Omphalitis and Concurrent Serious Bacterial Infection

OBJECTIVE

Describe the clinical presentation, prevalence of concurrent serious bacterial infection (SBI), and outcomes among infants with omphalitis.

METHODS

Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants ≤90 days of age with omphalitis seen in the emergency department from January 1, 2008, to December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized.

RESULTS

Among 566 infants (median age 16 days), 537 (95%) were well-appearing, 64 (11%) had fever at home or in the emergency department, and 143 (25%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 472 (83%), 326 (58%), and 222 (39%) infants, respectively. Pathogens grew in 1.1% (95% confidence interval [CI], 0.3%-2.5%) of blood, 0.9% (95% CI, 0.2%-2.7%) of urine, and 0.9% (95% CI, 0.1%-3.2%) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 320 (57%) infants, with 85% (95% CI, 80%-88%) growing a pathogen, most commonly methicillin-sensitive Staphylococcus aureus (62%), followed by methicillin-resistant Staphylococcus aureus (11%) and Escherichia coli (10%). Four hundred ninety-eight (88%) were hospitalized, 81 (16%) to an ICU. Twelve (2.1% [95% CI, 1.1%-3.7%]) had sepsis or shock, and 2 (0.4% [95% CI, 0.0%-1.3%]) had severe cellulitis or necrotizing soft tissue infection. There was 1 death. Serious complications occurred only in infants aged <28 days.

CONCLUSIONS

In this multicenter cohort, mild, localized disease was typical of omphalitis. SBI and adverse outcomes were uncommon. Depending on age, routine testing for SBI is likely unnecessary in most afebrile, well-appearing infants with omphalitis.

Neonatal Mastitis and Concurrent Serious Bacterial Infection

OBJECTIVES

Describe the clinical presentation, prevalence, and outcomes of concurrent serious bacterial infection (SBI) among infants with mastitis.

METHODS

Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants aged ≤90 days with mastitis who were seen in the emergency department between January 1, 2008, and December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized.

RESULTS

Among 657 infants (median age 21 days), 641 (98%) were well appearing, 138 (21%) had history of fever at home or in the emergency department, and 63 (10%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 581 (88%), 274 (42%), and 216 (33%) infants, respectively. Pathogens grew in 0.3% (95% confidence interval [CI] 0.04-1.2) of blood, 1.1% (95% CI 0.2-3.2) of urine, and 0.4% (95% CI 0.01-2.5) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 335 (51%) infants, with 77% (95% CI 72-81) growing a pathogen, most commonly methicillin-resistant Staphylococcus aureus (54%), followed by methicillin-susceptible S aureus (29%), and unspecified S aureus (8%). A total of 591 (90%) infants were admitted to the hospital, with 22 (3.7%) admitted to an ICU. Overall, 10 (1.5% [95% CI 0.7-2.8]) had sepsis or shock, and 2 (0.3% [95% CI 0.04-1.1]) had severe cellulitis or necrotizing soft tissue infection. None received vasopressors or endotracheal intubation. There were no deaths.

CONCLUSIONS

In this multicenter cohort, mild localized disease was typical of neonatal mastitis. SBI and adverse outcomes were rare. Evaluation for SBI is likely unnecessary in most afebrile, well-appearing infants with mastitis.

Height of fever and invasive bacterial infection

OBJECTIVE

We aimed to evaluate the association of height of fever with invasive bacterial infection (IBI) among febrile infants <=60 days of age.

METHODS

In a secondary analysis of a multicentre case-control study of non-ill-appearing febrile infants <=60 days of age, we compared the maximum temperature (at home or in the emergency department) for infants with and without IBI. We then computed interval likelihood ratios (iLRs) for the diagnosis of IBI at each half-degree Celsius interval.

RESULTS

The median temperature was higher for infants with IBI (38.8°C; IQR 38.4-39.2) compared with those without IBI (38.4°C; IQR 38.2-38.9) (p<0.001). Temperatures 39°C-39.4°C and 39.5°C-39.9°C were associated with a higher likelihood of IBI (iLR 2.49 and 3.40, respectively), although 30.4% of febrile infants with IBI had maximum temperatures <38.5°C.

CONCLUSIONS

Although IBI is more likely with higher temperatures, height of fever alone should not be used for risk stratification of febrile infants.

Characteristics of Afebrile Infants ≤60 Days of Age With Invasive Bacterial Infections

OBJECTIVES

To describe the characteristics and outcomes of afebrile infants ≤60 days old with invasive bacterial infection (IBI).

