Early-onset Bacteremia Research Articles

Changes in the epidemiology of neonatal bacteremia during the COVID-19 pandemic in Wuhan, China.

To investigate the incidence, pathogen distribution, and antibiotic susceptibility of early- and late-onset neonatal bacteremia, and to analyze pathogen trends before and during the COVID-19 pandemic. Between January 2016 to December 2022, we collected 879 blood and cerebrospinal fluid specimens from newborns with bacteremia. Bacterial identification used biochemical methods and MALDI-TOF, and antibiotic susceptibility was tested with the VITEK 2 system. Incidence per 1,000 admissions was calculated with Wilson's 95% confidence intervals, and categorical variables were compared using χ²-test or Fisher's exact test. Early-onset bacteremia incidence was 2.6 per 1,000 admissions, and late-onset bacteremia was 26.3, with a significant decline from 70.7 to 10.5 per 1,000 admissions over the study period. Late-onset bacteremia was more common before COVID-19, while early-onset bacteremia increased during the pandemic. The top five pathogens were CoNS(39.9%), E. faecalis(17.7%), E. faecium(13.7%), E. coli(8.4%), and GBS(5.8%). During the COVID-19 pandemic, the incidence of CoNS and S. aureus infections significantly decreased. Throughout the entire study period, CoNS and S. aureus showed high resistance to penicillin G and erythromycin but were sensitive to vancomycin and linezolid. E. faecalis and E. faecium were susceptible to vancomycin, linezolid, and teicoplanin but resistant to erythromycin, tetracycline, and rifampin. MRCoNS and MRSA were detected in 72.7% and 31.0% of isolates, respectively. Resistance rates of E. faecium and E. faecalis to ampicillin decreased significantly, clindamycin resistance in GBS decreased during the pandemic. This study highlights notable shifts in neonatal bacteraemia patterns during the COVID-19 Pandemic that were likely influenced by increased infection control and disruptions in maternal care, leading to changes in pathogen distribution and antimicrobial resistance.

Whole Genome Sequencing for the Identification of a Streptococcus agalactiae Outbreak in Neonatal Intensive Care Unit

Background: While Streptococcus agalactiae (Group B Streptococcus [GBS]) infections in infants usually result from maternal transmission, healthcare-associated cases, particularly in the neonatal intensive care unit (NICU), can occur. Whole genome sequencing (WGS) can aid in investigating GBS outbreaks among infants in hospital settings. The aim of the study is to describe the investigation of GBS infections in NICU using WGS. Methods: Infection prevention and control (IPAC) at our hospital monitors the occurrence of late-onset GBS disease (LOD) in our 57-bed NICU, which consists of all private rooms. The occurrence of 2 cases of LOD within 2 weeks triggered an investigation, including WGS of the two isolates and isolates causing invasive GBS during the last 6 months in the unit. GBS isolates underwent WGS using Illumina at Canada’s National Microbiology Laboratory. All affected patients underwent chart-review. Outbreak description and investigation: In August 2023, two NICU neonates (patients 2,3) experienced LOD two weeks apart, one with bacteremic meningitis and the other with two bacteremic episodes three weeks apart. While WGS was pending two additional cases of late-onset GBS bacteremia (patients 4,5) occurred. Isolates from Pts 2,3 and 5 were indistinguishable from each other and from an isolate from an infant admitted to the NICU with early onset bacteremia on July 27, 2023 (day 1 of life) (patient 1). Weekly point prevalence for throat and rectal colonization over 3 weeks identified five infants colonized with unrelated strains. An additional long-stay infant (patient 6) developed GBS conjunctivitis due to a strain indistinguishable from (patient 4) by pulse field gel electrophoresis, WGS for the second cluster is pending. IPAC interventions: Lapses in IPAC practices were observed, with no commonalities among cases other than similar geographic location within the unit. We hypothesized transmission was due to horizontal transmission between babies due to these lapses. Basic IPAC measures, including hand hygiene and environmental cleaning, were reinforced; Additional Precautions were not used due to private rooms’ unit structure. No environmental samples were taken due to lack of an obvious environmental point or common source. Point prevalence monitoring persisted until no new cases related to the outbreak strains were further identified in three consecutive weekly point prevalence. Conclusions: Increased awareness of healthcare-associated transmission is crucial in NICU as LOD GBS emerges. WGS plays a key role in identifying transmission. Detecting a multi-strain outbreak can appropriately redirect investigations. Legend: Figure 1: Timeline of stay at NICU and infection timing for patients 1-6

