Pertussis surveillance in French hospitals: results from a 10 year period

We present 10 years of results from a paediatrician hospital network surveillance in France, set up in 1996 to monitor the trend of pertussis (whooping cough) in children and the impact of the vaccination strategies. Microbiologists from 43 hospitals that participate in the network on a voluntary basis notify pertussis diagnosis, and paediatricians complete a questionnaire for the infants under 6 months that fulfil the microbiological, clinical or epidemiological case definition. The network covers about 30% of pertussis cases seen in French hospitals. Around 300 cases of pertussis are notified in France annually. Two peaks occurred in 1997 and 2000. The estimated national incidence rate for the 0-2 months old children is 276/100 000 on average. Since March 1996, the network has described 1688 cases under-6 month. The male-female ratio was 1.0 and 63 % were less than 3 months of age. Most patients (96%) were hospitalised with 17% admitted in intensive care. The case fatality ratio was 2% with 32 deaths. Vaccination status was confirmed through medical records for 83% of children and 78% were not vaccinated. The source of contamination was identified for 53 % of cases and was in majority the parents. The Renacoq data confirmed the risk for young children, the role of parents as source of infection and the need of a pertussis vaccination in time. Vaccination is now recommended to adults who hope to become parents, and this should help to reduce this burden.