|Year : 2018 | Volume
| Issue : 1 | Page : 47-51
Prevalence of urinary tract infection in febrile children <2 years of age
Bindu T Nair, Amit Kumar Rai
Department of Pediatrics, Army College of Medical Sciences, New Delhi, India
|Date of Web Publication||21-May-2018|
Dr. Bindu T Nair
Department of Pediatrics, Army College of Medical Sciences, Delhi Cantt, New Delhi - 110 010
Background: Urinary tract infection (UTI) is identified by presence of both pyuria and at least 50,000 colonies/mL of a single uropathogenic organism in an appropriately collected specimen of urine. In young children, the only presentation of a UTI may be fever. Young children may show nonspecific signs such as irritability, feeding poorly, vomiting, sleeping more, or show signs of jaundice. Aim: To study the prevalence of UTI in febrile children <2 years of age presenting to the hospital and to compare urine analysis with urine culture in detecting UTI early in young febrile children with no localizing signs. Materials and Methods: All consecutive children from 1 month to 2 years of age with fever (rectal temperature of 38°C or 100.4°F) without any focus reporting to outpatient department or admitted to the ward of Paediatric Department in our hospital were included in the study. Further evaluation was performed based on the American Academy of Paediatrics and Indian Society of Paediatric Nephrology guidelines. Statistical Analysis Used: Data were analyzed using SPSS Software version 15. Results: Out of 1000 cases of febrile children with no localizing signs who were included in the study, 370 (37.0%) were females and 630 (63.0%) were males. In 86.6% of cases, Escherichia coli was the predominant cause of febrile UTI. In these cases of febrile patients, urine analysis was positive in 7% of cases only whereas urine culture was positive in 15% of cases suggesting UTI. Conclusions: Urine culture should form an essential part of evaluation of a young febrile child with no localizing signs.
Keywords: Febrile young child, urinary tract infection, urine analysis, urine culture
|How to cite this article:|
Nair BT, Rai AK. Prevalence of urinary tract infection in febrile children <2 years of age. Sahel Med J 2018;21:47-51
| Introduction|| |
Urinary tract infection (UTI) is one of the most common pediatric infections. Pediatric UTI account for 0.7% of outpatient department (OPD) visits and 5%–14% of emergency department visits by children annually. UTIs are the highest in children during the first 2 years of life. The incidence is much less in older children. In neonates and young infants who have fever with no localization, the reported rates of UTI vary from 7% to 15%.,,
In children <2 years, the only symptom of a UTI may be fever. Infants may have poor feeding, recurrent vomiting or show excessive sleepiness. In older children, UTI may present as new onset urinary incontinence. Thus presenting signs and symptoms of UTI in young children are often very nonspecific. Therefore, pediatricians are frequently in a decision dilemma whether or not to obtain a urine sample for urine analysis and culture.
Fever without a focus refers to a rectal temperature of 38°C (100.4°F) or higher as the sole presenting feature. Febrile infants younger than 2 years constitute an important subset of children who may present with fever without a focus. The workup of fever in these children should always include evaluation for UTI. Even a single confirmed UTI should be taken seriously, especially in young children. The main long term consequence of complicated UTI or pyelonephritis is renal scarring which may lead to hypertension and end-stage renal disease which require long term follow up.
The main aim of this study is to determine the prevalence of UTI in young children presenting with an acute febrile illness in primary care. Under-diagnosis of UTI in children is thought to be responsible for a large number of patients developing end-stage renal failure as a consequence of acquired renal scarring. Therefore, it becomes paramount to evaluate every febrile infant for the possibility of UTI.
| Materials and Methods|| |
The study was conducted in the Pediatric Department of Military Hospital in New Delhi, India. It was a descriptive, cross-sectional, and prospective study. One thousand children aged 1 month to 2 years with fever (axillary temp of >38°C or >100.4°F) without any focus reporting to OPD or admitted to the ward of Pediatric Department were chosen. Subjects were selected by consecutive nonprobability sampling. The study was conducted over 6 months from January 2014 to Jun 2014. These subjects were selected by the Pediatric resident doctors on duty.
Children were included in the study after excluding other known causes of fever through history and clinical examination. Only those children without any previous history of UTI were included. Children who were on antibiotics or those with other major comorbidities (defined as neuromuscular conditions such as spina bifida, previous urologic surgery other than circumcision, immunodeficiency or those who are on immunosuppressive drugs) were excluded. Children with severe congenital anomalies of urinary tract making it difficult for urine sample collection such as ectopia vesicae, and hypospadias were also excluded.
