Cerebrospinal fluid pleocytosis in febrile infants 1-90 days with urinary tract infection

Respiratory viral detection in the plasma and cerebrospinal fluid (CSF) of young febrile infants

Background

Respiratory viral infections are common in febrile infants ≤90 days. However, the detection of viruses other than enterovirus in the blood and cerebrospinal fluid (CSF) of young infants is not well defined. We sought to quantify the occurrence of respiratory viruses in the blood and CSF of febrile infants ≤90 days.

Methods

We conducted a nested cohort study examining plasma and CSF samples from febrile infants 15-90 days via rtPCR. The samples were tested for respiratory viruses (respiratory syncytial virus, influenza, enterovirus, parechovirus, adenovirus, bocavirus). Clinical and laboratory data were also collected to determine the presence of serious bacterial infections (SBI).

Results

Twenty-four percent (30 of 126) of infants had plasma/CSF specimens positive for a respiratory virus. Enterovirus and parechovirus were the most commonly detected respiratory viruses. Viral positivity was highest in plasma samples at 25% (27 of 107) compared with CSF samples at 15% (nine of 62). SBIs (specifically urinary tract infections) were less common in infants with a sample positive for a respiratory virus compared to those without a virus detected (3% vs. 26%, p = 0.008).

Conclusions

Our findings support the use of molecular diagnostics to include the identification of parechovirus in addition to enterovirus in febrile infants ≤90 days. Additionally, these data support the utilization of blood specimens to diagnose enterovirus and parechovirus infections in febrile infants ≤90 days.

Clinical characteristics and outcomes in febrile infants aged 29-90 days with urinary tract infections and cerebrospinal fluid pleocytosis

Introduction

Fever without a focus is a common reason for medical evaluations, hospitalizations, and the antimicrobial treatment of infants younger than 90 days. The presence of cerebrospinal fluid (CSF) pleocytosis could be challenge for clinicians who treat febrile young infants with urinary tract infection (UTI). We evaluated the factors associated with sterile CSF pleocytosis and the clinical outcomes of the patients.

Methods

A retrospective review of patients aged 29-90 days with febrile UTIs who underwent a non-traumatic lumbar puncture (LP) at Pusan National University Hospital from January 2010 to December 2020 was conducted. CSF pleocytosis was defined as white blood cell (WBC) counts ≥9/mm³.

Results

A total of 156 patients with UTI were eligible for this study. Four (2.6%) had concomitant bacteremia. However, no patients had culture-proven bacterial meningitis. In correlation analysis, although weak strength, CSF WBC counts were positively correlated with C-reactive protein (CRP) level (Spearman r = 0.234; P = 0.003). Thirty-three patients had CSF pleocytosis [21.2%; 95% confidential interval (CI), 15.5-28.2]. The time from fever onset to the hospital visit, peripheral blood platelet counts, and CRP level at admission were statistically significant in patients with sterile CSF pleocytosis compared to those without CSF pleocytosis. In the multiple logistic regression, only CRP was independently associated with sterile CSF pleocytosis (cutoff, 3.425 mg/dl; adjusted odds ratio, 2.77; 95% CI, 1.19-6.88). The proportion of fever defervescence by hospital day 2 was 87.9% in patients with CSF pleocytosis and 89.4% in those without CSF pleocytosis (P = 0.759). There was no statistical difference in the fever defervescence curves between the two patient groups (P = 0.567). No patients had neurological manifestations or complications.

Conclusions

Coexisting sterile CSF pleocytosis among febrile infants with UTIs suggest a systemic inflammatory response. However, the clinical outcomes between the two groups were similar. A selective LP should be considered in young infants with evidence of UTI, and inappropriate antibiotic therapy for sterile CSF pleocytosis should be avoided.

Short-course intravenous antibiotics for young infants with urinary tract infection

OBJECTIVE

Shorter courses of intravenous antibiotics for young infants with urinary tract infection (UTI) have myriad advantages. As practice shifts toward shorter intravenous treatment courses, this study aimed to determine the safety of early intravenous-to-oral antibiotic switch and identify risk factors for bacteraemia with UTI.

METHODS

Retrospective audit of infants aged ≤90 days with a positive urine culture at a quaternary paediatric hospital over 4 years (2016-2020). Data were collected from the hospital electronic medical record and laboratory information system. Short-course intravenous antibiotic duration was defined as <48 hours for non-bacteraemic UTI and <7 days for bacteraemic UTI. Multivariate analysis was used to determine patient factors predicting bacteraemia.

