Since it was first detected in Wuhan City, Hubei, China, COVID-19 has been found in about 40 countries. Over 80,000 cases have been identified globally, including nearly 3,000 deaths, a death toll higher than that of the 2003 SARS epidemic. The Centers for Disease Control and Prevention (CDC) just announced the US can expect to see new cases within its borders.

Inevitably, there is much fear about COVID-19. This has been reflected in the global economy, as markets react to the disease. Last Monday, the Dow Jones Industrial Average declined over 1,000 points, then slipped more than 800 points the next day. The London-based bank HSBC Holding PLC has lowered expectations for growth in its Asia markets, and Apple has announced the virus will stop the company from reaching its first quarter revenue targets.

Anxieties about COVID-19 have led to many responses, from the precautionary—such as the widespread purchasing of respiratory masks—to the cruelly counterproductive; namely, a willingness to scapegoat people of Chinese descent.

Such scapegoating is, sadly, an old story. When unexpected, large-scale health challenges strike, especially infectious health challenges, the climate of fear and uncertainty can lead to a belief that some people are especially at fault for creating or spreading the disease. This stigmatization can produce new outbreaks—outbreaks of racism, xenophobia, hate.

Often, these outbreaks target groups which are already marginalized and treated as “the other.” When the Black Death struck Europe in the 14^th century, for example, ignorance of the disease’s true cause led to increased persecution of Jews, beggars, and foreigners.

The past also teaches that when health challenges like COVID-19 occur, it is not uncommon for pseudoscience and misinformation about disease to spread, as anxiety clouds our judgment about the soundness of the information we consume.

Earlier eras brought quack cures like the belief that drinking vinegar could ward off the Black Death, or the mistaken conviction that cholera was caused by miasma, or “bad air.” Misinformation is hardly less prevalent in the era of “fake news” and “alternative facts,” where the basic standards of truth itself have become, to some, open to debate.

We now see misinformation about COVID-19 infection rates, and conspiracy theories about its cause. In this context, it is important that we take a measured approach to COVID-19, hewing closely to what we know about the disease, rejecting unfounded speculation, and not letting fear eclipse our common sense.

So, here is what we know. COVID-19 is an infectious respiratory disease, not unlike the flu. It spreads mainly through coughing and sneezing. Risk of infection remains low for anyone not in direct contact with a patient. Preventing the disease means embracing the same precautions used against other communicable diseases—hand washing, covering one’s mouth when one coughs, reaching out to a health care provider when feeling sick, and avoiding others if one is infected.

For an up-to-date look at the disease’s symptoms, how COVID-19 spreads, and steps for remaining healthy, visit the CDC’s website. Or join us at the Boston University School of Public Health on March 12, for a seminar on the disease, an event which will also be available via online livestream.

And what are we to do to respond to COVID-19?  What can workplaces and institutions do?  

First of all, the epidemiology of the epidemic is evolving and this answer will change as we know more, as patterns of disease become clearer in the US.   But broadly speaking measures of control are those that make sense for other common respiratory illness. 

Common sense precautions that may extend to limiting large assemblies of people and using distance working tools until the epidemic passes. We are not at that place yet in the U.S., and the next few days and weeks will be telling.

But we do know some things that we should do that will not change. Faced with sudden, large-scale diseases, there is a temptation to divide ourselves into “us” and “them,” to build barriers between the healthy and the sick, or those assumed to be at greater risk of infection.

Part of this comes from the reasonable necessity of quarantine and social distancing, which can indeed help control the spread of disease. But this approach assumes that there are groups that are likelier at risk and who are “dangerous” to others.

Such assumptions are simply wrong. Infectious disease know no boundaries and do not stop with personal identities. Even worse, such approaches result in a climate of fear stoking bigotry and divisiveness. These attitudes are dangerous. Not only do they not keep us healthy, they actively make us sicker.

COVID-19 is a public health threat, worthy of international concern. As individuals, we can take prudent steps to protect ourselves. As communities and nations, we can refuse to embrace stigma, and instead work collectively towards better health for all.

Sandro Galea, MD, DrPH, is Professor and Dean at the Boston University School of Public Health. His recent book is, Well: What we need to talk about when we talk about health. Follow him on Twitter: @sandrogalea