METHODS

We conducted a secondary analysis of a cross-sectional study of infants ≤60 days old with IBI presenting to the emergency departments (EDs) of 11 children's hospitals from 2011 to 2016. We classified infants as afebrile if there was absence of a temperature ≥38°C at home, at the referring clinic, or in the ED. Bacteremia and bacterial meningitis were defined as pathogenic bacterial growth from a blood and/or cerebrospinal fluid culture.

RESULTS

Of 440 infants with IBI, 78 (18%) were afebrile. Among afebrile infants, 62 (79%) had bacteremia without meningitis and 16 (20%) had bacterial meningitis (10 with concomitant bacteremia). Five infants (6%) died, all with bacteremia. The most common pathogens were Streptococcus agalactiae (35%), Escherichia coli (16%), and Staphylococcus aureus (16%). Sixty infants (77%) had an abnormal triage vital sign (temperature <36°C, heart rate ≥181 beats per minute, or respiratory rate ≥66 breaths per minute) or a physical examination abnormality (ill appearance, full or depressed fontanelle, increased work of breathing, or signs of focal infection). Forty-three infants (55%) had ≥1 of the following laboratory abnormalities: white blood cell count <5000 or >15 000 cells per μL, absolute band count >1500 cells per μl, or positive urinalysis. Presence of an abnormal vital sign, examination finding, or laboratory test result had a sensitivity of 91% (95% confidence interval 82%-96%) for IBI.

CONCLUSIONS

Most afebrile young infants with an IBI had vital sign, examination, or laboratory abnormalities. Future studies should evaluate the predictive ability of these criteria in afebrile infants undergoing evaluation for IBI.

Febrile Infants ≤60 Days Old With Positive Urinalysis Results and Invasive Bacterial Infections

OBJECTIVES

We aimed to describe the clinical and laboratory characteristics of febrile infants ≤60 days old with positive urinalysis results and invasive bacterial infections (IBI).

METHODS

We performed a planned secondary analysis of a retrospective cohort study of febrile infants ≤60 days old with IBI who presented to 11 emergency departments from July 1, 2011, to June 30, 2016. For this subanalysis, we included infants with IBI and positive urinalysis results. We analyzed the sensitivity of high-risk past medical history (PMH) (prematurity, chronic medical condition, or recent antimicrobial receipt), ill appearance, and/or abnormal white blood cell (WBC) count (<5000 or >15 000 cells/μL) for identification of IBI.

RESULTS

Of 148 febrile infants with positive urinalysis results and IBI, 134 (90.5%) had bacteremia without meningitis and 14 (9.5%) had bacterial meningitis (11 with concomitant bacteremia). Thirty-five infants (23.6%) with positive urinalysis results and IBI did not have urinary tract infections. The presence of high-risk PMH, ill appearance, and/or abnormal WBC count had a sensitivity of 53.4% (95% confidence interval: 45.0-61.6) for identification of IBI. Of the 14 infants with positive urinalysis results and concomitant bacterial meningitis, 7 were 29 to 60 days old. Six of these 7 infants were ill-appearing or had an abnormal WBC count. The other infant had bacteremia with cerebrospinal fluid pleocytosis after antimicrobial pretreatment and was treated for meningitis.

CONCLUSIONS

The sensitivity of high-risk PMH, ill appearance, and/or abnormal WBC count is suboptimal for identifying febrile infants with positive urinalysis results at low risk for IBI. Most infants with positive urinalysis results and bacterial meningitis are ≤28 days old, ill-appearing, or have an abnormal WBC count.

Cerebrospinal Fluid Profiles of Infants ≤60 Days of Age With Bacterial Meningitis

OBJECTIVES

We aimed to describe the cerebrospinal fluid (CSF) profiles of infants ≤60 days old with bacterial meningitis and the characteristics of infants with bacterial meningitis who did not have CSF abnormalities.

METHODS

We included infants ≤60 days old with culture-positive bacterial meningitis who were evaluated in the emergency departments of 11 children's hospitals between July 1, 2011, and June 30, 2016. From medical records, we abstracted clinical and laboratory data. For infants with traumatic lumbar punctures (CSF red blood cell count of ≥10 000 cells per mm³), we used a red blood cell count/white blood cell (WBC) count correction factor of 1000:1 to determine the corrected CSF WBC count. We calculated the sensitivity for bacterial meningitis of a CSF Gram-stain and corrected CSF pleocytosis (≥16 WBCs per mm³ for infants ≤28 days old and ≥10 WBCs per mm³ for infants 29-60 days old).

