STANFORD, Calif. -- West Nile virus survived the winter and may be here to stay.
New York public health officials announced last week that the mosquito-borne virus, which in humans can cause a fatal inflammation of the brain, was discovered in mosquito populations and in several dead crows. Never before detected in the Western Hemisphere, the virus arrived in New York last summer, killing seven people and infecting hundreds.
Now, with the return of summer, North America braces for the annual onslaught of mosquitoes and another deadly outbreak.
Speculation that West Nile virus deliberately was introduced by Iraq rekindled public fear that sooner or later bio-terrorism will strike. The United States has invested heavily in domestic preparedness to cope with both chemical and biological terrorism following the 1995 release of the nerve gas sarin in the Tokyo subway by a religious cult.
Lately, however, public opinion has changed: it has become fashionable to argue that too much is spent on preparedness. But such thinking ignores the fact that most of the expenditures bolster our defense against infectious diseases, such as West Nile virus.
Since many likely biological weapons are naturally occurring pathogens, a covert biological attack may mimic an outbreak of infectious disease and therefore require the same coordinated response of the medical community. The public-health infrastructure -- America's best defense against infectious disease and bio-terrorism -- is in need.
In 1980, the United States celebrated a victory over infectious disease with the first of successive reductions in health spending. Since then, cost-containment policies have diminished the surge capacity of the health-care system and its ability to respond effectively to an epidemic -- be it anthrax or influenza -- among the civilian population.
Despite once-formidable biological weapons programs in Iraq and the former Soviet Union and forays by Osama bin Laden, for example, a large-scale biological attack on American soil remains unlikely.
States that use biological weapons against the United States risk severe retaliation; politically motivated groups that use them may alienate supporters. Biological weapons are perhaps most appealing to apocalyptic or extremist sects. But these groups are usually small and have few resources, and thus their efforts may be limited by technical difficulties in producing and dispersing the pathogens. Indeed, during the past century, a handful of small-scale biological attacks in the United States have caused only temporary illness; bio-terrorism has not claimed a single American life.
In contrast, infectious diseases are the third leading cause of death in the United States (170,000 fatalities in 1999, of which 10 percent were due to AIDS) and the leading cause worldwide.
In the past five years, unusual outbreaks of disease have occurred in all corners of the world; 30 new diseases have emerged since 1973 and many are still without cure. Diseases thought to be retreating -- tuberculosis, malaria and yellow fever -- are making a comeback, and antibiotic resistance has transformed once-treatable conditions into deadly infections. With 2 million people crossing international borders daily, no nation is immune to microbial traffic.
This year's federal budget calls for $1.4 billion to safeguard American citizens from chemical and biological terrorism, part of $10 billion for counter-terrorism efforts.
Recent bio-terrorism exercises in New York City and Washington are perhaps the most visible results of these expenditures, but most of the investment goes toward strengthening the public health infrastructure: improved communications between hospitals and government agencies, deployment of diagnostic tools and detectors, creation of emergency medical teams, stockpiling of antibiotics and developing methods for the rapid production of vaccines.
Although now thought to be of natural origin, the West Nile outbreak highlights the difficulty of differentiating between natural disease and bio-terrorism and the similar response required for either. What if the outbreak had been anthrax or Ebola? How many people would have died before it was even recognized?
West Nile virus, like the attack in the Tokyo subway, sounded an alarm: America is ill-equipped to respond to natural or intentional infectious threats. With continued investment in the public health infrastructure, however, we will be ready for both.
John T. Finn, who received a doctorate in biophysics from Johns Hopkins University, and Tessa L. Walters, a graduate of Harvard University, are fellows at the Center for International Security and Cooperation at Stanford University.