About

Jeffrey Stephen Gerber, M.D., Ph.D., M.S.C.E, is a Professor of Pediatrics (Infectious Diseases) at the Children's Hospital of Philadelphia. He serves as an Attending Physician in the Division of Infectious Diseases at the same hospital and is a Senior Scholar at the Center for Clinical Epidemiology and Biostatistics at the University of Pennsylvania. Dr. Gerber holds the position of Distinguished Chair in the Department of Pediatrics at the Children's Hospital of Philadelphia and is an Associate Chief Clinical Research Officer at the Children's Hospital of Philadelphia Research Institute. He is also the Deputy Director of the Center for Pediatric Clinical Effectiveness at the Children's Hospital of Philadelphia. His research expertise focuses on the epidemiology and outcomes of antimicrobial use, with clinical expertise in antimicrobial stewardship.

Research topics

• Medicine
• Microbiology
• Biochemistry
• Immunology
• Virology
• Environmental health
• Bioinformatics
• Pathology
• Biology
• Genetics
• Family medicine
• Pediatrics

Selected publications

• Malaria in Children at 9 US Hospitals: 2016–2023

  PEDIATRICS · 2026-05-08

  article

  OBJECTIVES: This study set out to describe imported pediatric malaria in the United States over an 8-year period, including patient demographics, clinical outcomes, and risk factors for severe disease. METHODS: A retrospective descriptive study of pediatric patients treated for malaria at 9 hospitals in the United States from 2016 to 2023 was conducted to analyze patient demographics, clinical outcomes, and risk factors for severe malaria. RESULTS: A total of 171 children were treated across the 9 US hospitals included in this study from 2016 to 2023. Most patients had traveled to West Africa to visit friends and relatives. Fever was the most common symptom recorded (90%), and most reported at least 1 abdominal symptom (66%). Thirty-two percent of patients were diagnosed with severe malaria. No deaths occurred. Delayed diagnoses were common (26%), occurred at similar rates across all hospitals in the study, and were a risk factor for severe malaria. CONCLUSIONS: Delayed diagnoses of travel-acquired malaria were common for pediatric patients presenting to hospitals in the United States and are associated with higher risk for severe malaria, which is associated with longer hospitalizations and increased morbidity. Chemoprophylaxis against travel-acquired malaria and prompt diagnosis of imported cases are crucial to improving patient outcomes.

  PublisherDOI

• Trends and Perioperative Outcomes in Gastric Cancer Surgery in Switzerland: A National Inpatient Database Analysis (1998–2021)

  British journal of surgery · 2025-05-01

  articleOpen access1st authorCorresponding

  Abstract Background Volume–outcome relationships have driven the implementation of minimum case volume regulations for various surgical procedures under the framework of Highly Specialised Medicine (HSM) in Switzerland. However, the regulation of gastric oncological resections remains a subject of debate. Aims To analyse volume–outcome relationships for oncological resections in gastric cancer patients in Switzerland. Methods A nationwide analysis of an inpatient database (Medical Statistics of Hospitals) from the Swiss Federal Statistical Office was conducted. Diagnoses and related health problems were coded according to the International Classification of Diseases, 10th Revision (ICD-10), and diagnostic and surgical procedures using the Swiss Classification of Operations (CHOP). Patients with gastric cancer undergoing surgical or endoscopic resection from 1998 to 2021 were identified. Data were stratified by annual surgical caseload (quartiles), hospital typology, and annual inpatient volume. Outcomes included in-hospital mortality, postoperative complications, and failure-to-rescue (FTR) rates. Results A total of 8708 cases from over 30 million hospitalisations were included. Yearly caseload increased over time (2000: 255; 2010: 383; 2020: 432). Overall mortality was 3.8%. Higher surgical caseload was associated with lower mortality (2.2% for centres with >20 annual gastric cancer surgeries vs. 2.6–4.5% for lower quartiles, p = 0.001), as were annual inpatient volume (2.3% vs. 4.1–5.0% with a threshold of 30,000 annual inpatient cases, p < 0.001), and hospital typology (1.9% for university hospitals vs. 4.2–4.1% for centrum/other hospitals, p < 0.001). While hospitals with higher caseload reported relatively more complications, including anastomotic leaks and peritonitis, the associated FTR rates were lower (10.8% vs. 12.3–25.0% with 20 annual gastric resections as the cut-off, p < 0.001). Conclusion The results indicate that patients who underwent gastric cancer surgery in hospitals with higher case volumes – both surgical and inpatient – experienced lower in-hospital mortality and reduced failure-to-rescue rates.

