During a recent epidemic of measles in the Southern Health and Social Services Board in Northern Ireland it became apparent that the level of notifications of measles by general practitioners did not reflect the true incidence of the disease at that time. In trying to establish a more accurate measure of the incidence of measles it became clear that much money and manpower had been used to treat this outbreak. We tried to cost a defined period covering 1 January to 30 June 1983 to draw attention to the possible benefits of a more effective measles vaccination programme in preventing disease and saving resources. The implications of our present poor rate of vaccination were measured for hospital services, primary medical care services, and related consequences. The costs for the defined period were approximately pounds 175 931, and if the outcome had been worse in a few cases it might have been as high as pounds 1 375 931.

We examined the notification of infectious diseases, including measles, by general practitioners over 18 months, which included a measles epidemic in the area covered by the Southern Health and Social Services Board in Northern Ireland. Of the 156 general practitioners who provided services in the area, 27 (17.3%) had a pattern of notification which might render them acceptable as "spotter" practices, a system which at present does not exist in Northern Ireland, although it is used in the rest of the United Kingdom. In future we hope to be able to; (i) predict impending epidemics of infectious disease; (ii) mobilise Health Service resources to minimise the effects of such epidemics; (iii) monitor the effects of improving the level of uptake of measles vaccine.