Plunge in respiratory viruses, outpatient antibiotics during pandemic
Respiratory virus detections and ambulatory antibiotic prescribing rates for respiratory tract infections (RTIs) fell dramatically during the pandemic compared with previous years, a finding that could have implications for future antibiotic stewardship and public health strategies, researchers from the University of Wisconsin reported today in JAMA Internal Medicine.
Using surveillance data from the Wisconsin State Laboratory of Hygiene and antibiotic prescribing data from University of Wisconsin Health, the researchers compared the pre–COVID-19 pandemic period (July 2018 to February 2020) to a period covering several waves of COVID-19 activity (April 2020 to February 2021).
They found that respiratory virus detections demonstrated seasonal variation during the pre-pandemic period but not during the pandemic period, and that detections of winter seasonal viruses (influenza, respiratory syncytial virus, and seasonal coronavirus) fell from an average of 4,800 per month to 12 per month. Other respiratory virus detections fell from 560 per month pre-pandemic to 228 per month during the pandemic.
Adjusting for seasonality, monthly antibiotic prescriptions for RTIs fell 79%, from 10.5 to 2.2 prescriptions per 1,000 patient encounters. Non-influenza virus detections demonstrated the strongest correlation with antibiotic prescribing for RTI.
“The data suggest that COVID-19 transmission mitigation strategies may help curb respiratory viral diseases beyond SARS-CoV-2 and, indirectly, decrease antibiotic prescribing,” the study authors wrote. “Notably, during COVID-19 surges in Wisconsin (October to December 2020), we did not observe increased ambulatory antibiotic prescriptions.”
In addition to the reduced detection of viruses, the authors hypothesize highly accessible, rapid tests for SARS-CoV-2 and influenza may have helped avert unnecessary antibiotic prescriptions.
Jun 21 JAMA Internal Med study
US analysis finds rising multidrug-resistance in urinary E coli
An analysis of Escherichia coli isolated from US urinary cultures indicates concerning levels of resistance to first-line antibiotics, along with rising levels of multidrug resistance, researchers reported late last week in Clinical Infectious Diseases.
Using E coli isolates from female urine cultures collected at US outpatient facilities from 2011 through 2019, the researchers analyzed susceptibility to nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), and fluoroquinolones, and assessed for extended-spectrum beta-lactamase production (ESBL+) and resistance to multiple antibiotic classes. Overall, more than 1.5 million non-duplicate E coli isolates from 295 outpatient facilities were included in the primary analysis, making it the largest published sample of E coli isolated US outpatient urine cultures.
The overall prevalence of E coli that were not-susceptible to TMP-SMX, fluoroquinolones, and nitrofurantoin was 25.4%, 21.1%, and 3.8%, respectively. ESBL+ was found in 6.4% of isolates, while 14.4% were not susceptible to two or more antibiotics and 3.8% were resistant to three or more. The highest overall prevalence for most not-susceptible phenotypes was in the East South Central census region, and the lowest prevalence was consistently found in the New England region, analysis showed.
Over the 9 years studied, the ESBL+ rate increased every year (except 2018), beginning at 4.1% and increasing to 7.3%. The prevalence of TMP-SMX resistance was consistently 25% or greater, while fluoroquinolone resistance declined from 21.9% to 20.3%, but was consistently over 20%. Modelling demonstrated a relative average yearly increase of 7.7% for ESBL+ isolates and 2.7% for isolates resistant to three or more antibiotics.
The study authors say the findings are concerning because resistance rates higher than 20% and rising levels of multidrug-resistance limit the empiric therapy options for treatment of uncomplicated urinary tract infections (UTIs), and will likely create a greater burden on emergency departments and acute care settings.
“Raising awareness of current regional patterns of not-susceptible E. coli isolates from outpatient UTIs can help to guide empiric treatment decisions of physicians and demonstrate the need for both antimicrobial stewardship efforts in outpatient settings, as well as new oral antibiotics to address the growing prevalence of resistant E. coli in the US,” they wrote.
Jun 18 Clin Infect Dis abstract
Prescribing in Scottish COVID-19 patients highlights need for stewardship
Antibiotic prescribing for suspected RTIs was commonly observed among COVID-19 patients in Scottish hospitals during the first wave of the pandemic, Scottish researchers reported last week in JAC-Antimicrobial Resistance.
The findings from a point prevalence survey (PPS) conducted in designated COVID-19 wards of 15 Scottish hospitals from Apr 20 to 30, 2020, show that of 820 patients surveyed, 33.3% received at least one antibiotic for suspected RTI on the survey day, and 58.8% tested positive for SARS-CoV-2. Antibiotics were empirical in 91.9% of patients, and amoxicillin (24.6%), doxycycline (20.5%), and co-amoxiclav (15%)—the antibiotics recommended in local guidelines for RTI—were most frequently prescribed.
Multivariable logistic regression analysis revealed that antibiotic prescribing for RTIs was independently and positively associated with COPD/chronic lung disease, purulent/bloody sputum, abnormal chest x-ray, and a C-reactive protein value of 100 milligrams per liter or higher. Probable and definite hospital-acquired COVID-19 and diabetes were associated with lower odds of receiving an antibiotic for RTI.
“The rates of observed empirical antibiotic prescribing for RTI highlights the importance of ongoing local and national initiatives to reinforce stewardship in the COVID-19 context and beyond,” the study authors wrote. “Clinical review and decision making, and early use of microbiological diagnostics, are central to limit unnecessary antibiotic therapy and other antibiotic-related harm.”
Jun 18 JAC-Antimicrob Resist study