As in past pandemics, co-circulating pathogens may play a role in the epidemiology of coronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In particular, experimental evidence indicates that influenza infection can up-regulate the expression of ACE2—the receptor of SARS-CoV-2 in human cells—and facilitate SARS-CoV-2 infection. Here we hypothesized that influenza impacted the epidemiology of SARS-CoV-2 during the early 2020 epidemic of COVID-19 in Europe. To test this hypothesis, we developed a population-based model of SARS-CoV-2 transmission and of COVID-19 mortality, which simultaneously incorporated the impact of non-pharmaceutical control measures and of influenza on the epidemiological dynamics of SARS-CoV-2. Using statistical inference methods based on iterated filtering, we confronted this model with mortality incidence data in four European countries (Belgium, Italy, Norway, and Spain) to systematically test a range of assumptions about the impact of influenza. We found consistent evidence for a 1.8–3.4-fold (uncertainty range across countries: 1.1 to 5.0) average population-level increase in SARS-CoV-2 transmission associated with influenza during the period of co-circulation. These estimates remained robust to a variety of alternative assumptions regarding the epidemiological traits of SARS-CoV-2 and the modeled impact of control measures. Although further confirmatory evidence is required, our results suggest that influenza could facilitate the spread and hamper effective control of SARS-CoV-2. More generally, they highlight the possible role of co-circulating pathogens in the epidemiology of COVID-19.
【저자키워드】 COVID-19, SARS-CoV-2, Influenza, mathematical modeling, virus–virus interaction, 【초록키워드】 coronavirus disease, coronavirus, Europe, Mortality, Epidemiology, SARS-COV-2 infection, Italy, Spread, SARS-CoV-2 transmission, Measures, pathogen, Spain, Pandemics, epidemiological, receptor, incidence, estimate, Belgium, Norway, expression, Evidence, Hypothesis, COVID-19 mortality, acute respiratory syndrome, influenza infection, average, measure, assumption, experimental evidence, effective, statistical, highlight, European country, robust, caused, remained, required, facilitate, indicate, variety, increase in, up-regulate, impacted, epidemic of COVID-19, 【제목키워드】 epidemiological,