Occurrence of subclinical post-streptococcal glomerulonephritis in family contacts.
OBJECTIVE
There are few data in the published literature on the occurrence of subclinical post-streptococcal glomerulonephritis. In order to estimate the incidence of subclinical disease, 75 families of index cases with sporadic clinical post-streptococcal glomerulonephritis were screened for the presence of subclinical disease.


METHODS
Three hundred and seventeen family contacts were investigated 1-7 days after the admission of the index cases. The diagnosis of subclinical disease was based on the presence of abnormal urinalysis, transitory hypocomplementaemia and increased antistreptolysin O titre.


RESULTS
No cases of clinical/subclinical disease were detected among 147 parents. Abnormal urinalyses were found in 22.3% of sibling contacts. The incidence of nephritis among 170 siblings was 9.4% and the calculated ratio subclinical/clinical disease was 0.11. There were 16 siblings (9.4%) whose abnormal urinalyses could not be explained by appropriate tests; 11 of them had dysmorphic microhaematuria and significantly elevated antistreptolysin O titre.


CONCLUSIONS
Sibling contacts have increased risk for the development of clinical/subclinical post-streptococcal glomerulonephritis compared with their parents. Sibling contacts with unexplained urinary abnormalities might have subclinical nephritis in evolution; their complement levels normalized before occurrence of nephritis in index cases.
Tasic
V
V
Department of Pediatric Nephrology, University Clinical Center, Skopje, Republic of Macedonia. vtasic@freemail.com.mk
Polenakovic
M
M
D000208:Acute Disease; D000328:Adult; D017677:Age Distribution; D000989:Antistreptolysin / Q000032:analysis; D002353:Carrier State; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D005190:Family; D005260:Female; D005921:Glomerulonephritis / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D018843:Republic of North Macedonia / Q000453:epidemiology; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D035781:Siblings; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D016482:Urinalysis
D000989:Antistreptolysin