Health authorities are tasked with protecting the health of the population and responding to public health emergencies. An adequate health response to public health emergencies, such as the current WHO-declared COVID-19 pandemic, requires up-todate information. To obtain this information, health authorities have the duty to conduct surveillance and to act without delay on the basis of information obtained. In the context of the COVID-19 pandemic, surveillance is needed to reduce some of the uncertainty that surrounds the virus and its consequences. Health authorities must ensure that the information is collected rigorously, that all relevant cases are reported, and that data are managed responsibly, always taking the benefit of the population into account.