Elin Gursky

n the fall of 2001, a series of anthrax spore-containing letters were mailed through the U.S. Postal System. The perpetrators of this act, as of yet, are still unknown. The result was 22 illnesses and five deaths from Bacillus anthracis and a country shocked by its first significant encounter with bioterrorism. One year later, a novel coronavirus, which is believed to have jumped species from a civet cat to a human host, resulted in 8,400 cases of infection across 27 countries, more than 800 deaths and a newly named disease, severe acute respiratory syndrome (SARS).

Such is the reach of microbial threats facing the fragmented public health system and underresourced hospitals of the United States. If we hope to ever address the full spectrum of potential health threats that are now a reality, we must develop a flexible and funded public health infrastructure capable of identifying, targeting and countering the diverse and multitudinous threats of our time as fervently as we have targeted single diseases in the past.

It has been a taxing three decades for public health systems globally. The Centers for Disease Control and Prevention has reported that since the early 1970s, the world has witnessed the appearance of nearly 40 newly identified infectious pathogens, including human immunodeficiency virus (HIV); hepatitis C; El Tor and O139 strains of Vibrio cholerae; E. coli O157:H7; and the viruses responsible for Hanta, Ebola, West Nile, and SARS outbreaks. At the same time, we have observed the newly invigorated spread of several age-old infectious diseases, including tuberculosis and malaria. The Institute of Medicine reports that worldwide, infectious disease has become the leading cause of death and the most daunting barrier to international development and stability. According to the White House Office of Science and Technology Policy, emerging and re-emerging infectious diseases caused the U.S. death rate from infectious diseases, excluding HIV/AIDS, to rise by 22 percent between 1980 and 1992.

The extent of this threat is greater than rising infection and mortality rates, however. These diseases pose a significant threat to domestic and global economies. According to the Institute of Medicine, infections caused by emerging drug-resistant bacteria alone cost the U.S. health care system up to $7 billion annually-nearly 1 percent of total U.S. health care costs. In late April, the global cost of fighting the SARS epidemic-including both the direct costs experienced by health care systems and the indirect costs associated with disrupted commerce, travel and education-reportedly approached $30 billion. The efforts to contain disease while sustaining worker productivity during the anthrax attacks and the SARS epidemic demonstrate the inextricable connectivity of security and economic issues in the global marketplace.

During the anthrax attacks of 2001, public health and health care delivery systems, both in and outside the anthrax epicenters, experienced an inordinate strain on resources from what can be considered a relatively small number of cases. Many public health departments directly involved in the anthrax attacks were overwhelmed by disease investigation and control responsibilities, including case-finding and monitoring, collecting and analyzing biologic and environmental samples, coordinating responses to the news media and answering hundreds of phone calls from the nonexposed "worried well." As a result, little of the routine, yet essential, public health work got done.

Hospitals at the five anthrax attack sites struggled to ensure adequate triage, develop "on the fly" clinical guidelines and coordinate diagnostic and treatment information among colleagues. Although anthrax cannot be transmitted from person to person, the future portends the probability of many large-scale communicable disease outbreaks-including, perhaps, the re-emergence of SARS. In such situations, hospitals will have all too few isolation facilities and air-handling systems to meet the challenges of containing disease spread and avoiding facility-wide contamination and illness.

To build systems that can respond to both naturally occurring disease and deliberate microbial attacks requires vision, flexibility and determination. To halt the spread of disease before it threatens the most vulnerable populations, we must be able to detect the earliest warning signs, whether they be the aerosol release of a bioweapon, the clinical symptoms in a human host or atypical disease patterns in a population. This will take time, because our systems are vast and fragmented. In the meantime, to prevent overwhelming our already limited hospital resources, we must put in place practices to guide people on how to protect themselves in their homes, at school and on the job. Additionally, personal protective equipment, vaccines and medical countermeasures must be available and swiftly administered to ensure the health of emergency workers, first responders and the clinical community so that they, in turn, can reduce the rates of illness and mortality among exposed populations. These steps should be the highest priority for our country's leadership.

Twenty-first century threats of disease must be met by 21st century solutions. Indeed, the technologies, resources and systems that are required to meet the challenges of both deliberate and naturally occurring outbreaks are basically the same. We call this "dual benefit." As public health and health care delivery systems labor to prepare for the next disease eventuality, their efforts-and the investment of federal resources-must focus on that duality of purpose. It is an opportunity we cannot afford to miss. Our homeland security will depend on it.