Exebacase in Addition to Standard-of-Care Antibiotics for Staphylococcus aureus Bloodstream Infections and Right-Sided Infective Endocarditis: A Phase 3, Superiority-Design, Placebo-Controlled, Randomized Clinical Trial (DISRUPT).

BACKGROUND: Novel treatments are needed for Staphylococcus aureus bacteremia, particularly for methicillin-resistant S. aureus (MRSA). Exebacase is a first-in-class antistaphylococcal lysin that is rapidly bactericidal and synergizes with antibiotics. METHODS: In Direct Lysis of Staph Aureus Resistant Pathogen Trial of Exebacase (DISRUPT), a superiority-design phase 3 study, patients with S. aureus bacteremia/endocarditis were randomly assigned to receive a single dose of intravenous exebacase or placebo in addition to standard-of-care antibiotics. The primary efficacy outcome was clinical response at day 14 in the MRSA population. RESULTS: A total of 259 patients were randomized before the study was stopped for futility based on the recommendation of the unblinded Data Safety Monitoring Board. Clinical response rates at day 14 in the MRSA population (n = 97) were 50.0% (exebacase + antibiotics; 32/64) versus 60.6% (antibiotics alone; 20/33) (P = .392). Overall, rates of adverse events were similar across groups. No adverse events of hypersensitivity related to exebacase were reported. CONCLUSIONS: Exebacase + antibiotics failed to improve clinical response at day 14 in patients with MRSA bacteremia/endocarditis. This result was unexpected based on phase 2 data that established proof-of-concept for exebacase + antibiotics in patients with MRSA bacteremia/endocarditis. In the antibiotics-alone group, the clinical response rate was higher than that seen in phase 2. Heterogeneity within the study population and a relatively small sample size in either the phase 2 or phase 3 studies may have increased the probability of imbalances in the multiple components of day 14 clinical outcome. This study provides lessons for future superiority studies in S. aureus bacteremia/endocarditis. Clinical Trials Registration.NCT04160468.

Effectiveness of mRNA Covid-19 Vaccine among U.S. Health Care Personnel.

BACKGROUND: The prioritization of U.S. health care personnel for early receipt of messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), allowed for the evaluation of the effectiveness of these new vaccines in a real-world setting. METHODS: We conducted a test-negative case-control study involving health care personnel across 25 U.S. states. Cases were defined on the basis of a positive polymerase-chain-reaction (PCR) or antigen-based test for SARS-CoV-2 and at least one Covid-19-like symptom. Controls were defined on the basis of a negative PCR test for SARS-CoV-2, regardless of symptoms, and were matched to cases according to the week of the test date and site. Using conditional logistic regression with adjustment for age, race and ethnic group, underlying conditions, and exposures to persons with Covid-19, we estimated vaccine effectiveness for partial vaccination (assessed 14 days after receipt of the first dose through 6 days after receipt of the second dose) and complete vaccination (assessed ≥7 days after receipt of the second dose). RESULTS: The study included 1482 case participants and 3449 control participants. Vaccine effectiveness for partial vaccination was 77.6% (95% confidence interval [CI], 70.9 to 82.7) with the BNT162b2 vaccine (Pfizer-BioNTech) and 88.9% (95% CI, 78.7 to 94.2) with the mRNA-1273 vaccine (Moderna); for complete vaccination, vaccine effectiveness was 88.8% (95% CI, 84.6 to 91.8) and 96.3% (95% CI, 91.3 to 98.4), respectively. Vaccine effectiveness was similar in subgroups defined according to age (<50 years or ≥50 years), race and ethnic group, presence of underlying conditions, and level of patient contact. Estimates of vaccine effectiveness were lower during weeks 9 through 14 than during weeks 3 through 8 after receipt of the second dose, but confidence intervals overlapped widely. CONCLUSIONS: The BNT162b2 and mRNA-1273 vaccines were highly effective under real-world conditions in preventing symptomatic Covid-19 in health care personnel, including those at risk for severe Covid-19 and those in racial and ethnic groups that have been disproportionately affected by the pandemic. (Funded by the Centers for Disease Control and Prevention.).

Mpox Surveillance Based on Rash Characteristics - 13 Emergency Departments, United States, June-December 2023.

