Adjunctive Diagnostic Studies Completed Following Detection of Candidemia in Children: Secondary Analysis of Observed Practice From a Multicenter Cohort Study Conducted by the Pediatric Fungal Network

BACKGROUND

Adjunctive diagnostic studies (aDS) are recommended to identify occult dissemination in patients with candidemia. Patterns of evaluation with aDS across pediatric settings are unknown.

METHODS

Candidemia episodes were included in a secondary analysis of a multicenter comparative effectiveness study that prospectively enrolled participants age 120 days to 17 years with invasive candidiasis (predominantly candidemia) from 2014 to 2017. Ophthalmologic examination (OE), abdominal imaging (AbdImg), echocardiogram, neuroimaging, and lumbar puncture (LP) were performed per clinician discretion. Adjunctive diagnostic studies performance and positive results were determined per episode, within 30 days from candidemia onset. Associations of aDS performance with episode characteristics were evaluated via mixed-effects logistic regression.

RESULTS

In 662 pediatric candidemia episodes, 490 (74%) underwent AbdImg, 450 (68%) OE, 426 (64%) echocardiogram, 160 (24%) neuroimaging, and 76 (11%) LP; performance of each aDS per episode varied across sites up to 16-fold. Longer durations of candidemia were associated with undergoing OE, AbdImg, and echocardiogram. Immunocompromised status (58% of episodes) was associated with undergoing AbdImg (adjusted odds ratio [aOR] 2.38; 95% confidence intervals [95% CI] 1.51-3.74). Intensive care at candidemia onset (30% of episodes) was associated with undergoing echocardiogram (aOR 2.42; 95% CI 1.51-3.88). Among evaluated episodes, positive OE was reported in 15 (3%), AbdImg in 30 (6%), echocardiogram in 14 (3%), neuroimaging in 9 (6%), and LP in 3 (4%).

CONCLUSIONS

Our findings show heterogeneity in practice, with some clinicians performing aDS selectively, potentially influenced by clinical factors. The low frequency of positive results suggests that targeted application of aDS is warranted.

2150. Surgical Prophylaxis in Pediatric Liver Transplant Recipients: Variations in Protocol and Impact on 30-Day Surgical Site Infections

Background

Children undergoing liver transplantation are at risk for surgical site infections (SSI). IDSA/ASHP/SIS/SHEA guidelines recommend surgical prophylaxis with a third-generation cephalosporin plus ampicillin or piperacillin-tazobactam alone. The study objectives were to describe the surgical prophylaxis used at our institution, obtain data on whether prophylactic antimicrobials are adjusted for multidrug resistant organisms and to determine whether adjustments correlate with SSI.

Methods

Pediatric liver transplant procedures, with associated peri-operative and intra-operative antimicrobials, were extracted from our institutions’ Anesthesia Record Keeping System (ARKS) between 2005-2022. Medical records were reviewed for demographics, microbiological data (e.g., colonization), protocol deviations and 30-day CDC/NHSN SSIs.

Results

Seventy-one procedures were performed in 69 patients, median age 3 years (range, 5 months- 17 years), where 89% had a pre-transplant infectious disease consultation. Variations from protocol occurred in 39% (n=28), of which 3 were consult-directed. Sixteen were colonized with an organism prior to transplant (3 MDRO and 1 Candida spp.), of which 10 had a protocol adjustment (p< 0.001). The most common additional antimicrobials were vancomycin (n=17) and fluconazole (n=8). Reasons for fluconazole were fulminant liver failure (n=2), surgeon concern (n=3), colonization or prolonged antimicrobials prior to transplant (n=2) and continuation of prophylaxis (n=1). Ten procedures were complicated by an SSI (14%). SSI rates did not differ in those with and without protocol adjustments (p=0.50).

Conclusion

Adjustments to guideline concordant surgical prophylaxis recommendations occurred in 39% of pediatric liver transplant procedures, with the most common being addition of vancomycin or fluconazole. Adjustments were based on a pre-transplant infectious disease consult recommendations in 11% of cases. Protocol adjustment correlated with any pretransplant microbiology culture result, but not with either MDRO colonization or subsequent SSI. Antimicrobial stewardship efforts may be indicated to address variations in antimicrobial prophylaxis in pediatric liver transplant patients.

Disclosures

All Authors: No reported disclosures.

Multicenter Prospective Study of Biomarkers for Diagnosis of Invasive Candidiasis in Children and Adolescents

BACKGROUND

Diagnosis of invasive candidiasis (IC) relies on insensitive cultures; the relative utility of fungal biomarkers in children is unclear.

METHODS

This multinational observational cohort study enrolled patients aged >120 days and <18 years with concern for IC from 1 January 2015 to 26 September 2019 at 25 centers. Blood collected at onset of symptoms was tested using T2Candida, Fungitell (1→3)-β-D-glucan, Platelia Candida Antigen (Ag) Plus, and Platelia Candida Antibody (Ab) Plus assays. Operating characteristics were determined for each biomarker, and assays meeting a defined threshold considered in combination. Sterile site cultures were the reference standard.

RESULTS

Five hundred participants were enrolled at 22 centers in 3 countries, and IC was diagnosed in 13 (2.6%). Thirteen additional blood specimens were collected and successfully spiked with Candida species, to achieve a 5.0% event rate. Valid T2Candida, Fungitell, Platelia Candida Ag Plus, and Platelia Candida Ab Plus assay results were available for 438, 467, 473, and 473 specimens, respectively. Operating characteristics for T2Candida were most optimal for detecting IC due to any Candida species, with results as follows: sensitivity, 80.0% (95% confidence interval, 59.3%-93.2%), specificity 97.1% (95.0%-98.5%), positive predictive value, 62.5% (43.7%-78.9%), and negative predictive value, 98.8% (97.2%-99.6%). Only T2Candida and Platelia Candida Ag Plus assays met the threshold for combination testing. Positive result for either yielded the following results: sensitivity, 86.4% (95% confidence interval, 65.1%- 97.1%); specificity, 94.7% (92.0%-96.7%); positive predictive value, 47.5% (31.5%-63.9%); and negative predictive value, 99.2% (97.7%-99.8%).

