Intussusception and the great smog of London, December 1952.

AIM To discuss the possible significance of the increased incidence of intussusception in children in relation to the "Great Smog" of London in December 1952. METHODS Cases of intussusception were recorded in two hospitals in East London for the years 1951, 1952, 1953, and 1954. For 1952 the actual dates of admission were recorded. RESULTS During the year 1952 the total number of cases of intussusception greatly exceeded that in the previous and succeeding years. Immediately during and after the fog there was a clustering of cases, which only occurred during this period. CONCLUSIONS The increased incidence of cases during 1952 is thought to reflect the annual variation in incidence resulting from changes in the prevalence of viruses capable of causing intussusception. The clustering of cases in relation to the fog may reflect a facilitated entry of virus through the wall of the terminal ileum due to the effect of swallowed irritants such as sulphurous acid and smoke particles.