title: Urinary schistosomiasis-associated morbidity in schoolchildren detected with urine albumin-to-creatinine ratio (UACR) reagent strips.
abstract: OBJECTIVE
  To evaluate urine albumin-to-creatinine ratio (UACR) reagent strips for detection of urinary tract pathology (UTP) associated with urinary schistosomiasis in schoolchildren from Zanzibar.
  
  
  METHODS
  Sixty-six schoolchildren were examined for urinary schistosomiasis and UTP using urine reagent strips (Hemastix, urine microscopy and portable ultrasonography. The UACR was estimated using Microalbustix; univariate and logistic regression methods were used to test for statistical associations.
  
  
  RESULTS
  Prevalence of egg-patent schistosomiasis was 65.2% while 77.3% had micro-haematuria and 66.1% had a least one ultrasound-identified UTP. Abnormal UACR (> or =3.4 mg/mmol) was frequent (88.4%) but an unsatisfactory identifier of UTP, albeit highly sensitive: sensitivity (SS) = 100.0%, specificity (SP) = 23.8%, positive predictive value (PPV) = 71.9%, negative predictive value (NPV) = 100.0%. When only severely abnormal UACR was considered (> or =33.9 mg/mmol), SS decreased while SP improved: SS = 58.5%, SP = 61.9%, PPV = 75.0%, NPV = 43.3%.
  
  
  CONCLUSIONS
  Abnormal and severely abnormal UACRs were strongly associated with egg-patent urinary schistosomiasis and UTP, although via different mechanisms: respectively, from venous blood released directly into the urine from bladder wall perforations, and from leaching sera released from chronic egg-induced lesions throughout the urinary tract. From a control perspective, Microalbustix reagent strips are therefore best applied in pre-screening protocols allowing selection, or rather confident exclusion, of schoolchildren with urinary schistosomiasis for more detailed investigations.
authors.affiliation: Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK. r.stothard@nhm.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Russell Stothard
authors.forename: Jose C
authors.initials: JC
authors.lastname: Sousa-Figueiredo
authors.forename: I
authors.initials: I
authors.lastname: Simba Khamis
authors.forename: Amadou
authors.initials: A
authors.lastname: Garba
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
mesh_terms: D000293:Adolescent; D000419:Albuminuria / Q000175:diagnosis / Q000453:epidemiology* / Q000652:urine*; D002648:Child; D003404:Creatinine / Q000652:urine*; D019353:Endemic Diseases; D006417:Hematuria / Q000175:diagnosis / Q000453:epidemiology / Q000652:urine; D006801:Humans; D016015:Logistic Models; D008403:Mass Screening / Q000379:methods; D009017:Morbidity; D011237:Predictive Value of Tests; D015995:Prevalence; D011934:Reagent Strips; D012553:Schistosomiasis haematobia / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000652:urine*; D012680:Sensitivity and Specificity; D013636:Tanzania / Q000453:epidemiology; D014463:Ultrasonography
chemical_list: D011934:Reagent Strips; D003404:Creatinine