Data are needed from outpatient settings to better inform antimicrobial stewardship. In this study, a random sample of outpatient antibiotic prescriptions by primary care providers (PCPs) at our health care system was reviewed and compared to consensus guidelines. Over 12 months, 3,880 acute antibiotic prescriptions were written by 76 PCPs caring for 40,734 patients (median panel, 600 patients; range, 33 to 1,547). PCPs ordered a median of 84 antibiotic prescriptions per 1,000 patients per year. Azithromycin (25.8%), amoxicillin-clavulanate (13.3%), doxycycline (12.4%), amoxicillin (11%), fluoroquinolones (11%), and trimethoprim-sulfamethoxazole (10.6%) were prescribed most commonly. Medical records corresponding to 300 prescriptions from 59 PCPs were analyzed in depth. The most common indications for these prescriptions were acute respiratory tract infection (28.3%), urinary tract infection (23%), skin and soft tissue infection (15.7%), and chronic obstructive pulmonary disease (COPD) exacerbation (6.3%). In 5.7% of cases, no reason for the prescription was listed. No antibiotic was indicated in 49.7% of cases. In 12.3% of cases, an antibiotic was indicated, but the prescribed agent was guideline discordant. In another 14% of cases, a guideline-concordant antibiotic was given for a guideline-discordant duration. Therefore, 76% of reviewed prescriptions were inappropriate. Ciprofloxacin and azithromycin were most likely to be prescribed inappropriately. A non-face-to-face encounter prompted 34% of prescriptions. The condition for which an antibiotic was prescribed was not listed in primary or secondary diagnosis codes in 54.5% of clinic visits. In conclusion, there is an enormous opportunity to reduce inappropriate outpatient antibiotic prescriptions.

We reviewed 37 patients treated for bacteremia due to carbapenemresistant (CR) Pseudomonas aeruginosa. Although 65% of isolates were multiple-drug resistant, therapeutic options were available, as all were susceptible to Ն1 antibiotic. A total of 92% of patients received active antimicrobial therapy, but only 57% received early active therapy (within 48 h). Fourteen-day mortality was 19%. Microbiologic failure occurred in 29%. The Pitt bacteremia score (P ϭ 0.046) and delayed active therapy (P ϭ 0.027) were predictive of death and microbiologic failure, respectively.

We argue that the COVID-19 pandemic will result in increased antimicrobial resistance (AMR). Broad-spectrum antibiotic use is common among hospitalized COVID-19 patients and in excess of reported secondary infection rates, suggesting unnecessary prescribing. Selection pressure is likely to be particularly intense in COVID-19 epicentres and within non-epicentre hospital units dedicated to COVID-19 care. Risk factors that increase the likelihood of hospitalization or poor outcomes among COVID-19 patients, such as advanced age, nursing home residence, debilitation, diabetes and cardiopulmonary or other underlying systemic diseases, also predispose to AMR infections. Worry for AMR emergence is heightened since first-wave COVID-19 epicentres were also AMR epicentres. Disruptive direct and indirect effects of COVID-19 globally on economic systems, governance and public health expenditure and infrastructure may fuel AMR spread. We anticipate that the impact of COVID-19 on AMR will vary between epicentres and non-epicentres, by geographic region, hospital to hospital within regions and within specific hospital units.

In nursing home residents with asymptomatic COVID-19 diagnosed through twice-weekly surveillance testing, single dose BNT162b2 vaccination (Pfizer-BioNTech) was associated with -2.4 mean log10 lower nasopharyngeal viral load than detected in absence of vaccination (p=0.004). Since viral load is linked to transmission, single dose mRNA SARS-CoV-2 vaccination may help control outbreaks.

We compared ceftazidime-avibactam, ceftolozane-tazobactam, ceftazidime, cefepime, and piperacillin-tazobactam MICs for 38 meropenem-resistant Pseudomonas aeruginosa isolates. No isolates harbored carbapenemases; 74% were oprD mutants. Ceftazidime-avibactam and ceftolozane-tazobactam were active against 92% of the isolates, including 80% that were resistant to all three ␤-lactams. Forty-three percent of ceftazidime-avibactam-susceptible isolates and 6% of ceftolozane-tazobactam-susceptible isolates exhibited MICs at the respective breakpoints. Ceftolozane-tazobactam and ceftazidime-avibactam are therapeutic options for meropenem-resistant P. aeruginosa infections that should be used judiciously to preserve activity.