Magnitude of asymptomatic microscopic hematuria and proteinuria in 7-12 years old school children in Addis Ababa, Ethiopia

Abstract

Background: Hematuria or proteinuria or mixed hematuria and proteinuria are one of the most important signs of renal or bladder disease in children and it can represent a process that is simple and benign or complex and life threatening. There is no research done in this country pertaining to this problem in pediatric practice and this study will assess the magnitude of asymptomatic microscopic hematuria and proteinuria in apparently healthy school children in Addis Ababa, Ethiopia. Objective: To assess the prevalence of asymptomatic microscopic hematuria and proteinuria in apparently healthy school children between the ages of 7-12 years in Addis Ababa, Ethiopia. Materials and Methods: This is a cross sectional survey done in apparently healthy school children (7-12 years of age) from the beginning of April 2014 to the end of May 2014 over a period of 8 weeks. After obtaining written consent from parents, a labeled  urine collection cup was given for each student with written instruction to the parents to take midstream early morning fresh urine to the level of the mark on the cup and send the cup to the child after proper sealing. The urine samples were received by the data collector and dipstick urinalysis was done within 1 hour of collection. A dipstick test (Multistix, Bayer Diagnostics, Miles Inc., USA) was performed on the un spun urine specimen by trained laboratory technician, with reagent strip designed to react progressively producing color changes at given intervals. The results were decided by visual comparison of the test strip with a color chart provided on the bottle. All positive hematuria results were screened for the second time after 2 weeks to check for persistence of hematuria. This time the positive dipstick results were confirmed by microscopy after centrifugation of 10ml of fresh urine and 5 or more RBC/HPF confirms hematuria. Results: In the first screening out of 382 school children 32 (8.4 %) tested positive for hematuria. Among these 7 (1.8%) were males and 25 (6.5%) were females. The difference between males and females was statistically significant (p=0.009). When compared with the three age groups (7-8, 9-10, 11-12 years) the
prevalence of hematuria was higher in the 7-8 age group (19%) as compared to 11-12 year old children (5.7%) and this is statistically significant (p=0.013). 75 students (19.6%) were tested positive for proteinuria. Among the children with proteinuria 32 (8.4%) were males and 43 (11.3%) were females and the difference was not statistically significant. 32 students (8.4%) were positive for leukocyte esterase all of which were females. Glycosuria and nitrituria was present in less than 1%. In the second screening, 14 children (3.7%) had isolated hematuria and 2 children (0.5%) mixed hematuria and proteinuria making the prevalence of hematuria and proteinuria 4.2% and 0.5% respectively. Age and sex differences in the prevalence of hematuria and proteinuria were not demonstrated. Among the 16 children with hematuria 6 children (37.5%) had red blood cell (RBC) casts in their urine suggesting glomerulonephritis as the possible cause of hematuria. Conclusions: The study demonstrated that the prevalence of hematuria (4.2%) and proteinuria (0.5%) is higher in Ethiopian children than most other African children and worldwide but nitrituria and glycosuria
were rare.