Meningococcal disease in the Norwegian Armed Forces 1967-1979. Some epidemiological aspects.

The epidemiology of meningococcal disease in the Norwegian Armed Forces has been studied for the years 1974-79 and compared with the situation in the years 1967-73. The clustering of cases was examined with special reference to vaccination. The annual incidence rate increased from 24 to 43 cases per 100,000 men. However, this is only half the relative total increase in Norway in the same period. When 1975-79 figures were weighted according to the military age distribution, the combined rate for conscripts was four times the civilian rate. The weekly risk during the three month recruit training was three to ten times greater than later on. A malignancy change was demonstrated by a fourfold increase in the proportion of septicaemia and a fivefold increase in the case fatality.