Incidence of Intussusception in Early Infancy: A Capture-Recapture Estimate for Germany

Abstract

Rotavirus (RV) vaccination with the first generation vaccine (Rotashield) has been associated with intussusception (IS). Reliable age specific baseline incidence data for children ≤6 months of age in particular is fundamental for further post marketing monitoring of potential effects of recently introduced new RV vaccines. IS incidence was estimated by a 2-source capture-recapture calculation (CRC) based on ESPED (German Paediatric Surveillance Unit) reports and on hospital discharge records for 2006 and 2007. ESPED as well as hospital records were validated according to the Brighton Collaboration's Group definition for definite IS. Children that have been treated for IS in a hospital in one of two states of Germany (North-Rhine Westphalia and Bavaria). The annual IS incidence for infants <1 year in Germany calculated with the CRC estimate in Germany was 61.7/100 000 (95% CI: 54.5-70.1). However, the incidence appeared to vary by month of age over a range of 19.2/100 000 cases (95% CI: 12.5-30.4) in the first 3 months of life to 98.5/100 000 cases (95% CI: 80.9-120.6) during the 6 (th) to 8 (th) month. The male to female ratio for infants was 1.7:1 (95%CI: 1.6-1.8). The average incidence estimate for IS in infants (< 1 year) confirms previous estimates in Germany and Switzerland. However, age specific baseline incidence estimates for IS substantially vary during the first year of life. This has to be taken into account when analysing episodes of IS potentially associated with RV vaccination.