RESULTS

Among 66 infants with bacterial meningitis, the sensitivity of a CSF Gram-stain was 71.9% (95% confidence interval [CI]: 59.2-82.4), and the sensitivity of corrected CSF pleocytosis was 80.3% (95% CI: 68.7-89.1). The sensitivity of combining positive Gram-stain results with corrected CSF pleocytosis was 86.4% (95% CI: 75.7-93.6). Of 9 infants with meningitis who had a negative Gram-stain result and no corrected CSF pleocytosis, 8 (88.9%) had either an abnormal peripheral WBC count (>15 000 or <5000 cells per μL) or bandemia >10%.

CONCLUSIONS

Most infants ≤60 days old with bacterial meningitis have CSF pleocytosis or a positive Gram-stain result. Infants with no CSF pleocytosis and a negative Gram-stain result are unlikely to have bacterial meningitis in the absence of other laboratory abnormalities.

Parenteral Antibiotic Therapy Duration in Young Infants With Bacteremic Urinary Tract Infections

OBJECTIVES

To determine the association between parenteral antibiotic duration and outcomes in infants ≤60 days old with bacteremic urinary tract infection (UTI).

METHODS

This multicenter retrospective cohort study included infants ≤60 days old who had concomitant growth of a pathogen in blood and urine cultures at 11 children's hospitals between 2011 and 2016. Short-course parenteral antibiotic duration was defined as ≤7 days, and long-course parenteral antibiotic duration was defined as >7 days. Propensity scores, calculated using patient characteristics, were used to determine the likelihood of receiving long-course parenteral antibiotics. We conducted inverse probability weighting to achieve covariate balance and applied marginal structural models to the weighted population to examine the association between parenteral antibiotic duration and outcomes (30-day UTI recurrence, 30-day all-cause reutilization, and length of stay).

RESULTS

Among 115 infants with bacteremic UTI, 58 (50%) infants received short-course parenteral antibiotics. Infants who received long-course parenteral antibiotics were more likely to be ill appearing and have growth of a non-Escherichia coli organism. There was no difference in adjusted 30-day UTI recurrence between the long- and short-course groups (adjusted risk difference: 3%; 95% confidence interval: -5.8 to 12.7) or 30-day all-cause reutilization (risk difference: 3%; 95% confidence interval: -14.5 to 20.6).

CONCLUSIONS

Young infants with bacteremic UTI who received ≤7 days of parenteral antibiotics did not have more frequent recurrent UTIs or hospital reutilization compared with infants who received long-course therapy. Short-course parenteral therapy with early conversion to oral antibiotics may be considered in this population.

A Prediction Model to Identify Febrile Infants ≤60 Days at Low Risk of Invasive Bacterial Infection

OBJECTIVES

To derive and internally validate a prediction model for the identification of febrile infants ≤60 days old at low probability of invasive bacterial infection (IBI).

METHODS

We conducted a case-control study of febrile infants ≤60 days old who presented to the emergency departments of 11 hospitals between July 1, 2011 and June 30, 2016. Infants with IBI, defined by growth of a pathogen in blood (bacteremia) and/or cerebrospinal fluid (bacterial meningitis), were matched by hospital and date of visit to 2 control patients without IBI. Ill-appearing infants and those with complex chronic conditions were excluded. Predictors of IBI were identified with multiple logistic regression and internally validated with 10-fold cross-validation, and an IBI score was calculated.

RESULTS

We included 181 infants with IBI (155 [85.6%] with bacteremia without meningitis and 26 [14.4%] with bacterial meningitis) and 362 control patients. Twenty-three infants with IBI (12.7%) and 138 control patients (38.1%) had fever by history only. Four predictors of IBI were identified (area under the curve 0.83 [95% confidence interval (CI): 0.79-0.86]) and incorporated into an IBI score: age <21 days (1 point), highest temperature recorded in the emergency department 38.0-38.4°C (2 points) or ≥38.5°C (4 points), absolute neutrophil count ≥5185 cells per μL (2 points), and abnormal urinalysis results (3 points). The sensitivity and specificity of a score ≥2 were 98.8% (95% CI: 95.7%-99.9%) and 31.3% (95% CI: 26.3%-36.6%), respectively. All 26 infants with meningitis had scores ≥2.

CONCLUSIONS

Infants ≤60 days old with fever by history only, a normal urinalysis result, and an absolute neutrophil count <5185 cells per μL have a low probability of IBI.

