The Epidemiological Characteristics And Related Meteorological Factors Of Measles In Shandong Province

Measles is an acute respiratory infectious disease that spreads through direct contact and respiratory droplets and is prevalent in densely populated areas.Anyone who is not immunized is susceptible to measles.Children who have not been vaccinated have the highest risk of measles and complications.Measles Attenuated Live Vaccine is the most effective measure to prevent measles.It has been the goal of countries all over the world to control measles morbidity and death,and eventually eliminate measles through immunization measures.In recent years,the epidemic of measles has re-emerged in many parts of the world,and measles outbreaks have occurred in many countries and regions such as Europe,America and Asia.The incidence and mortality of measles in China have decreased significantly in recent decades.However,the incidence of measles has been reported to be on the rise since 2013,bringing series public health problems that cannot be ignored.A number of studies have shown that the epidemiological characteristics of measles in many provinces of China are basically consistent with the overall trend in the country,but there are few studies in Shandong Province during this period.In the context of accelerated climate change and globalization,the health effects of meteorological factors have gradually attracted the attention of researchers.Many scholars have explored the relationship between meteorological conditions and the incidence of measles.Spearman correlation analysis,multiple regression analysis and distributed lag non-linear model have been used in a single area,but few research studied in a wide range of areas,and most studies did not consider the spatial autocorrelation and spatial heterogeneity of measles.Therefore,it is of great significance to understand the epidemiological characteristics of measles in Shandong Province,to explore the distribution of aggregate areas,and study the association between meteorological factors and the incidence of measles,which will helpful to prevent the spread and reduce the incidence of this disease in Shandong Province.This study used epidemiological methods to describe the epidemiological characteristics of measles in Shandong Province from 2009 to 2016.By spatial autocorrelation analysis and space-time scanning,the spatial distribution characteristics of measles incidence in Shandong Province were analyzed on the scale of counties and districts,and the aggregated areas and periods of measles incidence were explored.The spatial panel data models were constructed based on the meteorological variables and measles incidence data,taking into account the temporal and spatial distribution characteristics of measles.This study provides a reference for the formulation of measles prevention and control policies in Shandong Province,and provides theoretical support for the determination of key monitoring population,key prevention and control areas and periods of measles prevention and control,and the rational allocation of health resources in Shandong Province.Main results:1.In Shandong Province,a total of 15,224 cases of measles were reported in 2009-2016.The incidence of measles was firstly decreased and then increased.The highest incidence rate was in 2016(4.44/100,000).the number of male cases was higher than that of females,and the male-female ratio was 1.32:1.Children younger than 8 months have the highest number of cases(20.26%),followed by the 29-39 age group.Scattered children are at high risk for measles,accounting for 48.14%of all reported cases,followed by farmers(25.07%).The incidence of measles has obvious periodicity and seasonality,and the peak incidence occurs from February to May.In terms of spatial distribution,the incidence of measles in Shandong Province is high at west and low at east.2.The incidence of measles in Shandong Province from 2009 to 2016 has positively spatial autocorrelation.Except 2012,the global Moran’s I index in other years varies from 0.185 to 0.556,and both are statistically significant at the 1%significance level.Local spatial autocorrelation analysis shows that the central and western regions of Shandong Province are the "hot spots" of measles,and the eastern coastal area is the "cold spot" of this disease.Space-time scanning analysis detected one maximum possible aggregated area and three secondary aggregated areas.The maximum possible aggregated area was distributed in all counties of Jinan City,as well as several counties of Liaocheng City,Dezhou City and Tai’an City,with the aggregated period was January to April 2016.The most serious secondary aggregated area was located in some counties in Qingdao City,Rizhao City and Weifang City(R = 13.53,P<0.001),with the aggregated period was January to April 2015,the remaining two secondary gathering areas are distributed in several cities in southern Shandong and several counties in Weifang City,respectively.3.By fitting the spatial panel data models to multiple meteorological factors and the measles incidence with two weeks’,lags in Shandong Province of 2013-2015,it shows that the diurnal temperature difference had positive effect on the incidence of measles after two weeks of lag,with the regression coefficient being 0.1098,which means that for every 1 ℃ increase in the diurnal temperature difference,the incidence of measles increases by 10.98%,and the other meteorological factors had no significant effect on the incidence of measles.Conclusions:1.The incidence of measles in Shandong Province decreased firstly and then increased in 2009-2016.The number of measles had obvious seasonality,and the peak incidence occurs from February to May.The age distribution of measles cases had obvious "double peak" distribution characteristics.Children younger than 8 months and adults aged 29 to 39 are the two peak ages groups of this disease.The proportion of scattered children and farmers is the highest.The scattered boys from 0 to 6 years old and women aged 19 to 49 are at high risk of measles.Areas with high incidence are mainly concentrated in the central and western regions.2.The distribution of measles in Shandong Province has obvious spatial autocorrelation,and it has gradually increased in recent years.The epidemic "hot spots" are mainly distributed in the western and central regions of Shandong Province,as well as some areas of Qingdao City,where have more developed economy and dense population.The eastern coastal areas are "cold spot" of this disease.3.According to the results of the spatial panel data models,the diurnal temperature difference had positive effect on the incidence of measles after two weeks of lag,with the regression coefficient being 0.1098,which means that for every 1 ℃increase in the diurnal temperature difference,the incidence of measles increases by 10.98%.