[The obligatory notification of pertussis is not effective for the protection of unvaccinated children].

Objective: To determine the effectiveness of the obligatory notification of pertussis in the Netherlands and the measures based on this notification in the prevention of infection in unvaccinated or insufficiently vaccinated children.

Design: Descriptive, retrospective.

Method: The period between the first day of the illness and the date of notification was calculated for all 9310 cases of pertussis that were notified in the Netherlands in 2004. A period of 21 days is the maximum during which appropriate measures can be taken in the family of the index patient to protect unprotected siblings at risk from infection. For the province of Groningen (n = 411 notified cases), it was also determined whether there were actually children that were not or insufficiently vaccinated in the immediate environment and whether preventive measures were necessary.

Results: In the Netherlands in 2004, 890 (10.7%) of all notified pertussis cases were notified within a three-week period after the first day of illness. In Groningen, this number was 30 (9.1%) and in none of these cases was there an insufficiently vaccinated child in the family.

Conclusion: In an endemic situation with severe under-reporting, the obligatory notification of pertussis is not effective to prevent infection of insufficiently vaccinated children. Alternative vaccination strategies directed at the prevention of the spread of pertussis among insufficiently vaccinated children would probably be more effective and merit further investigation.