Introduction:The recurrent wheezing (RW) has a high prevalence in the early years of life. In this age group, there is a relationship between the occurrence of severe Respiratory Syncytial Virus (RSV) infection and evolution with subsequent RW, according to epidemiological studies. Some groups of children such as preterm infants with and without bronchopulmonary dysplasia and children with congenital heart disease with hemodynamic consequences are at high risk of developing severe RSV infection. This, in turn, leads to anatomical, functional and immunological lasting changes that can be related to RW.Objective: This study will evaluate the overall prevalence and the risk factors associated to RW development in infants with high risk of having severe RSV infections. Between risk factors, analyze the use of passive immunization with Palivizumabe modified the prevalence of RW. Methods: Cross sectional study conducted between June 2014 and August 2015, in reference center. The patients selected receiving Palivizumabe in 2012, born between 2010 and 2012 and preterm that did not receive passive immunization by not attending the using criterion, birth in 2011 and 2012. The evaluation was the guided questionnaire in telephone interview.
Results:The 512 children analyzed with mean age 39.3 ± 5.64 months and median 39 months (18 -54). In the first group, 261 children with mean gestational age 31.2 ± 4.94 weeks and median 29 weeks (24 -41) who received Palivizumab. In the second group, 251 preterm children with mean gestational age 34.0 ± 1.79 weeks and median 34 weeks (28 -36) who did not receiving passive immunization (p<0.001).The prevalence of RW among 512 children was 25.8% (95% CI: 22.1 -29.7). In the group receiving with Palivizumab, the prevalence was 30.7% (95% CI: 25.3 -36.5) and in the group without prophylaxis, it was 20.7% (95%CI: 16.0 -26.1). These results show a statistically significant difference (p = 0.010). Risk factors associated 10 with recurrent wheezing, by univariate analysis, were birth weight less than 1500g, gestational age below 32 weeks, lack of breastfeeding, hospitalization for wheezing in the first years of life, living with more than three children in the same household, food allergy and atopic dermatitis in children, food allergies and asthma in the parents. With multivariate analysis, associated factors were gestational age between