In 2022, a global mpox outbreak occurred, primarily affecting gay and bisexual men who have sex with men (GBMSM). To screen for mpox's reemergence and investigate potentially unsuspected cases among non-GBMSM, prospective surveillance of patients aged ≥3 months with an mpox-compatible rash (vesicular, pustular, ulcerated, or crusted) was conducted at 13 U.S. emergency departments (EDs) during June-December 2023. Demographic, historical, and illness characteristics were collected using questionnaires and electronic health records. Lesions were tested for monkeypox virus using polymerase chain reaction. Among 196 enrolled persons, the median age was 37.5 years (IQR = 21.0-53.5 years); 39 (19.9%) were aged <16 years, and 108 (55.1%) were male. Among all enrollees, 13 (6.6%) were GBMSM. Overall, approximately one half (46.4%) and one quarter (23.5%) of enrolled persons were non-Hispanic White and non-Hispanic Black or African American, respectively, and 38.8% reported Hispanic or Latino (Hispanic) ethnicity. Unstable housing was reported by 21 (10.7%) enrollees, and 24 (12.2%) lacked health insurance. The prevalence of mpox among ED patients evaluated for an mpox-compatible rash was 1.5% (95% CI = 0.3%-4.4%); all persons with a confirmed mpox diagnosis identified as GBMSM and reported being HIV-negative, not being vaccinated against mpox, and having engaged in sex with one or more partners met through smartphone dating applications. No cases were identified among women, children, or unhoused persons. Clinicians should remain vigilant for mpox and educate persons at risk for mpox about modifying behaviors that increase risk and the importance of receiving 2 appropriately spaced doses of JYNNEOS vaccine to prevent mpox.

A Randomized Trial Comparing Antibiotics with Appendectomy for Appendicitis.

BACKGROUND: Antibiotic therapy has been proposed as an alternative to surgery for the treatment of appendicitis. METHODS: We conducted a pragmatic, nonblinded, noninferiority, randomized trial comparing antibiotic therapy (10-day course) with appendectomy in patients with appendicitis at 25 U.S. centers. The primary outcome was 30-day health status, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire (scores range from 0 to 1, with higher scores indicating better health status; noninferiority margin, 0.05 points). Secondary outcomes included appendectomy in the antibiotics group and complications through 90 days; analyses were prespecified in subgroups defined according to the presence or absence of an appendicolith. RESULTS: In total, 1552 adults (414 with an appendicolith) underwent randomization; 776 were assigned to receive antibiotics (47% of whom were not hospitalized for the index treatment) and 776 to undergo appendectomy (96% of whom underwent a laparoscopic procedure). Antibiotics were noninferior to appendectomy on the basis of 30-day EQ-5D scores (mean difference, 0.01 points; 95% confidence interval [CI], -0.001 to 0.03). In the antibiotics group, 29% had undergone appendectomy by 90 days, including 41% of those with an appendicolith and 25% of those without an appendicolith. Complications were more common in the antibiotics group than in the appendectomy group (8.1 vs. 3.5 per 100 participants; rate ratio, 2.28; 95% CI, 1.30 to 3.98); the higher rate in the antibiotics group could be attributed to those with an appendicolith (20.2 vs. 3.6 per 100 participants; rate ratio, 5.69; 95% CI, 2.11 to 15.38) and not to those without an appendicolith (3.7 vs. 3.5 per 100 participants; rate ratio, 1.05; 95% CI, 0.45 to 2.43). The rate of serious adverse events was 4.0 per 100 participants in the antibiotics group and 3.0 per 100 participants in the appendectomy group (rate ratio, 1.29; 95% CI, 0.67 to 2.50). CONCLUSIONS: For the treatment of appendicitis, antibiotics were noninferior to appendectomy on the basis of results of a standard health-status measure. In the antibiotics group, nearly 3 in 10 participants had undergone appendectomy by 90 days. Participants with an appendicolith were at a higher risk for appendectomy and for complications than those without an appendicolith. (Funded by the Patient-Centered Outcomes Research Institute; CODA ClinicalTrials.gov number, NCT02800785.).

Interim Estimates of Vaccine Effectiveness of Pfizer-BioNTech and Moderna COVID-19 Vaccines Among Health Care Personnel - 33 U.S. Sites, January-March 2021.

Throughout the COVID-19 pandemic, health care personnel (HCP) have been at high risk for exposure to SARS-CoV-2, the virus that causes COVID-19, through patient interactions and community exposure (1). The Advisory Committee on Immunization Practices recommended prioritization of HCP for COVID-19 vaccination to maintain provision of critical services and reduce spread of infection in health care settings (2). Early distribution of two mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) to HCP allowed assessment of the effectiveness of these vaccines in a real-world setting. A test-negative case-control study is underway to evaluate mRNA COVID-19 vaccine effectiveness (VE) against symptomatic illness among HCP at 33 U.S. sites across 25 U.S. states. Interim analyses indicated that the VE of a single dose (measured 14 days after the first dose through 6 days after the second dose) was 82% (95% confidence interval [CI] = 74%-87%), adjusted for age, race/ethnicity, and underlying medical conditions. The adjusted VE of 2 doses (measured ≥7 days after the second dose) was 94% (95% CI = 87%-97%). VE of partial (1-dose) and complete (2-dose) vaccination in this population is comparable to that reported from clinical trials and recent observational studies, supporting the effectiveness of mRNA COVID-19 vaccines against symptomatic disease in adults, with strong 2-dose protection.

Emergence of Extended-Spectrum ß-Lactamase Urinary Tract Infections Among Hospitalized Emergency Department Patients in the United States.

