Asymptomatic bacteriuria in haemodialysis patients

ABSTRACT

This study was designed to assess the frequency significance and possible pathogenic factors of asymptomatic bacteriuria in chronic haemodialysis patients. A hundred patients suffering from endstage renal failure under regular haemodialysis treatment [divided into 3 groups according to the underlying cause of renal failure whether primary glomerulonephritis [forty cases] tubulointerstitial nephritis [thirty cases] or diabetic nephropathy [thirty cases] were randomely selected from the dialysis unit of Ain Shams University Hospital, El Sahil Teaching Hospital and Cairo Kidney Centre. None of these patients suffered symptoms nor signs suggestive of urinary tract infection and all were subjected to full history and clinical examination, clean catch midstream urine analysis with culture [aerobic and anaerobic]. Bacterial isolates were identified by bacteriological methods and sensitivity [when needed] in addition to microscopic examination for pus cells. Also, assessment of blood urea and serum creatinine were done. A subgroup of patients [proved to have asymptomatic bacteriuria 10 cases] as well as an equal subgroup of those having no significant bacteriuria were further studied by assessment of residual kidney function, total and differential WBCs counts, serum Ig[G], Ig[A] level, urinary Ig[A] level, opsonophagocytic function and migration inhibition test. Though we had high prevalence of significant bacteriuria in our patients [50%]. Pyuria was detected in only 14% of cases, all except one were associated with significant bacteriuria and the most prevalent organism was Staphylococcus aureus followed by Staph. saprophyticus. We didn't detect any significant correlation between significant bacteriuria and either age of the patients, duration, frequency of dialysis, blood urea or serum creatinine but female patients and chronic interstitial nephritis were associated with significant high prevalence of assymptomatic bacteriuria. In the two subgroups studied no correlation was detected between significant bacteriuria and either W.B.Cs count, residual kidney function, macrophage migration inhibition test, opsonophagocytic activity, Ig[A] or Ig[M] level. Though low Ig[G] level was associated with higher prevalence of asymptomatic bacteriuria. It is conducted that local factors may be more important than systemic factors in the pathogenesis of asymptomatic bacteriuria in haemodialysis patients and that routine urine analysis should be regularly performed in these patients to detect and possibly treat such cases especially female patients and cases of chronic interstitial nephritis