CONCLUSIONS

T2Candida alone or in combination with Platelia Candida Ag Plus may be beneficial for rapid detection of Candida species in children with concern for IC.

CLINICAL TRIALS REGISTRATION

NCT02220790.

Comparative Effectiveness of Echinocandins vs Triazoles or Amphotericin B Formulations as Initial Directed Therapy for Invasive Candidiasis in Children and Adolescents

BACKGROUND

Invasive candidiasis is the most common invasive fungal disease in children and adolescents, but there are limited pediatric-specific antifungal effectiveness data. We compared the effectiveness of echinocandins to triazoles or amphotericin B formulations (triazole/amphotericin B) as initial directed therapy for invasive candidiasis.

METHODS

This multinational observational cohort study enrolled patients aged >120 days and <18 years with proven invasive candidiasis from January 1, 2014, to November 28, 2017, at 43 International Pediatric Fungal Network sites. Primary exposure was initial directed therapy administered at the time qualifying culture became positive for yeast. Exposure groups were categorized by receipt of an echinocandin vs receipt of triazole/amphotericin B. Primary outcome was global response at 14 days following invasive candidiasis onset, adjudicated by a centralized data review committee. Stratified Mantel-Haenszel analyses estimated risk difference between exposure groups.

RESULTS

Seven-hundred and fifty invasive candidiasis episodes were identified. After exclusions, 541 participants (235 in the echinocandin group and 306 in the triazole/amphotericin B group) remained. Crude failure rates at 14 days for echinocandin and triazole/amphotericin B groups were 9.8% (95% confidence intervals [CI]: 6.0% to 13.6%) and 13.1% (95% CI: 9.3% to 16.8%), respectively. The adjusted 14-day risk difference between echinocandin and triazole/amphotericin B groups was -7.1% points (95% CI: -13.1% to -2.4%), favoring echinocandins. The risk difference was -0.4% (95% CI: -7.5% to 6.7%) at 30 days.

CONCLUSIONS

In children with invasive candidiasis, initial directed therapy with an echinocandin was associated with reduced failure rate at 14 days but not 30 days. These results may support echinocandins as initial directed therapy for invasive candidiasis in children and adolescents.

CLINICAL TRIALS REGISTRATION

NCT01869829.

Physician-to-Physician Electronic Consultation: A Tool for the Pediatric Infectious Diseases Specialist to Document Encounters and Quantify Effort

E-consults replace "curbside" interactions, facilitate provider-specialist communication, document within the medical record, and track relative value units (RVUs). Pediatric infectious diseases (PID) E-consults commonly relate to vaccines, exposures, diagnoses, and treatments. The documented RVU effort of 197 consecutive PID E-consults was equivalent to 70 level 4 new outpatient consults.

Congenital syphilis: Missed opportunities and the case for rescreening during pregnancy and at delivery

Two infants treated for syphilis born to at risk mothers who screened negative at their first prenatal visit but were not rescreened at delivery are described. The first presented with classic, but unrecognized, features of congenital syphilis. In the second case, possible early maternal syphilis was diagnosed soon after delivery using the treponemal first reverse-screening algorithm. Although the child's physical exam was normal and the maternal rapid plasma reagin (RPR) negative, the child was treated for syphilis because maternal confirmatory treponemal tests suggested recent seroconversion. Given the re-emergence of congenital syphilis, our report aims to demonstrate the importance of rescreening women at increased risk and improve awareness of common manifestations of the syphilis disease in the newborn. For women at increased risk, repeat syphilis testing early in the third trimester and again at delivery in communities and populations with a high prevalence of syphilis is recommended.

A multicenter study to define the epidemiology and outcomes of Clostridioides difficile infection in pediatric hematopoietic cell and solid organ transplant recipients

Hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients are at increased risk for Clostridioides difficile infection (CDI). We conducted a multicenter retrospective study to describe the incidence of CDI in children transplanted between January 2010 and June 2013. Nested case-control substudies, matched 1:1 by transplant type, institution, patient age, and time of year (quartile) of transplant, identified CDI risk factors. Cohorts included 1496 HCT and 1090 SOT recipients. Among HCT recipients, 355 CDI episodes were diagnosed in 265 recipients (18.2%). Nested case-control study identified prior history of CDI (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.5-4.7), proton pump inhibitors (PPIs; OR 2.1, 95% CI 1.3-3.4), and exposure to third- (OR 2.4, 95% CI 1.4-4.2) or fourth-generation (OR 2.1, 95% CI 1.2-3.7) cephalosporins as risk factors. Notably, fluoroquinolone exposure appeared protective (OR 0.6, 95% CI 0.3-0.9). Ninety-two episodes of CDI were diagnosed among 79 SOT recipients (7.3%), and exposure to PPIs (OR 2.4, 95% CI 1.1-5.4) and third-generation cephalosporin therapy (OR 3.9, 95% CI 1.4-10.5) were identified as risk factors. Strategies to decrease PPI use and changes in the class of prophylactic antibiotics may impact CDI incidence and warrant further study.

782. Provider to Provider Electronic Consultation (E-consult): A Tool for the Pediatric Infectious Diseases Specialist to Document Encounters and Quantify Effort

Background

Curbside consultation is a ubiquitous practice within the medical field informally providing advice to community providers. The electronic consult (E-Consult) allows direct provider-to-provider communication between the primary care provider (PCP) and specialists using a secure electronic platform while documenting these interactions within the patient’s medical record (EMR). They offer PCP’s a forum for asking nonurgent questions. For the specialist, it allows review of the EMR, reduces medical liability of the curbside consult and provides a mechanism for generating RVUs. This service was implemented in our healthcare network (of over 300 pediatricians and pediatric specialists who see more than 500,000 pediatric visits each year) in April 2018. Our aim was to review and analyze the E-consults provided by the Pediatric Infectious Diseases (PID) service.

