Bacteraemic urinary tract infection: management and outcomes in young infants.

OBJECTIVES: To determine predictors of parenteral antibiotic duration and the association between parenteral treatment duration and relapses in infants <3 months with bacteraemic urinary tract infection (UTI). DESIGN: Multicentre retrospective cohort study. SETTING: Eleven healthcare institutions across the USA. PATIENTS: Infants <3 months of age with bacteraemic UTI, defined as the same pathogenic organism isolated from blood and urine. MAIN OUTCOME MEASURES: Duration of parenteral antibiotic therapy, relapsed UTI within 30 days. RESULTS: The mean (±SD) duration of parenteral antibiotics for the 251 included infants was 7.8 days (±4 days), with considerable variability between institutions (mean range 5.5-12 days). Independent predictors of the duration of parenteral antibiotic therapy included (coefficient, 95% CI): age (-0.2 days, -0.3 days to -0.08 days, for each week older), year treated (-0.2 days, -0.4 to -0.03 days for each subsequent calendar year), male gender (0.9 days, 0.01 to 1.8 days), a positive repeat blood culture during acute treatment (3.5 days, 1.2-5.9 days) and a non-Escherichia coli organism (2.2 days, 0.8-3.6 days). No infants had a relapsed bacteraemic UTI. Six infants (2.4%) had a relapsed UTI (without bacteraemia). The duration of parenteral antibiotics did not differ between infants with and without a relapse (8.2 vs 7.8 days, p=0.81). CONCLUSIONS: Parenteral antibiotic treatment duration in young infants with bacteraemic UTI was variable and only minimally explained by measurable patient factors. Relapses were rare and were not associated with treatment duration. Shorter parenteral courses may be appropriate in some infants.

Blood culture time to positivity in febrile infants with bacteremia.

IMPORTANCE: Blood cultures are often obtained as part of the evaluation of infants with fever and these infants are typically observed until their cultures are determined to have no growth. However, the time to positivity of blood culture results in this population is not known. OBJECTIVE: To determine the time to positivity of blood culture results in febrile infants admitted to a general inpatient unit. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, retrospective, cross-sectional evaluation of blood culture time to positivity. Data were collected by community and academic hospital systems associated with the Pediatric Research in Inpatient Settings Network. The study included febrile infants 90 days of age or younger with bacteremia and without surgical histories outside of an intensive care unit. EXPOSURES: Blood culture growing pathogenic bacteria. MAIN OUTCOMES AND MEASURES: Time to positivity and proportion of positive blood culture results that become positive more than 24 hours after placement in the analyzer. RESULTS: A total of 392 pathogenic blood cultures were included from 17 hospital systems across the United States. The mean (SD) time to positivity was 15.41 (8.30) hours. By 24 hours, 91% (95% CI, 88-93) had turned positive. By 36 and 48 hours, 96% (95% CI, 95-98) and 99% (95% CI, 97-100) had become positive, respectively. CONCLUSIONS AND RELEVANCE: Most pathogens in febrile, bacteremic infants 90 days of age or younger hospitalized on a general inpatient unit will be identified within 24 hours of collection. These data suggest that inpatient observation of febrile infants for more than 24 hours may be unnecessary in most infants.

Time to detection of bacterial cultures in infants aged 0 to 90 days.

OBJECTIVE: To determine the time to detection (TTD) of positive results on blood, urine, and cerebrospinal fluid (CSF) cultures taken during the evaluation for serious bacterial infection (SBI) in otherwise healthy infants aged 0 to 90 days. METHODS: This study was a retrospective chart review of infants aged 0 to 90 days with positive blood, urine, or CSF cultures drawn during evaluation for SBI in the emergency department or inpatient setting. The TTD of positive culture results, reason for testing, and age of the infant were recorded. RESULTS: A total of 283 charts were reviewed related to 307 positive culture results. Of the 101 positive results on blood culture, 38% were true pathogens with a mean TTD of 13.3 hours; 97% were identified in < or = 36 hours. Blood cultures with TTD > or = 36 hours were 7.8 times more likely to be contaminants compared with those with TTD < 36 hours. Of 192 positive results on urine culture, 58% were true pathogens with a mean TTD of 21 hours; 95% were identified in < or = 36 hours. Fifty percent of 14 positive CSF culture results were true pathogens with a mean TTD of 28.9 hours; 86% were identified in < or = 36 hours. When data for infants < or = 28 days of age were analyzed separately, TTD followed the same patterns for positive blood and urine culture results as seen in all infants aged 0 to 90 days. CONCLUSIONS: In certain clinical situations, the inpatient observation period for infants under evaluation for SBI may be decreased to 36 hours.

Epidemiology of bacteremia in febrile infants in the United States.

BACKGROUND: Fever in infants is a common clinical dilemma. The objective of this study was to present data from hospital systems across the northeast, southeast, mid-west, and western United States to identify the pathogens causing bacteremia in febrile infants admitted to general care units. METHODS: This was a retrospective review of positive blood culture results in febrile infants aged ≤90 days admitted to a general care unit across 6 hospital systems. Data were collected from January 1, 2006 through December 31, 2012 from emergency departments and general inpatient units. Cultures from ICUs, central lines, or infants who had complex comorbidities were excluded, as were repeat cultures positive for the same bacteria. Common contaminants were considered pathogens if they were treated as such. RESULTS: We identified 181 cases of bacteremia in 177 infants. The most common pathogen was Escherichia coli (42%), followed by group B Streptococcus (23%). Streptococcus pneumoniae was more likely in older infants (P = .01). Non-low-risk bacteremic infants were more likely to have E. coli or group B Streptococcus than low-risk bacteremic infants. We identified no cases of Listeria monocytogenes. Variation between sites was minimal. CONCLUSIONS: This is the largest and most geographically diverse study to date examining the epidemiology of bacteremia in infants. We suggest E. coli is the most common cause of bacteremia in previously healthy febrile infants admitted to a general inpatient unit. We identified no cases of L monocytogenes and question whether empirical therapy remains necessary for this pathogen.