RESULTS

Among 427 infants with non-bacteraemic UTI, 257 (60.2%) were treated for <48 hours. Clinicians prescribed shorter intravenous courses to infants who were female, aged >30 days, afebrile and those without bacteraemia or cerebrospinal fluid pleocytosis. Treatment failure (30-day UTI recurrence) occurred in 6/451 (1.3%) infants. All had non-bacteraemic UTI and one received <48 hours of intravenous antibiotics. None had serious complications (bacteraemia, meningitis, death). Follow-up audiology occurred in 21/31 (68%) infants with cerebrospinal fluid pleocytosis, and one had sensorineural hearing loss. Bacteraemia occurred in 24/451 (5.3%) infants, with 10 receiving <7 days intravenous antibiotics with no treatment failure. Fever and pyelonephritis were independent predictors of bacteraemia.

CONCLUSION

Short-course intravenous antibiotics for <48 hours for young infants with non-bacteraemic UTI should be considered, provided meningitis has been excluded. Treatment failure and serious complications were rare in young infants with UTI.

Short Intravenous Antibiotic Courses for Urinary Infections in Young Infants: A Systematic Review

CONTEXT

Urinary tract infections (UTIs) are common in young infants, yet there is no guidance on the optimal duration of intravenous (IV) treatment.

OBJECTIVE

To determine if shorter IV antibiotic courses (≤7 days) are appropriate for managing UTIs in infants aged ≤90 days.

METHODS

PubMed, the Cochrane Library, Medline, and Embase (February 2021) were used as data sources. Included studies reported original data for infants aged ≤90 days with UTIs, studied short IV antibiotic durations (≤7 days), and described at least 1 treatment outcome. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Studies were screened by 2 investigators, and bias was assessed by using the Newcastle-Ottawa Scale and the Revised Cochrane Risk-of-Bias Tool.

RESULTS

Eighteen studies with 16 615 young infants were included. The largest 2 studies on bacteremic UTI found no difference in the rates of 30-day recurrence between those treated with ≤7 vs >7 days of IV antibiotics. For nonbacteremic UTI, there was no significant difference in the adjusted 30-day recurrence between those receiving ≤3 vs >3 days of IV antibiotics in the largest 2 studies identified. Three studies of infants aged ≥30 days used oral antibiotics alone and reported good outcomes, although only 85 infants were ≤90 days old.

CONCLUSIONS

Shorter IV antibiotic courses of ≤7 days and ≤3 days with early switch to oral antibiotics should be considered in infants aged ≤90 days with bacteremic and nonbacteremic UTI, respectively, after excluding meningitis. Further studies of treatment with oral antibiotics alone are needed in this age group.

Evaluation and Management of Well-Appearing Febrile Infants 8 to 60 Days Old

This guideline addresses the evaluation and management of well-appearing, term infants, 8 to 60 days of age, with fever ≥38.0°C. Exclusions are noted. After a commissioned evidence-based review by the Agency for Healthcare Research and Quality, an additional extensive and ongoing review of the literature, and supplemental data from published, peer-reviewed studies provided by active investigators, 21 key action statements were derived. For each key action statement, the quality of evidence and benefit-harm relationship were assessed and graded to determine the strength of recommendations. When appropriate, parents' values and preferences should be incorporated as part of shared decision-making. For diagnostic testing, the committee has attempted to develop numbers needed to test, and for antimicrobial administration, the committee provided numbers needed to treat. Three algorithms summarize the recommendations for infants 8 to 21 days of age, 22 to 28 days of age, and 29 to 60 days of age. The recommendations in this guideline do not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate.

Core-shell nanoparticles as platform technologies for paper based point-of-care devices to detect antimicrobial resistance

