Underreporting of congenital rubella in Italy, 2010–2014

In accordance with the goals of the World Health Organization Regional Committee for Europe, the Italian national Measles and Rubella Elimination Plan 2010–2015 aimed to reduce the incidence of congenital rubella cases to <1 case/100,000 live births by 2015. In Italy, a passive national surveillance system for congenital rubella and rubella in pregnancy is active since 2005. We estimated the degree of underreporting of congenital rubella, performing a capture-recapture analysis of cases detected through two independent sources: the national surveillance system and the national hospital discharge database, in the years 2010–2014. We found that 6 out of 11 cases tracked in the retrospective case-finding from hospital registries had not been notified to the surveillance system, and we estimated a degree of underreporting of 53% for the period 2010–2014. This approach showed to be simple to perform, repeatable, and effective.Conclusion: In order to reduce underreporting, some actions aimed at strengthening surveillance procedures are needed. The adoption on a routine basis of the review of hospital discharge registries for case-finding, monthly zero-reporting, and actions to train and sensitize all the specialists involved in the care of pregnant women and the newborns to notification procedures are recommended.What is Known• In Italy, the incidence of congenital rubella was below the WHO target of 1/100,000 live births in 2005–2015, except for two peaks in 2008 and 2012 (5 and 4/100,000, respectively).• Further efforts are required to improve congenital rubella surveillance so that it is more sensitive and specific. The WHO proposes retrospective case-finding from hospital records as an alternative approach to detect infants with congenital rubella.Whatis New• Underreporting of congenital rubella in Italy was 53% in 2010–2014.• Hospital discharge registries resulted to be an appropriate source to detect congenital rubella cases.