Study On The Epidemiological Characteristics,Risk Factors And The Immunization Status Of Measles Among Floating Children In Shenzhen

ObjectiveThis study investigated the epidemiological characteristics and the risk factors of measles among floating children in Shenzhen,in order to understand the distributions and current status of measles,and to analyze the risk of measles,which was to provide some more reasonable bases for the more appropriate prevention.At the same time,measles antibody testing and related research were conducted among part of healthy floating children in Shenzhen,to understand the immunization status and the factors affecting the immunization status of floating children;attitudes and knowledge level of parents to measles also had been surveyed,which was to further strengthen the immunization status of floating children.MethodStudied on the epidemiological characteristics of measles among floating children in Shenzhen:descriptive study was conducted in this study,measles cases data was collected from the Shenzhen legal infectious disease reporting system during 2010 to 2018,which accorded with the analyzed laboratory-confirmed cases and with floating children characteristics;floating children were defined as non-household registration population,aged<18 years,temporarily resided in Shenzhen with parents or other guardians.Studied on the risk factors of the measles in floating children:group-matched case-control study was used to investigate the risk factors in laboratory-confirmed measles cases from the infectious disease reporting system during 2014?2018 in Shenzhen,167 cases were collected by divided from the age of<8 months and?8 months;controls matched according to gender and age;the survey process was conducted by trained investigators with questionnaires;univariate analysis was using the?² test,and multivariate analysis was using conditional logistic regression models.Studied on the immunization status of measles among part of healthy floating children:probability-proportional-to-size sampling was used to extract a portion of healthy floating children form hospitals and schools in Bao'an district of Shenzhen as a representative.With obtaining the consent,the venous blood was collected from the children,and the following survey was completed by investigators;measles antibody detection used Elisa to quantitatively detect IgG antibodies,calculated geometric mean titers,and divided antibody levels;qualitative variable analysis and non-conditional logistic regression analysis,and quantitative variables were based on homogeneity of variance and normality test to decided using t test or rank-sum test for analysis.ResultsStudied on the epidemiological characteristics of measles among floating children in Shenzhen:a total of 1339 measles cases of floating children were reported during 2010-2018.The highest incidence rate was in2013.Cases were mainly concentrated in May to July in the 2012-2015,but there is no obvious month concentration in other year;the cases came from other provinces were mainly including Hunan?19.94%?,Hubei?8.81%?,Jiangxi?8.81%?,from Guangdong province were mainly including Jieyang?8.26%?,Meizhou?3.67%?and Shanwei?3.67%?;most of the cases were younger than 18 months and without immunization history,and the most clinical significances of the cases were fever,rash and cough.Studied on the risk factors of the measles in floating children:Among floating children,included having the medical history in 7 to 21 days before the onset of measles?aOR=6.48,95%CI:3.63 to 11.58,P<0.001?,having the outgoing history of crowded places in 7 to 21 days before the onset of measles?aOR=2.64,95%CI:1.47?4.75,P=0.001?;having the exposure history of fever-rash patients?aOR=7.89,95%CI:3.15?19.72,P<0.001?;and receiving immunization on time as a protective factors of childhood measles?aOR=0.10,95%CI:0.04?0.22,P<0.001?.Studied on the immunization status of measles among part of healthy floating children:A total of 1096 people were tested,and the positive rate was 86.59%,and the geometric mean concentration of antibody titer of was789.81 mIU/ml.Multivariate logistic regression analysis of affecting immunization status showed that the age get older?aOR=0.80,95%CI:0.78?0.83,P<0.001?,the measles antibody titer will get lower.With the more enough vaccination doses?aOR=6.11,95%CI:4.80?7.11,P<0.001?,the higher the degree of antibody protection.And in the survey of floating children of preschool and school-age,with the increase of school status,the degree of antibody protection decreased(?²_trend=49.34,P<0.00).Surveys about awareness and attitudes of parents toward measles showed that floating children's parents generally lacked of the knowledge of measles?91.42%?,but sat a positive attitude towards measles vaccine.Conclusion1.Surveillance data showed that measles cases reported by floating children in Shenzhen has gradually decreased,and the concentrate months of the measles were not obvious.Most of the reported cases heaved not been immunized and younger than 18 months old.2.Having the medical history in 7 to 21 days before the onset of measles,having the outgoing history of crowded places in 7 to 21 days before the onset of measles,and having the exposure history of fever-rashes were risk factors for measles in floating children;vaccination on time was the protective factors about the measles.3.Floating children have a high antibody-positive rates and good positive conversion situation,but the measles antibody titer has decreased over time;on time and full doses of vaccination has an important meaning for increasing antibody titers and positive rates;most of floating children's parents did not had a enough knowledge about measles.