Investigation on an aggregation event of cypermethrin exposure in a school in Shenzhen

YAN huimin; MEI Shujiang; ZHANG Yali; LIAN Yingying; YANG Nan; LI Yuan

doi:10.19821/j.1671-2781.2025.01.021

Abstract：Objective To investigate a cluster of unexplained eye diseases in school,find out the causes and risk factors,and put forward scientific treatment suggestions.Methods Through descriptive epidemiology,field hygiene investigation and retrospective cohort study,Chi-square test was used to compare different infection rates,and suspected risk factors were screened by univariate analysis and multivariate logistic regression model.Results A total of 177 cases were found,and 71.8％of the cases were reported to be a pain in eyes and skins,and 37.3％of the cases were reported to be burning,and 13.6％of the case appeared rashes.The highest incidence rate was in primary school grade 1(39.38％),while the lowest rate(10.74％)was in primary school grade 2.The difference of the incidence rate in different grade was statistically significant(x2=52.09,P＜0.05).The results of retrospective cohort studies showed that the incidence rates with rubbing eye behavior was higher than that of no rubbing eye behavior(x2=298.88,P＜0.05).There was a statistical significance in the incidence rate of the moving chairs behavior higher than that of the non-moving chairs(x2=7.15,P＜0.05).The results of single factor analysis show that the students'rubbing eye habits(OR=34.10,95％CI:20.25-57.41)and the behavior of moving chairs(OR=1.70,95％CI:1.15-2.52)were the risk factors for cypermethrin exposure.Multivariate logistic regression model analysis showed that students'eye rubbing habit(OR=34.90,95％CI:20.60-59.11)was the risk factor for cypermethrin exposure.Conclusion This is a student allergy that happens to be in school,and the allergen is the cypermethrin residues.It is recommended that schools use chemical insecticide to kill insects in strict accordance with the requirements of the code,and the residue should be removed after treatment.