STUDY OBJECTIVE: Enterobacteriaceae resistant to ceftriaxone, mediated through extended-spectrum ß-lactamases (ESBLs), commonly cause urinary tract infections worldwide, but have been less prevalent in North America. Current US rates are unknown. We determine Enterobacteriaceae antimicrobial resistance rates among US emergency department (ED) patients hospitalized for urinary tract infection. METHODS: We prospectively enrolled adults hospitalized for urinary tract infection from 11 geographically diverse university-affiliated hospital EDs during 2018 to 2019. Among participants with culture-confirmed infection, we evaluated prevalence of antimicrobial resistance, including that caused by ESBL-producing Enterobacteriaceae, resistance risk factors, and time to in vitro-active antibiotics. RESULTS: Of 527 total participants, 444 (84%) had cultures that grew Enterobacteriaceae; 89 of 435 participants (20.5%; 95% confidence interval 16.9% to 24.5%; 4.6% to 45.4% by site) whose isolates had confirmatory testing had bacteria that were ESBL producing. The overall prevalence of ESBL-producing Enterobacteriaceae infection among all participants with urinary tract infection was 17.2% (95% confidence interval 14.0% to 20.7%). ESBL-producing Enterobacteriaceae infection risk factors were hospital, long-term care, antibiotic exposure within 90 days, and a fluoroquinolone- or ceftriaxone-resistant isolate within 1 year. Enterobacteriaceae resistance rates for other antimicrobials were fluoroquinolone 32.3%, gentamicin 13.7%, amikacin 1.3%, and meropenem 0.3%. Ceftriaxone was the most common empirical antibiotic. In vitro-active antibiotics were not administered within 12 hours of presentation to 48 participants (53.9%) with ESBL-producing Enterobacteriaceae infection, including 17 (58.6%) with sepsis. Compared with other Enterobacteriaceae infections, ESBL infections were associated with longer time to in vitro-active treatment (17.3 versus 3.5 hours). CONCLUSION: Among adults hospitalized for urinary tract infection in many US locations, ESBL-producing Enterobacteriaceae have emerged as a common cause of infection that is often not initially treated with an in vitro-active antibiotic.

Lefamulin efficacy and safety in a pooled phase 3 clinical trial population with community-acquired bacterial pneumonia and common clinical comorbidities.

BACKGROUND: Lefamulin, a first-in-class pleuromutilin antibiotic approved for intravenous and oral use in adults with community-acquired bacterial pneumonia (CABP), was noninferior to moxifloxacin in the Lefamulin Evaluation Against Pneumonia (LEAP) 1 intravenous-to-oral switch study and the LEAP 2 oral-only study. Using pooled LEAP 1/2 data, we examined lefamulin efficacy/safety overall and within subgroups of patients presenting with comorbidities typical in CABP management. METHODS: In LEAP 1, adults with CABP were randomized to receive intravenous lefamulin (150 mg every 12 h) for 5‒7 days or moxifloxacin (400 mg every 24 h) for 7 days, with optional intravenous-to-oral switch if predefined improvement criteria were met. In LEAP 2, adults with CABP were randomized to receive oral lefamulin (600 mg every 12 h) for 5 days or moxifloxacin (400 mg every 24 h) for 7 days. Both studies assessed early clinical response (ECR) at 96 ± 24 h after first study drug dose and investigator assessment of clinical response (IACR) at test-of-cure (5‒10 days after last dose). Pooled analyses of the overall population used a 10% noninferiority margin. RESULTS: Lefamulin (n = 646) was noninferior to moxifloxacin (n = 643) for ECR (89.3% vs 90.5%, respectively; difference - 1.1%; 95% CI - 4.4 to 2.2); IACR success rates at test-of-cure were similarly high (≥ 85.0%). High efficacy with both lefamulin and moxifloxacin was also demonstrated across all well-represented patient subgroups, including those with advanced age, diabetes mellitus, a history of cardiovascular diseases (e.g., hypertension, congestive heart failure, or arrhythmia) or chronic lung diseases (e.g., asthma or chronic obstructive pulmonary disease), elevated liver enzymes, or mild-to-moderate renal dysfunction. No new safety signals were identified. CONCLUSIONS: Lefamulin may provide a valuable intravenous/oral monotherapy alternative to fluoroquinolones or macrolides for empiric treatment of patients with CABP, including cases of patients at risk for poor outcomes due to age or various comorbidities. TRIAL REGISTRATION: ClinicalTrials.gov LEAP 1 (NCT02559310; Registration Date: 24/09/2015) and LEAP 2 (NCT02813694; Registration Date: 27/06/2016).

Oral 5-Day Lefamulin for Outpatient Management of Community-Acquired Bacterial Pneumonia: Post-hoc Analysis of the Lefamulin Evaluation Against Pneumonia (LEAP) 2 Trial.

