Epidemiology of scarlet fever in Ningbo, Zhejiang, 2004-2011

Objective understand the epidemiological characteristics of scarlet fever in Ningbo and provide scientific evidence for the prevention and control of the disease. Methods The incidence data of scarlet fever in Ningbo from 2004 to 2011 was collected from national disease reporting information system to conduct descriptive epidemiological analysis. Results A total of 955 scarlet fever cases were reported during this period with the average annual incidence of 1.77/lakh. The reported incidence of scarlet fever in 2011 was 425% higher than that in 2010.The reported case numbers in 44 weeks of 52 weeks in 2011 reached or exceeded the threshold. The incidence of scarlet fever had obvious seasonality, which peaked during April-May with the exception in 2006 and 2011. The male to female ratio of the cases was 1.80:1. The cases were mainly distributed in children aged 0-15 years, especially in children aged 3-9 years. The incidence was highest in age group 6 years (32.40/lakh). Conclusion The overall incidence of scarlet fever began to decline slowly in 2007 in Ningbo, but incidences in some areas were still high. Schools and child care settings are the places where scarlet fever is prone to occur, the prevention and control of the disease in these settings should be strengthened.