Factors Associated with Adverse Outcomes among Febrile Young Infants with Invasive Bacterial Infections

OBJECTIVE

To determine factors associated with adverse outcomes among febrile young infants with invasive bacterial infections (IBIs) (ie, bacteremia and/or bacterial meningitis).

STUDY DESIGN

Multicenter, retrospective cohort study (July 2011-June 2016) of febrile infants ≤60 days of age with pathogenic bacterial growth in blood and/or cerebrospinal fluid. Subjects were identified by query of local microbiology laboratory and/or electronic medical record systems, and clinical data were extracted by medical record review. Mixed-effect logistic regression was employed to determine clinical factors associated with 30-day adverse outcomes, which were defined as death, neurologic sequelae, mechanical ventilation, or vasoactive medication receipt.

RESULTS

Three hundred fifty infants met inclusion criteria; 279 (79.7%) with bacteremia without meningitis and 71 (20.3%) with bacterial meningitis. Forty-two (12.0%) infants had a 30-day adverse outcome: 29 of 71 (40.8%) with bacterial meningitis vs 13 of 279 (4.7%) with bacteremia without meningitis (36.2% difference, 95% CI 25.1%-48.0%; P < .001). On adjusted analysis, bacterial meningitis (aOR 16.3, 95% CI 6.5-41.0; P < .001), prematurity (aOR 7.1, 95% CI 2.6-19.7; P < .001), and ill appearance (aOR 3.8, 95% CI 1.6-9.1; P = .002) were associated with adverse outcomes. Among infants who were born at term, not ill appearing, and had bacteremia without meningitis, only 2 of 184 (1.1%) had adverse outcomes, and there were no deaths.

CONCLUSIONS

Among febrile infants ≤60 days old with IBI, prematurity, ill appearance, and bacterial meningitis (vs bacteremia without meningitis) were associated with adverse outcomes. These factors can inform clinical decision-making for febrile young infants with IBI.

Risk Stratification of Febrile Infants ≤60 Days Old Without Routine Lumbar Puncture

: media-1vid110.1542/5840460609001PEDS-VA_2018-1879Video Abstract OBJECTIVES: To evaluate the Rochester and modified Philadelphia criteria for the risk stratification of febrile infants with invasive bacterial infection (IBI) who do not appear ill without routine cerebrospinal fluid (CSF) testing.

METHODS

We performed a case-control study of febrile infants ≤60 days old presenting to 1 of 9 emergency departments from 2011 to 2016. For each infant with IBI (defined as a blood [bacteremia] and/or CSF [bacterial meningitis] culture with growth of a pathogen), controls without IBI were matched by site and date of visit. Infants were excluded if they appeared ill or had a complex chronic condition or if data for any component of the Rochester or modified Philadelphia criteria were missing.

RESULTS

Overall, 135 infants with IBI (118 [87.4%] with bacteremia without meningitis and 17 [12.6%] with bacterial meningitis) and 249 controls were included. The sensitivity of the modified Philadelphia criteria was higher than that of the Rochester criteria (91.9% vs 81.5%; P = .01), but the specificity was lower (34.5% vs 59.8%; P < .001). Among 67 infants >28 days old with IBI, the sensitivity of both criteria was 83.6%; none of the 11 low-risk infants had bacterial meningitis. Of 68 infants ≤28 days old with IBI, 14 (20.6%) were low risk per the Rochester criteria, and 2 had meningitis.

CONCLUSIONS

The modified Philadelphia criteria had high sensitivity for IBI without routine CSF testing, and all infants >28 days old with bacterial meningitis were classified as high risk. Because some infants with bacteremia were classified as low risk, infants discharged from the emergency department without CSF testing require close follow-up.

Epidemiology and Etiology of Invasive Bacterial Infection in Infants ≤60 Days Old Treated in Emergency Departments

OBJECTIVES

To help guide empiric treatment of infants ≤60 days old with suspected invasive bacterial infection by describing pathogens and their antimicrobial susceptibilities.

STUDY DESIGN

Cross-sectional study of infants ≤60 days old with invasive bacterial infection (bacteremia and/or bacterial meningitis) evaluated in the emergency departments of 11 children's hospitals between July 1, 2011 and June 30, 2016. Each site's microbiology laboratory database or electronic medical record system was queried to identify infants from whom a bacterial pathogen was isolated from either blood or cerebrospinal fluid. Medical records of these infants were reviewed to confirm the presence of a pathogen and to obtain demographic, clinical, and laboratory data.

