Pertussis and pertussis prophylaxis in Denmark

In Denmark, pertussis is notifiable in children aged <2 years (the age group at which pertussis is considered potentially dangerous), when the child has clinical whooping cough which is laboratory confirmed. In 2001, there were 196 notifications in children: 95 boys and 101 girls (1). This is marginally higher than in 1999 and 2000, when there were 166 and 178 cases respectively (2, 3). In 66% of cases, the Statens Serum Institut’s department of epidemiology had to remind the clinician to submit a notification form. A total of 80 children (41%) were aged <3 months, 119 children (61%) were <5 months and 161 children (82%) were <1 year. Between three and 38 cases per month were notified, most of them in the second half of the year. The total annual incidence for children <2 years was 146 per 100 000. Most of the notified cases (72%) were confirmed by polymerase chain reaction (PCR) alone, while 28% were confirmed by culture with or without positive PCR.