Research On Measles Epidemiology And Etiology

Objective:In order to know the chang of measles attenuated live vaccine efficacy,We analysis the NA (neutralization antibody ) difference of measles attenuated live vaccine and measles wild-type virus to the serum of primary–vaccinated. Using exponential smoothing to evaluate the effectiveness of measles vaccination campaign in 2007,forecasting measles prevalence in hebei province in2009. Providing scientific evidence for strategy and measure to accelerate control and eliminate measles prevalence.Methods:1 Identification of measles virus①sample collection : collect swab sample of acute stage patients②viral isolation: according to WHO defining method isolate measles virus③identification of virus: indirect immunofluorescence experiment identify measles virus.2 Amplification virus and measure tissue culture infective dose,TCID50:Inoculate measles virus to Vero / slam cells.When the CPE(cytopathic effect) exceed percent seventy-five we put it to -70 centi-degree then freeze thawing thrice, preserving at -70℃. Measuring tissue culture infective dose based on "EPI technology management point of order".3 Neutralization experiment:Using the methodof random- ized blocks design the experiment,The experiment technology refers to "Medicine Virology Foundation And Experiment Technology",With the serum of primary- vaccinated neutralize measles vaccine and two measles wild- typevirus which were separated by Hebei Province,Calculating the neutralizing antib- ody titer respectively, Analyzing whether the difference is existing.In order to know the chang of measles attenuated live vaccine efficacy.4 Monitoring of the crowd,IgG: Using stratified random sampling method to take a number of the crowd ,collecting venous blood or ear blood to detect the measles IgG by ELISA (enzyme-linked immunosorbent assay) .5 Collection and analyze information of measles vaccina- tion campaign:Collecting the informationof measles vaccination campaign to compute the report inoculation rate respective such as city,country,age.at the same time, Aalculating the estimation inoculation rate based on the available information.6 Evaluation the effectiveness of the measles vaccin- ation campaign: Collecting measles cases from January 1998 to October 2008 each month in hebei province,Analysising date to establish exponential smoothing predictive model.Using it pre- dict the incidence of measles of Hebei Province in 2007,Then compared to the actual incidence.To evaluate the effectiveness of measles vaccination campaign objectively.7 Collection and analyze information of measles prevalen ce: It was collected to the report information from the Informa- tion System for China Disease Prevention and Control in 2007 -2008, Analysising epidemiology chang after vaccination cam- paign.8 The anticipation for measles prevalence: forecasting measles prevalence in hebei province in 2009 with the expone- ntial smoothing predictive model established by SPSS.Results:1 Identification of virus: Indirect immunofluorescence experiment confirm the wild-typevirus which were used by NT experiment were measles virus.2 Neutralization experiment: Calculating the neutralizing antibody titer Hebei07- 4 1:16.77,Hebei08-1 1:17.51,S191 1:157.15 respectively.The variance of Hebei07-4 and Hebei 08-1is not obviously but the NA is different between attenuated live vaccine and wild-typevirus to the serum of primary - vaccinated, The NA of measles attenuated live vaccine is 8.98～9.37 times of wild-typevirus, The ability for neutral vaccine is higher than wild poisonous obviously.From the above we can say that the antigenic variation of measles wild-typevirus has decreased the protective effect of measles attenuated live vaccine.3 Antibody level of the crowd: The improvement of the crowd antibody level is significantly after immunization one month.So the measles vaccination campaign can improve antibody level quickly.4 The measles vaccination campaign which is carryied out by Hebei province has met the goal requirements basically. 5 The choice of exponential smoothing predictive model is reasonable based on residual error chart. Comparing the distribution chart which is predict measles case of Hebei Province in 2007 each month to the actual,We can discove that the result of fiting is well before measles vaccination campaign,But about a maximum latent period late , The actual measlea cases is lower than the predicting obviously,The above demonstrate that the effectiveness of measles vaccination campaign to control measles prevalence is favourable.6 The change of measles seasonal character is not obviously after measles vaccination campaign,The age of measles case still show an upward trend in the large age groups.7 The anticipation for measles prevalence with expon- ential smoothing predictive model :Forecasting measles preva- nce in hebei province in 2009 with exponential smoothing predictive model established by SPSS.The result show that the measles prevalence in 2009 will homoplastic with the measles prevalence in 2008.Conclusion:1 The antigenic variation is obviously between the measl- es attenuated live vaccine and the measles wild- typevirus.The ability for the serum of primary-vaccinated neutral vaccine is higher than wild poisonous obviously. The protective effect of measles attenuated live vaccine has decreased. However,The succeed carry out of measles vaccination campaign degrade the attack rate of measles. 2 The epidemiology character is not changed after measles vaccination campaign.3 The measles prevalence in 2009 will homoplastic with the measles prevalence in 2008.