BACKGROUND: Safe and effective oral antibiotics are needed for outpatient management of moderate to severe community-acquired bacterial pneumonia (CABP). OBJECTIVE: We describe a post-hoc analysis of adults with CABP managed as outpatients from the Lefamulin Evaluation Against Pneumonia (LEAP) 2 double-blind, noninferiority, phase 3 clinical trial. METHODS: LEAP 2 compared the efficacy and safety of oral lefamulin 600 mg every 12 h (5 days) vs. oral moxifloxacin 400 mg every 24 h (7 days) in adults (inpatients and outpatients) with Pneumonia Outcomes Research Team (PORT) risk classes II‒IV. RESULTS: Overall, 41% (151 of 368) of patients receiving lefamulin and 43% (159 of 368) of patients receiving moxifloxacin started treatment as outpatients-44% and 40%, respectively, were PORT risk class III/IV, and 21% in both groups had CURB-65 scores of 2‒3. Early clinical response (at 96 ± 24 h) and investigator assessment of clinical response success rates at test of cure (5‒10 days after last study drug dose) were high and similar in both groups among all (lefamulin, 91% vs. moxifloxacin, 89‒90%), PORT risk class III/IV (89‒91% vs. 88‒91%), and CURB-65 score 2‒3 (87‒90% vs. 82‒88%) outpatients. Few outpatients (lefamulin, 2.6%; moxifloxacin, 2.5%) discontinued the study drug because of treatment-emergent adverse events (TEAEs). No outpatient in the lefamulin group was hospitalized for a TEAE, compared with 5 patients (3%), including two deaths, in the moxifloxacin group. CONCLUSIONS: These data suggest that 5 days of oral lefamulin can be given in lieu of fluoroquinolones for outpatient treatment of adults with CABP and PORT risk class III/IV or CURB-65 scores of 2‒3.

Derivation and Validation of a Clinical Decision Guideline for Influenza Testing in 4 US Emergency Departments.

BACKGROUND: An accurate diagnosis of influenza is essential for appropriate antiviral treatment, in accordance with Centers for Disease Control and Prevention (CDC) guidelines. However, no clear guidance exists on which patients should be tested. We sought to develop a clinical decision guideline (CDG) to inform influenza testing decisions for those adult emergency department (ED) patients deemed appropriate for antiviral treatment by CDC guidelines. METHODS: A prospective cohort study was performed at 4 US EDs. From November 2013 to April 2014, we enrolled adult ED patients with fever or respiratory symptoms who met criteria for antiviral treatment, per 2013 CDC guidelines. All patients were tested for influenza using polymerase chain reaction. Data were randomly split into derivation (80%) and validation (20%) data sets. A discrete set of independent variables was selected by logistic regression, using the derivation set to create a scoring system, with a target sensitivity of at least 90%. The derived CDG was then validated. RESULTS: Of 1941 enrolled participants, 183 (9.4%) had influenza. The derived CDG included new or increased cough (2 points), headache (1 point), subjective fever (1 point), and triage temperature >100.4°C (1 point), with a score of ≥3 indicating influenza testing was warranted. The CDG had a sensitivity and specificity of 94.1% and 36.6%, respectively, in the derivation set and of 91.5% and 34.6%, respectively, in the validation set. CONCLUSIONS: A CDG with high sensitivity was derived and validated. Incorporation into practice could standardize testing for high-risk patients in adult EDs during influenza seasons, potentially improving diagnoses and treatment. CLINICAL TRIAL REGISTRATION: NCT01947049.

Performance of PCR/Electrospray Ionization-Mass Spectrometry on Whole Blood for Detection of Bloodstream Microorganisms in Patients with Suspected Sepsis.

Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the United States (n = 13) and Europe (n = 3). First, on testing of 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true-positive and 97.2% true-negative results. Second, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC positive and PCR/ESI-MS negative, 4.3%; BC positive and PCR/ESI-MS positive, 10.3%; BC negative and PCR/ESI-MS positive, 15.3%; and BC negative and PCR/ESI-MS negative, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were >94% for all individual species. Patients who had received prior antimicrobial medications (n = 603) had significantly higher PCR/ESI-MS positivity rates than patients without prior antimicrobial treatment-31% versus 22% (P < 0.0001)-with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics to be used with whole blood for detection of bloodstream microorganisms in sepsis.

Trimethoprim-Sulfamethoxazole versus Placebo for Uncomplicated Skin Abscess.

