Pediatric emergency medicine trisk 2291 2291
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bacteria in the urine, arising from any site in the urinary tract, with or without symptoms. Significant bacteriuria
describes the presence of bacteria in sufficient quantity such that infection is more likely than contamination or
colonization. Significant bacteriuria may be asymptomatic, and the clinical syndromes mentioned previously may
occur in the absence of infection. Because cystitis and pyelonephritis may coexist or be difficult to distinguish
clinically and share a similar etiology, they are discussed together, using the common term UTI.
The predominant pathogen isolated in UTIs is E. coli, which is recovered in 90% of cases. Next in frequency are
other members of the Enterobacteriaceae family, including Enterobacter and Klebsiella. Among the gram-positive
organisms, enterococci are seen at all ages, staphylococcal species (Staphylococcus saprophyticus ) occur most
often in adolescents, and group B streptococci are recovered primarily in infants and during pregnancy. P.
aeruginosa, C. albicans, and a number of other bacteria and fungi infect patients with immunocompromise,
anatomic obstruction, or indwelling catheters. Cystitis may be caused, in addition, by adenoviruses. S. aureus is
not a common pathogen unless there is bacteremia, a renal abscess, urinary tract abnormality, or indwelling
hardware.
The frequency of infections of the urinary tract varies by age, gender, and race ( e-Table 94.11 ). Overall,
infections occur commonly in neonates, decrease in frequency during childhood, and then rise in incidence after
puberty in sexually active females. Males are more commonly infected than females in the first 6 months of life, in
part because of a higher incidence of congenital urinary tract anomalies, but they rarely acquire infections beyond
this period unless uncircumcised, and even these infections are uncommon beyond a year of age. Females have a
rather high incidence of symptomatic infection between 6 months and 2 years of age and of asymptomatic
bacteriuria throughout childhood. Children with UTIs have a higher incidence of genitourinary anomalies than the
general population, although in most infections, no anatomic or functional abnormalities are identified.
Goals of Treatment
Treatment begins with the recognition of which children are at risk for UTIs. The clinical team should consider
prior culture results and regional antibiotic susceptibility patterns for children with urinalyses consistent with
UTIs.
Clinical Considerations
Clinical recognition: The manifestations of UTIs vary with age, being particularly nonspecific in infancy. In
neonates, a septic appearance or fever is often the only finding. UTIs in infants may also cause vomiting, diarrhea,
and irritability. Beyond 2 to 3 years of age, symptoms more often localize to the urinary tract. Differentiation
between upper and lower tract disease in children, as compared to adults, is not feasible for the clinician. In most
cases, children who are febrile (greater than or equal to 38.5°C [101.3°F]) should be assumed to have
pyelonephritis. However, some patients will have typical syndromes that localize disease to the upper or lower
tract. Typically, children with cystitis appear relatively well and complain of dysuria and suprapubic pain. On
examination, they have a lower-grade fever and tenderness on the suprapubic area. In contrast, patients with
pyelonephritis may be toxic and usually have additional symptoms, including vomiting and flank pain. The
physician is often able to elicit tenderness to percussion in the costovertebral area, either unilaterally or bilaterally.
Triage considerations: Young children (girls <2 years of age, circumcised boys <6 months of age,
uncircumcised boys <12 months of age), children with a history of UTIs, and children with known anatomic
anomalies that would predispose to UTIs (e.g., neurogenic bladder) should be evaluated for UTIs if they present
with fever without localizing source and/or dysuria. Tachycardia may be the first sign of urosepsis.
Clinical assessment: The diagnosis of UTI usually is based on urinalysis in the ED. The performance
characteristics of various aspects of the urinalysis are reviewed in Table 94.16 . Urinalysis performance is 94%
sensitive and 91% specific for the diagnosis of UTI even in young (0- to 60-day-old) infants. Either spun or
unspun urine may be studied through the microscope, with or without the aid of a Gram stain. Urine culture should
be obtained in any child in whom a UTI is suspected, as some young infants will not develop pyuria in response to
a UTI and the urinalysis may be falsely negative. Urine cultures are documented in terms of colony counts ( Table
94.17 ).
Bacteremia accompanies UTIs primarily during the first 12 months of life. In the very young infant, bacteremia
may be present in the absence of fever and should be suspected in any child during the first year of life with a
temperature ≥102.2°F (39°C). Indications for a CBC count and blood culture with a suspected UTI include (i)
signs of clinical toxicity (extreme tachycardia, low blood pressure, shaking chills); (ii) age younger than 3 months;
and (iii) ages 3 months to 1 year and temperature greater than or equal to 39°C.
