Evaluation of reliability of full hemogram and urinalysis in relation tourine culture as diagnostic tools for urinary tract bacterial infections in Trans-Nzoia county referral hospital, Kenya

Abstract

In routine clinical practice, urinary tract bacterial infections (UTBIs) are diagnosed using urinalysis assay and urine culture is used as a confirmatory test to determine the infecting bacteria. Urinalysis assay relies on the levels of leukocytes, proteins, nitrites and red blood cells in the urine sample. However, in public and private hospitals without blood and urine culture tests, the levels of neutrophils and monocytes from full hemogram assay are commonly interpreted as indications of bacterial infections upon which treatment is prescribed. Prescription of broad-spectrum antibiotics based on such non-specific diagnosis may result in multi drug resistance, human suffering and unnecessary expenses. The general objective of the study was to evaluate the reliability of full hemogram assay and urinalysis assay in relation to urine culture as diagnostic tools for urinary tract bacterial infections at Trans-Nzoia County Referral Hospital in Trans-Nzoia County, in Kenya. The specific objective of this cross-sectional study was to; determine the correlation between counts of neutrophils and monocytes from full hemogram assay, determine the correlation of counts of leukocytes, proteins, nitrites and red blood cells from urinalysis assay and determine the extent of reliability of counts of full hemogram assay and urinalysis assay in relation to urine culture test. The study obtained Informed Consent from the participants prior to participation and through Simple random sampling technique, 173 participants were recruited from both in-patient and out-patient departments at the hospital. About 2-4ml of urine sample was obtained from the patients for urinalysis and urine culture tests. Urine culture in this case was used as a gold standard diagnosis for urinary tract bacterial infections. About 1ml of blood was drawn by venipuncture from the same study participants for full hemogram assay to determine the counts of monocyte and neutrophils. Out of 173 study patients, 122 patients were confirmed positive for urinary tract bacterial infections by urine culture test. Out of these positive cases, 55 patients were neutrophilic, 24 patients presented with monocytosis and 39 patients had leukocytosis. On contrast, 51 samples tested negative by urine culture and were used as control group in the study. The study used a desired confidence level of 95% and an acceptable margin error of 5%. There was no correlation between the counts of neutrophils and monocytes from full hemogram assay with value of r=0.0794 and p-value of 0.299.However, there were correlations between the variables of urinalysis assay and their means had a significant relationship with a p-value of <0.0001on one way Analysis of Variance test. Urinalysis assay was not reliable tool with an overall score of 0.17 on Cronbach's Alpha scale while full hemogram was not reliable tool with the best score of 45% in relation to urine culture test. On ranking of reliability of the variables from both assays, Neutrophils were most reliable with 45.08%, Leukocytes 31.97%, Proteins 20.49%, Monocytes 19.67% and RBCs at 9.84% in relation to confirmatory urine culture technique. In conclusion, full hemogram assay and urinalysis assay are not reliable tools for diagnosis of urinary tract bacterial infectionsin relation to the confirmatory test of urine culture technique. From the study outcome, it is recommended that hospitals should use urine culture techniques in diagnosis of urinary tract bacterial infections.