BACKGROUND: U.S. emergency department visits for cutaneous abscess have increased with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). The role of antibiotics for patients with a drained abscess is unclear. METHODS: We conducted a randomized trial at five U.S. emergency departments to determine whether trimethoprim-sulfamethoxazole (at doses of 320 mg and 1600 mg, respectively, twice daily, for 7 days) would be superior to placebo in outpatients older than 12 years of age who had an uncomplicated abscess that was being treated with drainage. The primary outcome was clinical cure of the abscess, assessed 7 to 14 days after the end of the treatment period. RESULTS: The median age of the participants was 35 years (range, 14 to 73); 45.3% of the participants had wound cultures that were positive for MRSA. In the modified intention-to-treat population, clinical cure of the abscess occurred in 507 of 630 participants (80.5%) in the trimethoprim-sulfamethoxazole group versus 454 of 617 participants (73.6%) in the placebo group (difference, 6.9 percentage points; 95% confidence interval [CI], 2.1 to 11.7; P=0.005). In the per-protocol population, clinical cure occurred in 487 of 524 participants (92.9%) in the trimethoprim-sulfamethoxazole group versus 457 of 533 participants (85.7%) in the placebo group (difference, 7.2 percentage points; 95% CI, 3.2 to 11.2; P<0.001). Trimethoprim-sulfamethoxazole was superior to placebo with respect to most secondary outcomes in the per-protocol population, resulting in lower rates of subsequent surgical drainage procedures (3.4% vs. 8.6%; difference, -5.2 percentage points; 95% CI, -8.2 to -2.2), skin infections at new sites (3.1% vs. 10.3%; difference, -7.2 percentage points; 95% CI, -10.4 to -4.1), and infections in household members (1.7% vs. 4.1%; difference, -2.4 percentage points; 95% CI, -4.6 to -0.2) 7 to 14 days after the treatment period. Trimethoprim-sulfamethoxazole was associated with slightly more gastrointestinal side effects (mostly mild) than placebo. At 7 to 14 days after the treatment period, invasive infections had developed in 2 of 524 participants (0.4%) in the trimethoprim-sulfamethoxazole group and in 2 of 533 participants (0.4%) in the placebo group; at 42 to 56 days after the treatment period, an invasive infection had developed in 1 participant (0.2%) in the trimethoprim-sulfamethoxazole group. CONCLUSIONS: In settings in which MRSA was prevalent, trimethoprim-sulfamethoxazole treatment resulted in a higher cure rate among patients with a drained cutaneous abscess than placebo. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00729937.).

Identification of Clinical Characteristics Associated With High-Level Care Among Patients With Skin and Soft Tissue Infections.

STUDY OBJECTIVE: Serious adverse outcomes associated with skin and soft tissue infections are uncommon, and current hospitalization rates appear excessive. It would be advantageous to be able to differentiate between patients who require high-level inpatient services and those who receive little benefit from hospitalization. We sought to identify characteristics associated with the need for high-level inpatient care among emergency department patients presenting with skin and soft tissue infections. METHODS: We conducted a nonconcurrent review of existing records to identify emergency department (ED) patients treated for skin and soft tissue infections. For each case, we recorded the presence or absence of select criteria and whether the patient needed high-level care, defined as ICU admission, operating room surgical intervention, or death as the primary outcome. We applied recursive partitioning to identify the principal criteria associated with high-level care. RESULTS: We identified 2,923 patients, including 84 experiencing high-level events. Recursive partitioning identified 6 variables associated with high-level outcomes: abnormal computed tomography, magnetic resonance imaging, or ultrasonographic imaging result; systemic inflammatory response syndrome; history of diabetes; previous infection at the same location; older than 65 years; and an infection involving the hand. One or more of these variables were present in all 84 patients requiring high-level care. CONCLUSION: A limited number of simple clinical characteristics appear to be able to identify skin and soft tissue infection patients who require high-level inpatient services. Further research is needed to determine whether patients who do not exhibit these criteria can be safely discharged from the ED.

Effect of Initial Bedside Ultrasonography on Emergency Department Skin and Soft Tissue Infection Management.

STUDY OBJECTIVE: We examine the utility of emergency department (ED) ultrasonography in treatment of skin and soft tissue infections. METHODS: We enrolled ED patients with skin and soft tissue infections and surveyed clinicians in regard to their pre-ultrasonography certainty about the presence or absence of an abscess, their planned management, post-ultrasonography findings, and actual management. We determined sensitivity and specificity of ultrasonography and clinical evaluation, and assessed appropriateness of management changes based on initial clinical assessment and outcomes through 1-week follow-up. RESULTS: Among 1,216 patients, clinicians were uncertain of abscess presence in 105 cases (8.6%) and certain for 1,111 cases (91.4%). Based on surgical exploration and follow-up through 1 week, sensitivity and specificity for abscess detection by clinical evaluation were 90.3% and 97.7%, and by ultrasonography were 94.0% and 94.1%, respectively. Among 1,111 cases for which the clinician was certain, sensitivity and specificity of clinical evaluation were 96.6% and 97.3% compared with ultrasonographic evaluation sensitivity and specificity of 95.7% and 96.2%, respectively. Of 105 uncertain cases, sensitivity and specificity of ultrasonography were 68.5% and 80.4%. Ultrasonography changed management in 13 of 1,111 certain cases (1.2%), appropriately in 10 of 13 (76.9%) and inappropriately in 3 of 13 (23.1%). Of 105 uncertain cases, ultrasonography changed management in 25 (23.8%), appropriately in 21 of 25 (84.0%) and inappropriately in 4 of 25 (16.0%). CONCLUSION: Ultrasonography rarely changed management when clinicians were certain about the presence or absence of an abscess. When they were uncertain, ultrasonography changed drainage decisions in approximately one quarter of cases, of which most (84%) were appropriate.