Before starting the study, permission from hospital ethical committee was taken (approved on 6th September 2012). Parents were educated regarding possibility of underlying UTI and the importance of detecting it. Thereafter, informed written consent was taken and the importance to carry out further investigations in children depending on their age group was explained to the parents. According to the 2011, American Academy of Paediatrics (AAP) Clinical Guidelines for children 2–24 months of age, in children who are not toilet trained, a catheterized or suprapubic aspirate urine sample should be obtained. Since our study population was not toilet trained, urine sample was collected for urine analysis and urine culture under strict aseptic precautions by suprapubic aspiration (SPA) or urethral catheterization.
Data collection and variables
For urine analysis, sample of urine was collected in a sterile container. The sample was processed within an hour of collection. Sample from container was transferred to centrifuge tube and spun at 1500 revolutions per minute (rpm) for 5 min. Supernatant was discarded and sediment was taken. Slide was first seen with ×10 objective and then on ×40 objective microscope piece for detection of leukocytes. More than 5 leukocytes/high power field (hpf) was considered significant.
Urine culture was considered the gold standard test for the diagnosis of UTI. A SPA or urethral catheterization was performed to minimize contamination while obtaining samples. Urinary catheterization was first tried and sample collected. If sample could not be collected in this manner, we waited for the bladder to get full and then, SPA was tried. The urine specimens were promptly plated within 1 h of collection into nutrient, cysteine, lactose electrolyte deficient and Mac Conkey agar plates with 0.01 mL calibrated Nichrome V wire loops. This was then incubated at 37°C and examined for growth for next 2 days. A positive urine culture was defined as growth of >5 × 104 colony forming unit/mL on urethral catheterization or any number of urinary tract pathogen if sample collected by SPA.
Urine culture was repeated if contamination was suspected, for example, mixed growth of two pathogens or growth of organisms that normally constitute the per urethral flora (lactobacilli in infants and toddlers). Children who were urine culture positive were treated with appropriate antibiotics and further radiological evaluation was performed as per guidelines laid down by the AAP and Indian Society of Pediatric Nephrology in 2011., All the children who were culture positive underwent ultrasonography (USG) of kidney and urinary bladder. All the children with abnormal USG, underwent micturating cysto-urethrogram (MCU) 2–3 weeks after treatment of UTI and dimercaptosuccinic acid (DMSA) scan 2–3 months of treatment of UTI.
Data analysis was performed with the help of Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.). Quantitative data are represented using mean and standard deviation. Qualitative data are presented with the help of Frequency and Percentage table. Association among study groups is assessed with the help of Chi-square test or Fisher's exact test. The value of P < 0.05 is taken as statistically significant level.
| Results|| |
A total of 1032 consecutive children who came with fever and no localizing signs were taken in the study population. Of these, 25 patients refused to give consent to join the study and seven patients were lost in follow up. Remaining 1000 children were analyzed for the presence or absence of UTI. An age-wise analysis showed that 80 (8.0%) were <6 months of age, 350 (35.0%) were between 6 months and 1 year of age, 280 (28.0%) were between 1 and 1 1/2 years of age and 290 (29.0%) children were between 11/2 and 2 years of age [Table 1].
Out of these 1000 children included in the study, 370 (37.0%) were females and 630 (63.0%) were males. Among them, on urine analysis 75 (7.5%) children were found to have 5 or more pus cells in centrifuged urine sample and remaining 925 (92.5%) children either did not show any pus cell or showed <5 pus cells/hpf. Both urine analysis and urine culture identified more male children to have UTI as compared to female children. However, this difference was not statistically significant [Table 1]. Urine culture was positive in 15% of children, of whom 4% of patients were females and rest were males and the Chi-square P value was 0.392 which was again not statistically significant.
Duration of fever and age of children was compared in both urine analysis and urine culture negative and positive groups of febrile children. There was no statistical difference in the two groups [Table 2]. Distribution of children in the study depending on their urine analysis results and duration of fever showed a P = 0.861 which was not statistically significant. Distribution of children age-wise depending on their urine culture results showed P of 0.047 which was not statistically significant. Distribution of children based on their urine culture results and duration of fever showed a P = 0.154 which was again not significant statistically [Table 2].
|Table 2: Comparison of urine analysis versus urine culture positivity in urinary tract infection cases|
Click here to view
Sensitivity of urine culture was 96.7% and specificity of urine culture was 91.4% for detecting UTI in febrile children with no focus. Chi-square P < 0.001 which is highly significant statistically was found on comparing urine culture results with urine analysis results. Thus, urine culture should be the investigation of choice in febrile children <2 years of age presenting with no focus [Table 3]. Urine culture was positive in 150 children, out of which Escherichia More Details coli was grown in 130 (86.66%) cases, 10 culture was positive for Klebsiella organism (6.66%) and another 10 (6.66%) culture was positive for Morganella morganii [Table 4].
