An Epidemic Case of Dysentery due to Shigella dysenteriae type 1 and Inquiry into the Causal Factors in this Incidence, and Supplement to Knowledge on the Properties of the Agent : I. Epidemiological investigation on the prevalence state and on so-called Source and Routes of Infection in this case (I)

The report consists of 3 parts, the Report I, II and III. In this paper, the investigation is limited to the so-called source and modes of infection only, and the description about these factors is not yet finished. All results on the Report I will be summarized, together with the one of following Report II