BACKGROUND: As of 31(st) March 2010, more than 127,000 confirmed cases of 2009 pandemic @entity683 (H1N1), including 800 @entity204 , were reported in mainland China. The distribution and characteristics of the confirmed cases in the initial phase of this pandemic in this country are largely unknown. The present study aimed to characterize the geographic distribution and @entity1 characteristics of @entity281 in the 2009 pandemic as well as to identify potential risk factors associated with adverse @entity1 outcome in China, through retrospective analyses of 885 hospitalized cases with confirmed @entity281 . METHODOLOGY/PRINCIPAL FINDINGS: The proportional hazards model was employed to detect risk factors for adverse outcome; the geo-statistical maps were used to characterize the distribution of all 2668 confirmed H1N1 @entity1 throughout mainland China. The number of new cases increased slowly in May, 2009, but rapidly between June and August of the year. Confirmed cases were reported in 26 provinces; Beijing, Guangdong, Shanghai, Zhejiang and Fujian were the top five regions of the incidence of the @entity778 . After being adjusted for gender, age, chronic @entity358 and other general symptoms, delay for more than two days before hospital admission (HR: 0.6; 95%CI: 0.5-0.7) and delayed onset of the H1N1-specific @entity1576 (HR: 0.3; 95%CI: 0.2-0.4) were associated with adverse @entity1 outcome. CONCLUSIONS/SIGNIFICANCE: The 2009 pandemic @entity683 affected east and southeast coastal provinces and most populous cities more severely than other regions in mainland China due to higher risk of high level traffic-, high population density-, and high population mobility-associated H1N1 transmission.The clinical symptoms were mild in the initial phase of infection. Delayed hospital admission and delayed appearance of @entity1576 were among the major risk factors for poor @entity1 outcome. These findings may have significant implications in the future pandemic preparedness and response.

Geographic distribution and risk factors of the initial adult hospitalized cases of 2009 pandemic XXXX in mainland China.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity778 :: ('MESH:D015658', 'Disease') :: ['virus infection'] @entity683 :: ('MESH:D007251', 'Disease') :: ['influenza A'] @entity281 :: ('MESH:D007239', 'Disease') :: ['H1N1 infection'] @entity358 :: ('MESH:D008171', 'Disease') :: ['pulmonary disease'] @entity1576 :: ('MESH:D012131', 'Disease') :: ['respiratory symptoms'] @entity204 :: ('MESH:D003643', 'Disease') :: ['deaths']
@entity778 :: (MESH:D015658,Disease) :: ['influenza A (H1N1) virus infection']
