Predictors of positive cerebrospinal fluid cultures in infants with bacteremia

Role of microbiological tests and biomarkers in antibiotic stewardship

Laboratory tests are critical in the detection and timely treatment of infection. Two categories of tests are commonly used in neonatal sepsis management: those that identify the pathogen and those that detect host response to a potential pathogen. Decision-making around antibiotic choice is related to the performance of tests that directly identify pathogens. Advances in these tests hold the key to progress in antibiotic stewardship. Tests measuring host response, on the other hand, are an indirect marker of potential infection. While an important measure of the patient's clinical state, in the absence of pathogen detection these tests cannot confirm the appropriateness of antibiotic selection. The overall impact these tests then have on antibiotic utilization depends the test's specificity for bacterial infection, clinical scenario where it is being used and the decision-rule it is being integrated into for use. In this review we discuss common and emerging laboratory tests available for assisting management of neonatal infection and specifically focus on the role they play in optimizing antibiotic utilization.

Microbial Distribution and Antibiotic Susceptibility of Lower Respiratory Tract Infections Patients From Pediatric Ward, Adult Respiratory Ward, and Respiratory Intensive Care Unit

Introduction

Lower respiratory tract infections (LRTIs) account for significant morbidity and mortality in patients admitted to hospitals worldwide, especially in children and elderly. The prevalent microorganisms and antibiotic susceptibility were investigated among LRTI patients from the pediatric ward, adult respiratory ward, and respiratory intensive care unit (RICU) in order to achieve more efficient treatment protocols and better recovery.

Methods

In this retrospective cross-sectional study (January 2016 to December 2019), 4,161 positive culture samples out of 18,798 different specimens (9,645 respiratory tract samples and 9,153 blood samples) from LRTI patients were analyzed for pathogen incidence and antibiotic sensitivity.

Results

Among the respiratory tract cultures, the frequency of Gram-negative bacterial strains was higher than Gram-positive bacterial strains. Pseudomonas aeruginosa was the dominant pathogen in both the adult respiratory ward (n = 156, 21.49%) and RICU (n = 975, 35.67%), whereas Staphylococcus aureus (n = 66, 19.19%) was the most common bacterium in the pediatric ward. Among the blood cultures, Gram-positive bacteria remained the major microorganisms involved in LRTIs, and the most frequent pathogen was Staphylococcus epidermidis (n = 59, 47.20%) in the pediatric ward and Staphylococcus aureus (n = 10, 21.8%) in adult respiratory ward. However, Gram-negative bacteria were the main pathogens in the RICU, of which Klebsiella pneumoniae (n = 51, 27.57%) is the most prevalent. Pseudomonas aeruginosa of LRTI patients remained highly susceptible (>70%) to routine antibiotics in pediatric ward. However, it only had high susceptibility to amikacin, tobramycin, gentamicin in both the adult respiratory ward and RICU and its antibiotic sensitivity to meropenem and imipenem was moderate in the adult respiratory ward and mild (<30%) in the RICU. Staphylococcus aureus isolated from LRTI patients was highly susceptible to linezolid, daptomycin, teicoplanin, vancomycin, tigecycline, rifampicin, and trimethoprim/sulfamethoxazole in all three wards, moderately susceptible to gentamicin in both the adult respiratory ward and RICU and to clindamycin, oxacillin, moxifloxacin only in the adult respiratory ward.

Conclusions

Microbial distribution and their patterns of antibiotic susceptibility revealed a high divergence among LRTI patients admitted to different wards in this hospital. Thus, different antibiotic therapies should be considered for distinct age groups.

Surfactant Administration in Preterm Infants: Drug Development Opportunities

OBJECTIVE

To evaluate how frequently surfactant is used off-label in preterm infants.

STUDY DESIGN

We conducted a retrospective cohort analysis of prospectively collected administrative data for 2005-2015 from 348 neonatal intensive care units in the US. We quantified off-label administration of poractant alfa, calfactant, or beractant in inborn infants born at <37 weeks of gestational age (GA). Off-label surfactant administration was defined according to the Food and Drug Administration (FDA) label.

