The prevention of COVID-19 and the need for reliable data

The previously unknown coronavirus (SARS-CoV-2) is the cause of the novel infectious coronavirus disease 2019 (COVID-19), which has been declared a global pandemic by the World Health Organisation. How much of a threat this pandemic poses in terms of infectiousness, virulence, need for medical care and case fatalities is unknown. Reliable data on the prevalence and incidence of SARS-CoV-2 and the number of deaths of (and not just with) COVID-19 confirmed at autopsy in representative random samples of the general population is currently unavailable. Exact figures are crucially important when introducing public health measures as far-reaching as prolonged social distancing and economic lockdowns. The imperiling of livelihoods resulting from drastic economic interventions is likely to put at risk the mental and physical health of those affected. Reliable epidemiological data describing the real course of the pandemic is urgently needed. In the uncertain scientific and political environment of the present coronavirus crisis, it may seem advisable to prepare for the worst. Measures capable of preventing the spread of the virus should be employed, thereby flattening the curve of infections and avoiding overwhelmed health systems unable to provide essential treatment for common diseases, resulting in avoidable deaths. Historical analyses may provide clues to the feasibility and effectiveness of public health measures in halting the spread of infections. During the influenza pandemic of 1918–1919, non-pharmaceutical interventions introduced across cities in the United States, such as personal hygiene, quarantine and limitations of public gatherings, were implemented unevenly. The key to flattening the curve of infection in 1918 appeared to be social distancing. However, this worked only when introduced decisively and quickly. In relation to social (physical) distancing, a similar pattern may be found during the current pandemic when comparing the effects of the uneven application of this measure in various countries in Asia, Europe and America. Multiple interventions, such as mandatory wearing of face masks and physical distancing, can be expected to delay the progression and decrease the peak of the COVID-19 pandemic. These measures may reduce the potential strain on health care systems and allow more time for collecting representative epidemiological data and for developing therapies. Once the number of new infections has been reduced significantly, widespread viral testing, contact tracing and isolation of people with the virus may be the best way to tackle the pandemic. Following this approach, restrictive measures may be confined to a limited number of people instead of the entire population.The evidence base underlying the assumption of a worst-case scenario and the need for drastic measures such as lockdowns is, at present, insufficient. A major goal should therefore be the collection of representative and reliable data allowing a more profound and accurate risk analysis of the infectiousness and virulence of the virus, the role of predisposing factors (age, other medical conditions, environment), the full clinical presentation of COVID-19 (organs affected other than the lungs), medical care required and the case fatality ratio. The search for effective and safe medications and vaccines should be encouraged. Societies may need to adapt to a modus vivendi that controls the spread of coronavirus while affecting economic, social, cultural and political life as little as possible. Striking a balance between protection of public health and economic considerations will be a challenge facing governments worldwide