Primary and secondary schoolchildren in Hateruma and Ishigaki, small islands of Ryukyu, and Koza City, Okinawa Prefecture, were subjected to throat culture for Hemolytic Streptococci (HS), in March and July 1971, and March 1972, in order to study the incidences of HS, the group and type distribution. The results were compared with those obtained in primary and secondary schoolchildren in Fuchu district in Tokyo by the same methods as above performed in June 1969, 1970 and 1971.
As a whole, the incidences of HS were higher in Hateruma (60.8%, 43.7% and 62.5% in the three surveys, respectively), Ishigaki (50.8% in the one survey) and Koza (71.4% in the one survey) than in Fuchu (26.2%, 25.2% and 24.4% in the three surveys, respectively). The incidences of Group A streptococci were also higher in Hateruma, Ishigaki and Koza than in Fuchu. In typing of Group A streptococci by means of T-agglutination, it was much interesting to find that in Hateruma and Ishigaki the predominant type was T-11, while in Fuchu and Koza, same as the other various districts in the world, it was T-12. The high incidence of T-11 is worth mentioning, but its pathogenicity is not yet determined.
