ABSTRACT
Objective To investigate the relationship between risk factors and recurrent respiratory tract infections( RRTI) in children. Methods A case-control study was carried out in 204 children with RRTI,com-pared with 400 children without RRTI in control group. Results Second-hand smoking,breastfeeding,malnutri-tion,zinc deficiency,pet at home,home decoration and use of glucocorticoid were associated with RRTI in chil-dren. But the association between breastfeeding and RRTI was only found in children less than 5 years old. The second hand smoking was associated with RRTI only among boys,rather than girls. Home decoration,zinc defi-ciency,malnutrition and breastfeeding were associated with RRTI only among girls,but not among boys. Conclu-sion Recurrent respiratory tract infections are associated with multiple factors. Different risk factors have differ-ent affections on RRTI on gender.