Evaluation of extensively drug-resistant gram-negative bacteremia among solid-organ transplant recipients: a multicenter study

The aim of this study is to evaluate the distribution, sources, clinical features, and mortality rates of bacteremia due to evaluation of extensively drug-resistant (XDR) gram negative among solid-organ transplant (SOT) recipients. A retrospective study of SOT recipients with bacteremia due to XDR gram-negative pathogens in 11 centers between 2016 and 2018 was conducted. Patients’ records were evaluated. Of 171 bacteremia that occurred in 164 SOT recipients, 93 (56.7%) were liver, 46 (28%) kidney, 14 (8.5%) heart, and 11 (6.7%) lung recipients. Bacteremia episodes were recorded in the first year in 63.7% of the patients (n = 109), early-onset bacteremia was recorded in 45% (n = 77) of the episodes. In multivariate analysis, catheter-associated bacteremia was an independent risk factor for 7-day mortality (p = 0.037), and early-onset bacteremia was found as an independent risk factor for 30-day mortality (p = 0.017). Difficult-to-treat infections due to XDR bacteria in SOT recipients shadow the success of transplantation. Central venous catheters seem to be the main risk factor. Judicious use of medical devices is of pivotal importance.

Changing epidemiology and resistance patterns of pathogens causing neonatal bacteremia.

To conduct a survey of the local prevalent bacteria and antibiotic resistance in a referral tertiary neonatal intensive care unit (NICU), in order to assess the efficacy of local antibiotic policies. We reviewed all positive blood and cerebrospinal fluid cultures obtained between January 2007 and December 2017 in the NICU of Schneider Children's Medical Center of Israel. Early and late-onset bacteremia were defined as episodes occurring within or after the first 3 calendar days of life respectively. Empiric treatment included ampicillin and gentamicin or piperacillin-tazobactam and amikacin for early or late-onset bacteremia respectively. The prevalence and antibiotic resistance of the bacteria were described and compared over time. Eight hundred and twenty nine of 15,947 (5.2%) newborns had at least one episode of bacteremia; 81 had multiple episodes. The most common bacteria were Escherichia coli (32.35%) and group B Streptococcus (19.11%) or coagulase negative Staphylococcus (CoNS) (60.5%) and Klebsiella sp. (12.4%) in early or late-onset bacteremia respectively. Overall, all Gram-positive bacteria were susceptible to vancomycin and most non-CoNS to ampicillin. Nosocomial vs. vertical bacteremia had increased resistance to ampicillin and cephalosporins. Resistance of nosocomial bacteria to piperacillin-tazobactam was 22.4%, to amikacin 3.3%, and to meropenem 1.8%. Changes over time: Gram-negative bacteria had a significant increase in resistance to cotrimoxazole and piperacillin. The resistance to gentamicin doubled. Our empiric antibiotic regimen covers the most frequent isolates. Amikacin may replace gentamicin for selected sick patients in early-onset bacteremia. Piperacillin-tazobactam should be combined with amikacin until susceptibility is available.

Risk Factors of Bacteremia following Multiple Traumas.

Background Bacteremia is a major nosocomial infection that frequently occurs in trauma patients, increasing morbidity and mortality. The aim of this study was to identify risk factors and to describe epidemiological patterns for early onset (EOB) and late onset (LOB) bacteremia after trauma. Methods We retrospectively reviewed medical records of all trauma patients admitted to the surgical intensive care unit and general ward between January 2011 and December 2015. The information was collected for each patient and recorded in a computer database: early onset bacteremia (EOB) was defined as when onset occurred within 7 days after trauma, and late onset bacteremia (LOB) was defined as when onset occurred after 7 days from trauma. Results Thirty-four patients of 859 (4%) developed bacteremia during their hospital stay: 4 (11.8%) developed EOB, 26 (76.4%) LOB, and 4 (11.8%) patients developed both of them. Sixty events of bacteremia happened to these patients: 9 (15.0%) EOB and 51 (85.0%) LOB. Gram-positive cocci were isolated more frequently than Gram-negative bacilli in both groups. Gram-positive cocci were more frequently isolated in EOB than in LOB; otherwise, there was no statistical significance (77.8% vs. 64.7%, p=0.683). Central line-associated blood stream infection (CLABSI) and surgical site infection (SSI) were the most common identified source for LOB. Presence of liver (OR: 2.66, p=0.035) and pelvic injury (OR: 2.25, p=0.038), gastrointestinal tract perforation (OR: 5.48, p=0.002), and massive transfusion (OR: 3.36, p=0.006) represented risk factors for bacteremia. Conclusions Presence of pelvic and liver injury on arrival in emergency department, gastrointestinal tract perforation, and massive transfusion within the first 24 hours after trauma appears to be significant risk factors for bacteremia.

