To evaluate the appropriateness of empiric initiation of meropenem in the intensive care unit (ICU) and to determine the agreement between internal medicine (IM) residents and infectious diseases (ID) physicians/pharmacists on appropriateness.

Retrospective observational study.

ICU in a tertiary care community teaching hospital.

Adult patients admitted to the ICU and started empirically on meropenem between April 1 and October 31, 2021.

Meropenem usage was categorized as appropriate or inappropriate according to criteria developed from previously published indications and modified by ID physicians/pharmacists to reflect local practices. Two investigators (an IM resident and either an ID physician or pharmacist) assessed the appropriateness, with a second ID physician resolving any disagreements. Inter-rater reliability was measured using the kappa statistic.

Ninety-seven participants were enrolled, with a mean age of 68 (SD, 17.0) years. Pneumonia was the most common infection (30.9%). Among the participants, 92.8% received an ID consultation, with 55.6% of these occurring before meropenem initiation. IM residents deemed 56.7% of meropenem administrations appropriate, whereas an ID physician/pharmacist deemed only 48.5% appropriate, agreeing on 79.4% of cases (kappa statistic 0.59, P <.001). After a third reviewer’s assessment was included, agreement between the resident and at least one of the two reviewers reached 90.7% (kappa 0.81, P <.001).

Approximately half of empiric meropenem started in the ICU was deemed inappropriate using institution-specific criteria. There was good agreement between IM residents and ID physicians/pharmacists on meropenem appropriateness. IM residents could contribute to antimicrobial stewardship efforts, like prospective audit and feedback, using standardized criteria for appropriateness.

To determine antibiotic prescribing appropriateness for respiratory tract diagnoses (RTD) by season.

Retrospective cohort study.

Primary care practices in a university health system.

Patients who were seen at an office visit with diagnostic code for RTD.

Office visits for the entire cohort were categorized based on ICD-10 codes by the likelihood that an antibiotic was indicated (tier 1: always indicated; tier 2: sometimes indicated; tier 3: rarely indicated). Medical records were reviewed for 1,200 randomly selected office visits to determine appropriateness. Based on this reference standard, metrics and prescriber characteristics associated with inappropriate antibiotic prescribing were determined. Characteristics of antibiotic prescribing were compared between winter and summer months.

A significantly greater proportion of RTD visits had an antibiotic prescribed in winter [20,558/51,090 (40.2%)] compared to summer months [11,728/38,537 (30.4%)][standardized difference (SD) = 0.21]. A significantly greater proportion of winter compared to summer visits was associated with tier 2 RTDs (29.4% vs 23.4%, SD = 0.14), but less tier 3 RTDs (68.4% vs 74.4%, SD = 0.13). A greater proportion of visits in winter compared to summer months had an antibiotic prescribed for tier 2 RTDs (80.2% vs 74.2%, SD = 0.14) and tier 3 RTDs (22.9% vs 16.2%, SD = 0.17). The proportion of inappropriate antibiotic prescribing was higher in winter compared to summer months (72.4% vs 62.0%, P < .01).

Increases in antibiotic prescribing for RTD visits from summer to winter were likely driven by shifts in diagnoses as well as increases in prescribing for certain diagnoses. At least some of this increased prescribing was inappropriate.

To determine metrics and provider characteristics associated with inappropriate antibiotic prescribing for respiratory tract diagnoses (RTDs).

Retrospective cohort study.

Primary care practices in a university health system.

Patients seen by an attending physician or advanced practice provider (APP) at their primary care office visit with International Classification of Disease, Tenth Revision, Clinical Modification (ICD-10-CM)–coded RTDs.

Medical records were reviewed for 1,200 randomly selected office visits in which an antibiotic was prescribed to determine appropriateness. Based on this gold standard, metrics and provider characteristics associated with inappropriate antibiotic prescribing were determined.

Overall, 69% of antibiotics were inappropriate. Metrics utilizing prespecified RTDs most strongly associated with inappropriate prescribing were (1) proportion prescribing for RTDs for which antibiotics are almost never required (eg, bronchitis) and (2) proportion prescribing for any RTD. Provider characteristics associated with inappropriate antibiotic prescribing were APP versus physician (72% vs 58%; P = .02), family medicine versus internal medicine (76% vs 63%; P = .01), board certification 1997 or later versus board certification before 1997 (75% vs 63%; P = .02), nonteaching versus teaching practice (73% vs 51%; P < .01), and nonurban vs urban practice (77% vs 57%; P < .01).

