Image courtesy of Clark County Health District Office of Epidemiology
The war on terrorism has cast a new, brighter light on the work of epidemiologists.
Even so, the fundamentals of the profession remain the same whether the response is to a naturally occurring disease or a biological weapon.
"Our strongest defense is intensive training in disease detection and control the way we've always known it," said Dr. Patrick O'Carroll, an epidemiologist with the U.S. Centers for Disease Control.
O'Carroll, who is assigned to the University of Washington as an affiliate associate professor of epidemiology, was one of four speakers at a "Bioterrorism and Public Health" forum hosted last month at Metropolitan Park East by the Epidemiology Program of the Hutch Public Health Sciences Division.
In the wake of an incident like the anthrax mailings, the public expects a response that will make it impervious to the threat, O'Carroll said.
"Most people want vaccinations for themselves and their families," he said. "It's a perfectly natural reaction."
But mass vaccination in the face of an outbreak of smallpox, for example, is not consistent with tried-and-true public-health methods, forum speakers emphasized.
Instead, they said that in the event of such a bioterrorist attack, public-health professionals would work aggressively to identify cases of disease, identify those who may have been exposed to those cases and vaccinate and monitor that segment of the population.
For epidemiologists, that's a textbook response. That's how Dr. David Thomas, a PHS epidemiologist and a UW epidemiology professor, helped stop an epidemic of smallpox - one of the most dreaded possible agents of bioterrorist - in Calcutta in the 1970s.
"If it can be done in Calcutta, it can be done in Seattle or anyplace else," he said.
Even so, for many Americans, that strategy may seem too tame if bioterrorists strike, especially if the attack is more widespread than the anthrax letters. That's why it's important to educate the public so people know what to expect if an incident occurs, O'Carroll said.
Another speaker, Dr. Jeffrey Duchin, chief of communicable disease, epidemiology and immunization for Seattle/King County Public Health, said that unlike a chemical, nuclear or explosive attack, a widespread biological attack would thrust public-health workers into the role of first responders. It also, he said, would require them to work closely with entities that they otherwise wouldn't, such as police, fire and the military.
Noting that "we've been disinvesting in our public-health system for years," O'Carroll said the public-health system could look for guidance to the way that police, fire and military personnel prepare for emergencies.
"They drill and train all the time," said O'Carroll. "There's just as much need for intensive training and even conducting drills in public health."
Panelists also noted the need for doing innovative as well as traditional public-health surveillance to detect unusual patterns of disease that might suggest bioterrorism.
By surveillance, panelists did not mean spying, but rather to systematically gather and analyze case reports to identify and track outbreaks of disease at its earliest possible stage.
Locally, Seattle/King County Public Health is working hard to become better prepared to respond to bioterrorism, Duchin said.
That includes beefing up its surveillance capabilities. Although the department has a highly trained Bioterrorism Emergency Response Team, many other employees are not familiar with epidemiology or how to respond to bioterrorism.
"We're now educating large numbers of our staff so they can be knowledgeable, too," Duchin said.
The department also has begun to strengthen communication among agencies and organizations that would respond to a local bioterrorist attack. It also has started to develop consistent criteria for recognizing and reacting to potential threats such as the anthrax-laced letters that circulated on the East Coast, Duchin said.
In the case of threats such as the anthrax letters, it's up to law enforcement to initially determine if circumstantial evidence warrants laboratory testing of a suspicious substance, he said.
But what if terrorists are smart enough not to leave circumstantial evidence, a member of the audience asked.
"You're saying that if it defies detection, how can we detect it?" Duchin responded. "I can't really answer that."
Another audience member wondered if her childhood vaccination against smallpox would protect her as an adult. Thomas said the vaccine is almost 100 percent effective for the first 10 years but weakens as time passes, leaving people susceptible.
"That's the bad news," he said. "The good news is you've got some resistance to the disease, and you probably wouldn't die from it."
Earlier in the forum, Thomas noted that it felt odd to be talking about smallpox after it was eradicated in the 1970s - an occurrence that led to the end of smallpox vaccinations in this country but which has now left half the population vulnerable to viruses saved for military purposes.
Duchin's and Thomas' answers may not have been totally reassuring, but they illustrated the unavoidable risks that bioterrorism presents.
"We're prepared, but we're under-prepared," said Dr. Mark Oberle, associate dean for public-health practice at the UW School of Public Health and Community Medicine, who moderated the forum. "It depends on the nature of the attack."
If a mass attack caused tens of thousands of casualties, it would overwhelm the health system of any area, he said. However, such an attack would likely require logistical support from a foreign government - support that is unlikely to come because it would trigger severe retaliation, he said. Instead, any attacks are more likely to be made by small groups on a small scale, he said, and for that "we're prepared."
Georgia Green, Hutch Epidemiology program administrator, and Dr. Scott Davis, PHS epidemiologist who also chairs the UW Epidemiology Department, organized the forum after attending an Oct. 11 Day of Remembrance at the UW for the attacks on the World Trade Center and the Pentagon.
"I thought it made sense that Center faculty and staff should have more information about the work of public-health agencies in the community after the terrorist attacks," Green said. "If anyone should be armed with accurate information about biological threats and community preparedness, it's those of us in PHS. The more knowledgeable we are, the easier it might make the work of our public-health professionals."