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Background: In 2022-2023, 15- and 20-valent pneumococcal conjugate vaccines (PCV15/PCV20) were recommended for infants. We aimed to estimate the incidence of outpatient visits and antibiotic prescriptions in U.S. children (≤17 years) from 2016-2019 for acute otitis media, pneumonia, and sinusitis associated with PCV15- and PCV20-additional (non-PCV13) serotypes to quantify PCV15/20 potential impacts., Methods: We estimated the incidence of PCV15/20-additional serotype-attributable visits and antibiotic prescriptions as the product of all-cause incidence rates, derived from national healthcare surveys and MarketScan databases, and PCV15/20-additional serotype-attributable fractions. We estimated serotype-specific attributable fractions using modified vaccine-probe approaches incorporating incidence changes post-PCV13 and ratios of PCV13 versus PCV15/20 serotype frequencies, estimated through meta-analyses., Results: Per 1000 children annually, PCV15-additional serotypes accounted for an estimated 2.7 (95% confidence interval 1.8-3.9) visits and 2.4 (1.6-3.4) antibiotic prescriptions. PCV20-additional serotypes resulted in 15.0 (11.2-20.4) visits and 13.2 (9.9-18.0) antibiotic prescriptions annually per 1,000 children. PCV15/20-additional serotypes account for 0.4% (0.2-0.6%) and 2.1% (1.5-3.0%) of pediatric outpatient antibiotic use., Conclusions: Compared with PCV15-additional serotypes, PCV20-additional serotypes account for >5 times the burden of visits and antibiotic prescriptions. Higher-valency PCVs, especially PCV20, may contribute to preventing pediatric pneumococcal respiratory infections and antibiotic use., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2024.)

Antimicrobial use data reported to the National Healthcare Safety Network's Antimicrobial Use and Resistance Module between January 2019 and July 2022 were analyzed to assess the impact of the COVID-19 pandemic on inpatient antimicrobial use., Competing Interests: Potential conflicts of interest . L. A. H. reports an unpaid role as Vice Chair of Clinical Guidelines Committee, American College of Physicians. All remaining authors declare no conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2023.)

Background: The coronavirus disease 2019 (COVID-19) pandemic may have impacted outpatient antibiotic prescribing in low- and middle-income countries such as Brazil. However, outpatient antibiotic prescribing in Brazil, particularly at the prescription level, is not well-described., Methods: We used the IQVIA MIDAS database to characterize changes in prescribing rates of antibiotics commonly prescribed for respiratory infections (azithromycin, amoxicillin-clavulanate, levofloxacin/moxifloxacin, cephalexin, and ceftriaxone) among adults in Brazil overall and stratified by age and sex, comparing prepandemic (January 2019-March 2020) and pandemic periods (April 2020-December 2021) using uni- and multivariate Poisson regression models. The most common prescribing provider specialties for these antibiotics were also identified., Results: In the pandemic period compared to the prepandemic period, outpatient azithromycin prescribing rates increased across all age-sex groups (incidence rate ratio [IRR] range, 1.474-3.619), with the greatest increase observed in males aged 65-74 years; meanwhile, prescribing rates for amoxicillin-clavulanate and respiratory fluoroquinolones mostly decreased, and changes in cephalosporin prescribing rates varied across age-sex groups (IRR range, 0.134-1.910). For all antibiotics, the interaction of age and sex with the pandemic in multivariable models was an independent predictor of prescribing changes comparing the pandemic versus prepandemic periods. General practitioners and gynecologists accounted for the majority of increases in azithromycin and ceftriaxone prescribing during the pandemic period., Conclusions: Substantial increases in outpatient prescribing rates for azithromycin and ceftriaxone were observed in Brazil during the pandemic with prescribing rates being disproportionally different by age and sex. General practitioners and gynecologists were the most common prescribers of azithromycin and ceftriaxone during the pandemic, identifying them as potential specialties for antimicrobial stewardship interventions., Competing Interests: Potential conflicts of interest. L. A. H. is an unpaid volunteer member on the Society for Healthcare Epidemiology of America Board of Trustees and the American College of Physicians Clinical Guidelines Committee. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2023.)

Background: Trends in prescribing for nursing home (NH) residents, which may have been influenced by the coronavirus disease 2019 (COVID-19) pandemic, have not been characterized., Methods: Long-term care pharmacy data from 1944 US NHs were used to evaluate trends in prescribing of antibiotics and drugs that were investigated for COVID-19 treatment, including hydroxychloroquine, famotidine, and dexamethasone. To account for seasonal variability in antibiotic prescribing and decreased NH occupancy during the pandemic, monthly prevalence of residents with a prescription dispensed per 1000 residents serviced was calculated from January to October and compared as relative percent change from 2019 to 2020., Results: In April 2020, prescribing was significantly higher in NHs for drugs investigated for COVID-19 treatment than 2019; including hydroxychloroquine (+563%, 95% confidence interval [CI]: 5.87, 7.48) and azithromycin (+150%, 95% CI: 2.37, 2.63). Ceftriaxone prescribing also increased (+43%, 95% CI: 1.34, 1.54). Prescribing of dexamethasone was 36% lower in April (95% CI: .55, .73) and 303% higher in July (95% CI: 3.66, 4.45). Although azithromycin and ceftriaxone prescribing increased, total antibiotic prescribing among residents was lower from May (-5%, 95% CI: .94, .97) through October (-4%, 95% CI: .94, .97) in 2020 compared to 2019., Conclusions: During the pandemic, large numbers of residents were prescribed drugs investigated for COVID-19 treatment, and an increase in prescribing of antibiotics commonly used for respiratory infections was observed. Prescribing of these drugs may increase the risk of adverse events, without providing clear benefits. Surveillance of NH prescribing practices is critical to evaluate concordance with guideline-recommended therapy and improve resident safety., (Published by Oxford University Press for the Infectious Diseases Society of America 2021.)

