In the latter part of December, 1911, Chicago was visited by an epidemic of sore throat, which for widespread distribution and severity was unique in the history of the city. The greatest number of cases appeared about Christmas and New Year's Day, but during the months of January and February there were lesser outbreaks of new cases and a notable number of relapses and complications from an earlier infection. Some of the cases were at first mistaken for diphtheria, which had been quite prevalent in November. During the latter month the health department received for diagnostic purposes 637 cultures that contained Klebs Loeffier bacilli and 1,045 cultures that were negative. In the month of December, although the positive diphtheria cultures fell to 379, the negative cultures increased to 1,234.
The onset was usually abrupt and was characterized by chilliness or rigor, general muscular soreness, a dull headache, and in