Acute poststreptococcal glomerulonephritis: public health implications of recent clusters in New South Wales and epidemiology of hospital admissions

Acute poststreptococcal glomerulonephritis (APSGN) is an inflammatory kidne y condition that can complicate Group A streptococcal infections. Two clust ers of APSGN occurred recently in New South Wales (NSW), Australia; one in a rural town in December 1999 and the other in a Sydney suburb in January 2 000. We interviewed carers of the affected children but found no common exp osures except three of the Sydney cases were cousins in frequent contact. T o assess the probability of these clusters occurring, we analysed hospital admissions for acute glomerulonephritis, as a proxy for APSGN in younger pa tients. The incidence of acute glomerulonephritis in NSW during 1989/90-199 7/8 in residents aged under 20 years was 2(.)2/100000/year (95% CI 2(.)0-2( .)5). Incidence was highest in children aged 5-9 years, boys and Aboriginal children. We found no evidence for other clusters during that period. The recent clusters highlight the continued potential for unexpected future out breaks of APSGN.