Tetanus in Japan: trends of mortality, case fatality and causes of death.

The rapid decline of tetanus mortality in recent years, from 2.84 to 0.02 per 10(5) population during the period of 1947-1982 was largely due to the decrease in neonatal tetanus mortality which declined from 36.1 to 0 per 10(5) live birth during the same period (1947-1979). The incidence of neonatal tetanus was inversely related to the percent of babies born in medical institutions. Vaccination against tetanus contributed to the rapid decline of tetanus mortality in the 0 to 9 years old group excluding the neonates, but not necessarily in the other age groups. There was a conspicuous decline in case fatality from about 50-40% during 1940-1970 to 20% and 10% in the periods from 1971-1980 and 1981-1982, respectively. This is attributed to the recent trend of treating tetanus patients in intensive care units where even the most extremely moribund patients have come to be successfully treated in the past few decades. The causes of death of tetanus patients changed from about 1975. Respiratory insufficiency with or without pulmonary infection was predominant in the period from 1961-1974. Unexpected complications, i.e. perforation of esophageal fistula, bleeding from gastrointestinal ulcers, myocardial infarction, respiratory insufficiency due to hyalinosis of alveolar septae associated with prolonged artificial respiration etc. were the major causes of death in the years 1975-1985.