Aboriginal communities in Northern Australia with high rates of
group A streptococcal (GAS)
skin infection in childhood also have high rates of renal failure in adult
life. In a cross-sectional study of one such high risk community, albuminuria was used as
a marker of renal
disease. The prevalence of albuminuria increased from 0/52 in subjects
aged 10–19 years to
10/29 (32·9%) in those aged 50 or more (P<0·001).
Antibodies to streptococcal M protein,
markers of past GAS infection, were present in 48/52 (92%) at ages
10–19 years, 16/32 (50%)
at ages 30–39, and 20/29 (69%) in those aged 50 or more. After
allowing for the age-dependencies of albuminuria and of M protein antibodies (P<0·001)
albuminuria was
significantly associated with M protein antibodies (P<0·01).
Thus, 72% of adults aged 30 or
more with M protein antibodies also had albuminuria, compared with only
21% of those who
were seronegative. More detailed modelling suggested that although most
Aboriginal people in
this community developed M protein antibodies following GAS infection in
childhood, the
development of proteinuria was associated with the persistence of such
seropositivity into adult
life. The models predicted that proteinuria developed at a mean age of
30 years in seropositive
persons, at 45 years in seronegative persons who were overweight, and at
62 years in
seronegative persons of normal weight. We demonstrated a clear association
between evidence
of childhood GAS infection and individual risk of proteinuria in adult
life. This study provided
a strong rationale for prevention of renal disease through the more effective
control of GAS
skin infections in childhood and through the prevention of obesity in adult
life.