title: Estimate of 2009 H1N1 influenza cases in Shenzhen--the biggest migratory city in China.
abstract: The 2009 novel H1N1 influenza pandemic had a significant impact on Shenzhen's population with 2063 laboratory-confirmed human H1N1 cases and five deaths being reported. We used parameters from two population-based surveys and the Shenzhen Influenza Surveillance System to estimate the total number of H1N1 influenza infections in Shenzhen in the 2009 pandemic. The attack rate of influenza-like illness (ILI) in family households was 11·2% (95% CI 9·4-13·0), with 80·2% (95% CI 77·8-82·5) seeking medical care. The ILI attack rate in workers was 38·1% (95% CI 34·3-41·7) with 72·5% (95% CI 66·9-78·0) seeking medical care. The average H1N1 positive rate in individuals reporting ILI and testing by polymerase chain reaction was 22·7%. A total of 611 000-768 000 people, or 4·7-5·9% of the Shenzhen population, are estimated to have experienced H1N1 influenza. The estimated total number of cases of H1N1 is likely to be 330 times greater than the number of laboratory-confirmed cases.
authors: Shenzhen Center for Disease Control and Prevention, No. 8 Longyuan Road, Shenzhen, Guangdong, People's Republic of China.
authors: X
authors: X
authors: Xie
authors: S Q Y
authors: SQ
authors: Lu
authors: J Q
authors: JQ
authors: Cheng
authors: X W
authors: XW
authors: Cheng
authors: Z H
authors: ZH
authors: Xu
authors: J
authors: J
authors: Mou
authors: S J
authors: SJ
authors: Mei
authors: D F
authors: DF
authors: Kong
authors: X
authors: X
authors: Wang
authors: Y
authors: Y
authors: Li
authors: G
authors: G
authors: Fellmeth
authors: H W
authors: HW
authors: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000821:virology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D055815:Young Adult