Follow-up of patients with epidemic poststreptococcal glomerulonephritis

In 1998 there was a large outbreak of acute glomerulonephritis (GN) in Nova Serrana, Brazil, caused by group C Streptococcus zooepidemicus and linked to the consumption of contaminated cheese produced with unpasteurized milk. This study describes the follow-up of these patients after a mean of 2 years following the acute episode. Of 134 patients identified in 1998, 69 patients were reexamined and underwent measurements of blood pressure, 24-hour creatinine clearance, microalbuminuria (radioimmunoassay), and urine sediment analysis. Of the original group of 134 patients, 3 patients died in the acute phase and 5 patients (3.7%) required chronic dialysis. Of 69 patients reevaluated, 65 patients (94%) were adults (mean age, 39 +/- 2 [SE] years) and 47 patients (68%) were women. At the follow-up examination, we found arterial hypertension in 42% of subjects (27 of 64 subjects), serum creatinine levels greater than 1.2 mg/dL in 12% (10 of 68 subjects), reduced creatinine clearance (<80 mL/min/1.73 m(2)) in 30% (20 of 67 subjects, 2 of them on chronic dialysis therapy), and increased microalbuminuria (>20 microg/min) in 34% (22 of 65 subjects). Increased microalbuminuria and/or reduced creatinine clearance were detected in 48% of the subjects (31 of 65 subjects). Patients with microalbuminuria had greater diastolic blood pressure than those without microalbuminuria (mean, 98 +/- 4 versus 88 +/- 2 mm Hg; P = 0.02). In conclusion, after a mean of 2 years, patients with epidemic poststreptococcal GN caused by S zooepidemicus present a high rate of hypertension and frequent abnormalities of renal function, with some having reached end-stage renal disease. Longer follow-up will be important to define the prognosis of these patients.