Epidemiological Characteristics Of Hand Foot And Mouth Disease And Study On Risk Factors Associated With The Occurrence Of Severity In Shenzhen City

Objective1. To assess the epidemiology of hand foot and mouth disease (HFMD) in Shenzhenfrom2010to2012, and understand the time distribution, space distribution,population distribution, and major pathogenic virus type.2. To investigate risk factors associated with severe hand foot and mouth disease, andpropose comprehensive prevention and control measures, in order to reduce incidenceand mortality for severe hand foot and mouth disease in Shenzhen.Methods1. We report the surveillance finds of hand foot and mouth disease (HFMD) collectedfrom Shenzhen information system for disease prevention and control between2010and2012, and the method of descriptive epidemiological analysis was adopted tounderstand epidemic trends on season, district and population for hand foot andmouth disease, including age, sex and classification.2. A total of326cases of HFMD were investigated by questionnaire from Shenzhenchildren’s hospital, the people’s hospital of BaoAn district in Shenzhen and the centralhospital of LongGang district in Shenzhen, in order to collect basic situation, medical treatment behavior of study objects, and knowledge for hand foot and mouth diseaseof caretakers. After cases were divided into severe and mild cases, univariate andmultivariate logistic regression analysis was conducted to determine risk factors ofsevere cases and strength of the association.Results1. There were23289cases of HFMD patients in2010in Shenzhen, the incidence ratewas299.56per100thousand, along with92cases of severe HFMD patients and6deaths. There were24827cases of HFMD patients in2011, the incidence rate was239.80per100thousand, along with151cases of severe HFMD patients and6deaths.There were30021cases of HFMD patients in2012, the incidence rate was289.97per100thousand along with56cases of severe HFMD patients and2deaths.2. During3-year study period, it increased in the number of HFMD patients inShenzhen from the January each year, and a seasonal peak was detected in the warmermonths (May-June), along with a smaller winter peak (September-October). Afterthat time, it decreased constantly. The number of the first peak was4267,4615and5684. The second one was2264,2801and5547.3. BaoAn and LongGang district have a high incidence number of HFMD and severecases from2010to2012. Among of them, the number of HFMD in2012inLongGang district, which was the most, was14011. The number of severe HFMD in2011in LongGang district,which was the most, was55.4. Among the population distribution of HFMD patients in Shenzhen from2010to2012, males are more than females. However, it has no significance statistically (χ2：0.1027；P：0.7486). Age group between1and2year has the largest number of cases,which is6635,7645and9219respectively. Scattered children has the largest numberof cases, which is17147,18985and22343respectively. 5. Among the types of virus in Shenzhen, being detected by laboratory, the positiverate of the EV71from2010to2012is65.29%,72.12%and69.09%respectively, thepositive rate of COXA16is33.53%,15.15%and9.09%respectively.6. The logistic regression results show that vaccination and having infectious diseasesone month before the onset of incidence can reduce the risk of severe HFMD, andEV71can cause more severe HFMD cases than other types of enteroviruses.ConclusionHFMD has a high incidence during the summer period (May-July) and winter period(September-October), there is the largest number of cases in BaoAn and LongGangdistrict.Among the HFMD patients in Shenzhen, males are more than females, thenumber of the patient is the largest in the age group between1and2year, scatteredchildren and kindergarten children are observed frequently.The major pathogenicviruses are EV71and COXA16, among of them, EV71is more likely to cause severecases.It can reduce the risk of the severe HFMD by vaccination, even other vaccines.