Clustering and Influencing Factors of Streptococcus Pneumoniae Carriage among Kindergarten Children

OBJECTIVE To study the clustering and influencing factors of Streptococcus pneumoniae carriage among kindergarten children, and to provide a scientific basis for the prevention of pneumococcal diseases. METHODS The multi-stage stratified cluster sampling method was used to collect nasal swabs via the nasal vestibule at both sides from 1 702 kindergarten children in Liuzhou, China. A questionnaire survey was performed on their parents. The chi-square test and the random effects logistic regression analysis were used to analyze data. RESULTS The carriage rate of Streptococcus pneumoniae was 13.16% (224/1 702) among kindergarten children. The clustering analysis showed that the class-level random effect of Streptococcus pneumoniae carriage was statistically significant (Z=2.07, P=0.038), with an intraclass correlation coefficient of 5.9%. The random effects logistic regression analysis showed that the children aged 5-7 years had a lower risk of Streptococcus pneumoniae carriage than those aged 2-< 5 years (OR=0.55, 95%CI:0.40-0.76, P=0.001), and the children with ≥ 5 family members living together had a higher risk of Streptococcus pneumoniae carriage than those with < 5 family members (OR=1.34, 95%CI:1.01-1.79, P=0.043). CONCLUSIONS Streptococcus pneumoniae carriage shows a class-level clustering effect, and age and the number of cohabitants are important influencing factors for Streptococcus pneumoniae carriage in children.