Epidemiology of the avian influenza A (H7N9) outbreak in Zhejiang Province, China

SUMMARYNo published studies have discussed details of the prognosis and survival of patients with severe avian influenza A(H7N9) infection. In this study we analysed 128 laboratory-confirmed cases of severe H7N9 infection in Zhejiang province, the most affected region during the H7N9 epidemic in mainland China. We found that an increase in patient age by 5 years was associated with a 1·41 [95% confidence interval (CI) 1·19–1·67] times odds ratio for fatality. In addition, the time interval between the first clinical visit after symptom onset and hospital admission was inversely associated with survival time since admission. Of the 47 patients who died of the disease, when the time interval between the first clinical visit and hospital admission increased by 1 day, the duration of survival was 0·78 times (95% CI 0·62–0·98) as long. Our results suggest that patients with severe influenza H7N9 infection at older ages were at a higher risk of fatality, and that a delay in hospital admission was associated with more rapid death. More studies are required to corroborate our major findings.

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Comparison of the three waves of avian influenza A(H7N9) virus circulation since live poultry markets were permanently closed in the main urban areas in Zhejiang Province, July 2014-June 2017

Influenza and Other Respiratory Viruses ◽

10.1111/irv.12532 ◽

2018 ◽

Vol 12 (2) ◽

pp. 259-266 ◽

Cited By ~ 6

Author(s):

Wei Cheng ◽

Xiaoxiao Wang ◽

Ye Shen ◽

Zhao Yu ◽

Shelan Liu ◽

...

Keyword(s):

Avian Influenza ◽

Urban Areas ◽

Influenza A ◽

Zhejiang Province ◽

H7n9 Virus ◽

Live Poultry ◽

Live Poultry Markets

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Epidemiology of human infections with avian influenza A(H7N9) virus in the two waves before and after October 2013 in Zhejiang province, China

Epidemiology and Infection ◽

10.1017/s095026881400257x ◽

2014 ◽

Vol 143 (9) ◽

pp. 1839-1845 ◽

Cited By ~ 17

Author(s):

X. Y. WANG ◽

C. L. CHAI ◽

F. D. LI ◽

F. HE ◽

Z. YU ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Case Fatality ◽

Zhejiang Province ◽

H7n9 Virus ◽

Virus Infections ◽

Before And After ◽

Live Poultry ◽

Second Wave ◽

Live Poultry Markets

SUMMARYWe compared the epidemiological and clinical features of avian influenza A(H7N9) virus infections in the population in Zhejiang province, China, between March and April 2013 (first wave) and October 2013 and February 2014 (second wave). No statistical difference was found for age, sex, occupation, presence of underlying conditions, exposure history, white blood cell count, lymphocyte percentage and illness timeline and duration (all P > 0·05). The virus spread to 30 new counties compared to the first wave. The case-fatality rate was 22% in the first wave and 42% in the second (P = 0·023). Of those infected, 66% in the first wave and 62% in the second wave had underlying conditions. The proportion of those exposed to live poultry markets were 80% and 66%, respectively. We recommend permanent closure of live poultry markets and reformation of poultry supply and sales.

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