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• P-90. Culture negative vs Culture positive Acute Hematogenous Osteomyelitis in Pediatrics: A single study experience

  Open Forum Infectious Diseases · 2025-01-29

  articleOpen accessSenior author

  Abstract Background Acute hematogenous osteomyelitis (AHO) is a rare but serious infection in children that can result in acute and chronic sequelae. Despite guidelines, optimal management continues to be a source of debate, particularly in children without positive cultures. We examined treatment approaches and outcomes in AHO patients stratified by culture positivity. Consort Flow Diagram of the Study on Culture Negative vs. Culture Positive Acute Hematogenous Osteomyelitis in Pediatrics. This diagram illustrates the participant flow through each stage of the retrospective study, including enrollment, allocation, follow-up, and analysis. The numbers of participants assessed for eligibility, included in the study, and analyzed for the primary outcome are detailed, alongside reasons for exclusions at each stage. Methods This retrospective cohort study included children (< 19y) admitted at CHOP from 2005-2020 with a primary diagnosis of AHO. Cases were identified by APR-DRG and ICD-9 codes followed by chart review to determine inclusion/exclusion criteria (Table 1). Patients were divided into culture-positive (CX+) and culture-negative (CX-) groups. Wilcoxon rank sum tests were used to compare continuous variables and Chi-square test was used to compare categorical variables between groups. Inclusion/Exclusion criteria for defining AHO cohort This table details the criteria used to identify pediatric patients for inclusion and exclusion in the Study on Culture Negative vs. Culture Positive Acute Hematogenous Osteomyelitis in Pediatrics. Inclusion criteria focus on patient characteristics and clinical presentation necessary for study entry, including age, hospitalization duration, diagnosis, symptomology, and relevant imaging findings. Exclusion criteria are subdivided into primary factors, which identify general patient disqualifications, and secondary factors, which specifically differentiate between culture-positive and culture-negative cases. These criteria ensure a focused and relevant patient cohort for analysis. Results Of 796 children with a primary diagnosis of AHO, 395 [236 (59.7%) culture-negative and 159 (40.2%) culture-positive] met no secondary exclusion criteria. Patient characteristics are shown in Table 2. Blood culture was performed more frequently in CX+ cases (94.3% vs 84.1%, p=0.004), as were bone cultures (54.8% vs. 11.1%, p< 0.001). The proportion of CX- cases decreased over time (2005-8: 66%, 2009-12: 60%, 2013-16: 59%, 2017-20: 57%; p=0.12). The most common organisms identified in CX+ group were MSSA (73.6%) and MRSA (21.4%). CX+ more often received narrow-spectrum beta-lactams empirically (27.5% vs. 10.1%, p< 0.001) and as definitive therapy (60.9% vs 18.0%, p< 0.001). CX+ less often received anti-MRSA antibiotics empirically (65.2% vs. 83.1%, p< 0.001) or as definitive treatment (30.4% vs 78.1%, p< 0.001). CX+ patients had a shorter median hospital stay (4 days) than CX- patients (5 days, p< 0.001). There was no difference in treatment duration, treatment failure or need for repeat surgical intervention. Features of culture-positive and culture-negative AHO cases This table summarizes the demographic and clinical characteristics, site of infection, presenting features, and laboratory values at admission for pediatric patients diagnosed with AHO, categorized by culture-positive and culture-negative cases. Data are presented as medians with interquartile ranges (IQR) or as numbers with percentages. Statistical significance between groups is evaluated and shown in the rightmost column as p-values, highlighting differences in infection sites, symptom presentation, and initial laboratory findings between the two groups. Conclusion Nearly two-thirds of AHO cases were culture-negative at our hospital. The benefits of obtaining cultures (narrower spectrum therapy, shorter hospital stay) should be weighed since outcomes were similar between these groups. Disclosures Kevin J. Downes, MD, Paratek, Inc.: Grant/Research Support|Veloxis Pharmaceuticals, Inc.: Grant/Research Support

