[Epidemiological survey of group A hemolytic streptococci isolated in Osaka during the 21-year period between 1967 and 1987. Part I. Annual change of epidemic serotype].
During the 21-year period between 1967 and 1987, a total of 6157 strains of group A streptococci isolated in Osaka were type-classified by T-agglutination method. The results were summarized as follows. 1. Sixteen serotypes were differentiated by the T-method during the course of investigation. The most common serotype was T-12 (37.1%), followed by T-4 (13.4%) and T-1 (10.4%). 2. The most dominant serotype was T-12 during 1968-1978, and other relatively frequent serotypes were T-4 in 1971, T-1 in 1972 and T-3 in 1974 throughout the period. Though T-12 was the main serotype in the isolates thereafter, other serotypes such as T-4 in 1979 and T-3 in 1985 also became prevalent, and they occupied the highest percentage. But they declined rapidly, and their duration period was relatively short. After 1976, no definite serotype showed the long-term epidemics, while several types (T-3, T-4 and T-12) showed short-term epidemics lasting a few years. 3. Group A streptococci were isolated most frequently from the patients aged 4-8 years, whereas the isolation rates were extremely lower from the 0- to 2-year-old children. Therefore, younger children seemed to have something which made it difficult to be infected with group A streptococci.
Katsukawa
C
C
Harada
K
K
Nakasone
C
C
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D013997:Time Factors