Oral Lefamulin vs Moxifloxacin for Early Clinical Response Among Adults With Community-Acquired Bacterial Pneumonia: The LEAP 2 Randomized Clinical Trial.

IMPORTANCE: New antibacterials are needed to treat community-acquired bacterial pneumonia (CABP) because of growing antibacterial resistance and safety concerns with standard care. OBJECTIVE: To evaluate the efficacy and adverse events of a 5-day oral lefamulin regimen in patients with CABP. DESIGN, SETTING, AND PARTICIPANTS: A phase 3, noninferiority randomized clinical trial conducted at 99 sites in 19 countries that included adults aged 18 years or older with a Pneumonia Outcomes Research Team (PORT) risk class of II, III, or IV; radiographically documented pneumonia; acute illness; 3 or more CABP symptoms; and 2 or more vital sign abnormalities. The first patient visit was on August 30, 2016, and patients were followed up for 30 days; the final follow-up visit was on January 2, 2018. INTERVENTIONS: Patients were randomized 1:1 to receive oral lefamulin (600 mg every 12 hours for 5 days; n = 370) or moxifloxacin (400 mg every 24 hours for 7 days; n = 368). MAIN OUTCOMES AND MEASURES: The US Food and Drug Administration (FDA) primary end point was early clinical response at 96 hours (within a 24-hour window) after the first dose of either study drug in the intent-to-treat (ITT) population (all randomized patients). Responders were defined as alive, showing improvement in 2 or more of the 4 CABP symptoms, having no worsening of any CABP symptoms, and not receiving any nonstudy antibacterial drug for current CABP episode. The European Medicines Agency coprimary end points (FDA secondary end points) were investigator assessment of clinical response at test of cure (5-10 days after last dose) in the modified ITT population and in the clinically evaluable population. The noninferiority margin was 10% for early clinical response and investigator assessment of clinical response. RESULTS: Among 738 randomized patients (mean age, 57.5 years; 351 women [47.6%]; 360 had a PORT risk class of III or IV [48.8%]), 707 (95.8%) completed the trial. Early clinical response rates were 90.8% with lefamulin and 90.8% with moxifloxacin (difference, 0.1% [1-sided 97.5% CI, -4.4% to ∞]). Rates of investigator assessment of clinical response success were 87.5% with lefamulin and 89.1% with moxifloxacin in the modified ITT population (difference, -1.6% [1-sided 97.5% CI, -6.3% to ∞]) and 89.7% and 93.6%, respectively, in the clinically evaluable population (difference, -3.9% [1-sided 97.5% CI, -8.2% to ∞]) at test of cure. The most frequently reported treatment-emergent adverse events were gastrointestinal (diarrhea: 45/368 [12.2%] in lefamulin group and 4/368 [1.1%] in moxifloxacin group; nausea: 19/368 [5.2%] in lefamulin group and 7/368 [1.9%] in moxifloxacin group). CONCLUSIONS AND RELEVANCE: Among patients with CABP, 5-day oral lefamulin was noninferior to 7-day oral moxifloxacin with respect to early clinical response at 96 hours after first dose. TRIAL REGISTRATIONS: ClinicalTrials.gov Identifier: NCT02813694; European Clinical Trials Identifier: 2015-004782-92.

Subgroup Analysis of Antibiotic Treatment for Skin Abscesses.

STUDY OBJECTIVE: Two large randomized trials recently demonstrated efficacy of methicillin-resistant Staphylococcus aureus (MRSA)-active antibiotics for drained skin abscesses. We determine whether outcome advantages observed in one trial exist across lesion sizes and among subgroups with and without guideline-recommended antibiotic indications. METHODS: We conducted a planned subgroup analysis of a double-blind, randomized trial at 5 US emergency departments, demonstrating superiority of trimethoprim-sulfamethoxazole (320/1,600 mg twice daily for 7 days) compared with placebo for patients older than 12 years with a drained skin abscess. We determined between-group differences in rates of clinical (no new antibiotics) and composite cure (no new antibiotics or drainage) through 7 to 14 and 42 to 56 days after treatment among subgroups with and without abscess cavity or erythema diameter greater than or equal to 5 cm, history of MRSA, fever, diabetes, and comorbidities. We also evaluated treatment effect by lesion size and culture result. RESULTS: Among 1,057 mostly adult participants, median abscess cavity and erythema diameters were 2.5 cm (range 0.1 to 16.0 cm) and 6.5 cm (range 1.0 to 38.5), respectively; 44.3% grew MRSA. Overall, for trimethoprim-sulfamethoxazole and placebo groups, clinical cure rate at 7 to 14 days was 92.9% and 85.7%; composite cure rate at 7 to 14 days was 86.5% and 74.3%, and at 42 to 56 days, it was 82.4% and 70.2%. For all outcomes, across lesion sizes and among subgroups with and without guideline antibiotic criteria, trimethoprim-sulfamethoxazole was associated with improved outcomes. Treatment effect was greatest with history of MRSA infection, fever, and positive MRSA culture. CONCLUSION: Treatment with trimethoprim-sulfamethoxazole was associated with improved outcomes regardless of lesion size or guideline antibiotic criteria.

