The Research On Epidemic Characteristics Of Scarlet Fever And Impact Of Meteorological Factors On Scarlet Fever In Jiangsu Province

Background: Scarlet fever,an acute respiratory infectious diseas caused by Group A Streptococcus pyogenes,is one of class B notifiable infectious disease in China.During 18-19 th century,scarlet fever was a common infectious with high mortality,while with improved health care and wide speard use of antibiotics,scarlet fever became a mild contagious dieases in the 20 th century.However,as a result of the change in climate,the pathogen or other unknown factors,outbreaks and increasing incidence of scarlet fever were reported in many countries in the past decades.But the analyses on characteristics and impact factors of scarlet fever are lacked in Jiangsu Province.Objective: 1.To analyze the epidemiological characteristics of scarlet fever in Jiangsu Province.2.To explore the spatiotemporal clusters of scarlet fever for developing targeted prevention and control strategies.3.To examine the relationships between meteorological factors and the incidence of scarlet fever for forecasting the epidemic trend of scarlet fever.Methods: The data of scarlet fever cases during 2005-2015 in Jiangsu Province were obtained from Notifiable Infectious Disease Reporting Information System.Demographic data and monthly meteorological data for the same period in Jiangsu Province were collected from Scientific Data Sharing Center of Public Health and China Meteorological Data Service Center,respectively.Descriptive statistics were used to illustrate epidemiological characteristics of scarlet fever in Jiangsu Province.Retrospective space-time analysis based on a discrete Poisson model was untilized to detect clusters of scarlet fever in the study area from 2005 to 2015.Generalized additive model was conducted to estimate the impact of meteorological factors on scarlet fever.Results: 1.A total of 15873 cases(9897 males and 5976 females)of scarlet fever occurred during 2005-2015 in Jiangsu Province,with an average annual incidence rate of 1.87 per 100,000.Incidence in men was higher than that in women(c2 = 968.58,P<0.0001).The group < 15 years accounted for 96.79% of all reported scarlet fever cases.2.The temporal characterisitics of scarlet fever presented a long-term trend of gradually ascending from 2012 to 2015,while the incidence of the disease held steady during 2005-2010.Two incidence peaks were observed in each year,the higher between March and July,and the lower between November and the following Junuary.Additionally,two incidence rate troughs were observed in each year.3.The incidence of scarlet fever in the southern regions of the province was generally higher than that in the northern regions.Two high endemic regions were observed,with one mainly located in Nantong city and the other in Lianyungang city.4.In retrospective space-time analysis,seven cluster were detected in the study period,and six of them occurred between April and June.The most likely cluster located Nantong and Suzhou areas coverd 13 counties,with relative risk of 10.31.5.In generalized additive model,the risk of scarlet fever increased gradually with the temperature rising in both age groups.Interestingly,with the monthly mean temperature above 20°C,the risk of scarlet fever presented a declining trend in those aged 3-14 years,while kept stable in the age group ? 2 years.In addition,the temperature range showed a positive effect in the population aged 3-14 years when it was above 9°C.Conclusions:1.The incidence of scarlet fever presented an increasing trend from 2005 to 2015 in Jiangsu Provicne.Public health authorities should enhance the surveillance of scarlet fever in kindergarten and primary school during the two epidemic peaks to reduce the incidence of the disease.2.Two high endemic regions(Nantong city and Lianyungang city)and seven clusters were the focus of surveillance and control.Furthermore,surveillance should also be given due importance.3.This study revealed the different effects of meteorological factors on scarlet fever in different population.Targeted prevention and control strategies in different population should be conducted in Jiangsu Provicne to improve the efficiency of works.