  PublisherOA PDFDOI

• Comparison of metrics of neonatal intensive care unit antibiotic use

  Infection Control and Hospital Epidemiology · 2025-08-19

  articleOpen access

  OBJECTIVE: To compare temporal trends, variation, and correlations between antibiotic use metrics across U.S. neonatal intensive care units (NICUs) and assess associations with mortality. METHODS: We conducted a retrospective cohort study of 438,156 infants admitted to 272 NICUs from 2017 to 2021 using the Premier Health Database. Antibiotic use rate (AUR), days of therapy (DOT), and antibiotic spectrum index (ASI) per 1,000 patient or therapy days were calculated both cumulatively by year and at the center level. Mixed-effects models adjusted for center-level characteristics were used for all analyses. RESULTS: < 0.001). None were significantly associated with center-level mortality. ASI had the least variability, indicating more uniform antibiotic selection and lower center-level discriminatory value. CONCLUSIONS: DOT and AUR were comparable measures of antibiotic consumption, both showing significant declines. ASI exhibited the least variability, reflecting more consistency in antibiotic selection. The similarity in dispersion and decline between AUR and DOT suggests that neonatal antibiotic exposure is primarily influenced by initiation and discontinuation decisions rather than regimen complexity. Given its ease of calculation, AUR may be the most practical metric for evaluating the impact of antibiotic stewardship interventions at the center level.