Early-Onset and Late-Onset Bacteremias After Liver Transplantation

Background Bacteremia is a significant cause of mortality after liver transplantation. The spectrum of pathogens and patterns of antibiotics susceptibility can vary owing to the variable local epidemiologic data and antibiotics modality. The aim of this study was to investigate bacteremic incidence, pathogenic spectrum, and clinical outcomes according to period after liver transplantation. Methods We retrospectively analyzed 393 subjects (267 male, 126 female) who had undergone liver transplantation from 2008 to 2015. Early-onset bacteremia was defined as bacteremia occurring within 6 months after liver transplantation, whereas bacteremia occurring beyond this period was classified as late-onset bacteremia. Results A total of 92 bacteremic patients with 156 episodes were identified. A total of 101 episodes of bacteremia occurred within 6 months after transplantation, among them, enterococcus spp. was the most common etiologic pathgen(n=27, 26.7%), followed by coagulase stapylococcus spp. (n=25, 24.8%), Acinetobacter spp. (n=15, 14.9%) and K. pnuemoniae (n=12, 11.9%). Among 55 late-onset bacteremia, Enteroccous spp. (n=11, 20.0%) and E. coli (n=11, 20.0%) was the most common pathogen, followed by Klebsiella spp. (n=10, 18.2%), Acinetobacter spp. (n=6, 10.9%). Gram positive cocci were more frequent as a pathogen of early onset bacteremia than late-onset bacteremia (n=59, 58.4% vs. n=20, 36.4%, p=0.031). As a source, catheter-related infection was a more common source of early-onset bacteremia (n=29, 29.0% vs. n=2, 3.6%), however, pneumonia (n=2, 2.0%, vs. n=8, 14.5%) was a more common source of late-onset bacteremia. Patients with early-onset bacteremia showed highest mortality compared with patients with late-onset bacteremia or nonbacteremia (31.3% [21/67] vs. 8.0% [2/25]. Vs. 10.0% [30/301]), p=0.0001). Among mortality cases, Enterococcus spp. (n=14) and Acinetobacter spp. (n=9) were most common pathogens. Conclusion Mortality and sources of bacteremia were statistically significant different between early onset and late-onset bacteremia after transplantation. Our data showed different strategies are needed to reduce mortality after transplantation according to the post-transplant period.

Analysis of early-onset bloodstream infection due to Escherichia coli infection in premature babies.

In early-onset bacteremia among preterm neonates, Escherichia coli (E. coli) is the main pathogen and can cause a high mortality rate. Thus, the predictive factors of mortality and extended-spectrum β-lactamase (ESBL)-producing E. coli in preterm babies with E. coli early-onset bacteremia were reported.We retrospectively reviewed preterm neonates who had E. coli bacteremia occurring within 3 days after birth between 2004 and 2015. Maternal and perinatal information were collected from their medical records and analyzed by comparing the survival and nonsurvival groups, and also the ESBL-producing and non-ESBL-producing E. coli bacteremia groups. Mann–Whitney U test, Fisher exact test, and multivariate Cox proportional-hazard model were used for statistical analysis.A total of 27 preterm babies had E. coli bacteremia. The overall mortality rate was 55.56% (15 deaths). Five babies had ESBL-producing E. coli. The low systolic blood pressure of <48 mm Hg and low absolute neutrophil count of <2318 cells/mm3 were the most significant factors in predicting mortality. Moreover, the level of serum alanine aminotransferase was significantly lower in the ESBL-producing E. coli group than that in the non-ESBL-producing E. coli group.Therefore, the lower systolic blood pressure and absolute neutrophil count were the risk factors of mortality in preterm babies with early-onset E. coli bacteremia, and alanine aminotransferase could be a significant factor in predicting ESBL-producing E. coli.