Methods

Cross-sectional study of E-consults performed by the PID from April 11 -2018-April 22 2019. Clinical queries were categorized by type and tabulated. Consult Billing was as following: Level 1=5 minutes (min); Level 2 =10min; Level 3= 15 minutes; Level 4= 25 minutes. RVU values were institutionally derived and assigned.

Results

We performed 171 E- consults with an average of 13 per month (range 3–18) generated from 59 providers (52 (88%) physicians and 7 (12%) certified nurse practitioners). Common reasons for the E-consult included: vaccine questions (25.7%), diagnosis questions (21.6%), exposure questions (20.4%) and treatment recommendations (10.5%). Of vaccine questions, 43% related to vaccine schedules /boosters, 13% vaccines for travel and 11.3% vaccines for the immunocompromised host. Consultation in the PID clinic was recommended for 25.7% patients, 9% requiring urgent evaluation. Of the 171 E-consults, 12.2% were evaluated in the PID clinic and 5% by another specialty. Billing was performed for 168 of the E consults= 9 level 1, 35 level 2, 83 level 3 and 41 level 4 generating 161 RVUs (equivalent to 53 level 4 new outpatient visits at our institution).

Conclusion

E-consults are an alternative to informal curbside consults for nonurgent clinical queries. Encounters are documented in the EMR and professional effort devoted to the task is tracked providing an additional source of RVU generation for the PID physician.

Disclosures

All authors: No reported disclosures.

2401. Epidemiology of Clostridium difficile Infection in Intestinal and Multivisceral Transplant Patients at a Single Transplant Center

Background

Clostridium difficile infection (CDI) is the leading cause of infectious diarrhea in the healthcare setting. Solid-organ transplant (SOT) recipients are at increased risk compared with the general hospitalized population (7.4–20% vs. 0.9%). Our center recently expanded its intestinal and multivisceral transplant (IMVT) program, providing the opportunity to examine the epidemiology of CDI in this vulnerable population.

Methods

We conducted a retrospective study of all IMVT recipients between 2009 and 2018. CDI was defined as presence of diarrhea with a positive polymerase chain reaction (PCR) test for the toxin B gene. Early CDI constituted an episode of CDI within the first 6 months post-transplant. Data were collected on demographics, transplant characteristics, CDI episode, and outcomes.

Results

We identified 86 patients who underwent a total of 94 transplants: 60 (64%) isolated intestinal transplants, 21 (22%) intestine/liver/pancreas, 10 (11%) intestine/pancreas, two (2%) intestine/liver/pancreas/kidney, and one (1%) intestine/kidney transplant. All but three patients received perioperative metronidazole. Four patients (5%) had CDI prior to transplant, but none of them recurred in the first 6 months post-transplant. Five patients developed a total of seven mild-moderate episodes of early CDI (attack rate = 5.9%). Three patients (60%) with early CDI developed rejection, similar to the incidence (70%) in patients without CDI. Two patients with early CDI developed recurrence; both underwent intestinal re-transplantation. One-year mortality was similar among patients with and without early CDI (20% vs. 23%).

Conclusion

CDI is associated with allograft loss, rejection, and mortality in some SOT recipients. Although limited by sample size, we observed that early CDI was not associated with those outcomes in our population. Multicenter studies are merited to explore risk factors for CDI and associations with outcomes in IMVT.

Disclosures

All authors: No reported disclosures.

2484. Pre-Transplant Vaccination Adherence in Pediatric Solid Organ Transplant Patients at a Large Academic Medical Center

Background

Adherence rates for recommended pre-transplant (pre-txp) vaccinations in pediatric solid-organ transplant (SOT) patients are variable and practice-dependent. Cleveland Clinic Children’s Hospital (CCCH) pre-txp adherence rates for select vaccines have not been described. The purpose of this study was to evaluate pre-txp adherence rates for the following vaccines: hepatitis B, influenza, pneumococcal conjugate (PCV13), pneumococcal polysaccharide (PPSV23), and hepatitis A (if at-risk).

Methods

This retrospective cohort study included patients undergoing initial pediatric heart, kidney, liver, or intestine/multi-visceral transplant at CCCH between 1/1/14 and 7/31/17. Data collected from the electronic medical record and Ohio Department of Health Statewide Immunization Information System included demographics, transplant-related data, immunization administration history, and quantitative/qualitative values for titer/serology. The primary objective of vaccination adherence rate was defined as the aggregate of patients who had completed the vaccine series, had positive titer/serology data, or were ineligible to receive the vaccine due to age or administration restrictions. Data are descriptive in nature and reported as number (percent) or median (interquartile range), as appropriate.

Results

64 pediatric SOT recipients met inclusion criteria. Median age was 7.9 (2.1, 15.8) years. Majority of patients were American (73%) and male (63%). Most common organ was heart (41%), followed by liver (25%), kidney (21%), and intestine/multi-visceral (13%). Sixty-three (98%) patients underwent ID pre-txp evaluation. CCCH adherence rates were highest for hepatitis B at 92%, followed by PCV13 and PPSV23 at 84%, and influenza at 72%. Thirty-two (50%) patients were indicated to receive the hepatitis A vaccine and the respective adherence rate was 91%. Vaccination adherence by SOT team is described in Figure 1.

Conclusion

CCCH pre-txp vaccination adherence rates are higher than previously reported. Opportunities for improvement include influenza vaccination adherence across all SOT teams and PCV13/PPSV23 vaccination adherence in intestine/multi-visceral transplant patients.

Disclosures

All authors: No reported disclosures.