Background: Antimicrobial stewardship programs (ASPs) promote the principle of de-escalation: moving from broad- to narrow-spectrum agents and stopping antibiotics when no longer indicated. A standard, objective definition of de-escalation applied to electronic data could be useful for ASP assessments., Methods: We derived an electronic definition of antibiotic de-escalation and performed a retrospective study among 5 hospitals. Antibiotics were ranked into 4 categories: narrow-spectrum, broad-spectrum, extended-spectrum, and agents targeted for protection. Eligible adult patients were cared for on inpatient units, had antibiotic therapy for at least 2 days, and were hospitalized for at least 3 days after starting antibiotics. Number of antibiotics and rank were assessed at 2 time points: day of antibiotic initiation and either day of discharge or day 5. De-escalation was defined as reduction in either the number of antibiotics or rank. Escalation was an increase in either number or rank. Unchanged was either no change or discordant directions of change. We summarized outcomes among hospitals, units, and diagnoses., Results: Among 39 226 eligible admissions, de-escalation occurred in 14 138 (36%), escalation in 5129 (13%), and antibiotics were unchanged in 19 959 (51%). De-escalation varied among hospitals (median, 37%; range, 31-39%, P < .001). Diagnoses with lower de-escalation rates included intra-abdominal (23%) and skin and soft tissue (28%) infections. Critical care had higher rates of both de-escalation and escalation compared with wards., Conclusions: Our electronic de-escalation metric demonstrated variation among hospitals, units, and diagnoses. This metric may be useful for assessing stewardship opportunities and impact., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: The Core Elements of Outpatient Antibiotic Stewardship provide a framework to improve antibiotic use. We report the impact of core elements implementation within Veterans Health Administration sites., Methods: In this quasiexperimental controlled study, effects of an intervention targeting antibiotic prescription for uncomplicated acute respiratory tract infections (ARIs) were assessed. Outcomes included per-visit antibiotic prescribing, treatment appropriateness, ARI revisits, hospitalization, and ARI diagnostic changes over a 3-year pre-implementation period and 1-year post-implementation period. Logistic regression adjusted for covariates (odds ratio [OR], 95% confidence interval [CI]) and a difference-in-differences analysis compared outcomes between intervention and control sites., Results: From 2014-2019, there were 16 712 and 51 275 patient visits within 10 intervention and 40 control sites, respectively. Antibiotic prescribing rates pre- and post-implementation within intervention sites were 59.7% and 41.5%, compared to 73.5% and 67.2% within control sites, respectively (difference-in-differences, P < .001). Intervention site pre- and post-implementation OR to receive appropriate therapy increased (OR, 1.67; 95% CI, 1.31-2.14), which remained unchanged within control sites (OR,1.04; 95% CI, .91-1.19). ARI-related return visits post-implementation (-1.3% vs -2.0%; difference-in-differences P = .76) were not different, but all-cause hospitalization was lower within intervention sites (-0.5% vs -0.2%; difference-in-differences P = .02). The OR to diagnose non-specific ARI compared with non-ARI diagnoses increased post-implementation forintervention (OR, 1.27; 95% CI, 1.21 -1.34) but not control (OR, 0.97; 95% CI, .94-1.01) sites., Conclusions: Implementation of the core elements was associated with reduced antibiotic prescribing for RIs and a reduction in hospitalizations. Diagnostic coding changes were observed., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

Background: The objective of our study was to describe trends in US outpatient antibiotic prescriptions from January through May 2020 and compare with trends in previous years (2017-2019)., Methods: We used data from the IQVIA Total Patient Tracker to estimate the monthly number of patients dispensed antibiotic prescriptions from retail pharmacies from January 2017 through May 2020. We averaged estimates from 2017 through 2019 and defined expected seasonal change as the average percent change from January to May 2017-2019. We calculated percentage point and volume changes in the number of patients dispensed antibiotics from January to May 2020 exceeding expected seasonal changes. We also calculated average percent change in number of patients dispensed antibiotics per month in 2017-2019 versus 2020. Data were analyzed overall and by agent, class, patient age, state, and prescriber specialty., Results: From January to May 2020, the number of patients dispensed antibiotic prescriptions decreased from 20.3 to 9.9 million, exceeding seasonally expected decreases by 33 percentage points and 6.6 million patients. The largest changes in 2017-2019 versus 2020 were observed in April (-39%) and May (-42%). The number of patients dispensed azithromycin increased from February to March 2020 then decreased. Overall, beyond-expected decreases were greatest among children (≤19 years) and agents used for respiratory infections, dentistry, and surgical prophylaxis., Conclusions: From January 2020 to May 2020, the number of outpatients with antibiotic prescriptions decreased substantially more than would be expected because of seasonal trends alone, possibly related to the coronavirus disease 2019 pandemic and associated mitigation measures., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

