Urinary schistosomiasis-associated morbidity in schoolchildren detected with urine albumin-to-creatinine ratio (UACR) reagent strips.
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.
Russell Stothard
J
J
Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK. r.stothard@nhm.ac.uk
Sousa-Figueiredo
Jose C
JC
Simba Khamis
I
I
Garba
Amadou
A
Rollinson
David
D
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
D011934:Reagent Strips; D003404:Creatinine