Epidemiological investigations eventually established that the cause was allergy to soya bean dust released into the atmosphere when cargoes of beans were unloaded in the harbour. Increasing recognition of environmental hazards from substances introduced by man into his environment, as a result of the application of new technology, has led to a demand for large scale monitoring systems based on automated record linkage. Whether or not such systems come into Operation, clinicians' awareness of changes in disease frequency or of the appearance of clusters of unusual cases will continue to be crucial to the early detection of new epidemics. Clinicians have a special responsibility in the early detection of epidemics caused by medication. The rise in mortality during the 1960s among asthmatic patients who used pressurised aerosols, and the Occurrence of corneal damage, rashes, and various other adverse effects of practolol are two of many examples of epidemics resulting from prescription of new drugs.
New diseases continue to appear.
The name legionnaires' disease was given to an outbreak of pneumonia at a convention of American Legionnaires in Philadelphia, Pennsylvania, USA, in 1976. There were 29 deaths. This stimulated an intensive epidemiological investigation whose successful outcome was the identification of a Gram negative bacillus as the causative agent. The ratio of men to women was 15 to 1, and the epidemiology suggested an infectious agent usually transmitted by homosexual intercourse. AIDS seemed to be a new disease.