Epidemiology: global spread, risk factors for disease incidence, severity and mortality

ABSTRACT

There are many unknowns surrounding COVID-19 and the ongoing pandemic. Standard epidemiological methods helped to determine the initial and ongoing distribution of COVID-19 in time and space, with unprecedented global coverage in almost real-time, and the forecasting methods used already had a reasonable predictive ability. Cumulative incidence and other complex epidemiological estimators have been widely disseminated via the media and are becoming lay terms thanks to persistent use, but their thresholds to determine public health interventions are yet to achieve consensus. The natural history of SARS-CoV-2, the interplay of risk factors and the effectiveness of mitigating factors in subpopulations remain unmet challenges. Establishing standard definitions of COVID-19 and its consequences is essential to the implementation of research. Pending widespread vaccine coverage, the world is experiencing unleashed community transmission in many countries, and the COVID-19 endgame is a distant goal. Several characteristics differentiate the transmissibility of SARS-CoV-2 from other viruses, making COVID-19 much more difficult to control with universal hygiene interventions. Epidemiology remains a necessary discipline to help end the COVID-19 pandemic;economic, social and health policy decision-making analysis are also needed.Copyright © ERS 2021.