 patients awaits authentication by analysis of more patients.
Influenza in Birds ; Influenza A Virus, H7N9 Subtype ; Communicable Diseases ; Laboratories

Humans ; Influenza A Virus, H5N1 Subtype ; Influenza A Virus, H7N9 Subtype ; Influenza, Human ; drug therapy

OBJECTIVETo assess the risk of local outbreaks of H7N9 avian influenza infection in Zhejiang province and to explore the semi-quantitative assessment method for public health risks in emergency.

METHODSRisk index system of human infection with H7N9 avian influenza caused by local transmission were reviewed. The weights of indexes were calculated by analytic hierarchy process, which was combined with the TOPSIS method to calculate the risk comprehensive index.

RESULTSFour primary indexes and 23 secondary indexes were identified for risk assessment in local outbreaks of H7N9 avian influenza infection. The weights ranked on the top five were:morbidity (0.0972), closure measures (0.0718), sterilization measures (0.0673), fatality rate (0.0651), and epidemic spread (0.0616). The comprehensive index of the risk of local outbreaks of H7N9 avian influenza ranged from high to low were Hangzhou (0.5910), Shaoxing (0.5711), Jiaxing (0.5199), Taizhou (0.5198), Huzhou (0.4662), Ningbo (0.3828), Wenzhou (0.3719), Jinhua (0.3392), Lishui (0.2727), Quzhou (0.2001) and Zhoushan (0.0508).

CONCLUSIONSA semi-quantitative method has been established in this study, which provides scientific basis for prevention and control of H7N9 avian influenza epidemic in Zhejiang province.

Animals ; Birds ; China ; Humans ; Influenza A Virus, H7N9 Subtype ; Influenza in Birds ; transmission ; Influenza, Human ; transmission ; Risk Assessment

In 2013, two episodes of influenza emerged in China and caused worldwide concern. A new H7N9 avian influenza virus (AIV) first appeared in China on February 19, 2013. By August 31, 2013, the virus had spread to ten provinces and two metropolitan cities. Of 134 patients with H7N9 influenza, 45 died. From then on, epidemics emerged sporadically in China and resulted in several victims. On November 30, 2013, a 73-year-old woman presented with an influenza-like illness. She developed multiple organ failure and died 9 d after the onset of disease. A novel reassortant AIV, H10N8, was isolated from a tracheal aspirate specimen that was obtained from the patient 7 d after onset. This case was the first human case of influenza A subtype H10N8. On 4 February, 2014, another death due to H10N8 avian influenza was reported in Jiangxi Province, China.
Aged ; China ; epidemiology ; Female ; Humans ; Influenza A Virus, H10N8 Subtype ; classification ; Influenza A Virus, H7N9 Subtype ; classification ; Influenza A Virus, H9N2 Subtype ; classification ; Influenza, Human ; epidemiology ; virology ; Phylogeny ; Reassortant Viruses ; classification

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

Hotlines ; Humans ; Influenza A Virus, H7N9 Subtype ; Influenza, Human ; prevention & control ; virology ; Internet ; Preventive Health Services ; methods

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.

Animals ; Birds ; China ; epidemiology ; Influenza A Virus, H7N9 Subtype ; pathogenicity ; Influenza in Birds ; epidemiology ; Temperature

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

We developed a method for accurate quantification of the intact virus particles in inactivated avian influenza virus feedstocks. To address the problem of impurities interference in the detection of inactivated avian influenza virus feedstocks by direct high performance size exclusion chromatography (HPSEC), we firstly investigated polyethylene glycol (PEG) precipitation and ion exchange chromatography (IEC) for H5N8 antigen purification. Under the optimized conditions, the removal rate of impurity was 86.87% in IEC using DEAE FF, and the viral hemagglutination recovery was 100%. HPSEC was used to analyze the pretreated samples. The peak of 8.5-10.0 min, which was the characteristic adsorption of intact virus, was analyzed by SDS-PAGE and dynamic light scattering. It was almost free of impurities and the particle size was uniform with an average particle size of 127.7 nm. After adding antibody to the IEC pretreated samples for HPSEC detection, the characteristic peak disappeared, indicating that IEC pretreatment effectively removed the impurities. By coupling HPSEC with multi-angle laser scattering technique (MALLS), the amount of intact virus particles in the sample could be accurately quantified with a good linear relationship between the number of virus particles and the chromatographic peak area (R²=0.997). The established IEC pretreatment-HPSEC-MALLS assay was applied to accurate detection of the number of intact virus particles in viral feedstocks of different subtypes (H7N9), different batches and different concentrations, all with good applicability and reproducibility, Relative standard deviation < 5%, n=3.
Animals ; Reproducibility of Results ; Influenza A Virus, H7N9 Subtype ; Influenza in Birds ; Chromatography, Gel ; Virion ; Lasers