OUTBREAK OF ACUTE GLOMERULONEPHRITIS IN CHILDREN - OBSERVED ASSOCIATION WITH THE T1-SUBTYPE OF GROUP-A STREPTOCOCCAL INFECTION IN NORTHERN KYUSHU, JAPAN

Group A streptococcal infection is associated with the occurrence of a cute glomerulonephritis (AGN) and rheumatic fever (RFI. A surveillance study in the Saga area, in northern Kyushu, Japan, showed a small var iation in the reported number of group A streptococcal infections in t he period 1988-94. However, of the AGN cases reported in this period, more than half were observed in 1992. In order to examine whether some change had occurred in the serotype distribution of Streptococcus pyo genes during the period, patients in the Saga area diagnosed as having group A streptococcal infection and patients with AGN or RF were anal yzed. Serological T-typing of S. pyogenes was carried out for patients with group A streptococcal infections, and the association between th e occurrence of AGN or RF and the distribution of each different T sub type was analyzed. M-typing of S. pyogenes was also carried out and th e correlation between T and M types was examined. From 1988 to 1994, t he annual number of patients with group A streptococcal infections in the Saga area showed a small variation, range 65-100 patients/year. Of the 42 patients with AGN and three with RF observed in this period, 2 7 with AGN (64%) and one with RF (33.3%) were detected in 1992. Only t he TI subtype increased in 1992; the other T subtypes showed little va riation in incidence. The number of patients with the T1 subtype was s ignificantly correlated with the occurrence of AGN by regression analy sis (P < 0.01). Of the 170 subjects tested for both T and M subtypes, 44 of the 45 T1-typed subjects had the M1 protein. Our epidemiological study suggested that the T1 subtype of streptococcal infection was as sociated with an outbreak of AGN in 1992 in the Saga area.