  PublisherDOI

• New Test, Old Dilemma: Distinguishing Viral From Bacterial Infections

  PEDIATRICS · 2025-12-19

  articleSenior author

  Differentiating viral from bacterial infections is one of the greatest challenges in pediatrics. As our awareness of the harms associated with antibiotic use in children has increased, the tension between the desire to avoid unnecessary antibiotics and the imperative to identify and treat invasive bacterial infections, including bacteremia and meningitis, in a timely fashion has escalated. Countless algorithms, guidelines, recommendations, and tests have been developed to support clinical decision-making around antibiotic use. Yet, we still struggle.In this issue of Pediatrics, Kalmovich et al report on the use of a host-protein biomarker test intended to distinguish viral from bacterial infections at urgent care centers.1 The test, MeMed BV (MMBV), is a rapid immunoassay that measures a viral-induced protein called tumor necrosis factor–related apoptosis-inducing ligand, interferon-gamma inducible protein of 10 kDA and C-reactive protein. MMBV incorporates these results into a score from 0 to 100, with scores of 0 to less than 35 indicating viral infection, 35 to 65 being considered equivocal, and 66 to 100 being consistent with bacterial infection. In prior validations, MMBV has been reported to have high sensitivity and specificity as well as high positive and negative predictive values for bacterial infections as compared with gold standards that include additional diagnostic tests and adjudication by experienced pediatricians.2,3 In this study, the authors sought to assess how this test impacts real-world decision-making by urgent care physicians.MMBV was implemented at 10 outpatient urgent care centers in Israel in conjunction with education about when to order the test and how to interpret its results. Clinicians were asked about their likelihood to refer to the emergency department (ED) and/or prescribe antibiotics at the time of ordering MMBV and, at the end of the visit, whether the test results influenced their decisions. Investigators evaluated antibiotic prescribing at the index visit, referral to the ED, and antibiotic prescription or hospital admission within 7 days of discharge.In more than 2000 encounters, MMBV was consistent with bacterial infection in 20%, equivocal in 12%, and consistent with viral infection in 69%. Across multiple comparisons, physician ED referral and antibiotic prescribing rates generally aligned with test results, without measurable harm. There was no difference in outcomes based on whether clinician prescribing aligned with MMBV results.This study was designed to understand how MMBV might impact real-world decision-making. Although MMBV use coincided with safe reductions in ED referrals, further comparative studies are needed to evaluate how it actually impacts outcomes in children, such as overall antibiotic use, antibiotic-associated adverse events, and hospitalizations. A recent randomized controlled trial in adults with lower respiratory tract infections (LRTIs) in whom clinicians were considering prescribing antibiotics did find that antibiotic prescribing was less frequent in the group with access to MMBV.4 Additional research is needed to understand whether the same will hold true in pediatric populations—and in which clinical scenarios—because adult LRTI is a very different, and much narrower, population than all children presenting to urgent care.Most children seen in urgent care (and in this study) have acute respiratory tract infections (ARTIs). These are most commonly viral, but there are 4 ARTIs for which antibiotics are sometimes indicated—acute otitis media, acute sinusitis, streptococcal pharyngitis, and pneumonia—for which evidence-based guidelines already exist to guide diagnosis.5–8 Future studies should evaluate whether incorporating MMBV into standard practice guided by high-quality evidence-based recommendations for these specific diagnoses improves outcomes. Other diagnostics have not always cleared that bar. For example, procalcitonin raised interest as a stewardship tool when studies in adults showed that it reduced antibiotic durations for pneumonia and sepsis.9 However, on closer inspection, the treatment durations in the control groups have often been longer than evidence-based guidelines recommend, suggesting that if clinicians followed evidence-based recommendations and used the shortest effective antibiotic courses, benefit of procalcitonin may be limited.10 Indeed, several studies in children have shown that procalcitonin does not significantly reduce antibiotic use, particularly in settings with active stewardship programs, and is not cost-effective.11,12Implementation strategies heavily influence the utility of diagnostic testing. In the present study, alignment between MMBV and clinician prescribing was 78%, but clinicians still prescribed antibiotics to 20% of children whose MMBV indicated viral infection. As the authors acknowledge, there may be many reasons for this, including parental pressure or other conflicting testing, but the benefit of any test will be limited if clinicians fail to act on its results. The approach to implementation can be as important as the test itself, as demonstrated by rapid blood culture identification tests, which decrease unnecessary antibiotics for gram-positive infections but typically only if implemented in conjunction with clear oversight and guidance from a stewardship program.13 Further work is necessary to identify best practices in implementation to maximize clinical impact of MMBV.Beyond optimizing uptake of novel diagnostic tests, it is crucial to prevent their use in scenarios wherein they offer limited value or may cause potential harm. In the present study, physicians were instructed that MMBV has not been studied in children with symptoms for more than 7 days, gastrointestinal tract infections, or a number of comorbidities, including immunosuppression, and were discouraged from using it for suspected tonsilitis, urinary tract infections, and skin infections. Nevertheless, 28% of the patients in whom MMBV was performed fell outside of the advised use cohort. At best, inappropriate test use generates unnecessary costs, but, at worst, it can lead to diagnostic error. Respiratory viral tests have faced similar overuse challenges. Their clinical utility lies in early identification of viruses that might benefit from treatment, such as influenza and RSV, or when identification of a virus might lead a clinician not to prescribe antibiotics when they otherwise would have. In reality, they are often used in patients with low likelihood of bacterial infection or when positive results do not dissuade clinicians from using antibiotics, adding cost without reducing antibiotic use. Their use has skyrocketed without added value, now becoming a frequent target of deimplementation efforts.14,15 Instead of addressing overuse after overly broad application, future efforts should focus on strategies to optimize MMBV use in appropriate cohorts, potentially using electronic medical record decision support to restrict use to validated scenarios.The authors argue that a test that helps support decision-making is valuable in this age of high decision burden and decision fatigue in urgent care centers and EDs. However, of the 80% of visits wherein MMBV influenced providers, in 64%, it supported the existing plan and only changed management in 16%. The question is whether, in an already crowded field of diagnostic tests, adding another one that rarely changes management will help relieve the burden of clinical decision-making or further muddy an increasingly complicated clinical picture while adding costs and (potentially) time. To ensure that MMBV adds value will require successful demonstration of its benefit compared with existing evidence-based diagnostic strategies and, if found to be useful, identification of implementation strategies that can optimize application in appropriate clinical scenarios and limit unvalidated use.