Our objective was to describe the duration of antibiotic therapy for the management of common outpatient conditions. The median duration of antibiotic courses for most common conditions, except for acute cystitis, was 10 days, in many cases exceeding guideline-recommended durations., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

The proportion of antibiotic prescriptions prescribed in US physician offices and emergency departments that were unnecessary decreased slightly, from 30% in 2010-2011 to 28% in 2014-2015. However, a greater decrease occurred in children: 32% in 2010-2011 to 19% in 2014-2015. Unnecessary prescribing in adults did not change during this period., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Improving appropriate antibiotic use is crucial for combating antibiotic resistance and unnecessary adverse drug reactions. Acute respiratory illness (ARI) commonly causes outpatient visits and accounts for ~41% of antibiotics used in the United States. We examined the influence of influenza vaccination on reducing antibiotic prescriptions among outpatients with ARI., Methods: We enrolled outpatients aged ≥6 months with ARI from 50-60 US clinics during 5 winters (2013-2018) and tested for influenza with RT-PCR; results were unavailable for clinical decision making and clinical influenza testing was infrequent. We collected antibiotic prescriptions and diagnosis codes for ARI syndromes. We calculated vaccine effectiveness (VE) by comparing vaccination odds among influenza-positive cases with test-negative controls. We estimated ARI visits and antibiotic prescriptions averted by influenza vaccination using estimates of VE, coverage, and prevalence of antibiotic prescriptions and influenza., Results: Among 37 487 ARI outpatients, 9659 (26%) were influenza positive. Overall, 36% of ARI and 26% of influenza-positive patients were prescribed antibiotics. The top 3 prevalent ARI syndromes included: viral upper respiratory tract infection (47%), pharyngitis (18%), and allergy or asthma (11%). Among patients testing positive for influenza, 77% did not receive an ICD-CM diagnostic code for influenza. Overall, VE against influenza-associated ARI was 35% (95% CI, 32-39%). Vaccination prevented 5.6% of all ARI syndromes, ranging from 2.8% (sinusitis) to 11% (clinical influenza). Influenza vaccination averted 1 in 25 (3.8%; 95% CI, 3.6-4.1%) antibiotic prescriptions among ARI outpatients during influenza seasons., Conclusions: Vaccination and accurate influenza diagnosis may curb unnecessary antibiotic use and reduce the global threat of antibiotic resistance., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: The Standardized Antimicrobial Administration Ratio (SAAR) is a risk-adjusted metric of antimicrobial use (AU) developed by the Centers for Disease Control and Prevention (CDC) in 2015 as a tool for hospital antimicrobial stewardship programs (ASPs) to track and compare AU with a national benchmark. In 2018, CDC updated the SAAR by expanding the locations and antimicrobial categories for which SAARs can be calculated and by modeling adult and pediatric locations separately., Methods: We identified eligible patient-care locations and defined SAAR antimicrobial categories. Predictive models were developed for eligible adult and pediatric patient-care locations using negative binomial regression applied to nationally aggregated AU data from locations reporting ≥9 months of 2017 data to the National Healthcare Safety Network (NHSN)., Results: 2017 Baseline SAAR models were developed for 7 adult and 8 pediatric SAAR antimicrobial categories using data reported from 2156 adult and 170 pediatric locations across 457 hospitals. The inclusion of step-down units and general hematology-oncology units in adult 2017 baseline SAAR models and the addition of SAARs for narrow-spectrum B-lactam agents, antifungals predominantly used for invasive candidiasis, antibacterial agents posing the highest risk for Clostridioides difficile infection, and azithromycin (pediatrics only) expand the role SAARs can play in ASP efforts. Final risk-adjusted models are used to calculate predicted antimicrobial days, the denominator of the SAAR, for 40 SAAR types displayed in NHSN., Conclusions: SAARs can be used as a metric to prompt investigation into potential overuse or underuse of antimicrobials and to evaluate the effectiveness of ASP interventions., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

