Respiratory illness after severe respiratory syncytial virus disease in infancy in The Gambia

Objective: To determine the frequency of later respiratory tract morbidity after respiratory syncytial virus (RSV) disease in infancy. Design: Cohort study with passive, clinic-based surveillance. Setting: Outpatient department in The Gambia. Subjects: One hundred five children admitted to the hospital with severe RS V disease (case cohort), 105 control children matched for age-not admitted to the hospital during the previous RSV season (control cohort 1), and 102 control children born after the RSV season (control cohort 2). Main outcome measures: Frequencies of pneumonia, wheezing, and hospital adm ission with acute lower respiratory tract infection. Results: Pneumonia was more common in case children than in both control gr oups (adjusted incidence rate ratio [IRR, 95% CI]: 3.80 [2.73,6.10]), as wa s wheezing (IRR 7.33 [3.10,17.54]), pneumonia or wheezing (IRR 3.96 [2.60, 6.04]), and admission with pneumonia or wheezing (IRR 3.40 [1.87, 6,15]). T he incidence rate per 100 child-years for pneumonia in the dry season for, 12-month-old children was 27 for case patients. 8.1 for control cohort 1, a nd 6.51 for control cohort 2. By 3 years of age, the rates:had fallen-to lo w levels in all groups. Conclusions: Pneumonia and wheezing are significantly more common in childr en after RSV-associated lower respiratory tract disease than in control sub jects, but the incidence declines rapidly with increasing age.