More infantile hypertrophic pyloric stenosis?

In 1978 there was a disproportionate increase in the number of cases of Infantile Hypertrophic Pyloric Stenosis (IHPS) admitted to the Cambridge Military Hospital Aldershot. This increase has not been sustained in subsequent years, although the mean incidence for the period 1979/82 was slightly higher than the preceding years 1975/77. Analysis of the cases occurring in 1978 did not reveal any unusual factor relating to the increased incidence.