An Epidemiological Study of Streptococcus Haemolyticus; Ten-year-period (1956-1965) Observations on Outpatients

Abstract

Through pharyngeal swab cultures, isolation of Streptococcus haemolyticus (S.h.) was carried out fon 11893 persons who were among the patients visiting the department of internal medicine of this hospital as outpatients during a 10-year-period (1956-1965). On isolated S.h., grouping and typing were attempted by Lancefield's test. In most positive cases quantitative colony counting was done.
Further, from epidemiological viewpoint, the authors divided the patients into two categories. One (Group 1) is the patients group having such diseases as Angina Lacunalis, Angina Simplex, Acute and Chronic Nephritis, Grippe Syndrome, Bronchitis, Empyema, and Rheumatic Arthritis. The other (Group 2) is the group not having these diseases. The authors' consideration is that some relationship with S.h. is referred to these diseases and the S.h. positive patients in Group 2 are considered to be non-manifested carriers. In this respect, some observations were made separately on Group 1 and Group 2.
The results were as follows:
1) The positive cultures as a whole were 819 (6.8%) out of 11893, Group A being 396 (48.3% of 819), Group G 217 (26.4%), and C 89 (10.9%). The positive cultures for S.h. groups other than A, C, and G were 117 (14.4%), 0 and K being prominent, and F, L the rarest.
2) The total number of Group 1 was 2552 (21.5%), Group 2, 9341 (78.5%).
3) In Group 2: The number of positive cultures was 523 (5.5%), Group A occupying about a half (229), being numerically followed by G and C. It is noticeable that the distribution of all kinds of S.h.groups could be seen in this group. In this group, the S.h. possesing rate was highest (12.3 %) in the Lage group 12-14, followed by 7.7% in 15-19. and 4.3-6.4% in 20-29. 30-39, 40-49, over 50 each. The curve of S.h. possessing rate was highest (10.3%) in 1956, then kept declining until it reached to the bottom (2.8%) in 1964, and was in upward trend in 1965 (3.3%). Out of isolated 229 Group A, a half (115) could be typed into 24 types, among which Type 1 and Type 12 were prominent in number.
4) In Group 1: The positive cultures were 296 (11.6%) out of total 2552. The incidence was highest in Angina Lacunalis (42 out of 71, 59.1%), followed by Angina Simplex (23.3%), Acute and Chronic Nephritis (17.8%, 15.3%). In those cases, Group A was always remarkably predominent. The result of quantitative colony counting demonstrated the strong relationship between Group A and the above mentioned diseases and Empyema. Contrarily, Grippe Syndrome, Brochites, and Rheumatic Arthritis were proved rarely related with it.
5) Group B, DF, F, and L, however, did not happen to be isolated from Group 1. The relationship between isolated S.h. belonging to the groups other than Group A, C, and G and diseases has not sufficiently clarified yet.