Clostridium difficile Infection Among US Emergency Department Patients With Diarrhea and No Vomiting.

STUDY OBJECTIVE: The incidence of Clostridium difficile infection has increased and has been observed among persons from the community who have not been exposed to antibiotics or health care settings. Our aims are to determine prevalence of C difficile infection among emergency department (ED) patients with diarrhea and the prevalence among patients without traditional risk factors. METHODS: We conducted a prospective observational study of patients aged 2 years or older with diarrhea (≥3 episodes/24 hours) and no vomiting in 10 US EDs (2010 to 2013). We confirmed C difficile infection by positive stool culture result and toxin assay. C difficile infection risk factors were antibiotic use or overnight health care stay in the previous 3 months or previous C difficile infection. We typed strains with pulsed-field gel electrophoresis. RESULTS: Of 422 participants, median age was 46 years (range 2 to 94 years), with median illness duration of 3.0 days and 43.4% having greater than or equal to 10 episodes of diarrhea during the previous 24 hours. At least one risk factor for C difficile infection was present in 40.8% of participants; 25.9% were receiving antibiotics, 26.9% had health care stay within the previous 3 months, and 3.3% had previous C difficile infection. Forty-three participants (10.2%) had C difficile infection; among these, 24 (55.8%) received antibiotics and 19 (44.2%) had health care exposure; 17 of 43 (39.5%) lacked any risk factor. Among participants without risk factors, C difficile infection prevalence was 6.9%. The most commonly identified North American pulsed-field gel electrophoresis (NAP) strains were NAP type 1 (23.3%) and NAP type 4 (16.3%). CONCLUSION: Among mostly adults presenting to US EDs with diarrhea and no vomiting, C difficile infection accounted for approximately 10%. More than one third of patients with C difficile infection lacked traditional risk factors for the disease. Among participants without traditional risk factors, prevalence of C difficile infection was approximately 7%.

Antibiotics-First Versus Surgery for Appendicitis: A US Pilot Randomized Controlled Trial Allowing Outpatient Antibiotic Management.

STUDY OBJECTIVE: Randomized trials suggest that nonoperative treatment of uncomplicated appendicitis with antibiotics-first is safe. No trial has evaluated outpatient treatment and no US randomized trial has been conducted, to our knowledge. This pilot study assessed feasibility of a multicenter US study comparing antibiotics-first, including outpatient management, with appendectomy. METHODS: Patients aged 5 years or older with uncomplicated appendicitis at 1 US hospital were randomized to appendectomy or intravenous ertapenem greater than or equal to 48 hours and oral cefdinir and metronidazole. Stable antibiotics-first-treated participants older than 13 years could be discharged after greater than or equal to 6-hour emergency department (ED) observation with next-day follow-up. Outcomes included 1-month major complication rate (primary) and hospital duration, pain, disability, quality of life, and hospital charges, and antibiotics-first appendectomy rate. RESULTS: Of 48 eligible patients, 30 (62.5%) consented, of whom 16 (53.3%) were randomized to antibiotics-first and 14 (46.7%) to appendectomy. Median age was 33 years (range 9 to 73 years), median WBC count was 15,000/µL (range 6,200 to 23,100/µL), and median computed tomography appendiceal diameter was 10 mm (range 7 to 18 mm). Of 15 antibiotic-treated adults, 14 (93.3%) were discharged from the ED and all had symptom resolution. At 1 month, major complications occurred in 2 appendectomy participants (14.3%; 95% confidence interval [CI] 1.8% to 42.8%) and 1 antibiotics-first participant (6.3%; 95% CI 0.2% to 30.2%). Antibiotics-first participants had less total hospital time than appendectomy participants, 16.2 versus 42.1 hours, respectively. Antibiotics-first-treated participants had less pain and disability. During median 12-month follow-up, 2 of 15 antibiotics-first-treated participants (13.3%; 95% CI 3.7% to 37.9%) developed appendicitis and 1 was treated successfully with antibiotics; 1 had appendectomy. No more major complications occurred in either group. CONCLUSION: A multicenter US trial comparing antibiotics-first to appendectomy, including outpatient management, is feasible to evaluate efficacy and safety.