Improving antibiotic prescribing in outpatient settings is a public health priority. In the United States, urgent care (UC) encounters are increasing and have high rates of inappropriate antibiotic prescribing. Our objective was to characterize antibiotic prescribing practices during UC encounters, with a focus on respiratory tract conditions. This was a retrospective cohort study of UC encounters in the Intermountain Healthcare network. Among 1.16 million UC encounters, antibiotics were prescribed during 34% of UC encounters and respiratory conditions accounted for 61% of all antibiotics prescribed. Of respiratory encounters, 50% resulted in antibiotic prescriptions, yet the variability at the level of the provider ranged from 3% to 94%. Similar variability between providers was observed for respiratory conditions where antibiotics were not indicated and in first-line antibiotic selection for sinusitis, otitis media, and pharyngitis. These findings support the importance of developing antibiotic stewardship interventions specifically targeting UC settings., (Published by Oxford University Press for the Infectious Diseases Society of America 2019. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: While antibiotics are life-saving drugs, their use is not without risk, including adverse events and antibiotic resistance. The majority of US antibiotic prescriptions are prescribed in outpatient settings, making outpatient antibiotic prescribing an important antibiotic stewardship target. The primary objective of this study was to describe trends in US outpatient oral antibiotic prescriptions from 2011-2016., Methods: We estimated annual oral antibiotic prescription rates using national prescription dispensing count data from IQVIA Xponent, divided by census estimates for 2011-2016. We calculated the ratio of broad- to narrow-spectrum prescriptions by dividing broad-spectrum prescription rates by narrow-spectrum prescription rates. We used Poisson models to estimate prevalence rate ratios, comparing 2011 and 2016 antibiotic prescription rates, and linear models to evaluate temporal trends throughout the study period., Results: Oral antibiotic prescription rates decreased 5%, from 877 prescriptions per 1000 persons in 2011 to 836 per 1000 persons in 2016. During this period, rates of prescriptions dispensed to children decreased 13%, while adult rates increased 2%. The ratio of broad- to narrow-spectrum antibiotics decreased from 1.62 in 2011 to 1.49 in 2016, driven by decreases in macrolides and fluoroquinolones. The proportion of prescriptions written by nurse practitioners and physician assistants increased during the study period; in 2016, these providers prescribed over one-quarter of all antibiotic prescriptions., Conclusions: Outpatient antibiotic prescription rates, especially of broad-spectrum agents, have decreased in recent years. Clinicians who prescribe to adults, including nurse practitioners and physician assistants, are important targets for antibiotic stewardship., (Published by Oxford University Press for the Infectious Diseases Society of America 2019.)

In 2016, 42% of nursing homes enrolled in the National Healthcare Safety Network reported meeting all 7 of the Centers for Disease Control and Prevention's Core Elements of Antibiotic Stewardship. Bivariate analyses suggested that implementation of all core elements differed by ownership type and amount of infection prevention staff hours., (Published by Oxford University Press for the Infectious Diseases Society of America 2019.)

Background: The epidemiology of Mycoplasma pneumoniae (Mp) among US children (<18 years) hospitalized with community-acquired pneumonia (CAP) is poorly understood., Methods: In the Etiology of Pneumonia in the Community study, we prospectively enrolled 2254 children hospitalized with radiographically confirmed pneumonia from January 2010-June 2012 and tested nasopharyngeal/oropharyngeal swabs for Mp using real-time polymerase chain reaction (PCR). Clinical and epidemiological features of Mp PCR-positive and -negative children were compared using logistic regression. Macrolide susceptibility was assessed by genotyping isolates., Results: One hundred and eighty two (8%) children were Mp PCR-positive (median age, 7 years); 12% required intensive care and 26% had pleural effusion. No in-hospital deaths occurred. Macrolide resistance was found in 4% (6/169) isolates. Of 178 (98%) Mp PCR-positive children tested for copathogens, 50 (28%) had ≥1 copathogen detected. Variables significantly associated with higher odds of Mp detection included age (10-17 years: adjusted odds ratio [aOR], 10.7 [95% confidence interval {CI}, 5.4-21.1] and 5-9 years: aOR, 6.4 [95% CI, 3.4-12.1] vs 2-4 years), outpatient antibiotics ≤5 days preadmission (aOR, 2.3 [95% CI, 1.5-3.5]), and copathogen detection (aOR, 2.1 [95% CI, 1.3-3.3]). Clinical characteristics were non-specific., Conclusions: Usually considered as a mild respiratory infection, Mp was the most commonly detected bacteria among children aged ≥5 years hospitalized with CAP, one-quarter of whom had codetections. Although associated with clinically nonspecific symptoms, there was a need for intensive care in some cases. Mycoplasma pneumoniae should be included in the differential diagnosis for school-aged children hospitalized with CAP.

The Food and Drug Administration warned against fluoroquinolone use for conditions with effective alternative agents. An estimated 5.1% of adult ambulatory fluoroquinolone prescriptions were for conditions that did not require antibiotics, and 19.9% were for conditions where fluoroquinolones are not recommended first-line therapy. Unnecessary fluoroquinolone use should be reduced.

