The Possibility of Urinary Tract Infection in Primary School Students with A Diagnosis of Febrile Pharyngotonsillitis

Background: Urinary tract infection (UTI) is one of the commonest bacterial infection seen in children, ranking second only to those of the respiratory tract. Material & Methods: One hundred and five 6-12 years old school children with pharyngotonsillitis visit our outpatient clinic were recruited in this study. Urinalysis and mid-stream urine collection culture after disinfection of the private area were performed in all children. Serum procalcitonin, CRP and DMSA were performed in student with significant positive urine culture. Results: The urine culture results showed positive rate in 48.6%, negative rate in 39% and contamination urine culture was 12.4%. Urinalysis did not indicate the possibility of positive urine culture. Also, the procalcitonin and CRP could not indicate upper UTI when compared with the results of DMSA. Conclusion: This study indicates that urine tract evaluation is important and should be performed in children who are suspected with pharyngotonsillitis.


Introduction
Urinary tract infections are common in children. They may present with a range of severity form cystitis to febrile UTI or pyelonephritis. The presentation may be vague and have nonspecific symptoms. The younger the child is the more symptoms are atypical. Therefore, a UTI should be considered in all children with a fever and it is even possible associated with febrile pharyngotonsillitis [1,2]. In Scholer SJ study (1996) stated that an acute complaint of abdominal pain in children occurs in 5.1% nonscheduled visits. Close follow-up will identify the 1% to 2% who proceeds to have a more serious disease process including UTI [3]. The clinical prediction rules for UTI was developed. Its sensitivity and specificity were 0.95 and 0.31 respectively if patient confirm to have 2 or more of the following 5 variables: less than 12 months old, white race, temperature of 39 °C or higher, fever for 2 days or more, and absence of another source of fever on examination [4]. The gold standard for UTI diagnosis is significant colony counts of a single organism in urine obtained in a sterile manner. Positive urine culture was defined as 50,000 or more colony-forming units per milliliter of a urinary tract pathogen [5]. The most common uropathogens were E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus mirabilis [6].
However, children with Enterococcus species, Klebsiella species, and Pseudomonas aeruginosa were significantly less likely to exhibit pyuria, positive leukocyte esterase on dipstick urinalysis than children with [7]. Moreover, high prevalence of Staphylococcus saprophyticus is in patients > 10 years and Proteus mirabilis is predominant in males [8]. Acute UTIs are relatively common in children, with 8% of girl and 2% of boys having at least one episode by seven years of age. Renal parenchymal defect are present in 3% to 15% of children within one to two years of their first diagnosed UTI. Evaluation of older children may depend on the clinical presentation and symptoms that toward a urinary

Material and Methods
One hundred and five primary school children (Male=47, female=58) who were diagnosed with pharyngotonsillitis in outpatient clinic were involved in this study. Their common symptoms were fever, emesis, decreased appetite, sore throat, headache and abdominal pain. Urinalysis and mid-stream urine collection cultures were done in all participants. Serum procalcitonin, CRP and DMSA were also performed in students with significant positive urine culture (50,000 or more colony-forming units per milliliter of a single urinary tract pathogen).

Results
The urinalysis results including esterase, nitrite, proteinuria, occult blood, white blood cells and red blood cells were not significant, it cannot predict the possibility of urine culture. Culture of urine showed uropathgen positive rate 48.6% (n=51), negative rate 39% (n=41) and the contamination rate 12.4% (n=13) respectively. was the only bacteria showed in culture. Also, the procalcitonin and CRP levels were mostly lower than their cutoff levels (0.5ng/ml and 20mg/L) respectively. Even the higher levels could not indicate upper UTI when compared with the results of DMSA.

Discussion
Twenty percent of febrile children have fever without an apparent source of infection after history and physical examination. Of these, a small proportion may have an occult bacterial infection, including bacteremia, UTI, occult pneumonia. Also, in children with fever without source, occult UTIs occur 3% to 4% of boy younger than 1 year and 8% to 9% of girls younger than 2 years of age [10]. In this current study, the absolute number of WBCs or red blood cells in the urine and the presence of proteinuria, leukocyte esterase and nitrite were not associated with positive culture or urinary infection as proposed by Hooker JB (2014) study [11]. In review of literature, routine urinalysis had limited sensitivity, but moderate specificity, in predicting UTI in children. The composite urinalysis and moderate or large leukocyte esterase both had good negative predictive values for the outcome of UTI [12]. According to the procalcitonin, CRP against the results of acute-phase DMSA scan in children aged 0 to 18 years with culture confirmed episode of UTI, the cutoff values were used for the primary analysis of UTI: 0.5mg/mL for procalcitonin, 20mg/L for CRP [13]. Moreover, certain unopathogens: Enterococcus species, Klebsiella species, and Psiudomonas aeruginosa were less likely to exhibit pyuria (>/=5 WBCs per high power field or >/=10 WBCs per cubic millimeter) [14]. Therefore, the definitive diagnosis of UTI is based on the urine culture but clinicians should remember a higher contamination rate was found in the early stream (51%) and midstream sample (16%). The benefit of catching midstream urine samples for the diagnosis of UTI is most important [15,16]. In conclusion, collecting a viable urine sample for urine culture for diagnosis of UTI using clean voided methods in primary school students with fibril pharyngotonsillitis is feasible.