Late-onset bacteremia in uncomplicated pediatric liver-transplant recipients after a febrile episode.

The aim of this study was to analyze the incidence and risk factors of bacteremia after a febrile episode in uncomplicated pediatric recipients more than 2 months after liver transplantation, which has not previously been studied. This cross-sectional study was conducted over a 4-year period. Patients with known risk factors for sepsis at the time of admission were excluded from the study. Seventy-one patients were hospitalized on 128 occasions, with bacteremia occurring in the case of 11 admissions (8.6%). No laboratory tests were predictive of bacteremia. The bacteremic group most frequently presented with ill appearance ( P<0.001), lethargy ( P<0.01), decreased physical activity, and a history of early-onset bacteremia after transplantation and segmental graft ( P<0.05). This study identified a significant incidence of bacteremia in uncomplicated patients many months after liver transplantation.

Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia.

BackgroundThe hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus.MethodsExperimental meningitis in rats was induced by intracisternal injection of live pneumococci. The study comprised of four experimental groups. I. Uninfected controls (n = 8); II. Meningitis (n = 11); III. Meningitis with early onset bacteremia by additional i.v. injection of live pneumococci (n = 10); IV. Meningitis with attenuated bacteremia by treatment with serotype-specific anti-pneumococcal antibodies (n = 14). T2 and diffusion weighted MR images were used to analyze changes in hippocampus volume and water diffusion (ADC). The results were correlated to ADC of the cortex, to ventricular volume, and to the extent of hippocampal apoptosis.ResultsBoth ADC and the volume of hippocampus were significantly increased in meningitis rats compared to uninfected controls (Kruskal-Wallis test, p = 0.0001, Dunns Post Test, p < 0.05), and were significantly increased in meningitis rats with an early onset bacteremia as compared to meningitis rats with attenuated bacteremia (p < 0.05). Hippocampal ADC and the volume and size of brain ventricles were positively correlated (Spearman Rank, p < 0.05), whereas no association was found between ADC or volume and the extent of apoptosis (p > 0.05).ConclusionsIn experimental meningitis increase in volume and water diffusion of the hippocampus are significantly associated with accompanying bacteremia.

Impact of Bacteremia on the Pathogenesis of Experimental Pneumococcal Meningitis

Bacteremia plays a major role in the outcome of pneumococcal meningitis. This experimental study investigated how bacteremia influences the pathophysiologic profile of the brain. Rats with Streptococcus pneumoniae meningitis were randomized to 1 of 3 groups of infected study rats: (1) rats with attenuated bacteremia resulting from intravenous injection of serotype-specific pneumococcal antibody, (2) rats with early-onset bacteremia resulting from concomitant intravenous infection, or (3) a meningitis control group. The blood-brain barrier (BBB) breakdown, ventricle size, brain water distribution, and brain pathologic findings were analyzed using magnetic resonance morphological and functional imaging. Laboratory data and clinical disease scores were obtained. Attenuation of the bacteremic component of pneumococcal meningitis improved clinical disease symptoms and significantly reduced ventricle expansion and BBB breakdown (P< .05). Early-onset bacteremia did not further increase ventricle size or BBB leakage. Significantly increased brain edema developed among rats with both attenuated and early-onset bacteremia (P< .05). Focal brain pathologic findings were unaffected by bacteremia and were found to be associated with cerebrospinal fluid inflammation. Although brain lesions appear to result from local meningeal infection, systemic infection significantly contributes to clinical disease presentation and the pathophysiology of BBB breakdown and ventricle expansion. The different end points affected by the systemic and local infectious processes should be addressed in future studies.

THE EPIDEMIOLOGY OF EARLY-ONSET VERSUS LATE-ONSET BLOODSTREAM INFECTIONS IN A NEONATAL INTENSIVE CARE UNIT.