Background: Previous studies suggest that duration of antibiotic therapy for community-acquired pneumonia (CAP) often exceeds national recommendations and might represent an important opportunity to improve antibiotic stewardship nationally. Our objective was to determine the average length of antibiotic therapy (LOT) for patients treated for uncomplicated CAP in US hospitals and the proportion of patients with excessive durations., Methods: Records of retrospective cohorts of patients aged 18-64 years with private insurance and aged ≥65 years with Medicare hospitalized for CAP in 2012-2013 were used. Inpatient LOT was estimated as a function of length of stay. Outpatient LOT was based on prescriptions filled post discharge based on data from outpatient pharmacy files. Excessive duration was defined as outpatient LOT >3 days., Results: Inclusion criteria were met for 22128 patients aged 18-64 years across 2100 hospitals and 130746 patients aged ≥65 years across 3227 hospitals. Median total LOT was 9.5 days. LOT exceeded recommended duration for 74% of patients aged 18-64 years and 71% of patients aged ≥65 years. Patients aged 18-64 years had a median (quartile 1-quartile 3) 6 (3-7) days outpatient LOT and those aged ≥65 years had 5 (3-7) days., Conclusions: In this nationwide sample of patients hospitalized for CAP, median total LOT was just under 10 days, with more than 70% of patients having likely excessive treatment duration. Better adherence to recommended CAP therapy duration by improving prescribing at hospital discharge may be an important target for antibiotic stewardship programs.

Background: Improving antibiotic use has the potential to decrease healthcare costs by reducing the incidence of antibiotic-resistant infections, antibiotic-associated adverse events, and expenditures due to unnecessary prescriptions. Antibiotic expenditures in 2009 totaled $10.7 billion in the United States. Since then, national and local antibiotic stewardship initiatives have grown. The purpose of this study was to assess trends in antibiotic expenditures by healthcare setting in the United States between 2010 and 2015., Methods: Systemic (nontopical) antibiotic expenditures from January 2010 to December 2015 were extracted from the QuintilesIMS National Sales Perspectives database. These data represent a statistically valid projection of US medication purchases. Regression analyses evaluated trends in expenditures over the study period., Results: Antibiotic expenditures totaled $56.0 billion over the 6-year period; the majority (59.1%) of expenditures were associated with the outpatient setting. Overall antibiotic expenditures in 2015 ($8.8 billion) were 16.6% lower than in 2010 ($10.6 billion). Antibiotic expenditures similarly decreased in the community by 25.5% (P = .05), but outpatient clinics and mail service pharmacy expenditures experienced significant growth (148% and 67% increase, respectively; P < .01 for both). In 2015, 16.5% of antibiotic expenditures in the community were for parenteral formulations, an increase of 25%., Conclusions: From 2010 to 2015, antibiotic expenditures decreased. The majority of antibiotic expenditures were in the outpatient setting, specifically community pharmacies. Expenditures for intravenous agents in the community are increasing and may represent increased use. These results reinforce the importance of antibiotic stewardship efforts across the spectrum of healthcare., (Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Antimicrobial stewardship programs (ASPs) positively impact patient care, but metrics to assess ASP impact are poorly defined. We used a modified Delphi approach to select relevant metrics for assessing patient-level interventions in acute-care settings for the purposes of internal program decision making. An expert panel rated 90 candidate metrics on a 9-point Likert scale for association with 4 criteria: improved antimicrobial prescribing, improved patient care, utility in targeting stewardship efforts, and feasibility in hospitals with electronic health records. Experts further refined, added, or removed metrics during structured teleconferences and re-rated the retained metrics. Six metrics were rated >6 in all criteria: 2 measures of Clostridium difficile incidence, incidence of drug-resistant pathogens, days of therapy over admissions, days of therapy over patient days, and redundant therapy events. Fourteen metrics rated >6 in all criteria except feasibility were identified as targets for future development., (Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Objectives: The objectives of this study were: to examine trends in the use of prescription antibiotics overall and by population subgroups between 1999 and 2012; and to examine trends in the use of categories of antibiotics and individual antibiotics., Methods: Use of antibiotics was examined among 71 444 participants in the nationally representative National Health and Nutrition Examination Survey (NHANES; 1999-2012). Use of an antibiotic in the past 30 days was the main outcome variable. Analyses of trends were conducted overall and separately by population subgroups (i.e. age, sex, race/Hispanic origin, health insurance status and respiratory conditions) across four time periods (1999-2002, 2003-06, 2007-10 and 2011-12)., Results: The percentage of the US population that used a prescription antibiotic in the past 30 days significantly declined from 6.1% in 1999-2002 to 4.1% in 2011-12 (P < 0.001). Declines were also identified for five age groups (0-1 year, 6-11 years, 12-17 years, 18-39 years and 40-59 years), both sexes, non-Hispanic white and non-Hispanic black persons, persons with and without insurance and among those who currently had asthma. Significant declines were also observed for three categories of antibiotics (penicillins, cephalosporins and macrolide derivatives). Of the most common antibiotics prescribed, only amoxicillin use decreased significantly., Conclusions: Overall, there was a significant decline in the use of antibiotics between 1999-2002 and 2011-12. Due to concerns about antimicrobial resistance, it is important to continue monitoring the use of antibiotics., (Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: Healthcare-associated Legionnaires' disease (LD) is a preventable pneumonia with a 30% case fatality rate. The Centers for Disease Control and Prevention guidelines recommend a high index of suspicion for the diagnosis of healthcare-associated LD. We characterized an outbreak and evaluated contributing factors in a hospital using copper-silver ionization for prevention of Legionella growth in water., Methods: Through medical records review at a large, urban tertiary care hospital in November 2012, we identified patients diagnosed with LD during 2011-2012. Laboratory-confirmed cases were categorized as definite, probable, and not healthcare associated based on time spent in the hospital during the incubation period. We performed an environmental assessment of the hospital, including collection of samples for Legionella culture. Clinical and environmental isolates were compared by genotyping. Copper and silver ion concentrations were measured in 11 water samples., Results: We identified 5 definite and 17 probable healthcare-associated LD cases; 6 case patients died. Of 25 locations (mostly potable water) where environmental samples were obtained for Legionella-specific culture, all but 2 showed Legionella growth; 11 isolates were identical to 3 clinical isolates by sequence-based typing. Mean copper and silver concentrations were at or above the manufacturer's recommended target for Legionella control. Despite this, all samples where copper and silver concentrations were tested showed Legionella growth., Conclusions: This outbreak was linked to the hospital's potable water system and highlights the importance of maintaining a high index of suspicion for healthcare-associated LD, even in the setting of a long-term disinfection program., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: Appropriate antibiotic prescribing is an essential strategy to reduce the spread of antibiotic resistance. US prescribing practices have not been thoroughly characterized. We analyzed outpatient antibiotic prescribing data to identify where appropriate antibiotic prescribing interventions could have the most impact., Methods: Oral antibiotic prescriptions dispensed during 2011 were extracted from the IMS Health Xponent database. The number of prescriptions and census denominators were used to calculate prescribing rates. Prescription totals were calculated for each provider specialty. Regression modeling was used to examine the association between socioeconomic and population health factors and prescribing rates., Results: Healthcare providers prescribed 262.5 million courses of antibiotics in 2011(842 prescriptions per 1000 persons). Penicillins and macrolides were the most common antibiotic categories prescribed. The most commonly prescribed individual antibiotic agent was azithromycin. Family practitioners prescribed the most antibiotic courses (24%). The prescribing rate was higher in the South census region (931 prescriptions per 1000 persons) than in the West (647 prescriptions per 1000 persons; P < .001); this pattern was observed among all age groups, including children ≤ 2 and persons ≥ 65 years of age. Counties with a high proportion of obese persons, infants and children ≤ 2 years of age, prescribers per capita, and females were more likely to be high prescribing by multivariable analysis (adjusted odds ratio, >1.0)., Conclusions: Efforts to characterize antibiotic prescribing practices should focus on the South census region and family practitioners. Further understanding of the factors leading to high prescribing among key target populations will inform appropriate prescribing interventions., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

