Analysis of seroepidemiology of enterovirus 71 diseases in children in Jiangsu province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the dynamic pattern and the distributive characteristics of neutralizing antibody against enterovirus 71 (EV-A71 ) in children aged 6-35 months in Jiangsu province from 2012 to 2014.</p><p><b>METHODS</b>From March, 2012 to March, 2014, a total of 1 276 children aged between 6 and 35 months were regularly followed up on day 0, year 1 and year 2 for EV-A71 neutralizing antibody test based on the enterovirus surveillance system, with the method of reporting by their guardian or being visited in Ganyu Sheyang Taixing Donghai Pizhou and Baoying in Jiangsu province. At the same time, samples were taken from the suspected persons infected by enterovirus. The χ(2) test or variance analysis was used to compare the difference of the positive rates and the geometric mean titer(GMT) of EV-A71 neutralizing antibody in different subjects.</p><p><b>RESULTS</b>In 2 years follow-up, the positive rates of EV-A71 antibody increased as the growth of the age,and the positive rates on day 0, year 1 and year 2 were 22.57% (288/1 276), 37.72%(444/1 177) and 42.84%(422/985), respectively (χ(2) values were 39.33, 56.41, 32.25; P< 0.001).The GMTs were 9.95, 15.37 and 24.05, respectively (F values were 22.90,46.36,41.58;P<0.001). In 2 years, the annually new infection rates were 13.47%(158/1 173) and 20.73%(192/926),respectively, and the annually decay rates of EV-A71 antibody were 2.81%(33/1 173) and 8.10%(75/926).</p><p><b>CONCLUSIONS</b>In 2012 to 2014, the positive rates and the GMTs of EV-A71 antibody of children increased as the growth of the age in Jiangsu. The higher annually new infection rate was in children aged 3 to 4 years. The EV-A71 neutralizing antibody level could maintain at least two years after natural infection.</p>

Epidemiological characteristics of enterovirus type 71 diseases / 中华流行病学杂志

Objective The objective of this study was to investigate the epidemiological characteristics of disease caused by enterovirus type 71.Methods A total of 10 158 children aged between 6 and 35 months,were recruited from 7 sites where EV71 inactivated vaccine phase 3 clinical trial was carded out.All the subjects were followed up to one year to investigate the epidemiological characteristics of the disease caused by EV71.Results The accumulate incidence density of disease caused by EV71 was 15.17/1 000 person-year.Of all the cases,hand,foot and mouth disease (HFMD),herpangina,respiratory system diseases,digestive system diseases and other diseases accounted for 82.00％,2.67％,13.33％,1.33％ and 0.67％,respectively.The difference of the incidence density between boys and girls showed no statistical significance.Majority of the patients were between 12 and 23 months of age,which accounted for 58.67％ of the total patients.The differences of incidence density between different months of age were statistically significant (x2=7.789,P=0.020).The peak incidence density of disease caused by EV71 occurred from April to June.Nine cases showed severe symptoms or signs that accounted for 6.00％ of all the cases.All severe cases were identified as HFMD,of which 7 were boys and 2 were girls.The number of severe cases in different months of age appeared to be 1,7,and 1,all occurred between April and June.The median courses of HFMD cases and non-HFMD cases were 9 and 6 days,with difference statistically significant (Z=-4.000,P＜0.001).Median of excretion cycle for HFMD and non-HFMD cases were 9 and 11 days respectively.But with no statistically significant difference between the two.Conclusion Majority of the disease that caused by EV71 appeared as HFMD.Most of them were younger children and with seasonal variation.

Epidemiological investigation on an outbreak of autumn tsutsugamushi disease in Taizhou region of Jiangsu Province / 中华传染病杂志

Objective To analyze the epidemiological and clinical characteristics of an outbreak of tsutsugamushi disease in Taizhou region of Jiangsu Province,and to clarify new changes of endemic focus of tsutsugamushi disease in Jiangsu Province.Methods The definition of tsutsugamushi infected cases was determined,field epidemiological investigation with analysis of clinical features and polymerase chain reaction (PCR) results to diagnose tsutsugamushi disease were combined.Some of the positive samples were conducted genotyping by amplification and sequencing.Results The outbreak occurred from October to November,2011.The endemic focus located on the plain with humid climate and abundant rainfall.Fifteen cases of tsutsugamushi disease were found,including 6 PCR confirmed cases,5 clinically diagnosed cases,and 4 suspected cases.The main clinical symptoms were fever in 15 cases,skin rash in 14 cases,lymphadenectasis in 3 cases,skin eschar or ulcer in 12 cases,and liver dysfunction in 3 cases.None of the patients developed severe complications,and all recovered rapidly after the treatment.Comparing the sequencing results of positive samples with standard strains,the homology of base sequences was 99.00％ with that of Kawasaki.Conclusions The outbreak of tsutsugamushi disease in Jiangsu Province in 2011 is of autumn type in transitional endemic focus,and the pathogen is Kawasaki Orientia tsutsugamushi.