  PublisherDOI

• P-1118. Clinician knowledge, attitudes, and practices around empiric vancomycin use in the pediatric intensive care unit

  Open Forum Infectious Diseases · 2025-01-29

  articleOpen access

  Abstract Background Overuse of empiric vancomycin is common in pediatric intensive care units (PICU) despite a low prevalence of infections requiring vancomycin. Determinants of excess vancomycin prescribing are unknown. Our objective was to evaluate PICU clinician knowledge, attitudes, and practices regarding empiric vancomycin.Table 1.Demographic variables of survey respondents Methods We conducted a cross-sectional survey of PICU attendings, fellows, residents, and advanced practice providers in five tertiary care PICUs. The survey was distributed by email in August-September 2023. Survey items included Likert scale (1-5), ranking, and multiple-choice responses. Agree/Strongly Agree and Disagree/Strongly Disagree were collapsed to Agree and Disagree for analysis. Data were analyzed using descriptive statistics.Figure 1.Clinician attitudes about vancomycin use Results A total of 134 of 297 eligible clinicians (45%) answered the survey (Table 1). Knowledge of the spectrum of activity of vancomycin was low with only 14 of 117 (12%) respondents answering all questions correctly. Just over half of clinicians agreed that vancomycin overuse was a significant problem (72/134, 54%); this proportion varied from 0% to 65% across sites. Most clinicians (105/133, 79%) agreed that reducing vancomycin overuse would reduce antibiotic-associated adverse events. Clinicians had greater confidence in determining when vancomycin should be given to a patient with sepsis as compared to a hemodynamically stable patient with a fever (107/134, 80% vs 80/131, 61%). Respondents were most confident in determining when vancomycin could be stopped (113/134, 84% agreed) (Figure 1). Illness severity was the factor influencing the decision to start vancomycin ranked highest by the most respondents (55%), followed by suspected source of infection (19%), followed by patient history of methicillin-resistant Staphylococcus aureus (MRSA) (18%); local prevalence of MRSA was ranked highest least often (4%) (Figure 2).Figure 2.Factors influencing clinician decisions to administer empiric vancomycin Respondents ranked each possible factor 1-7 with 1 being the most influential factor in choosing to give vancomycin and 7 being the least influential. The blue shading reflects more influential factors and the gray shading reflects less influential factors. Conclusion Most PICU clinicians in this multi-site study felt confident about when to stop or start vancomycin, though many misunderstood the spectrum of vancomycin activity. Focusing stewardship efforts on improving clinician knowledge and supporting decision making, particularly for patients without sepsis, may address these barriers. Disclosures Jason G. Newland, MD, MEd, Moderna: Grant/Research Support|Pfizer: Grant/Research Support

  PublisherOA PDFDOI

• Antibiotic exposure is associated with minimal gut microbiome perturbations in healthy term infants