|Table 3: Correlation between urine analysis results and urine culture results|
Click here to view
All patients who were found to have culture positive UTI were followed up with USG and DMSA scan. Abnormal USG findings was present in 40/150 (26.67%) children with culture positive UTI. Out of these 40 children with abnormal USG, 25 patients had bilateral hydronephrosis, five patients had ureteric dilatation, two children had dilatation of the renal calyces and four had dilatation of the collecting system. One patient each had a double collecting system, a small renal cyst, a renal scar and another one had two small renal abscesses. DMSA scan was abnormal in three cases and 22 children showed grade I to IV vesico – ureteric reflux (VUR) in MCU study.
| Discussion|| |
UTI is defined by the presence of organisms in the urinary tract, which is usually sterile. Young children with UTI may present with nonspecific symptoms such as poor feeding, vomiting, irritability, or fever alone. Over last few decades, the importance of UTI has been increasingly understood, especially the role of UTI as an occult cause of febrile illness in young children. Hence, a broader approach to screening may be appropriate. Two previous studies of the prevalence of UTI among children presenting to an emergency department with fever found rates ranging from 3.5% to 5.5%., The epidemiology of UTI during childhood also varies by age, gender, and other factors.
The gold standard for diagnosis of UTI is positive urine culture. If the culture shows >50,000 colonies of a single pathogen (suprapubic or catheter sample), or if there are 10,000 colonies and the child is symptomatic, the child is considered to have a UTI. In a bag sample, if the urinalysis result is positive, the patient is symptomatic, and there is a single organism cultured with a colony count >100,000, there is a presumed UTI. If any of these criteria are not met, confirmation of infection with a catheterized sample is recommended.
In our study, positive urine culture results were observed in 15.0% of febrile infants with no localizing signs. The incidence of UTI is the highest in the first 2 years of life for all children but decreases substantially among boys after infancy. However, in our study, only 10% of patients with culture positive urine samples were infants <1 year. This could be attributed to the small sample size in infants <1 year age as compared to in older age children.
Amongst culture positive children, majority were males as compared to females [Table 1]. Incidence of UTI in our study was found to be 11.0% and 4.0% in male and female children, respectively. UTI occurrence rates varied widely depending on age, sex, and race. Other studies , also showed similar prevalence rates in male and female infants with fever and no localizing signs as in our study. The reason in our country could be due to the gender bias of bringing more febrile male children to seek medical attention than female children.
In our study, E. coli was grown in 130 (86.66%) cultures, 10 (6.66%) culture was positive for Klebsiella organism and 10 (6.66%) culture was positive for M. morganii [Table 4]. Most common organism is E. coli and this is consistent with two Indian studies too. In one Indian study from South India, E. coli was found in 62.8% of cases and another Indian study from Chandigarh  showed, E. coli in 62.2% of cases. Thus, E. coli was found to be the most commonly isolated pathogen (60%), followed by other Gram-negative organisms such as Klebsiella (12%) and Enterococcus faecalis (10%). However, in South Indian study, 21.2% of the other organisms comprised of Candida, Enterococci, Streptococcus agalactiae and Streptococcus pyogenes.Enterococcus as the second most common uropathogen was described by various authors usually as a nosocomial pathogen.,
Febrile UTIs have long been considered amongst the most common serious bacterial infections in childhood with renal scarring a frequent outcome. Our study showed USG to be abnormal in 26.67% of cases and MCU showed VUR in 14.67%. These results reiterate the importance of further investigating and following up these children with UTI so that necessary management of structural abnormalities can be done and also prevent long term complications. DMSA revealed renal scars in three cases. Other studies also have shown the importance of DMSA scan in children <2 years with UTI.,
Our study had a few limitations. It involved a moderate sample size. Selection bias existed, including the exclusion criteria for contaminated samples and the exclusion of presumed diagnosis of fever due to otitis media etc., Although SPA is regarded as the “gold standard” for collecting urine specimens, obtaining parental consent is more difficult because SPA is a more invasive and painful urine collection method. Besides, its success rate in correctly diagnosing a UTI has been reported to range from 23% to 90%. Because of the variable success rates, ultra-sonographic guidance, and greater technical experience are required for the conduct of this sample collection technique.,
| Conclusions|| |
Urine culture should be a mandatory investigation in febrile children <24 months of age with no focus. First UTI in these children should be investigated thoroughly with USG, MCU and DMSA scan so that long term complications can be prevented by early detection of a correctable structural abnormality and adequate antibiotic prophylaxis.
