Epidemiological Studies on the Streptococcus Hemolyticus

Abstract

Streptococcus hemolyticus was investigated from June, 1957 to December, 1958 with healthy persons and patients suffering from nephritis, upper respiratory tract and dermal diseases. The total isolation rate and that according to it's group, type monthly distribution and age were studied. Furthermore, the sensitivity test against various antibiotics was carried out.
The results obtained were as follows:
1) The isolation rate of the microorganism from the pharinx of healthy persons was 20.2% and 8.6% respectively in children and adults. Consequently, the children play a great role as carrier.
2) The monthly distribution of isolation rate demonstrated a curve with two peaks in May-June and in November.
3) According to the age, the rate was highest in the age of 5-9.
4) According to the group, the A and G group predominated among the other groups. In adults, however, the C group followed these groups in the isolation rate.
5) As for the type, 5 types (1, 3, 6, 9, 12) were most frequently encountered. An increasing tendency was observed with type 13 and type 44.
6) Among various diseases, nephritis and angina demonstrated a high isolation rate.
7) In epidemics of scarlet fever, the number of carriers who demonstrated the same type of streptococcus as that causing the epidemic increased.
8) The isolation rate from the nephritis patients was higher in children than in adults.
9) The type 12 was isolated more frequently in the initial stage of nephritis (within the 7th day) than in the later stages, coinciding with the results of Rammelkamp.
However, the rate was different according to the age. It was assumed that the other types also might cause nephritis.
10) No aggravation was observed in the course of nephritis, when a upper respiratory tract infection due to the other types occurred.
11) The isolation rate was 32.1% from the pyodermal patients.
12) No coincidence of type was found between the streptococci isolated from the pharynx and the pyodermal foci.
13) No decrease of sensitivity against various antibiotics was noticed in the majority of the streptococci isolated. However, 2 strains of the A group demonstrated a low sensitivity against Bacitracine, a strain of the C group against tetracycline and a strain of the K group against penicillin, respectively.