  Microbiome · 2025-01-24 · 10 citations

  articleOpen access

  BACKGROUND: The evolving infant gut microbiome influences host immune development and later health outcomes. Early antibiotic exposure could impact microbiome development and contribute to poor outcomes. Here, we use a prospective longitudinal birth cohort of n = 323 healthy term African American children to determine the association between antibiotic exposure and the gut microbiome through shotgun metagenomics sequencing as well as bile acid profiles through liquid chromatography-mass spectrometry. RESULTS: Stool samples were collected at ages 4, 12, and 24 months for antibiotic-exposed (n = 170) and unexposed (n = 153) participants. A short-term substudy (n = 39) collected stool samples at first exposure, and over 3 weeks following antibiotics initiation. Antibiotic exposure (predominantly amoxicillin) was associated with minimal microbiome differences, whereas all tested taxa were modified by breastfeeding. In the short-term substudy, we observed microbiome differences only in the first 2 weeks following antibiotics initiation, mainly a decrease in Bifidobacterium bifidum. The differences did not persist a month after antibiotic exposure. Four species were associated with infant age. Antibiotic exposure was not associated with an increase in antibiotic resistance gene abundance or with differences in microbiome-derived fecal bile acid composition. CONCLUSIONS: Short-term and long-term gut microbiome perturbations by antibiotic exposure were detectable but substantially smaller than those associated with breastfeeding and infant age.

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• Antibiotic exposure and infection epidemiology among newborns with congenital diaphragmatic hernia

  Journal of Perinatology · 2025-08-18

  article
  PublisherDOI

• P-1640. Antibiotic prescribing guideline-concordance for sinusitis in adult and pediatric primary care practices

  Open Forum Infectious Diseases · 2025-01-29

  articleOpen access

  Abstract Background Antibiotics are only sometimes indicated for acute sinusitis, a commonly diagnosed infection in the ambulatory setting and an important target for antibiotic stewardship. However, assessment of the appropriateness of antibiotic use for sinusitis is based on clinical signs and symptoms, and therefore requires manual chart abstraction. We present a study assessing the appropriateness of antibiotic prescribing in adult and pediatric sinusitis visits. Methods Outpatient encounters for sinusitis in adult and pediatric primary care practices within two health systems with an antibiotic prescribed from July 1, 2017 through June 30, 2021 were identified by ICD-10 code (J01 and J32). Of these, 600 encounters were randomly selected for review (300 from adult practices; 300 from pediatric practices). Five trained physician annotators reviewed prescriber notes from these encounters and identified relevant signs/symptoms, duration of illness, and disease trend and severity; annotators used these findings to assess overall guideline concordance of antibiotic prescribing using definitions adapted from clinical guidelines (table 1). Two physicians performed adjudication for disagreements (LD, KWH). Results Demographics and characteristics of included encounters are reported in Table 2. In adults, 19 encounters were excluded after review due to a note being unrelated to the sinusitis encounter; of the remaining 281, 37 (13.2%) were considered guideline concordant, 157 (55.9%) were considered not guideline-concordant, and 87 (31.0%) were potentially guideline concordant but with insufficient information. In pediatrics, 184 (61.3%) were considered guideline concordant, 99 (33.0%) were considered not guideline-concordant, and 17 (5.7%) were potentially guideline concordant but with insufficient information. Common reasons for guideline non-concordance are described in Table 3. Conclusion Antibiotic prescribing forsinusitis was frequently not concordant with guidelines. Prescribing was more frequently concordant in pediatric compared to adult-care settings. In both groups, duration of symptoms was frequently documented as fewer than 10 days, suggesting a potential target for antibiotic stewardship interventions. Disclosures All Authors: No reported disclosures

  PublisherDOI

• Evaluating the association of antibiotic spectrum and treatment responses of cystic fibrosis pulmonary exacerbations

  Journal of Cystic Fibrosis · 2025-12-17

  articleOpen access
  PublisherOA PDFDOI

Frequent coauthors

• Adam L. Hersh

  236 shared

• Jason G. Newland

  Washington University in St. Louis

  166 shared

• Theoklis E. Zaoutis

  National and Kapodistrian University of Athens

  163 shared

• Susan Coffin

  Children's Hospital of Philadelphia

  128 shared

• Karen M. Puopolo

  Children's Hospital of Philadelphia

  111 shared

• Matthew P. Kronman

  Seattle Children's Hospital

  110 shared

• Ruth Lynfield

  Minnesota Department of Health

  110 shared

• Rachael Ross

  Columbia University

  104 shared

Labs

• Gerber LabPI