Bloodstream infections in neonates continue to be a significant ailment despite improvements in health care practice, most likely due to multiple risk factors affecting both early-onset and late-onset sepsis. Objective To compare the epidemiologic characteristics of early-onset and late-onset bloodstream infections in neonates treated at the University of California, Irvine neonatal intensive care unit (UCI-NICU) over a 7-year period. Methods All neonates with positive blood cultures treated at UCI-NICU between January 1998 and December 2004 were identified and their medical records were reviewed. Early-onset bacteremia was defined as an episode of bacteremia within the first 7 days of life. Results We identified 56 episodes of early onset and 160 episodes of late-onset bloodstream infections (see Table). Gram-negative bacteria caused bloodstream infections more frequently in early onset compared with late onset, whereas coagulase-negative Staphylococcus (CONS) was more common in late-onset infections. Comparing risk factors for patients with early-onset and late-onset bloodstream infections, as expected, those with early-onset infections were less likely to have had surgeries (5.4% vs 38%), prior antibiotic therapy (37.5% vs 90%), shorter duration of intubation (2 days vs 13.7 days), and shorter duration of central lines (3.7 days vs 28.7 days). Conclusions The predominant bacterial causes of early-onset and late-onset bloodstream infections are different. Elucidation of epidemiologic trends and risk factors associated with early- and late-onset bloodstream infections will have significant implications in developing measures to control the occurrence of these infections.

Late-onset bacteremia in uncomplicated pediatric liver-transplant recipients after a febrile episode

The aim of this study was to analyze the incidence and risk factors of bacteremia after a febrile episode in uncomplicated pediatric recipients more than 2 months after liver transplantation, which has not previously been studied. This cross-sectional study was conducted over a 4-year period. Patients with known risk factors for sepsis at the time of admission were excluded from the study. Seventy-one patients were hospitalized on 128 occasions, with bacteremia occurring in the case of 11 admissions (8.6%). No laboratory tests were predictive of bacteremia. The bacteremic group most frequently presented with ill appearance ( P<0.001), lethargy ( P<0.01), decreased physical activity, and a history of early-onset bacteremia after transplantation and segmental graft ( P<0.05). This study identified a significant incidence of bacteremia in uncomplicated patients many months after liver transplantation.

High mortality related with Staphylococcus aureus bacteremia after liver transplantation.

The aim of the present study was to analyze the characteristics of bacteremia occurring in liver-transplant patients in Andalusia, Spain, during the 1990s. At the three participating hospitals, 405 liver transplantations were performed during the study period, and 119 bacteremic episodes were observed following 91 of them (22.4%, 29.4 episodes/100 liver transplants). Gram-positive organisms were the predominant bacteria isolated in cases of early-onset bacteremia (70.7%, P=0.04). The most common sources of bacteremia were the abdomen (33.6%) and intravascular catheters (22.7%), but frequently the source of bacteremia was unknown (31.9%). Mortality at 30 days was 21%. Isolation of Staphylococcus aureus was the only independent risk factor for mortality (relative risk, 3.13; 95% confidence interval, 1.3-7.5; P=0.01). These results indicate that control measures are required in order to reduce the incidence of gram-positive bacteremia and catheter-related infection in this patient population. The observed etiology must be considered when empirical antimicrobial therapy is indicated while awaiting blood-culture results.

1067 SELECTIVE INTRAPARTUM CHEMOPROPHYLAXIS OF EARLYONSET GROUP B STREPTOCOCCAL DISEASE

We examined the effect of selective intrapartum chemoprophylaxis (SIC) on the incidence of group B streptococcal (GBS) early-onset disease in a randomized controlled trial. Parturients were eligible for the study if they had prenatal GBS colonization and either premature labor ( 12 hours). Treated mothers received 2 gm ampicillin IV followed by 1 gm IV Q4H until delivery. Blood cultures were obtained from all study infants at birth and from mothers or older infants if warranted clinically. Of the 175 randomized parturients, 93 received ampicillin and 82 did not. No infant whose mother received SIC had GBS early-onset bacteremia, whereas 5 (6.1%) of the infants whose mothers were not treated were bacteremic (p=0.02). We studied an additional 320 nonrandomized women with the same eligibility criteria. None of the infants born to 76 treated mothers had GBS early-onset bacteremia, whereas 7 of 224 (3.1%) whose mothers were not treated were bacteremic (p=0.13). Four untreated mothers (1 randomized, 3 nonrandomized) developed GBS obstetric sepsis. One infant born to a nonrandomized treated mother developed GBS late-onset sepsis. These results are the first prospective demonstration of the efficacy of SIC to prevent GBS invasive disease.