Clinical and Etiological Characteristics of a Measles outbreak during 1 a Recent 2 - Year Period admitted at Ditan Hospital , Beijing , China

21 Background: In 2009 and 2010 there were large outbreaks of measles in many 22 provinces of China, especially in Beijing 2010. We therefore conducted a study to 23 determine risk factors associated with measles amongst children, and provide 24 information for future disease prevention planning. Methods: A retrospective 25 case-control study was conducted in 200 children with clinical measles who were 26 matched by age and sex with 200 healthy children (who had never had a febrile rash) 27 living in the same areas as the cases. Patients who were clinically diagnosed as 28 measles at outpatient and ward between January 2009 and December 2010 were 29 included in the study. Results: The proportion of measles immunization was 30 significantly lower in the children who had measles compared to those without 31 immunization. The proportion of poor family socio-economic and parents' educational 32 status was obviously higher in children with measles and patients with severe and 33 complicated measles in 2010. The ratio of cases residing in urban areas (2010) was 34 lower than in 2009, and cases from other areas was higher in 2010 (57.2%) than in 35 2009 (39.9%). Conclusions: These findings suggest that the outbreak of measles in 36 2010 may be the populations displaced, and poor immunization coverage plays a 37 crucial role in measles outbreaks in Beijing. In this study, we illustrate that sudden 38 genotype shifts may occur, the genotype research of measles is going on. 39