Approximately 70 per cent of the isolated strains had acquired resistance against antibiotics, such as penicillin, streptomycin, tetracycline, erthromycin and neomycin, etc.
The group distribution of the strains which were isolated during the study were almost identical with these form patients with enteric infections previously reported.
It might be commented upon that the high percentage and wide range of distribution of subclinical and atypical enteric bacterial infections is due to:
1. Seoul City is equipped with a poor water and a poor sewage disposal system.
2. The living conditions of most of the citizens in Seoul are unsanitary.
3. The clinical diagnosis of enteric bacterial infection is not easily made because enteric bacteria are of numerous types and clinical symptoms for each type are not identical.
4. In Seoul, many mutant strains have acquired resistance against antibiotics due to inappropriate treatment. Those strains may cause atypical symptoms of enteric infections.
5. As a rule general practitioners do not request a laboratory examination before treating enteric infections.
6. The eating of unwashed vegetables and fruits exposed on the street must be a frequent cause.
A bacteriological study of subclinical and atypical enteric infections was undertaken in 1958. Three thousand one hundred seventy four persons were examined from February 1958 to February 1959 in Yonsei University, Severance Hospital, Seoul, Korea. Each person was given a physical examination. Enquiries were made
regarding of fever, nausea, vomiting, gastrointestinal disturbances, anemia, lymphadenopathy, rash and hepathomegaly.
Specimens of stool and blood were obtained and examined for enteric bacteria according to Edwards and Ewing's Procedures for the isolation of Salmonellae and by Widal Test for the detection of enteric fever antibodies.
Reference to the table reveals that 50 of the 3.174, or 1.58 per cent, were infected with pathogenic bacteria. Of these 29, or 0.91 per cent, were infected with Salmonellae and 21, or 0.66 per cent, with Shigellae. There was a marked uniformity in the incidence of infection in the group of healthy person (6 of 358,
or 1.68 per cent) and in patients (30 of 1,726, or 1.73 per cent). In the patient group there were 9 out 239, or 3.76 per cent, who had fever of unknown origin and 8 out of 256, or 3.14 per cent, whose disease was not diagnosed.
Most of the patients had atypical symptoms of enteric disease, but this disease was not suspected.
Those, however, who were given appropriate treatment for enteric infection recovered completely.
POSITIVE ISOLATION OF ENTERIC PRTHOGENS BY THE GROUPS