RESULTS

Of the 442 infants with invasive bacterial infection, 353 (79.9%) had bacteremia without meningitis, 64 (14.5%) had bacterial meningitis with bacteremia, and 25 (5.7%) had bacterial meningitis without bacteremia. The peak number of cases of invasive bacterial infection occurred in the second week of life; 364 (82.4%) infants were febrile. Group B streptococcus was the most common pathogen identified (36.7%), followed by Escherichia coli (30.8%), Staphylococcus aureus (9.7%), and Enterococcus spp (6.6%). Overall, 96.8% of pathogens were susceptible to ampicillin plus a third-generation cephalosporin, 96.0% to ampicillin plus gentamicin, and 89.2% to third-generation cephalosporins alone.

CONCLUSIONS

For most infants ≤60 days old evaluated in a pediatric emergency department for suspected invasive bacterial infection, the combination of ampicillin plus either gentamicin or a third-generation cephalosporin is an appropriate empiric antimicrobial treatment regimen. Of the pathogens isolated from infants with invasive bacterial infection, 11% were resistant to third-generation cephalosporins alone.

Time to Pathogen Detection for Non-ill Versus Ill-Appearing Infants ≤60 Days Old With Bacteremia and Meningitis

OBJECTIVES

We sought to determine the time to pathogen detection in blood and cerebrospinal fluid (CSF) for infants ≤60 days old with bacteremia and/or bacterial meningitis and to explore whether time to pathogen detection differed for non-ill-appearing and ill-appearing infants.

METHODS

We included infants ≤60 days old with bacteremia and/or bacterial meningitis evaluated in the emergency departments of 10 children's hospitals between July 1, 2011, and June 30, 2016. The microbiology laboratories at each site were queried to identify infants in whom a bacterial pathogen was isolated from blood and/or CSF. Medical records were then reviewed to confirm the presence of a pathogen and to extract demographic characteristics, clinical appearance, and the time to pathogen detection.

RESULTS

Among 360 infants with bacteremia, 316 (87.8%) pathogens were detected within 24 hours and 343 (95.3%) within 36 hours. A lower proportion of non-ill-appearing infants with bacteremia had a pathogen detected on blood culture within 24 hours compared with ill-appearing infants (85.0% vs 92.9%, respectively; P = .03). Among 62 infants with bacterial meningitis, 55 (88.7%) pathogens were detected within 24 hours and 59 (95.2%) were detected within 36 hours, with no difference based on ill appearance.

CONCLUSIONS

Among infants ≤60 days old with bacteremia and/or bacterial meningitis, pathogens were commonly identified from blood or CSF within 24 and 36 hours. However, clinicians must weigh the potential for missed bacteremia in non-ill-appearing infants discharged within 24 hours against the overall low prevalence of infection.

Fever in infants less than two months of age: spectrum of disease and predictors of outcome

Four hundred thirty-four febrile infants two months of age or younger were evaluated in the emergency departments of five major teaching hospitals over a one-year period. A culture-proven bacterial infection was present in 3.5% of the infants; bacteremia was detected in 3.3%. Bacterial meningitis was present in 2.4%, and aseptic meningitis was noted in 13.4%. Twenty-one percent had clinically apparent serious disease including pneumonia, otitis media, and gastroenteritis with dehydration. Six variables (age less than 1 month, lethargy, no contact with an ill individual, breast-feeding, total polymorphonuclear greater than or equal to 10,000/mm3 and band count greater than or equal to 500/mm3) were correlated with bacterial infection by step-wise discriminant analysis. However, these findings were neither sensitive nor specific enough to be clinically useful. Management varied, and 62% of the infants were hospitalized. Fifty-four percent, some of whom were managed as outpatients, received antibiotics. Febrile infants two months of age or younger require a comprehensive emergency department assessment, including appropriate laboratory studies (CBC, differential, urinalysis and culture, lumbar puncture, and blood culture), since 3.5% have bacterial infection that may be life-threatening. Hospitalization is warranted if the infant appears ill, laboratory studies indicate serious infection, or follow-up care is uncertain.

Primary herpes simplex pneumonia in a neonate

A 6-day-old male infant was treated for rapidly progressive pneumonia. The infection was not responsive to antibiotic and symptomatic treatment, and the infant died within 48 hours of admission. Herpes simplex type II grew from premortem respiratory and postmortem lung cultures, and immunoperoxidase staining confirmed the presence of this organism in lung tissue. Pathologic findings were limited to the lungs. A maternal origin for the virus was suspected but could not be proved. We believe this patient represents the first reported case of isolated herpes simplex type II pneumonia in a neonate.