A comparison of hospitalized children with enterovirus D68 to those with rhinovirus

BACKGROUND

During the Fall of 2014, numerous children were hospitalized with asthma or respiratory distress related to Enterovirus D68 (EV-D68). A large proportion initially tested positive for rhinovirus. During this period our laboratory noted a cross-reactivity between EV-D68 and the rhinovirus component of the GenMark multiplex respiratory viral panel. Many other laboratories used assays not designed to distinguish these Picornoviridae.

METHODS

To compare the presentation and outcomes of patients with rhinovirus and EV-D68, 103 GenMark rhinovirus positive nasopharyngeal swabs from hospitalized children were retested for EV-D68.

RESULTS

EV-D68 positive patients versus EV-D68 negative patients were more likely to have a history of asthma (33.3% vs. 11.0%, P = 0.02) and to present with acute respiratory illness (66.7% vs. 40.2%, P = 0.048), especially status asthmaticus (47.6% vs. 2.4%, P < 0.001). On admission they had more wheezing, respiratory distress, and lower respiratory tract involvement, and were more likely to be treated with steroids and discharged home on asthma medications. Respiratory viral coinfection was less common in EV-D68 positive vs EV-D68 negative patients. In patients without a respiratory viral coinfection the overall findings were similar.

CONCLUSION

Patients with EV-D68 versus rhinovirus were more likely to have a history of asthma, to present with status asthmaticus, to wheeze on admission, and to receive treatment with asthma medications in hospital and at discharge. The inability of common assays to distinguish EV-D68 from rhinoviruses raises the possibility that the role of EV-D68 as a viral trigger of asthma has been under appreciated. Pediatr Pulmonol. 2017;52:827-832. © 2017 Wiley Periodicals, Inc.

Mycobacterium genavense-induced spindle cell pseudotumor in a pediatric hematopoietic stem cell transplant recipient: Case report and review of the literature

We describe the first reported pediatric patient to our knowledge with a spindle cell pseudotumor caused by Mycobacterium genavense in a hematopoietic stem cell transplant recipient, and review the literature of such an entity in the transplant population.

Invasive Aspergillus infection requiring lobectomy in a CYP2C19 rapid metabolizer with subtherapeutic voriconazole concentrations

Individuals who carry the CYP2C19*17 gain-of-function allele have lower voriconazole exposure and are therefore at risk of failing therapy. Utilizing CYP2C19 genotype to optimize voriconazole dosage may be a cost-effective method of improving treatment outcomes. However, there are limited data describing what initial voriconazole dosage should be used in those with increased CYP2C19 metabolic capacity. Herein, we present a case report of a pediatric CYP2C19 rapid metabolizer (i.e., CYP2C19*1/*17) requiring a voriconazole dosage of 14 mg/kg twice daily (usual pediatric dosage ranges from 7 to 9 mg/kg twice daily). This case report supports the clinical utility of using CYP2C19 genotype to guide voriconazole dosing, and provides data for establishing an initial voriconazole dose in pediatric CYP2C19 rapid metabolizers.

Disseminated Bacillus Calmette-Guérin (BCG) infection following allogeneic hematopoietic stem cell transplant in a patient with Bare Lymphocyte Syndrome type II

We describe the first case, to our knowledge, of disseminated Mycobacterium bovis Bacillus Calmette-Guérin infection in a child with Bare Lymphocyte Syndrome type II after undergoing hematopoietic stem cell transplantation (HSCT). The patient presented 30 days post HSCT with fever and lymphadenitis. Lymph node, blood, and gastric aspirates were positive for M. bovis. The patient received a prolonged treatment course with a combination of isoniazid, levofloxacin, and ethambutol. Her course was further complicated by granulomatous lymphadenitis and otitis media associated with M. bovis that developed during immune suppression taper and immune reconstitution. Ultimately, the patient recovered fully, in association with restoration of immune function, and has completed 12 months of therapy.

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

Influenza A/H1N1/09-10 infections in a NICU during the 2009-2010 H1N1 pandemic

Few cases of the pandemic influenza A H1N1 have been reported in very low birth weight infants. We report here a small outbreak in our NICU of 3 cases of influenza A/H1N1/09-10 in very low birth weight infants during the 2009-2010 H1N1 pandemic and describe their clinical presentations and favorable outcomes despite the lack of treatment.

Staphylococcus aureus infections in adolescents

Staphylococcus aureus infections are important causes of morbidity and mortality in the pediatric population. Over the past decade, community-associated methicillin-resistant S. aureus has emerged as an adolescent pathogen with disease ranging from mild skin and soft tissue infections to severe sepsis syndrome. Various conditions and behaviors common to adolescents render them more susceptible to staphylococcal infections. This review focuses on the problem of S. aureus in the adolescent population, including an outline on the approach, treatment, and prevention of these infections.

Infective Pyomyositis and Myositis in Children in the Era of Community‐Acquired, Methicillin‐ResistantStaphylococcus aureusInfection

BACKGROUND

Cases of pyomyositis and myositis have been increasing in frequency at Texas Children's Hospital (Houston) since 2000. The increase appears to correlate with the emergence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA).

METHODS

The medical records of patients with pyomyositis and myositis hospitalized at Texas Children's Hospital during the period from January 2000 through December 2005 were reviewed. Available S. aureus isolates were obtained for susceptibility testing, to determine the presence of pvl (lukS-PV and lukF-PV), and for pulsed-field gel electrophoresis analysis.

RESULTS

Forty-five previously healthy children with bacterial pyomyositis or myositis were analyzed. The causes were S. aureus (in 57.8% of children) and Streptococcus pyogenes (in 2.2%); 40.0% of children had negative culture results. The number of cases increased between 2000 and 2005, primarily as a result of an increase in the prevalence of community-acquired MRSA. The mean patient age was 5.5 years (range, 0.06-15 years). The thigh (40.0% of children) and pelvis (28.9%) were the most commonly affected sites. The mean abscess diameter was 3.5 cm. Eighteen children required at least 1 muscle drainage procedure. Of the 24 available S. aureus isolates (15 community-acquired MRSA isolates and 9 community-acquired, methicillin-susceptible S. aureus [MSSA] isolates), 16 were found to be USA300 by pulsed-field gel electrophoresis, and 17 carried pvl. Patients with community-acquired MRSA, USA300, and/or pvl-positive strains required more drainage procedures than did those with community-acquired MSSA, non-USA300, and/or pvl-negative strains (81% vs. 40% [P=.05], 82% vs. 29% [P=.02], and 81% vs. 38% [P=.07], respectively).

