Has the COVID-19 pandemic wiped out the seasonality of outpatient antibiotic use and influenza activity? A time-series analysis from 2014 to 2021.

OBJECTIVE: To assess the influence of the emergence of severe acute respiratory syndrome coronavirus 2 and the implementation of public health measures on the seasonality of outpatient antibiotic use and their possible association with the incidence of influenza. METHODS: We performed a time-series ecological study in 1516 primary care centres of Andalusia, Spain, comparing the coronavirus disease 2019 period (April 2020 to March 2021) with the 6 previous years. We assessed the number of packs and defined daily doses per 1000 inhabitants of antibacterials and key antibiotics commonly used for acute respiratory tract infections and the number of influenza-positive cases per 100 000 inhabitants. We calculated the correlation between variables and analyzed the seasonal patterns and differences in quarterly antibiotic use. RESULTS: For all quarters, a significant correlation was observed between influenza activity and antibiotic use (Spearman's r = 0.94; p < 0.001). Before the pandemic period, both variables presented similar seasonal patterns. After the start of the pandemic, influenza activity was suppressed and the pattern of antibiotic use flattened into a straight line (R2 = 0.96; p = 0.022) with a quarterly change of 3.9% (p = 0.007). Total antibiotic use and antibiotics used for treating acute respiratory tract infections showed significant reductions in all quarters compared to the previous year (p < 0.01). DISCUSSION: The coronavirus disease 2019 pandemic has strongly influenced the seasonality of antibiotic use in primary care. The decline in respiratory viruses, among which the influenza virus is a major player that may act as a proxy for general prevalence, is proposed as a reason for the flattening of the seasonal fluctuations of outpatient antibiotic use in our region.

Has the COVID-19 pandemic wiped out the seasonality of outpatient antibiotic use and influenza activity? A time-series analysis from 2014 to 2021

Objectives To assess the influence of the emergence of SARS-CoV-2 and the implementation of public health measures on seasonality of outpatient antibiotic use and its possible association with the incidence of influenza. Methods We performed a time-series ecological study in 1,516 primary care centres of Andalusia, Spain, comparing the COVID-19 period (April 2020 to March 2021) with the six previous years. We assessed the number of packs and DDD per 1,000 inhabitants of antibacterials and key antibiotics commonly used for acute respiratory tract infections (ARTIs) and the number of influenza-positive cases per 100,000 inhabitants. We calculated the correlation between variables and analysed the seasonal patterns and differences in quarterly antibiotic use. Results For all the quarters, a significant correlation was observed between influenza activity and antibiotic use (Spearman’s r=0.94;p<0.001). Before the pandemic period, both variables presented similar seasonal patterns. After the start of the pandemic, the influenza activity was suppressed and the antibiotic use pattern flattened off turning into a straight line (R2=0.96;p=0.022) with a quarterly percentage of change of 3.9% (p=0.007). Total antibiotic use and antibiotics used for treating ARTIs showed significant reductions in all quarters compared to the previous year (p<0.01). Conclusions The COVID-19 pandemic has strongly influenced the seasonality of antibiotic use in primary care. The decline in respiratory viruses, for which the influenza virus is a major player and may act as a proxy, is proposed as a reason for the flattening out of the seasonal fluctuations of outpatient antibiotic use in our region.