The use of fluoroquinolones differs dramatically between adult and pediatric patients. For adults, they are the leading class of antibiotics prescribed in ambulatory care visits whereas in children, they are the least frequently prescribed class. The reasons for this difference in practice likely relate to perceptions of their potential for harm. This highlights the impact of physicians' perception of direct patient harm in antibiotic decision making which has implications for antibiotic stewardship., (© The Author 2014. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objectives: To determine patterns of ambulatory antibiotic prescribing in US adults, including the use of broad-spectrum versus narrow-spectrum agents, to provide a description of the diagnoses for which antibiotics are prescribed and to identify patient and physician factors associated with broad-spectrum antibiotic prescribing., Methods: We used data for patients aged ≥ 18 years from the National Ambulatory and National Hospital Ambulatory Medical Care Surveys (2007-09). These are nationally representative surveys of patient visits to offices, hospital outpatient departments and emergency departments (EDs) in the USA, collectively referred to as ambulatory visits. We determined the types of antibiotics prescribed, including the use of broad-spectrum versus narrow-spectrum antibiotics, and examined prescribing patterns by diagnoses. We used multivariable logistic regression to identify factors associated with broad-spectrum antibiotic prescribing., Results: Antibiotics were prescribed during 101 million (95% CI: 91-111 million) ambulatory visits annually, representing 10% of all visits. Broad-spectrum agents were prescribed during 61% of visits in which antibiotics were prescribed. The most commonly prescribed antibiotics were quinolones (25% of antibiotics), macrolides (20%) and aminopenicillins (12%). Antibiotics were most commonly prescribed for respiratory conditions (41% of antibiotics), skin/mucosal conditions (18%) and urinary tract infections (9%). In multivariable analysis, among patients prescribed antibiotics, broad-spectrum agents were more likely to be prescribed than narrow-spectrum antibiotics for respiratory infections for which antibiotics are rarely indicated (e.g. bronchitis), during visits to EDs and for patients ≥ 60 years., Conclusions: Broad-spectrum agents constitute the majority of antibiotics in ambulatory care. More than 25% of prescriptions are for conditions for which antibiotics are rarely indicated. Antibiotic stewardship interventions targeting respiratory and non-respiratory conditions are needed in ambulatory care.

