The field of “public health” is often thought to focus on national or international issues such as vaccination policies and global pandemics. But in reality, public health impacts our communities locally as well, from hospital operations to the food we keep at home. Although the field has evolved to meet shifting challenges, the principles of public health have remained largely unchanged. From cholera outbreaks in the mid-1800s to the present day, the field has been dominated by an overarching goal of using evidence, not speculation, to drive decisions that keep the public as safe as possible. Today, public health officials are as likely to target systemic illnesses as acute outbreaks, but the foundation of any intervention is data.

The challenge with data has traditionally been ensuring its reliability and gathering it with sufficient speed. The nature of an illness can hinder data collection, especially if the threat is so potent that local agencies cannot safely gather data, as was the case during the Ebola outbreak of 2013-2014. Political and societal forces can also prevent research into a public health threat (for example, in war or conflict zones).