Globally, rapid development of antibiotic resistance amongst pathogens has led to limited treatment options and high indirect costs to health management. There is a need to avoid misuse of available antibiotics and to develop rapid, affordable and accessible diagnostic technologies to detect drug resistance even in resource limited settings. This study reports the development of instrument-free point-of-care devices for detection of antibiotic resistance for rapid diagnosis of drug resistance in the penicillin, cephalosporin and carbapenem groups of antibiotics. The simple paper-based devices for flow through assay determine the presence of resistant bacteria in a sample by a visible colour change within 30 minutes. At the center of this technology is the unique sensing nanomaterial comprising of core-shell nanoparticles layered with specific antibiotics. The core is comprised of chitosan nanoparticles of size ∼15 nm coated with the starch-iodine indicator to form a shell increasing the size to ∼47 nm. The test strip is coated with the nanoparticles, air-dried and overlayed with the required antibiotic. In the presence of penicillin, cephalosporin and carbapenem resistant bacteria, the core-shell nanoparticles undergo a visible colour change from blue to white. The core-shell nanoparticles were deposited on paper to form a point-of-care device. Devices were developed to screen for three main classes of antibiotics namely penicillins, cephalosporins and carbapenems. The devices were validated using standard resistant and susceptible ATCC strains in three different sample types, pure colony, broth culture and saline suspensions. The change of colour from blue to white was considered a positive test. The time of detection was found to be 30 min, while the limit of detection was 10⁵ cfu ml^-1. The device exhibited 100% sensitivity and specificity with known resistant and susceptible cultures not only from pure colonies but also from direct samples of spiked saline suspensions with graded confounding factors of albumin, glucose, and urea. The inter-device reproducibility and storage stability of the devices was established. The developed point-of-care devices have potential as screening devices for antimicrobial resistance.

N-acetylcysteine inhibits bacterial lipopeptide-mediated neutrophil transmigration through the choroid plexus in the developing brain

The etiology of neurological impairments associated with prematurity and other perinatal complications often involves an infectious or pro-inflammatory component. The use of antioxidant molecules have proved useful to protect the neonatal brain from injury. The choroid plexuses-CSF system shapes the central nervous system response to inflammation at the adult stage, but little is known on the neuroimmune interactions that take place at the choroidal blood-CSF barrier during development. We previously described that peripheral administration to neonatal mice of the TLR2 ligand PAM3CSK4 (P3C), a prototypic Gram-positive bacterial lipopeptide, induces the migration of innate immune cells to the CSF. Here we showed in neonatal rats exposed to P3C that the migration of neutrophils into the CSF, which occurred through the choroid plexuses, is abolished following administration of the antioxidant drug N-acetylcysteine. Combining light sheet microscopy imaging of choroid plexus, a differentiated model of the blood-CSF barrier, and multiplex cytokine assays, we showed that the choroidal epithelium responds to the bacterial insult by a specific pattern of cytokine secretion, leading to a selective accumulation of neutrophils in the choroid plexus and to their trafficking into CSF. N-acetylcysteine acted by blocking neutrophil migration across both the endothelium of choroidal stromal vessels and the epithelium forming the blood-CSF barrier, without interfering with neutrophil blood count, neutrophil tropism for choroid plexus, and choroidal chemokine-driven chemotaxis. N-acetylcysteine reduced the injury induced by hypoxia-ischemia in P3C-sensitized neonatal rats. Overall, the data show that a double endothelial and epithelial check point controls the transchoroidal migration of neutrophils into the developing brain. They also point to the efficacy of N-acetylcysteine in reducing the deleterious effects of inflammation-associated perinatal injuries by a previously undescribed mechanism, i.e. the inhibition of innate immune cell migration across the choroid plexuses, without interfering with the systemic inflammatory response to infection.

Bacterial meningitis in febrile young infants acutely assessed for presumed urinary tract infection: a systematic review

Urinary tract infections, the most common severe bacterial infections in young infants, may be associated with co-existing meningitis. There is no consensus on when to perform a lumbar puncture in these infants. Our aim was to quantify the frequency of co-existing bacterial meningitis in febrile young infants acutely assessed for presumed urinary tract infections. We systematically reviewed PubMed, EMBASE, and the Cochrane Library for studies including infants ≤ 3 months with suspected/confirmed urinary tract infections, who underwent a lumbar puncture. Two investigators independently reviewed articles for inclusion and extracted relevant data. Our outcomes were culture-confirmed meningitis and identification of low-/high-risk criteria of meningitis. Overall 20/2079 studies, including 4191 infants, met inclusion criteria. A total of 11 infants had bacterial meningitis (frequency between 0 and 2.1% across studies) and were mostly neonates. Of 253 infants meeting the low-risk criteria (well-appearing, age > 21 days, procalcitonin ≤ 0.5 ng/ml, and C reactive protein ≤ 20 mg/L) none developed meningitis, but only 15 underwent lumbar puncture.Conclusion: Co-existing bacterial meningitis in febrile young infants with urinary tract infection is rare. In those meeting low-risk criteria, a lumbar puncture may not be indicated. A case by case assessment should be made in infants not meeting low-risk criteria.Trial registration: CRD42018105339 What is known: • When caring for febrile infants ≤ 3 months with urinary tract infections, clinicians may have uncertainty on whether to perform a lumbar puncture (LP) for possible co-existing meningitis What is new: • An up-to-date systematic review of 20 studies found the frequency of co-existing meningitis in this population to be between 0 and 2.1% • Despite limited data, an LP may not be indicated in infants meeting low-risk criteria (being well-appearing, age > 21 days, procalcitonin ≤ 0.5 ng/ml, C reactive protein ≤ 20 mg/L). Ill-appearance and neonatal age appear to be significant risk factors of co-existing meningitis.

