Time-space distribution of extrahepatic biliary atresia in The Netherlands and West Germany

Extrahepatic biliary atresia (EHBA) is an infrequent disease confined to early infancy. Its aetiology is not clear, but an infectious agent has been implicated. Demonstration of a time-space clustering would support this hypothesis. Therefore, we investigated the time-space distribution of all 89 cases of EHBA born in a 10-year period in the Netherlands. We carried out a similar study in West Germany and analysed 130 cases of EHBA, born between 1969 and 1986, from 4 paediatric surgical centres. Analysis of these cases did not reveal any evidence for clustering in specific years or in a specific period of the year. The places of birth of the patients also were randomly distributed over rural areas, villages and towns. Neither did a method to reveal time-space interaction give any support for clustering. This random distribution of patients with EHBA suggests that EHBA could be pathogenetically a heterogeneous disease.