Students have quarantined themselves to allay the fears of their roommates. Travel to certain areas is officially discouraged by the University. Harvard infectious disease experts estimate that three million in the Boston area could be infected in six months, with 100,000 deaths.

Nevertheless, it is still too soon to run out to buy more plastic sheeting and duct tape. The disease that has been deemed an epidemic by some news sources has received much more hype than it deserves. In a replay of the 2001 anthrax hysteria, the latest infectious beastie to hit America has brought with it far more fear than fevers and more hand-wringing than hacking coughs.

Fanning out across the globe at jet-speed, the deadly virus that causes SARS (Severe Acute Respiratory Syndrome) is suspected to have made it to Boston weeks ago. The key word here is “suspected.” Although there were nine “suspected” cases of SARS in Massachusetts as of Friday, none of those possible cases has ended in death. Nevertheless, the virus long ago claimed its first victim in Boston with the death of a sense of proportion about the risks of the disease for most people.

Part of the problem is that health officials have made the definition of the disease so broad that common respiratory viruses are likely showing up as SARS cases. Doctors are having trouble sorting SARS out from everyday infections. The resulting inflation in the number of suspected SARS cases stokes the public’s anxiety. Many of those suspected of suffering from SARS were not even hospitalized, according to the Massachusetts Department of Public Health. Thus, if there are SARS infections in the state, there are probably fewer than the numbers suggest.

“The problem is how do you know whom to put into that kind of care, how do you know who’s dangerous and who’s not,” Harvard Medical School Professor of Pediatrics Kenneth McIntosh ’58 told The Crimson earlier this month. “The answer is, all you can do is guess, because there’s no way of knowing exactly.”

Another problem is the dire predictions and catastrophic language being used to describe the spread of the disease. Headlines calling the disease an “epidemic” when the number of people possibly infected in this country is still miniscule make the disease appear much more serious and widespread than it has proven so far. (Although China, as usual, has been prevaricating about the extent of infection, and it might be larger there than Beijing admits.) Harvard’s recommended moratorium on University-related trips to East Asia is overcautious. The recommendation has added to the sense that SARS is something especially dangerous and contagious.

But the facts point to a different conclusion. Although SARS can kill, it has caused much more fear and economic devastation than the death toll might suggest. For example, there were 1,059 reported cases of SARS in Hong Kong as of Saturday, according to the South China Morning Post, with 32 reported deaths. Although the disease appears to be communicated easily from person to person, it seems to require close contact with an infected person. Most of the cases have been tracked back to single locations where one sick person infected many others. Moreover, there are 6.8 million people in Hong Kong, which means a there are now more than 60,000 people not infected for every infected person. The recovery rate is high, and the dead are more likely to be elderly or infirm. Epidemiologists using standard models for disease outbreaks now say that the disease has been mostly contained, according to the World Health Organization.

So why has SARS mania spread faster than lice in a pre-school? One explanation is the unwillingness of public health authorities to take any threatened disease lightly. If SARS were to cause many deaths in the U.S., public health authorities would look foolish if they failed to mount a vigorous response in the initial stages of the outbreak. This uncertainly gives officials an incentive to play up the threat of the virus.

To put SARS in perspective, plain influenza (which comes from southeast Asia and probably exploited the same mechanism that SARS did to become infectious) kills between a quarter and half a million people each year. The deadly Hantavirus, which was discovered in the U.S. in 1993, kills half of its victims. By contrast, SARS kills only about four percent if its victims, and has infected about 2,700 people as of Saturday.

New diseases should always be treated with caution, but the old ones are still the most deadly.

Jonathan H. Esensten ’04 is a biochemical sciences concentrator in Lowell House. His column appears on alternate Mondays.