First line of defense

They’re medicine’s SWAT team, intrepid warriors who are swiftly dispatched to global hot zones.

Whether a commonplace infection is sickening a city, an exotic microbe has hitchhiked on an international flight, or a deliberate contamination has panicked a nation, members of the Epidemic Intelligence Service are on the front lines, trying to prevent the spread of deadly diseases.

An arm of the U.S. Centers for Disease Control and Prevention in Atlanta, the service was founded at the dawn of the Cold War to monitor and contain epidemics -- and to serve as an early-warning network for possible biowarfare. Its mission is just as timely today.

With continued fears of bioterrorism, especially as we approach the second anniversary of the anthrax attacks, this once little-known medical cadre has assumed a much higher public profile. In an effort to increase the nation’s emergency preparedness, Health and Human Services Secretary Tommy G. Thompson recently beefed up funding so the service could post 20 additional officers -- supplementing a current staff of 167 serving in state and local health departments. And in July, in recognition of the officers’ unique role in fighting global disease, the World Health Organization announced plans to launch its own version of the service.

In the more than half-century since its inception, officers with the EIS have had a hand in more than 10,000 investigations. They spearheaded the global drive to eradicate smallpox and polio, discovered how the AIDS virus was transmitted, investigated outbreaks of West Nile and SARS, battled cholera in Guinea-Bissau and Ebola in Uganda, and helped search for the killer who masterminded the anthrax attacks.

“The community is our patient, not individuals,” says Dr. Bhrett Lash, Los Angeles County’s EIS officer.

“You get to see parts of the world you’d never see as a regular doctor,” says Dr. Laurene Mascola, a former EIS officer and now chief of acute communicable disease control for the Los Angeles County Department of Health. On any given day, the officers may be checking out an outbreak of TB in the local jail, says Mascola, or jumping on a plane to battle syphilis in Ethiopia, as she did during her EIS stint in the 1980s.

“We’re more of a global village,” says Dr. Robert Kim-Farley, a former field officer for the EIS serving in China and Africa and now stationed in Los Angeles with the CDC’s bioterrorism preparedness program. “Diseases know no boundaries and need no visas to cross borders.”

Normally, the source of an outbreak is not clear-cut. Typically, someone will show up in a doctor’s office or in a hospital emergency room feeling deathly ill. Local health officials, along with EIS officers, may be aware that another patient -- or perhaps two or three others -- was complaining of similar symptoms in another part of town, or in another state.

Several things will raise red flags: someone complaining of a rare disease, such as cholera; a group of patients who are suddenly stricken with a relatively uncommon disorder or who ingested unusual medicines; or someone who fell ill en route from a foreign country, such as an elderly Argentine man who came into one local ER recently complaining of watery diarrhea and was later diagnosed with cholera.

“The first step is determining what’s causing the outbreak -- the flu, the Norwalk virus or something else,” says Kim-Farley. Specimens of blood, bodily fluids or tissue samples are collected by EIS officers and other public health workers, then shipped to local health department labs for a diagnosis.

The officer then relays the results to the CDC in Atlanta, which monitors nationwide disease trends. By looking at the cluster of cases, sometimes a clear signal as to the source of the outbreak will emerge that can be heard above the noise of routine ailments.

Other times, however, unmasking the culprit requires weeks of work and entails sifting through reams of information to find the common entry point. Maybe all the victims went to a petting zoo. Maybe they all ate hot dogs from a particular booth at the county fair.

The tools EIS officers use to collect evidence are similar to those used by other sleuths -- interviews with witnesses and victims, maps dotted with pins where outbreaks occur, laboratory and forensic tests -- all done in hopes that patterns will emerge.

In 1985, for instance, the food-borne pathogen Listeria sickened 142 people, killing 48. When the first reports came trickling in, county health officials called local hospitals to see if there were any other cases, and soon realized they had an epidemic. Because those taken ill were usually pregnant Hispanic women, EIS officers and public health officials began trying to determine what the victims had in common.

“What do pregnant Hispanic women do that’s different than non-Hispanic pregnant women? Their diets,” says Mascola, “and that’s what we focused on.” Sure enough, the source of the infection was traced to contaminated Mexican cheese made at a plant in Artesia.

In October 2001, when a supermarket tabloid’s photo editor was sickened by anthrax, EIS officers worked round-the-clock in tandem with the FBI and state and local health departments to uncover the source of the deadly infection.

When two of the editor’s co-workers subsequently tested positive for anthrax, investigators uncovered anthrax spores in the tabloid’s mailroom. Soon after, an assistant to Tom Brokaw at NBC headquarters in New York developed anthrax after opening two envelopes.

Scientists realized that media outlets were the targets, and anthrax was being spread through the mail. Though the perpetrator has not yet been unmasked, because health officials realized the spores were moving through the mail, steps were taken to protect the public.

The anthrax scare, however, illuminated weak spots in the public health surveillance system, which officials have taken steps to repair. One problem, says Mascola, was the lack of communication between federal, state and local public health agencies. This slowed mobilization efforts in response to the attack and resulted in Americans receiving conflicting information from different agencies about the severity of the outbreak, and about how best to protect themselves.

Since then, public health officials have created a more cohesive national network, and forged stronger ties with other agencies responsible for health and safety, such as the FBI and local fire and police departments. In addition, money has poured in to local health departments to beef up disease detection systems, such as monitoring the air quality in post offices to identify biological agents, and to train medical epidemiologists.

“When SARS came along, there was a much faster, more efficient response,” says Mascola, “and it seemed like the machinery was really in place.”

Still, officials admit they dread the worst-case scenario, one in which they’re fielding 50 calls at once, with hundreds of people in several buildings that have possibly been contaminated with a highly infectious agent.

“But we’d respond to the challenge,” says Mascola. “We’d just grab everyone we have and make them work eight times as hard.”