Epidemiological and Bacteriological Investigation of a Classroom Outbreak of Scarlet Fever in an Elementary School in Tokyo

Abstract

A long term bacteriological investigation was carried out in a classroom outbreak of streptococcal infection among school children of an elementary school in Tokyo in 1966.
The results were as follows
1. The outbreak occurred in late 1966 and lasted till July, 1967. During this period, 6, cases of scarlet fever, 17 of acute sore throat, and 18 suspected cases were detected from 33 class mates.
2. Serotyping of streptococci isolated from throat swabs obtained from the patients revealed the causative agent to be Type 14 of Group A Streptococcus.The outbreak was bacteriologically proven to be unrelated with streptococcic infections of children in other classrooms or in the neighbourhood of the school.
3. A school child, the first case of scarlet, fever in the class, excreting streptococci from the throat for a long period following the illness, was considered to be a source of the outbreak.
4. Chemothrapies applied to streptococcal carriers failed to eliminate the Type 14 Streptococcus in the throat.
5. Serum ASLO titers of the patients were complicatedly influenced with various factors, for.example, with individual difference of the patients.
6. No correlation was established between behavour of Dick test using.the erythrogenic toxin A as antigen and clinical course of illness. This finding may be due to the qualitative difference between the toxins elavorated. by the standard strain used for Dick test and Type 14 Streptococcus.
7. No complications were seen in all the patients.
8. Though Group L Streptococcus has been isolated from several patients, this strain seems to be nonpathogenic to human beings.