Risk of Meningitis in Infants Aged 29 to 90 Days with Urinary Tract Infection: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the risk of bacterial meningitis in infants aged 29-90 days with evidence of urinary tract infection (UTI).

METHODS

PubMed (MEDLINE), Embase, and the Cochrane Library were systematically searched for studies reporting rates of meningitis in infants aged 29-90 days with abnormal urinalysis or urine culture. Observational studies in infants with evidence of UTI who underwent lumbar puncture (LP) reporting age-specific event rates of bacterial meningitis and sterile cerebrospinal fluid pleocytosis were included. Prevalence estimates for bacterial meningitis in infants with UTI were pooled in a random effects meta-analysis.

RESULTS

Three prospective and 17 retrospective cohort studies were included in the meta-analysis. The pooled prevalence of concomitant bacterial meningitis in infants with UTI was 0.25% (95% CI, 0.09%-0.70%). Rates of sterile pleocytosis ranged from 0% to 29%. Variation in study methods precluded calculation of a pooled estimate for sterile pleocytosis. In most studies, the decision to perform a LP was up to the provider, introducing selection bias into the prevalence estimate.

CONCLUSIONS

The risk of bacterial meningitis in infants aged 29-90 days with evidence of UTI is low. A selective approach to LP in infants identified as low risk for meningitis by other clinical criteria may be indicated.

Cerebrospinal Fluid Reference Values for Young Infants Undergoing Lumbar Puncture

OBJECTIVES

To determine age-specific reference values and quantify age-related changes for cerebrospinal fluid (CSF) white blood cell (WBC) counts and protein and glucose concentrations in infants ≤60 days of age.

METHODS

This multicenter, cross-sectional study included infants ≤60 days old with CSF cultures and complete CSF profiles obtained within 24 hours of presentation. Those with conditions suspected or known to cause abnormal CSF parameters (eg, meningitis) and those with a hospital length of stay of >72 hours were excluded. Reference standards were determined for infants ≤28 days of age and 29 to 60 days of age by using the third quartile +1.5 interquartile range for WBC and protein and the first quartile -1.5 interquartile range for glucose. CSF parameter centile curves based on age were calculated by using the LMST method.

RESULTS

A total of 7766 patients were included. CSF WBC counts were higher in infants ≤28 days of age (upper bound: 15 cells/mm³) than in infants 29 to 60 days of age (upper bound: 9 cells/mm³; P < .001). CSF protein concentrations were higher in infants ≤28 days of age (upper bound: 127 mg/dL) than in infants 29 to 60 days of age (upper bound: 99 mg/dL; P < .001). CSF glucose concentrations were lower in infants ≤28 days of age (lower bound: 25 mg/dL) than in infants 29 to 60 days of age (lower bound: 27 mg/dL; P < .001).

CONCLUSIONS

The age-specific CSF WBC count, protein concentration, and glucose concentration reference values identified in this large, multicenter cohort of infants can be used to interpret the results of lumbar puncture in infants ≤60 days of age.

Febrile infant update

PURPOSE OF REVIEW

The approach to febrile young infants remains challenging. This review serves as an update on the care of febrile infants less than 90 days of age with a focus on the changing epidemiology of serious bacterial infection (SBI), refinement of management strategies based on biomarkers, and the development of novel diagnostics.

RECENT FINDINGS

There is high variability in the emergency department management of febrile young infants without significant differences in outcomes. C-reactive protein (CRP) and procalcitonin have emerged as valuable risk-stratification tests to identify high-risk infants. When interpreting automated urinalyses for suspected urinary tract infection (UTI), urine concentration influences the diagnostic value of pyuria. Novel diagnostics including RNA biosignatures and protein signatures show promise in better identifying young febrile infants at risk of serious infection.

SUMMARY

The majority of febrile infants with an SBI will have a UTI but the diagnosis of invasive bacterial infection in infants continues to be challenging. The use of procalcitonin and CRP as biomarkers in prediction algorithms facilitates identification of low-risk infants.