Effect of Cephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Alone on Clinical Cure of Uncomplicated Cellulitis: A Randomized Clinical Trial.

IMPORTANCE: Emergency department visits for skin infections in the United States have increased with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). For cellulitis without purulent drainage, ß-hemolytic streptococci are presumed to be the predominant pathogens. It is unknown if antimicrobial regimens possessing in vitro MRSA activity provide improved outcomes compared with treatments lacking MRSA activity. OBJECTIVE: To determine whether cephalexin plus trimethoprim-sulfamethoxazole yields a higher clinical cure rate of uncomplicated cellulitis than cephalexin alone. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, double-blind, randomized superiority trial in 5 US emergency departments among outpatients older than 12 years with cellulitis and no wound, purulent drainage, or abscess enrolled from April 2009 through June 2012. All participants had soft tissue ultrasound performed at the time of enrollment to exclude abscess. Final follow-up was August 2012. INTERVENTIONS: Cephalexin, 500 mg 4 times daily, plus trimethoprim-sulfamethoxazole, 320 mg/1600 mg twice daily, for 7 days (n = 248 participants) or cephalexin plus placebo for 7 days (n = 248 participants). MAIN OUTCOMES AND MEASURES: The primary outcome determined a priori in the per-protocol group was clinical cure, defined as absence of these clinical failure criteria at follow-up visits: fever; increase in erythema (>25%), swelling, or tenderness (days 3-4); no decrease in erythema, swelling, or tenderness (days 8-10); and more than minimal erythema, swelling, or tenderness (days 14-21). A clinically significant difference was defined as greater than 10%. RESULTS: Among 500 randomized participants, 496 (99%) were included in the modified intention-to-treat analysis and 411 (82.2%) in the per-protocol analysis (median age, 40 years [range, 15-78 years]; 58.4% male; 10.9% had diabetes). Median length and width of erythema were 13.0 cm and 10.0 cm. In the per-protocol population, clinical cure occurred in 182 (83.5%) of 218 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 165 (85.5%) of 193 in the cephalexin group (difference, -2.0%; 95% CI, -9.7% to 5.7%; P = .50). In the modified intention-to-treat population, clinical cure occurred in 189 (76.2%) of 248 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 171 (69.0%) of 248 in the cephalexin group (difference, 7.3%; 95% CI, -1.0% to 15.5%; P = .07). Between-group adverse event rates and secondary outcomes through 7 to 9 weeks, including overnight hospitalization, recurrent skin infections, and similar infection in household contacts, did not differ significantly. CONCLUSIONS AND RELEVANCE: Among patients with uncomplicated cellulitis, the use of cephalexin plus trimethoprim-sulfamethoxazole compared to cephalexin alone did not result in higher rates of clinical resolution of cellulitis in the per-protocol analysis. However, because imprecision around the findings in the modified intention-to-treat analysis included a clinically important difference favoring cephalexin plus trimethoprim-sulfamethoxazole, further research may be needed. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00729937.

A Randomized Trial of Clindamycin Versus Trimethoprim-sulfamethoxazole for Uncomplicated Wound Infection.

BACKGROUND: With the emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) in the United States, visits for skin infections greatly increased. Staphylococci and streptococci are considered predominant causes of wound infections. Clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX) are commonly prescribed, but the efficacy of TMP-SMX has been questioned. METHODS: We conducted a randomized, double-blind, superiority trial at 5 US emergency departments. Patients >12 years of age with an uncomplicated wound infection received oral clindamycin 300 mg 4 times daily or TMP-SMX 320 mg/1600 mg twice daily, each for 7 days. We compared the primary outcome, wound infection cure at 7-14 days, and secondary outcomes through 6-8 weeks after treatment, in the per-protocol population. RESULTS: Subjects had a median age of 40 years (range, 14-76 years); 40.1% of wound specimens grew MRSA, 25.7% methicillin-susceptible S. aureus, and 5.0% streptococci. The wound infection was cured at 7-14 days in 187 of 203 (92.1%) clindamycin-treated and 182 of 198 (91.9%) TMP-SMX-treated subjects (difference, 0.2%; 95% confidence interval [CI], -5.8% to 6.2%; P = not significant). The clindamycin group had a significantly lower rate of recurrence at 7-14 days (1.5% vs 6.6%; difference, -5.1%; 95% CI, -9.4% to -.8%) and through 6-8 weeks following treatment (2.0% vs 7.1%; difference, -5.1%; 95% CI, -9.7% to -.6%). Other secondary outcomes were statistically similar between groups but tended to favor clindamycin. Adverse event rates were similar. CONCLUSIONS: In settings where MRSA is prevalent, clindamycin and TMP-SMX produce similar cure and adverse event rates among patients with an uncomplicated wound infection. Further study evaluating differential effects of antibiotics on recurrent infection may be warranted. CLINICAL TRIALS REGISTRATION: NCT00729937.