RESULTS

Of a total of 110 822 preterm infants who received surfactant, 68 226 (62%) received the surfactant off-label. The majority of infants who received surfactant off-label had a higher birth weight than those who received surfactant on-label (40 716 [37%]), had an older GA than those who received surfactant on-label (35 191 [32%]), or were treated with intubation and surfactant administration followed by immediate extubation (INSURE) (32 310 [29%]). Poractant alfa was administered via INSURE more frequently than beractant or calfactant (16 688 [38%], 7137 [20%], and 8485 [27%], respectively). An increasing number of infants received surfactant via INSURE from 2005 to 2015 (from 1697 [19%] to 3368 [36%]).

CONCLUSIONS

The majority of surfactant given to preterm infants is administered off-label. The uptrend in administration via INSURE coincides with increased supporting evidence. The gap between FDA labeling and current clinic practice exemplifies an opportunity for label expansion, which may require additional prospective or retrospective safety and/or effectiveness data for infants of older GA and higher birth weight.

Incidence, clinical features, and implications on outcomes of neonatal late-onset sepsis with concurrent infectious focus

BACKGROUND

Neonatal bloodstream infection (BSI) is the most important cause of morbidity and mortality in the neonatal intensive care unit (NICU). Although most neonatal BSIs are primary bacteremia, some are associated with a focus of infection. This distinction is not well characterized.

METHODS

All patients with neonatal late-onset sepsis (LOS) between January 2006 and December 2013 were enrolled. LOS was categorized as a BSI with a concurrent focus of infection if LOS occurred before or within 24 h after the diagnosis of a specific infectious entity, and as "primary bacteremia" if no concurrent focus of infection was identified. Data concerning demographics, hospital course, microbiology, and outcomes were compared via univariate and multivariate analyses.

RESULTS

Of 948 episodes of neonatal LOS, 781 (82.4%) were primary bacteremia, whereas 167 (17.6%) were associated with a known focus of infection, including meningitis (n = 51, 5.4%), ventilator-associated pneumonia (VAP) (n = 36, 3.8%), catheter-related bloodstream infections (n = 57, 6.0%), and necrotizing enterocolitis (NEC) (n = 21, 2.2%). The majority of NEC-associated BSIs were caused by gram-negative bacilli (85.7%). Group B streptococcus accounted for nearly one-third of all meningitis cases (29.4%). Although sepsis-attributable mortality was comparable between primary bacteremia and neonatal BSIs with a focus of infection, neonatal BSIs with meningitis, VAP, and NEC had significantly higher rates of infectious complications. The independent risk factors of sepsis-attributable mortality were infectious complications (Odds ratio [OR] 6.98; 95% confidence interval [CI] 3.64-13.39, P < 0.001); history of one or more than one previous episode(s) of BSI (OR 2.40 and 7.40; 95% CI 1.21-4.74 and 3.70-14.78, P = 0.012 and <0.001, respectively); and underlying secondary pulmonary hypertension in neonates (OR 4.77; 95% CI 1.91-11.96, P = 0.001).

CONCLUSIONS

A considerable proportion of neonatal LOS can be associated with known infectious foci in the NICU. The microbiologic etiology of neonatal LOS with a concurrent focus of infection is significantly different from that of primary bacteremia. Neonatal BSIs with concurrent meningitis, VAP, or NEC are significantly more likely to have infectious complications. This association independently leads to sepsis-attributable mortality.

Ventriculoperitoneal shunt infection with non-typhoidal Salmonella species in an infant

Shunt infections are common in pediatric neurosurgery. We present a case of a 3-month-old male with a history of a ventriculoperitoneal shunt for posthemorrhagic hydrocephalus after premature birth who presented to the emergency department with irritability and decreased oral intake. His presentation was concerning for shunt infection and evaluation for this was undertaken. He was found to have a shunt infection due to non-Salmonellatyphi species, a rare cause of meningitis in children in the United States and rarer cause of shunt infection. With effective treatment for this organism, the patient did well and was discharged home in good condition.