Acute respiratory tract infections during the first six years of life - results from the German birth cohort study LoewenKIDS

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, Page 107802

OBJECTIVES: Acute respiratory infections (ARI) often occur in early childhood and are mostly self-limited. However, they impose a high socioeconomic burden and can be associated with chronic diseases later in life. To date, data on self-reported ARI beyond infancy are limited. The aim of this study is to describe the incidence and characteristics of self-reported ARI in the first six years of life. METHODS: Data were obtained from the LoewenKIDS birth cohort study, including 782 children born between 2014 and 2018. Parents recorded daily ARI symptoms, which were classified into episodes for incidence and characteristics analysis. Regression analyses explored the influence of exposure factors on ARI incidence. RESULTS: This longitudinal birth cohort study of a subsample of 258 children found a mean cumulative duration of 51.5 weeks (95% CI: 47.5-55.6 weeks) of respiratory symptoms in the first six years of life, with large individual differences. Children with frequent infections in infancy had more infections in preschool age. Exposure factors explained only a small fraction of variation in incidence (5%). CONCLUSIONS: There is a substantial variation in susceptibility to ARI in childhood, which is not explained by exposure factors.

DOI: 10.1016/j.ijid.2025.107802