CONCLUSIONS

Community-acquired MRSA is an increasing cause of pyomyositis and myositis in children. Community-acquired MRSA, USA300, pvl-positive S. aureus isolates caused more severe disease than did community-acquired MSSA, non-USA300, and pvl-negative isolates, respectively.

Community-associated strains of methicillin-resistant Staphylococccus aureus as the cause of healthcare-associated infection

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with community-associated infection have been described as strains genetically distinct from the strains isolated from patients with healthcare-associated infection. This study examines the hypothesis that community-associated MRSA (CA-MRSA) strains now cause serious infections in hospitalized patients.

METHODS

Thirty-seven clinical MRSA isolates were randomly selected from blood isolates obtained from July 2003 through June 2004. Strains were tested for staphylococcal chromosomal cassette mec (SCCmec) type, pulsed-field gel electrophoresis (PFGE) type, and presence of Panton-Valentine leukocidin (PVL) genes. Medical records review and epidemiologic classification was performed by an investigator blinded to the results of the bacterial strain analysis. Episodes of bloodstream infection were independently classified as either community-associated or healthcare-associated infections, and bacterial isolates were independently classified as either CA-MRSA strains or healthcare-associated MRSA (HA-MRSA) strains, according to established definitions.

SETTING

A tertiary care Veterans Affairs Medical Center.

RESULTS

Twenty-four (65%) of 37 MRSA isolates were SCCmec type IV, a genetic type characteristic of CA-MRSA strains; 22 of these 24 isolates belonged to the CA-MRSA clone USA300 and carried PVL genes. Thirteen (35%) of the 37 strains were SCCmec type II, of which 12 were USA100-ST5 and 12 lacked PVL genes. Thirty patients (81%) had healthcare-associated infections; 18 (60%) of these 30 were infected with isolates carrying markers of CA-MRSA strains. Of 7 patients with CA-MRSA infections, 6 were infected with isolates belonging to the USA300 clone. Patients with healthcare-associated bloodstream infections were as likely to be infected with a CA-MRSA strain as patients with a community-associated infection (P = .38).

CONCLUSIONS

MRSA strains with molecular characteristics of CA-MRSA strains have emerged as an important cause of serious healthcare-associated infection in our hospital.

Venous thrombosis associated with staphylococcal osteomyelitis in children

BACKGROUND

Venous thrombosis (VT) in children with Staphylococcus aureus osteomyelitis occurs rarely. We describe clinical features of infections and molecular characterization of isolates of children at Texas Children's Hospital with S aureus osteomyelitis and VT.

METHODS

We reviewed records and imaging studies (chest radiographs, ultrasound, computed tomography, and MRI) of 9 patients at Texas Children's Hospital with acute S aureus osteomyelitis and new onset VT between August 1999 and December 2004. Isolates were fingerprinted by pulsed-field gel electrophoresis and tested for the presence of genes encoding selective virulence factors.

RESULTS

The mean age of the patients was 10.6 years. All 9 of the patients had osteomyelitis with sites of infection adjacent to the VT. The femoral and popliteal veins were most commonly affected. Two patients had VTs develop on the same side in which a central line had been in place. Four patients had chest radiographs consistent with septic emboli; inferior vena cava filters were placed in 3. Evaluation for hypercoagulable state revealed 3 patients with lupus anticoagulant, 1 with anticardiolipin IgG antibody, and 5 with no defect. Most laboratory abnormalities had resolved at follow-up. Seven patients had infections caused by methicillin-resistant S aureus belonging to the same clonal group (USA300); all were community acquired. Seven isolates carried the Panton-Valentine leukocidin (luk-S-PV and luk-F-PV) genes.

CONCLUSIONS

The predominant community-acquired, methicillin-resistant S aureus clone in Houston, Texas, (USA300) may have a unique propensity to cause VT in association with osteomyelitis. Management of the venous thrombosis in this setting may be complicated by the rapid evolution of septic emboli.

Three-year surveillance of community onset health care-associated staphylococcus aureus infections in children

BACKGROUND

Staphylococcus aureus causes skin and soft tissue or invasive infections in children in the community, in the hospital or in other ways associated with the health care system (HCA).

METHODS

Prospective community-acquired S. aureus infection surveillance at Texas Children's Hospital was initiated on August 1, 2001. Community onset HCA (CO HCA) infections were identified. Demographic and clinical data were collected. Antibiotic susceptibilities were determined. Data were analyzed by chi or Student's t test. CO HCO-isolates were characterized by pulsed field gel electrophoresis and staphylococcal chromosomal cassette carrying the mecA methicillin-resistant gene (SCCmec) typing.

RESULTS

From August 1, 2001 to July 31, 2004, 61.5% of 322 in year 1, 62.9% of 259 in year 2 and 56.9% of 318 in year 3 of CO HCA isolates were methicillin-resistant S. aureus (MRSA). Among the CO HCA-MRSA isolates, 8.9% of 542 were from children with invasive infections compared with 24.1% of 357 CO HCA-methicillin-susceptible S. aureus (MSSA; P < 0.001). Sixty-six percent of children with CO HCA-S. aureus isolates were admitted to the hospital. Clindamycin resistance increased over the 3 years (CO HCA-MRSA, from 3.5% to 18.8%, P < 0.001; CO HCA-MSSA, from 3.2% to 10.2%, P = 0.053). Thirty-three of 35 (94.3%) CO HCA-MRSA carried SCCmecIV; 30 were USA300. Only 3 of 35 MSSA were related to USA300 by pulsed field gel electrophoresis.