We acknowledge our deep felt gratitude to Department of Microbiology and Department of Biostatistics for all the support rendered to us.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Freedman AL; Urologic Diseases in America Project. Urologic diseases in North America Project: Trends in resource utilization for urinary tract infections in children. J Urol 2005;173:949-54.
Bonadio W, Maida G. Urinary tract infection in outpatient febrile infants younger than 30 days of age: A 10-year evaluation. Pediatr Infect Dis J 2014;33:342-4.
Ismaili K, Lolin K, Damry N, Alexander M, Lepage P, Hall M. Febrile urinary tract infections in 0- to 3-month-old infants: A prospective follow-up study. J Pediatr 2011;158:91-4.
Lin DS, Huang SH, Lin CC, Tung YC, Huang TT, Chiu NC, et al.
Urinary tract infection in febrile infants younger than eight weeks of Age. Pediatrics 2000;105:E20.
Nield LS, Kamat D. Fever without a focus. In: Kliegman RM, editor. Nelson's Textbook of Pediatrics. 20th
ed., Vol. 1, Ch. 177. Philadelphia, PA : Elsevier; 2016. p. 1280.
Elder S. Urinary tract infections. In: Kliegman RM, editor. Nelson's Textbook of Pediatrics. 20th
ed., Vol. 1, Ch. 177. Philadelphia, PA: Elsevier; c2016. p. 1280.
Subcommittee on Urinary Tract Infection, Steering Committee on Quality Improvement and Management, Roberts KB. Urinary tract infection: Clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics 2011;128:595-610.
Indian Society of Pediatric Nephrology, Vijayakumar M, Kanitkar M, Nammalwar BR, Bagga A. Revised statement on management of urinary tract infections. Indian Pediatr 2011;48:709-17.
Hoberman A, Charron M, Hickey RW, Baskin M, Kearney DH, Wald ER. Imaging studies after a first febrile urinary tract infection in young children. N
Engl J Med 2003;348:195-202.
Montini G, Zucchetta P, Tomasi L, Talenti E, Rigamonti W, Picco G, et al.
Value of imaging studies after a first febrile urinary tract infection in young children: Data from Italian renal infection study 1. Pediatrics 2009;123:e239-46.
Jakobsson B, Jacobson SH, Hjalmås K. Vesico-ureteric reflux and other risk factors for renal damage: Identification of high- and low-risk children. Acta Paediatr Suppl 1999;88:31-9.
Shaikh N, Morone NE, Bost JE, Farrell MH. Prevalence of urinary tract infection in childhood: A meta-analysis. Pediatr Infect Dis J 2008;27:302-8.
Mambatta AK, Jayarajan J, Rashme VL, Harini S, Menon S, Kuppusamy J. Reliability of dipstick assay in predicting urinary tract infection. J Family Med Prim Care 2015;4:265-8.
] [Full text]
Taneja N, Chatterjee SS, Singh M, Sivapriya S, Sharma M, Sharma SK. Validity of quantitative unspun urine microscopy, dipstick test leucocyte esterase and nitrite tests in rapidly diagnosing urinary tract infections. J Assoc Physicians India 2010;58:485-7.
Huysal K, Budak YU, Karaca AU, Aydos M, Kahvecioglu S, Bulut M, et al.
Diagnostic accuracy of uriSed automated urine microscopic sediment analyzer and dipstick parameters in predicting urine culture test results. Biochem Med (Zagreb) 2013;23:211-7.
Bandyopadhyay S, Thakur JS, Ray P, Kumar R. High prevalence of bacteriuria in pregnancy and its screening methods in North India. J Indian Med Assoc 2005;103:259-62, 266.
Supavekin S, Surapaitoolkorn W, Pravisithikul N, Kutanavanishapong S, Chiewvit S. The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood. Ann Nucl Med 2013;27:170-6.
Moorthy I, Wheat D, Gordon I. Ultrasonography in the evaluation of renal scarring using DMSA scan as the gold standard. Pediatr Nephrol 2004;19:153-6.
Deshpande PV, Jones KV. An audit of RCP guidelines on DMSA scanning after urinary tract infection. Arch Dis Child 2001;84:324-7.
Coulthard MG, Lambert HJ, Keir MJ. DMSAs after UTI – Scan more children, not less. Arch Dis Child 2001;85:348.
Davies HD, Canadian Pediatric Society, Infectious Disease and Immunization Committee. Bag urine specimens still not appropriate in diagnosing urinary tract infections in infants. Paediatr Child Health 2004;9:377-8.
Whiting P, Westwood M, Watt I, Cooper J, Kleijnen J. Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: A systematic review. BMC Pediatr 2005;5:4.
[Table 1], [Table 2], [Table 3], [Table 4]