During the five weeks from August 7 to September 10, inclusive, there have been reported in St. Louis City and St. Louis County 656 cases of encephalitis. It appears that the epidemic incidence for this area will not exceed a rate of about one case per thousand of population, and the reported extension of the infection to other places has thus far been remarkably slight. The case fatality rate will be about 20 per cent.
Only 13 per cent of the cases have occurred among the 25 per cent of the population which is under 15 years of age, and 23 per cent of the patients have been in the age group 15 to 34 years, which comprises 35 per cent of the total population. The recovery rate in these two age groups has been relatively high, with about half as many deaths in proportion to the number of cases