CONCLUSIONS

CO HCA-S. aureus infections remained steady over the 3-year study at Texas Children's Hospital. Clindamycin resistance increased >4-fold for CO HCA-S. aureus isolates over the 3 years and is no longer appropriate for empiric treatment of invasive infections suspected to be caused by CO HCA-MRSA at our hospital. In our setting, CO HCA-MRSA infections are steady in number despite substantial increases in community-acquired MRSA infections and both being related to the same clone.

Streptococcus pneumoniae serogroups 15 and 33: an increasing cause of pneumococcal infections in children in the United States after the introduction of the pneumococcal 7-valent conjugate vaccine

BACKGROUND

After the widespread use of the 7-valent pneumococcal conjugate vaccine, replacement serotypes have emerged. Serogroups 15 and 33 have emerged as nonvaccine serotypes causing invasive disease. We describe the clinical characteristics of children with infections caused by these serogroups and determined the genetic relationship of the strains.

MATERIALS AND METHODS

The United States Pediatric Multicenter Pneumococcal Surveillance Group has prospectively identified children with pneumococcal infections since 1993. Charts were reviewed retrospectively, isolates were serogrouped and serotyped and randomly selected strains were fingerprinted with the use of pulsed field gel electrophoresis. Selected strains were further characterized by multilocus sequence typing.

RESULTS

Between January 1994 and December 2004, 103 children had pneumococcal disease caused by serogroup 15, and 40 children had infections caused by serogroup 33. There was an increase from a mean of 7 cases per year for serogroup 15 in the prevaccine period to 14 cases per year in the postvaccine period and from 2 cases per year for serogroup 33 to 7 cases per year in the same periods. Isolates were susceptible to penicillin and ceftriaxone in both periods. A predominant clone was found in each serogroup representing 60% (30 of 50) of serogroup 15 strains and 83% (24 of 29) of the serotype 33F strains. The serogroup 15 clone comprised strains of serotypes 15B and 15C, whereas the 33 clone contained only serotype 33F strains. One isolate from each of the 15 and 33 clones was characterized by multilocus sequence typing and were found to be ST199 and 100, respectively.

CONCLUSIONS

Pneumococcal disease in children caused by penicillin-susceptible clones of serogroups 15 and 33 is increasing in the United States. Clinicians should consider replacement serotypes when encountered with invasive pneumococcal disease in vaccinated children.

Panton-Valentine leukocidin genes are associated with enhanced inflammatory response and local disease in acute hematogenous Staphylococcus aureus osteomyelitis in children

BACKGROUND

Staphylococcus aureus strains carrying the genes encoding Panton-Valentine leukocidin (pvl-positive [pvl+]) are associated with more febrile days and higher complication rates of osteomyelitis in children than are pvl-negative (pvl-) strains.

OBJECTIVES

Selected clinical, laboratory, and radiographic findings in children with osteomyelitis caused by pvl+ and pvl- S aureus strains were compared.

METHODS

The demographics, selected clinical features, laboratory values, and radiographic findings of children with community-acquired S aureus osteomyelitis prospectively identified at Texas Children's Hospital between August 2001 and July 2004 were reviewed. Polymerase chain reaction was performed to detect the genes for pvl (luk-S-PV and luk-F-PV) and fibronectin-binding protein (fnbB) in S aureus isolates. Chi2, 2-sample t test, and multiple logistic regression were used for statistical analysis.

RESULTS

Methicillin-susceptible and methicillin-resistant S aureus (MSSA and MRSA, respectively) caused osteomyelitis in 33 and 56 children, respectively. Twenty-six isolates were pvl- (26 MSSA), 59 were pvl+ (3 MSSA, 56 MRSA), and 4 were not available for analysis (4 MSSA). On univariate analysis, patients with pvl+ S aureus isolates had significantly higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level both at presentation and as a maximum value during hospitalization and were more likely to have a blood culture positive for S aureus during their admission. Patients with pvl+ S aureus isolates were significantly more likely to have concomitant myositis or pyomyositis compared with patients with pvl- S aureus isolates on MRI. In a multivariate analysis pvl remained significantly associated with ESR and CRP levels at presentation and blood culture positive for S aureus. pvl+ status and younger age were associated with myositis on MRI.

CONCLUSIONS

Osteomyelitis caused by pvl+ S aureus strains were associated with more severe local disease and a greater systemic inflammatory response compared with osteomyelitis caused by pvl- S aureus.

Epidemiology of pediatric tuberculosis using traditional and molecular techniques: Houston, Texas

OBJECTIVE

To investigate the transmission dynamics of pediatric tuberculosis (TB) by analyzing the clinical characteristics with the molecular profiles of Mycobacterium tuberculosis isolates during a 5-year period.

METHODS

A retrospective review of a prospective population-based active surveillance and molecular epidemiology project was conducted in private and public pediatric clinics within Houston and Harris County, Texas. The study population consisted of patients who had pediatric TB diagnosed from October 1, 1995, through September 30, 2000. Cases and potential source cases (PSC) were interviewed using a standardized questionnaire. Available Mycobacterium tuberculosis isolates from cases and PSCs were characterized and compared by IS6110 restriction fragment length polymorphism, spoligotyping, and genetic group assignment. Clinical characteristics were described, and molecular characterizations were compared. Data were analyzed by using EpiInfo 6.02b and SAS 8.2.

RESULTS

A total of 220 (92%) of 238 pediatric TB cases were included. Epidemiologic and clinical findings were consistent with previous studies. Molecular profiles from 3 cases did not match the profile of PSC. Four previously unknown PSCs were identified using molecular techniques. Fifty-one (71.8%) of 71 isolates matched at least 1 other Houston Tuberculosis Initiative TB database isolate and were grouped into 33 molecular clusters. Cases were more likely to be clustered when the patients were younger than 5 years, identified a source case, or were US born.

