Biomaterial Database

Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14. 2014

L Feng, and J T Wu, and X Liu, and P Yang, and T K Tsang, and H Jiang, and P Wu, and J Yang, and V J Fang, and Y Qin, and E H Lau, and M Li, and J Zheng, and Z Peng, and Y Xie, and Q Wang, and Z Li, and G M Leung, and G F Gao, and H Yu, and B J Cowling

Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.

Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.

UI	MeSH Term	Description	Entries
D007223	Infant	A child between 1 and 23 months of age.	Infants
D007251	Influenza, Human	An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.	Grippe,Human Flu,Human Influenza,Influenza in Humans,Influenza,Flu, Human,Human Influenzas,Influenza in Human,Influenzas,Influenzas, Human
D011200	Poultry	Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.	Fowls, Domestic,Domestic Fowl,Domestic Fowls,Fowl, Domestic,Poultries
D002681	China	A country spanning from central Asia to the Pacific Ocean.	Inner Mongolia,Manchuria,People's Republic of China,Sinkiang,Mainland China
D004196	Disease Outbreaks	Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.	Outbreaks,Infectious Disease Outbreaks,Disease Outbreak,Disease Outbreak, Infectious,Disease Outbreaks, Infectious,Infectious Disease Outbreak,Outbreak, Disease,Outbreak, Infectious Disease,Outbreaks, Disease,Outbreaks, Infectious Disease
D005260	Female		Females
D005585	Influenza in Birds	Infection of domestic and wild fowl and other BIRDS with INFLUENZA A VIRUS. Avian influenza usually does not sicken birds, but can be highly pathogenic and fatal in domestic POULTRY.	Avian Flu,Avian Influenza,Fowl Plague,Influenza, Avian,Avian Influenzas,Flu, Avian,Influenza in Bird,Influenzas, Avian,Plague, Fowl
D006760	Hospitalization	The confinement of a patient in a hospital.	Hospitalizations
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults