Staphylococcus aureus Bacteremia in Children: Antibiotic Resistance and Mortality

Cross-sectional Hospital-based Investigation on Clinical Characteristics of Pediatric Staphylococcus aureus Isolates in a Beijing Hospital from 2013 to 2022

Background

Staphylococcus aureus (S. aureus) was a prevalent pathogenic bacterium among children. Due to the extensive use of antibiotics, the sensitivity of S. aureus to these drugs has gradually declined. Since the 1960s, methicillin-resistant Staphylococcus aureus (MRSA) has emerged and spread worldwide, becoming a primary cause of both healthcare-associated (HA) and community-acquired (CA) infections. This retrospective study aimed to highlight the significance of S. aureus among bacteria isolated from children in Beijing, China, and to elucidate its antimicrobial resistance patterns.

Methods

Data on all S. aureus infections from 2013 to 2022 were collected from the microbiology department of Beijing Children's Hospital. Only the first isolate from the same kind of specimen was analyzed. Antimicrobial susceptibility tests were carried out by Vitek 2 automated system (bio Mérieux, France) or Kirby-Bauer disc diffusion method, according to the guidelines recommended by the Clinical and Laboratory Standards Institute (CLSI).

Results

During the decade-long research period, a total of 47,062 bacterial isolates were isolated from 433,081 submitted specimens, with 6477 of these isolates identified as S. aureus. The majority of patients with S. aureus infections belonged to the age group of infants under one-year-old, accounting for 37.9% of cases. S. aureus isolates were predominantly found in the Pneumology Department, and the most common source of these isolates was lower respiratory tract specimens, comprising 34.3% of the total. The resistance rates of S. aureus to penicillin and erythromycin were notably high, at 89.5% and 73.8%, respectively. In contrast, the resistance rates to linezolid, vancomycin, rifampicin, and moxifloxacin were remarkably low, at 0.0%, 0.0%, 1.3%, and 3.9%, respectively. The detection rate of MRSA was 27.8%. MRSA isolates were predominantly found in the newborn group, ICU, and sterile body fluids.

Conclusion

In our study, the most prevalent specimen type was derived from the lower respiratory tract, whereas the highest positive rate was observed in ear secretions. These findings underscored the pressing necessity for ongoing antimicrobial resistance (AMR) surveillance and the revision of treatment guidelines, particularly given the elevated detection of MRSA in ICU wards, sterile body fluids, and the neonatal age group. MRSA exhibited significant resistance to all β-lactam antibiotics, erythromycin, and ciprofloxacin. Therefore, future research endeavors should prioritize examining specific antimicrobial resistance populations and potential intervention strategies, as these were vital in mitigating the dissemination of antimicrobial-resistant isolates.

Risk Factors for Persistent Staphylococcus aureus Bacteremia in Children

BACKGROUND

Staphylococcus aureus is a leading cause of pediatric bacteremia. Persistent S. aureus bacteremia (SAB) is associated with increased morbidity and mortality in adults and children. Risk factors for S. aureus bacteremia have been well established, but there is a limited understanding of the factors that contribute to the development of persistent SAB in children.

METHODS

This is a single-center retrospective secondary analysis of a prospective observational study of pediatric patients hospitalized with S. aureus infection over a 3.5-year period at a large, quaternary, children's hospital.

RESULTS

Two hundred fifty-nine children with confirmed S. aureus infection were enrolled in the study. Sixty-five of these were found to have bacteremia, with 28 (43%) developing persistent bacteremia. Patients with persistent SAB were culture-positive for a median of 3.5 days compared with 1 day for those without (P ≤ 0.001). Children with persistent SAB were more likely to have an identified osteoarticular source of infection (93%, n = 26 vs. 62%, n = 23; P = 0.008) and had a shorter median duration to culture positivity than those without persistent SAB (16 hours vs. 20 hours; P ≤ 0.001). In addition, children with persistent SAB had higher median values of presenting erythrocyte sedimentation rate, peak erythrocyte sedimentation rate, presenting C-reactive protein and peak C-reactive protein. Not surprisingly, hospital length of stay was longer in children with persistent SAB compared with those without.

CONCLUSIONS

These findings suggest that a shorter time to culture positivity, osteoarticular infection, and higher presenting and peak values for select inflammatory markers are potential risk factors for persistent SAB in children.

Increasing Pediatric Infectious Diseases Consultation Rates for Staphylococcus aureus Bacteremia

Introduction

Staphylococcus aureus bacteremia (SAB) in children is associated with significant mortality and morbidity, including recurrent bacteremia. Infectious disease consultation (IDC) improves SAB outcomes in adult patients. However, increasing IDC and impact for pediatric patients with SAB is not well described.

Methods

This quality improvement project aimed to increase IDC for SAB events at a quaternary pediatric medical center. First, we evaluated the local practices regarding pediatric SAB and engaged stakeholders (July 2018-August 2020). We added an advisory comment supporting IDC for SAB to all blood culture results in September 2020. Using statistical process control charts, we monitored the number of SAB events with IDC before a SAB event without IDC. Finally, we evaluated SAB recurrences before and after initiating the advisory comment.

Results

In the baseline period, 30 of 49 (61%) SAB events received an IDC with a mean of 1.4 SAB events with IDC before a SAB event without IDC. Postintervention, 22 of 23 (96%) SAB events received IDC with a mean of 14 events with IDC before 1 event without IDC. The SAB recurrence rate was 8%, with 6 events in 4 children; none of the index cases resulting in recurrence received an IDC (P = 0.0002), and all occurred before any intervention.

Conclusions

An electronic advisory comment supporting IDC for SAB significantly increased the rate of pediatric IDC with no further SAB recurrence episodes following intervention. This low-resource intervention may be considered in other pediatric centers to optimize SAB management.

Assessment of infections rate due to community-acquired Methicillin-resistant Staphylococcus aureus and evaluation of risk factors in the paediatric population

AIM

We aimed at assessing the frequency of Community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infections, identifying its risk factors and evaluating resistance patterns of Staphylococcus aureus to various antibiotics in order to recommend the optimal empirical treatment for suspected Staphylococcus aureus infections.

METHODS

We reviewed the medical records of children who were treated at Shaare Zedek medical centre, located in Jerusalem, Israel, over the years 2008-2019 and had a positive culture for Staphylococcus aureus. Patients with CA-MRSA infections were compared with Methicillin-susceptible Staphylococcus aureus (CA-MSSA) infections.

RESULTS

In this study, 620 paediatric patients were included. The number of children in the CA-MRSA study group was 124, while the MSSA control group consisted of 496 children. Risk factors for CA-MRSA infections included young age (1-5 years), female sex, Arab ethnicity and residence in East Jerusalem. The incidence of CA-MRSA increased over the past decade, with an average of 11.2%. An increase in MSSA resistance to clindamycin was noted while Trimethoprim-Sulphamethoxazole resistance remained low.

CONCLUSION

The incidence of CA-MRSA in Jerusalem was rising, along with changes in resistance patterns of both MSSA and MRSA to various antibiotic agents. In order to optimise empirical treatment for suspected staphylococcal infection, continued monitoring of CA-MRSA prevalence and resistance rates is essential.

Impact of a Best Practice Advisory for Pediatric Patients With Staphylococcus aureus Bacteremia

BACKGROUND

Infectious diseases (ID) consultation and optimal antibiotic therapy improve outcomes in Staphylococcus aureus bacteremia (SAB). Data on strategies to improve adherence to these practices in children are limited.

METHODS

This was a quasi-experimental study evaluating the impact of an electronic medical record (EMR)-based best practice advisory (BPA) for SAB, recommending ID consult and optimal antibiotic therapy based on rapid mecA gene detection. Inpatients < 21 years old with SAB before (January 2015-July 2017) and after (August 2017-December 2018) BPA implementation were included. Primary outcome was receipt of ID consult. Secondary outcomes included receipt of optimal therapy, time to ID consult and optimal therapy, recurrent SAB, and 30-day all-cause mortality. ID consultation rates pre- and postimplementation were compared using interrupted time series (ITS) analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) for time to optimal therapy were calculated using Cox regression.

RESULTS

We included 99 SAB episodes (70 preintervention, 29 postintervention). Preintervention, 48 (68.6%) patients received an ID consult compared to 27 (93.1%) postintervention, but this was not statistically significant on ITS analysis due to a preexisting trend of increasing consultation. Median hours to optimal therapy decreased from 26.1 to 5.5 (P = .03), most notably in patients with methicillin-sensitive S. aureus (MSSA) (42.2 to 10.8; P < .01). On Cox regression, BPA implementation was associated with faster time to optimal therapy (HR, 3.22 [95% CI, 1.04-10.01]).

CONCLUSIONS

Implementation of an EMR-based BPA for SAB resulted in faster time to optimal antibiotic therapy, particularly for patients with MSSA. ID consultation increased throughout the study period and was not significantly impacted by the BPA.

The epidemiology of Staphylococcus aureus bacteraemia in Israeli children: Community- vs hospital-acquired or healthcare related infections

AIM

Incidences of Staphylococcus aureus bacteraemia (SAB) in Israeli children are unknown. The characteristics of SAB in children have not been evaluated.

METHODS

SAB from children aged ≤18 years old, admitted to a tertiary hospital in Israel during 2002-2015, were included. The proportional rate of SAB was calculated per 1000 admissions. SAB were classified as community acquired (CA), hospital acquired (HA) and healthcare related (HCR). Patients' characteristics, antibiotic susceptibility and outcomes were assessed in each group.

RESULTS

The rate of SAB was stable, 1.48 per 1000 admissions. HA, CA and HCR-SAB comprised 53%, 25% and 22%, respectively. Only 27/185 (14.6%) were caused by methicillin-resistant S aureus (MRSA): 22%, 6% and 5% of HA, CA and HCR-SAB, respectively. Central venous catheter, recent surgery, immunodeficiency and age <6 years were the main risk factors for HA and HCR-SAB (adjusted OR: 68.9, 7.5, 5.8 and 5.5, respectively). Treatment duration for CA was >21 days: and for HA and HCR, 14-20 days. All-cause in-hospital mortality and 30-day mortality were documented in 10 (5%) and 3 (2%) episodes, respectively.

CONCLUSION

The rate of SAB; the proportions of CA, HA and HCR-SAB; and the proportion of MRSA was stable over the years. MRSA was mainly in HA-SAB. Thirty-day mortality was rare.

Staphylococcus aureus Nasal Colonization in Spanish Children. The COSACO Nationwide Surveillance Study

Objective

To assess the prevalence and risk factors for S. aureus and methicillin-resistant S. aureus (MRSA) nasal colonization in Spanish children.

Methods

Cross-sectional study of patients <14 years from primary care centers all over Spain. Clinical data and nasal aspirates were collected from March to July 2018.

Results

A total of 1876 patients were enrolled. Prevalence of S. aureus and MRSA colonization were 33% (95% CI 30.9–35.1) and 1.44% (95% CI 0.9–2), respectively. Thirty-three percent of the children (633/1876) presented chronic conditions, mainly atopic dermatitis, asthma and/or allergy (524/633). Factors associated with S. aureus colonization were age ≥5 years (OR 1.10, 95% CI 1.07–1.12), male sex (OR 1.43, 95% CI 1.17–1.76), urban setting (OR 1.46, 95% CI 1.08–1.97) and the presence of asthma, atopic dermatitis or allergies (OR 1.25; 95% CI: 1.093–1.43). Rural residence was the only factor associated with MRSA colonization (OR 3.62, 95% CI 1.57–8.36). MRSA was more frequently resistant than methicillin-susceptible S. aureus to ciprofloxacin [41.2% vs 2.6%; p<0.0001], clindamycin [26% vs 16.9%; p=0.39], and mupirocin [14.3% vs 6.7%; p=0.18]. None of the MRSA strains was resistant to tetracycline, fosfomycin, vancomycin or daptomycin.

Conclusions

The main risk factors for S. aureus colonization in Spanish children are being above five years of age, male gender, atopic dermatitis, asthma or allergy, and residence in urban areas. MRSA colonization is low, but higher than in other European countries and is associated with rural settings.