In the fall of 2001, friends worried about anthrax started asking Philip Alcabes, an epidemiologist at Hunter College, if they should be ironing their mail. Alcabes was struck by how these New Yorkers seemed more alarmed by the anthrax panic, in which five people died, than they were by the World Trade Center attacks, which claimed 2,752 lives. Alcabes’s new book, Dread (Public Affairs, $26.95), is about the complex relationship between epidemics and the fears, anxieties and misconceptions that surround them.   —Christine Smallwood

What links modern epidemics with cholera and the plague?

Some of the ideas people have about epidemics today are really just the latest chapter in a very long story. The fear of the stranger goes back at least to the plague of Athens, around 400 BC. Thucydides wrote that people said it came from Ethiopia, which was the Athenians’ name for part of Africa. Already at that time people were talking about epidemics to verify anxieties they had.

Do you have a favorite anecdote from the book?

There’s a line in Susan Sontag’s essay "AIDS and Its Metaphors" about how during the time of the Black Death, cities and towns in Western Europe killed Jews. By my estimate, at least 10,000 Jews were killed in a quite organized way during a very short period, two or three years, in the late 1340s when the Black Death came. Now, the killing was organized, for the fourteenth century, but it turns out that many people didn’t really hold the Jews responsible for the plague. In fact, they often burned or killed Jews or expelled them before the plague arrived. Fortunately, we generally don’t burn people at the stake anymore when we think there’s an epidemic coming, but you do see this same kind of panic.

Where do you see that happening now?

We’re less insistent that the epidemics we talk about concern diseases at all, or have a definable set of causes. We talk about epidemics in order to point the finger at someone we suspect, or to highlight the way that some social crisis seems to be a validation of some set of anxieties. The leading example is the obesity "epidemic." Obesity wasn’t talked about as a disease until the mid-’90s, and the panic about obesity is even more recent than that. Although it does seem there are people for whom obesity is really dangerous and maybe deadly, the best study I know of attributes a little less than 5 percent of American deaths to obesity in some way or another, but something like 34 percent of Americans are considered obese by the body mass index standard. Most of the obese are not dying of obesity. In fact, most of those who are labeled obese don’t get the leading diseases that can be produced by obesity, which are diabetes and hypertension.

What’s going on?

For Americans, there’s an endless conflict between the Apollonian and the Dionysian. We’re always enthralled by our own appetites and also repelled by them. There is very little concern for the suffering of people who are overweight. If we’re adducing evidence that people who are overweight and obese get sick, then you would think that we would be concerned about the pain and suffering that arises from the illness. But in our society we think thin is beautiful, and therefore there’s a social marginalization that comes from being extremely fat, and maybe not even extremely.

There is a persistent idea that epidemics are punishment.

We know enough about the hegemony of the Catholic Church when the plague came to late medieval Europe in 1347 to say that people thought it was a punishment from God because they hadn’t been worshiping properly. And yet, AIDS comes in the 1980s, and quite educated people are talking about it as a punishment for tolerating homosexuality. It may not be surprising that the real ancients, before the Hebrews, before the ancient Greeks, understood disease as enchantment: you got sick because the spirits were up to something. Despite all our science and our devotion to science–there’s a way that science is a secular religion today–we often have these suspicions about punishment, that something bad is being done by unseen spirits.

Does germ theory obscure the social conditions of disease?

Among some reformers there’s an impetus to improve the lot of the poor, for reasons of charity or justice or practicality–those people are ill dressed and ill washed and ill fed, they’re going to get diseases that they could spread to us, so even though we might not care about them, it might be in our best interest to help them out. In fact, that’s an important impetus for the beginnings of liberal social reform in England in the 1830s. In a way, germ theory scotches a lot of the discussion about helping the poor, because germs provide a focus for those same kinds of worries, fantasies and fears about punishment, enchantment and bad spirits. Germs take on much of that anxiety and deflect attention from the lot of the poor.

You’ve written that it’s impossible to eliminate risk from life.

I think life’s short and everybody dies. Something bad is going to happen, and it will happen to you one day. Your hope, like mine about myself, is that it will be a long time from now. Do I think that means we should just lie down and take it? On the contrary. We could do a lot more to alleviate people’s suffering. Even the health professions are not sufficiently concerned about suffering. It’s often easy for us to mount these crusades about obesity, or crystal meth addiction, and lose sight of the way that people suffer because of these things and are harmed or stigmatized by the very crusade that’s been mounted, apparently, to help them.