CONCLUSIONS

Traditional contact tracing may not always be accurate, and molecular characterization can lead to identification of previously unrecognized source cases. Recent transmission plays a significant role in the transmission of TB to children as evident by the high degree of clustering found in our study population.

Pulmonary Manifestations in Children with Invasive Community-Acquired Staphylococcus aureus Infection

BACKGROUND

Primary pneumonia and metastatic pulmonary infection have become more common in patients with invasive community-acquired Staphylococcus aureus disease at Texas Children's Hospital (TCH; Houston).

METHODS

In this study, we sought to describe pulmonary involvement in children with community-acquired S. aureus invasive infection and to determine whether the presence of genes encoding Panton-Valentine leukocidin (PVL) (luk-S-PV and luk-F-PV) and collagen adhesin (cna) is correlated with pulmonary manifestations. Patients with invasive staphylococcal infections admitted to TCH between 1 August 2001 and 30 June 2004 were studied. Chest imaging and postmortem examination reports were reviewed. Isolates were tested for the presence of genes encoding PVL and collagen adhesin by PCR.

RESULTS

A total of 47 of 70 patients with community-acquired methicillin-resistant S. aureus (MRSA) infection had abnormal pulmonary imaging findings, compared with 12 of 43 patients with community-acquired methicillin-susceptible S. aureus (MSSA) infection (P < .001). Pneumonia and/or empyema, in addition to septic emboli, were the most common findings. Metastatic pulmonary disease occurred more frequently among patients with osteomyelitis. Severe necrotizing pneumonia was present in 3 children coinfected with influenza and parainfluenza virus. The presence of genes encoding PVL was investigated in 67 MRSA and 36 MSSA isolates. Abnormal chest imaging findings were observed for 51 of 80 patients with PVL-positive isolates, compared with 2 of 23 patients with PVL-negative isolates (P < .001). Only 2 isolates (both of which were MSSA) from patients with abnormal chest radiograph findings carried cna. PVL remained independently associated with abnormal chest imaging findings in patients with secondary pneumonia in a multivariate analysis (P = .03).

CONCLUSIONS

Pulmonary involvement is commonly observed in patients with invasive community-acquired S. aureus infections. Community-acquired MRSA may cause primary community-acquired pneumonia, as well as metastatic pulmonary disease. The presence of genes encoding PVL is highly associated with pulmonary involvement by S. aureus.

Three-Year Surveillance of Community-AcquiredStaphylococcus aureus Infections in Children

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) isolates are increasingly frequent causes of skin and soft-tissue infections or invasive infections in many communities.

METHODS

Prospective surveillance for community-acquired S. aureus infections at Texas Children's Hospital was initiated on 1 August 2001. Infections meeting the definition of community-acquired were identified. Demographic and clinical data were collected. Antibiotic susceptibilities, including inducible resistance to macrolide, lincosamide, and streptogramin B (MLSB), were determined in the clinical microbiology laboratory with the methodology of the NCCLS. All data were entered into a computer database. Data were analyzed by chi2 tests.

RESULTS

From 1 August 2001 to 31 July 2004, the percentage of community-acquired S. aureus isolates that were methicillin resistant increased from 71.5% (551 of 771 isolates) in year 1 to 76.4% (1193 of 1562 isolates) in year 3 (P = .008). The number of both community-acquired MRSA (CA-MSRA) isolates and community-acquired methicillin-susceptible S. aureus (CA-MSSA) isolates increased yearly, but the rate of increase was greater for the CA-MRSA isolates. Among the CA-MRSA isolates, 2542 (95.6%) were obtained from children with skin and soft-tissue infections, and 117 (4.4%) were obtained from children with invasive infections. Overall, 62% of children with CA-MRSA isolates and 53% of children with CA-MSSA isolates were admitted to the hospital (P = .0001). The rate of clindamycin resistance increased significantly for both CA-MRSA isolates (P = .003) and CA-MSSA isolates (P = .00003) over the 3 years. MLSB inducible resistance was found in 27 (44%) of 62 clindamycin-resistant CA-MSSA isolates, compared with 6 (4.5%) of 132 clindamycin-resistant CA-MRSA isolates (P < .000001).

CONCLUSIONS

CA-MRSA isolates account for an increasing percentage and number of infections at Texas Children's Hospital. Clindamycin resistance increased among community-acquired S. aureus isolates. Community surveillance of community-acquired S. aureus infections is critical to determine the appropriate empiric antibiotic treatment for either local or invasive infections.

Severe Staphylococcal sepsis in adolescents in the era of community-acquired methicillin-resistant Staphylococcus aureus

OBJECTIVE

More than 70% of the community-acquired (CA) staphylococcal infections treated at Texas Children's Hospital are caused by methicillin-resistant Staphylococcus aureus (MRSA). Since September 2002, an increase in the number of severely ill patients with S aureus infections has occurred. This study provides a clinical description of severely ill adolescent patients and an analysis of their isolates using molecular methods.

METHODS

We identified adolescent patients meeting criteria for severe sepsis requiring admission to the PICU. Patient records were reviewed, and isolates were obtained for susceptibility testing and DNA extraction. Isolates were tested for the presence of virulence genes (cna, tst, lukS-PV, and lukF-PV) and enterotoxin genes (sea, seb, sec, sed, seh, and sej) by polymerase chain reaction. Genomic fingerprints were determined by repetitive-element polymorphism polymerase chain reaction and pulse-field gel electrophoresis. SCCmec cassette type was determined.

RESULTS

Fourteen adolescents with severe CA S aureus infections were identified between August 2002 and January 2004. All were admitted to the PICU with sepsis and coagulopathy. Twelve patients had CA-MRSA infections; 2 had CA methicillin-susceptible Staphylococcus aureus (MSSA) infections. The mean age was 12.9 years (range: 10-15 years). Thirteen patients had pulmonary involvement and/or bone and joint infection; 10 patients had > or =2 bones or joints infected (range: 2-10); 4 patients developed vascular complications (deep venous thrombosis); and 3 patients died. All isolates were identical or closely related to the previously reported predominant clone in Houston, Texas (multilocus sequence type 8, USA300), and carried lukS-PV and lukF-PV genes as well as the SCCmec type IVa cassette (12 MRSA isolates) but did not contain cna or tst. Only 1 strain carried enterotoxin genes (sed and sej).