Objectives: Promoting appropriate antibiotic use has the potential to decrease healthcare costs by reducing unnecessary prescriptions and the incidence of resistant infections. However, little is known about where antibiotic costs are incurred in the US healthcare system. We evaluated antibiotic expenditures by healthcare setting and antibiotic class in the USA., Methods: Systemic antibiotic expenditures in 2009 were extracted from the IMS Health(©) National Sales Perspectives database. These data represent a statistically valid projection of all medication purchases in the USA from 1 January 2009 to 31 December 2009., Results: Antibiotic expenditures totalled $10.7 billion. The majority (61.5%) of expenditures were associated with the outpatient setting, especially from community pharmacies. Inpatient and long-term care settings accounted for 33.6% and 4.9% of expenditures, respectively. The class of antibiotics that accounted for the most antibiotic expenditure overall was the quinolones, followed by the penicillins., Conclusions: Over $10.7 billion was spent in 2009 on antibiotic therapy in the USA. Differences were observed in antibiotic expenditures by healthcare setting, with the majority in the outpatient setting, 87% of which was in community pharmacies.

Evidence-based guidelines for the diagnosis and initial management of suspected acute bacterial rhinosinusitis in adults and children were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America comprising clinicians and investigators representing internal medicine, pediatrics, emergency medicine, otolaryngology, public health, epidemiology, and adult and pediatric infectious disease specialties. Recommendations for diagnosis, laboratory investigation, and empiric antimicrobial and adjunctive therapy were developed.

Background: Streptococcus pneumoniae infections have become increasingly complicated and costly to treat with the spread of antibiotic resistance. We evaluated the relationship between antibiotic prescribing and nonsusceptibility among invasive pneumococcal disease (IPD) isolates., Methods: Outpatient antibiotic prescription data for penicillins, cephalosporins, macrolides, and trimethoprim-sulfamethoxazole were abstracted from the IMS Health Xponent database to calculate the annual number of prescriptions per capita. We analyzed IPD data from 7 of the Centers for Disease Control and Prevention's Active Bacterial Core surveillance sites (population, 18.6 million) for which data were available for the entire time period under study (1996-2003). Logistic regression models were used to assess whether sites with high antibiotic prescribing rates had a high proportion of nonsusceptible and serotype 19A IPD., Results: Yearly prescribing rates during the period 1996-2003 for children <5 years of age decreased by 37%, from 4.23 to 2.68 prescriptions per capita per year (P < .001), and those for persons ≥5 years of age decreased by 42%, from 0.98 to 0.57 prescriptions per capita per year (P < .001); increases in azithromycin prescribing were noted for both groups. Sites with high rates of antibiotic prescribing had a higher proportion of IPD nonsusceptibility than did low-prescribing sites (P = .003 for penicillin, P < .001 for every other antibiotic class). Cephalosporin and macrolide prescribing were associated with penicillin and multidrug nonsusceptibility and serotype 19A IPD (P < .001)., Conclusions: In sites where antibiotic prescribing is high, the proportion of nonsusceptible IPD is also high, suggesting that local prescribing practices contribute to local resistance patterns. Cephalosporins and macrolides seem to be selecting for penicillin- and multidrug-resistant pneumococci, as well as serotype 19A IPD. Antibiotic use is a major factor contributing to the spread of antibiotic resistance; strategies to reduce antibiotic resistance should continue to include judicious use of antibiotics.

In April 2009, following the first school closure due to 2009 pandemic influenza A (H1N1) (pH1N1) in Chicago, Illinois, area hospitals were inundated with patients presenting with influenza-like illness (ILI). The extent of disease spread into the surrounding community was unclear. We performed a household survey to estimate the ILI attack rate among community residents and compared reported ILI with confirmed pH1N1 cases and ILI surveillance data (ie, hospital ILI visits, influenza testing, and school absenteeism). The estimated ILI attack rate was 4.6% (95% confidence interval, 2.8%-7.4%), with cases distributed throughout the 5-week study period. In contrast, 36 (84%) of 43 confirmed pH1N1 cases were identified the week of the school closure. Trends in surveillance data peaked during the same week and rapidly decreased to near baseline. Public awareness and health care practices impact standard ILI surveillance data. Community-based surveys are a valuable tool to help assess the burden of ILI in a community.

Background: Mycoplasma pneumoniae continues to be a significant cause of community-acquired pneumonia (CAP). A more definitive methodology for reliable detection of M. pneumoniae is needed to identify outbreaks and to prevent potentially fatal extrapulmonary complications., Methods: We analyzed 2 outbreaks of CAP due to M. pneumoniae. Nasopharyngeal and/or oropharyngeal swab specimens and serum samples were obtained from persons with clinically defined cases, household contacts, and asymptomatic individuals. Real-time polymerase chain reaction (PCR) for M. pneumoniae was performed on all swab specimens, and the diagnostic utility was compared with that of 2 commercially available serologic test kits., Results: For cases, 21% yielded positive results with real-time PCR, whereas 81% and 54% yielded positive results with the immunoglobulin M and immunoglobulin G/immunoglobulin M serologic tests, respectively. For noncases, 1.8% yielded positive results with real-time PCR, whereas 63% and 79% yielded serologically positive results with the immunoglobulin M and immunoglobulin G/immunoglobulin M kits, respectively. The sensitivity of real-time PCR decreased as the duration between symptom onset and sample collection increased, with a peak sensitivity of 48% at 0-21 days. A specificity of 43% for the immunoglobulin M antibody detection assay was observed for persons aged 10-18 years, but the sensitivity increased to 82% for persons aged 19 years., Discussion: Thorough data analysis indicated that no single available test was reliable for the identification of an outbreak of CAP due to M. pneumoniae. A combination of testing methodologies proved to be the most reliable approach for identification of outbreaks of CAP due to M. pneumoniae, especially in the absence of other suspected respiratory pathogens.