Metrics utilizing proportion prescribing for RTDs for which antibiotics are almost never required and proportion prescribing for any RTD were most strongly associated with inappropriate prescribing. APPs and clinicians with family medicine training, with board certification 1997 or later, and who worked in nonteaching or nonurban practices had higher proportions of inappropriate prescribing. These findings could inform design of interventions to improve prescribing and could represent an efficient way to track inappropriate prescribing.

To determine the impact of total household decolonization with intranasal mupirocin and chlorhexidine gluconate body wash on recurrent methicillin-resistant Staphylococcus aureus (MRSA) infection among subjects with MRSA skin and soft-tissue infection.

Three-arm nonmasked randomized controlled trial.

Five academic medical centers in Southeastern Pennsylvania.

Adults and children presenting to ambulatory care settings with community-onset MRSA skin and soft-tissue infection (ie, index cases) and their household members.

Enrolled households were randomized to 1 of 3 intervention groups: (1) education on routine hygiene measures, (2) education plus decolonization without reminders (intranasal mupirocin ointment twice daily for 7 days and chlorhexidine gluconate on the first and last day), or (3) education plus decolonization with reminders, where subjects received daily telephone call or text message reminders.

Owing to small numbers of recurrent infections, this analysis focused on time to clearance of colonization in the index case.

Of 223 households, 73 were randomized to education-only, 76 to decolonization without reminders, 74 to decolonization with reminders. There was no significant difference in time to clearance of colonization between the education-only and decolonization groups (log-rank P=.768). In secondary analyses, compliance with decolonization was associated with decreased time to clearance (P=.018).

Total household decolonization did not result in decreased time to clearance of MRSA colonization among adults and children with MRSA skin and soft-tissue infection. However, subjects who were compliant with the protocol had more rapid clearance

Trial registration. ClinicalTrials.gov identifier: NCT00966446

Infect Control Hosp Epidemiol 2016;1–8

To identify risk factors for recurrent methicillin-resistant Staphylococcus aureus (MRSA) colonization.

Prospective cohort study conducted from January 1, 2010, through December 31, 2012.

Five adult and pediatric academic medical centers.

Subjects (ie, index cases) who presented with acute community-onset MRSA skin and soft-tissue infection.

Index cases and all household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as 2 consecutive sampling periods with negative surveillance cultures. Recurrent colonization was defined as any positive MRSA surveillance culture after clearance. Index cases with recurrent MRSA colonization were compared with those without recurrence on the basis of antibiotic exposure, household demographic characteristics, and presence of MRSA colonization in household members.

The study cohort comprised 195 index cases; recurrent MRSA colonization occurred in 85 (43.6%). Median time to recurrence was 53 days (interquartile range, 36–84 days). Treatment with clindamycin was associated with lower risk of recurrence (odds ratio, 0.52; 95% CI, 0.29–0.93). Higher percentage of household members younger than 18 was associated with increased risk of recurrence (odds ratio, 1.01; 95% CI, 1.00–1.02). The association between MRSA colonization in household members and recurrent colonization in index cases did not reach statistical significance in primary analyses.

A large proportion of patients initially presenting with MRSA skin and soft-tissue infection will have recurrent colonization after clearance. The reduced rate of recurrent colonization associated with clindamycin may indicate a unique role for this antibiotic in the treatment of such infection.

Infect. Control Hosp. Epidemiol. 2015;36(7):786–793

The major mechanism of fluoroquinolone (FQ) resistance in Pseudomonas aeruginosa (PSA) is modification of target proteins in DNA gyrase and topoisomerase IV, most commonly the gyrA and parC subunits. The objective of this study was to determine risk factors for PSA with and without gyrA or parC mutations.

Case-case-control study

Two adult academic acute-care hospitals

Case 1 study participants had a PSA isolate on hospital day 3 or later with any gyrA or parC mutation; case 2 study participants had a PSA isolate on hospital day 3 or later without these mutations. Controls were a random sample of all inpatients with a stay of 3 days or more.

Each case group was compared to the control group in separate multivariate models on the basis of demographics and inpatient antibiotic exposure, and risk factors were qualitatively compared.

Of 298 PSA isolates, 172 (57.7%) had at least 1 mutation. Exposure to vancomycin and other agents with extended Gram-positive activity was a risk factor for both cases (case 1 odds ratio [OR], 1.09; 95% confidence interval [CI], 1.04–1.13; OR, 1.14; 95% CI, 1.03–1.26; case 2 OR, 1.09; 95% CI, 1.03–1.14; OR, 1.13; 95% CI, 1.01–1.25, respectively).

Exposure to agents with extended Gram-positive activity is a risk factor for isolation of PSA overall but not for gyrA/parC mutations. FQ exposure is not associated with isolation of PSA with mutations.

Infect Control Hosp Epidemiol 2015;00(0): 1–7