CONCLUSIONS

Severe staphylococcal infections in previously healthy adolescents without predisposing risk factors have presented more frequently at Texas Children's Hospital since September 2002. CA MRSA and clonally related CA MSSA characterized as USA300 and sequence type 8 have been isolated from these patients.

Clonality of Streptococcus pneumoniae serotype 1 isolates from pediatric patients in the United States

We compared Streptococcus pneumoniae serotype 1 isolates causing disease among children in six geographic regions of the United States to determine genetic relatedness. Genomic fingerprints were determined by repetitive element polymorphism PCR (Rep-PCR). Multilocus sequence type characterization was performed on selected isolates. Four different genomic banding patterns were identified by Rep-PCR. One profile (clone 1) was predominant and matched sequence type 227.

Azithromycin compared with beta-lactam antibiotic treatment failures in pneumococcal infections of children

OBJECTIVE

To determine whether treatment failures occurred more commonly with azithromycin than with beta-lactam antibiotics in children who developed invasive pneumococcal disease within 30 days of receiving prior antimicrobial therapy.

METHODS

Retrospective review of medical records of children evaluated at Texas Children's Hospital between 1996 and 2002 who had received antimicrobials (azithromycin or a beta-lactam antibiotic) and developed invasive pneumococcal disease within 30 days. Treatment failure was defined as invasive pneumococcal infection that occurred while taking antimicrobials or within 3 days of stopping azithromycin treatment or 1 day of stopping beta-lactam treatment. Penicillin and azithromycin susceptibilities were determined and categorized according to National Committee for Clinical Laboratory Standards guidelines.

RESULTS

We identified 21 and 33 children with similar demographic features who had developed invasive pneumococcal disease within 1 month of receiving azithromycin or a beta-lactam antibiotic, respectively. Eleven (52%) children in the azithromycin group and 11 (33%) in the beta-lactam group met the definition for treatment failures (P = 0.34). Eight treatment failures while receiving azithromycin were caused by pneumococci with the macrolide-resistant (M) phenotype, 2 with the macrolide-, lincosamide- and streptogramin B-resistant (MLSB) phenotype and 1 by a macrolide-susceptible organism. In the beta-lactam group 7 had a penicillin-resistant isolate, 3 had an intermediately susceptible isolate and 1 had a susceptible isolate.

CONCLUSIONS

Our study suggests that treatment failures among patients who developed invasive disease within 30 days of receiving an antimicrobial occur as frequently in patients who receive beta-lactam antibiotics as in those who receive azithromycin. Furthermore macrolide resistant organisms are not more likely to be recovered after a macrolide treatment failure than a penicillin-nonsusceptible isolate being recovered after a beta-lactam treatment failure (P = 1.0).

Early markers of late-onset sepsis in premature neonates: clinical, hematological and cytokine profile

BACKGROUND

Late-onset sepsis in the NICU is a major problem associated with high morbidity and mortality.

OBJECTIVE

To determine if clinical characteristics, hematological parameters and serial measurements of serum IL-6 and IL-8 can detect late-onset sepsis in premature neonates prior to positive blood cultures.

DESIGN

The study was done in 2 phases. The first phase (S1) was a retrospective evaluation of clinical signs and timing of blood culture positivity in all neonates with late-onset cultures proven sepsis from 1991-1998. The second phase (S2) was a prospective study that enrolled infants > or = 72 hours old, suspected of sepsis based on the presence of criteria identified in S1. At that time (day 0), blood was drawn for a CBC with differential, blood culture, IL-6 and IL-8 levels; cytokine levels were repeated on day 1. Infants with positive cultures were diagnosed as confirmed sepsis; those with negative cultures, as no sepsis.

RESULTS

S1: Of the 48 episodes of culture proven, late-onset sepsis, 54% of the blood cultures were positive by 24 hours and 90% by 48 hours. The most common presenting signs were desaturations (50%) and increased gastric residuals (33%); I/T ratio > 0.16 differentiated between gram-positive, negative and fungal infections (p = 0.007). S2: 27 infants were enrolled. Eight (mean [SEM] gestational age of 28.2 [0.94] weeks; birth weight of 1.15 [0.11] kg) had positive blood cultures; 19 (gestational age of 27.7 [0.9] weeks; birth weight of 1.06 [0.13] kg) had no sepsis. Infants with sepsis were more likely to have apnea/bradycardia (p = 0.002); no differences in hematological profile, as compared to those with no sepsis. Seven (88%) infants had positive blood cultures by 48 hours. Median values of IL-6 (pg/ml) were higher in infants with sepsis vs. those with no sepsis on days 0 [40 vs. 13] (p = 0.03) and 1 [24 vs. 9] (p < 0.001). IL-8 levels were not significantly different.

CONCLUSIONS

In both S1 and S2, a majority of the blood cultures were positive by 48 hours. IL-6 levels on days 0 and 1 were significantly higher in infants with confirmed sepsis, prior to the blood culture being positive. IL-6 levels may be useful in the initiation as well as early termination of antibiotic therapy in late-onset neonatal sepsis.

Cat-scratch disease occurring in three siblings simultaneously

We report for the first time three siblings with cat-scratch disease occurring simultaneously. Case 1 was an 8-year-old boy with enlarged supraclavicular lymph nodes and fever. Case 2 was the 11-year-old sister whose presentation was a prolonged febrile illness. Case 3 was a 13-year-old male adolescent with adenitis of the neck and thigh. All three patients were treated with rifampin with improvement of their symptoms.