Background: We investigated an outbreak of severe neurologic disease and pneumonia that occurred among students at 4 schools in Rhode Island., Methods: We identified cases of encephalitis, encephalomyelitis, and pneumonia that occurred among schoolchildren from 1 September 2006 through 9 February 2007, and we performed serologic tests, polymerase chain reaction (PCR) analysis, and culture for the detection of multiple pathogens in oropharyngeal and nasopharyngeal specimens. Students with positive results of M. pneumoniae IgM serologic testing and no alternative diagnosis were considered to be infected with M. pneumoniae. At school A, we used questionnaires to identify students and their household contacts who made visits to physicians for pneumonia and cough. We compared observed and expected rates of pneumonia., Results: Rates of pneumonia among elementary students (122 cases/1000 student-years) were > 5-fold higher than expected. Three students had encephalitis or encephalomyelitis, and 76 had pneumonia. Of these 2 groups of students, 2 (66%) and 57 students (75%), respectively, had M. pneumoniae infection. M. pneumoniae was detected by PCR in 10 students with pneumonia; 5 of these specimens were cultured, and M. pneumoniae was isolated in 4. Of 202 households of students attending school A, 20 (10%) accounted for 61% of visits to physicians for pneumonia or cough. Of 19 household contacts of students with pneumonia, 8 (42%) developed pneumonia and 6 (32%) reported visits for cough., Conclusions: M. pneumoniae caused a community-wide outbreak of cough illness and pneumonia and was associated with the development of life-threatening neurologic disease. Although M. pneumoniae was detected in schools, its transmission in households amplified the outbreak. Interrupting household transmission should be a priority during future outbreaks.

Background: Widespread use of pneumococcal conjugate vaccine (PCV7) resulted in decreases in invasive disease among children and elderly persons. The benefits may be offset by increases in disease due to serotypes not included in the vaccine (hereafter, "nonvaccine serotypes"). We evaluated the effect of PCV7 on incidence of disease due to nonvaccine serotypes., Methods: Cases of invasive disease were identified in 8 geographic areas through the Centers for Disease Control and Prevention's Active Bacterial Core surveillance. Serotyping and susceptibility testing of isolates were performed. We calculated the incidence of disease for children aged <5 years and adults aged > or =65 years. We compared rates of serotype-specific disease before and after PCV7 was licensed for use., Results: The annual incidence of disease due to nonvaccine serotypes increased from an average of 16.3 cases/100,000 population during prevaccine years (1998-1999) to 19.9 cases/100,000 population in 2004 for children aged <5 years (P=.01) and from 27.0 cases/100,000 population during prevaccine years to 29.8 cases/100,000 population in 2004 for adults aged > or =65 years (P=.05). Significant increases in the incidences of disease due to serotypes 3, 15, 19A, 22F, and 33F were observed among children during this period (P<.05 for each serotype); serotype 19A has become the predominant cause of invasive disease in children. The incidence of disease due to these serotypes also increased among elderly persons., Conclusions: The incidence of pneumococcal disease caused by nonvaccine serotypes is increasing. Ongoing surveillance is needed to monitor the magnitude of disease caused by nonvaccine serotypes, to ensure that future vaccines target the appropriate serotypes.

Background: During March 2004, a large outbreak of legionnaires disease and Pontiac fever occurred among hotel guests in Oklahoma. An investigation was conducted to identify the source and evaluate the utility of the Legionella urine antigen assay and serologic testing for the identification of Pontiac fever., Methods: A retrospective cohort investigation of hotel guests and employees and an environmental evaluation were performed. Participants were interviewed, and clinical specimens were collected from consenting individuals., Results: Six cases of legionnaires disease and 101 cases of Pontiac fever were identified. Exposure to the indoor pool and hot tub area was associated with legionellosis (relative risk, 4.4; 95% confidence interval, 2.8-6.9). Specimens from the pool and hot tub tested positive for Legionella pneumophila serogroup 1 by polymerase chain reaction. For Pontiac fever, the sensitivity and positive predictive value were 35.7% and 100%, respectively, for the urine antigen assay, and 46.4% and 90%, respectively, for serologic testing. The specificity and negative predictive value were 100% and 47.8%, respectively, for the urine antigen assay, and 89.3% and 45.5%, respectively, for serologic testing., Conclusions: Urine antigen testing, with or without serologic testing, can be used to confirm outbreak-associated cases of Pontiac fever caused by L. pneumophila serogroup 1.