Screening for the health dangers

The White House recently released its new homeland security strategy and, unlike the initial 2002 version, this one focuses far more on natural disasters as opposed to terrorist strikes. That’s a welcome change not simply because Hurricane Katrina was a humbling experience, but because globalization’s growing connectivity means a naturally occurring pandemic is the most likely mega-disaster we’ll face in the near term.

Undoubtedly you’ve heard about avian flu: long endemic to birds in Southeast Asia, it’s gone global over the last half decade. As it spreads, the virus subtype known as H5N1 naturally mutates, leading researchers to conclude it’s only a matter of time before human-to-human transmission emerges. Among humans who have so far contracted the virus through extensive contact with infected birds, over half died.

A bird flu-triggered pandemic could easily become the most deadly global outbreak since the 1918 Spanish Flu, which killed at least 20 million people worldwide. In the United States alone, over one-quarter of the population became sick, with approximately 600,000 people succumbing to the virus. Extrapolated to today’s American population of 300 million, that yields a potential death count of 1.5 million to 2 million.

The global medical community has already committed substantial resources toward developing potential vaccines, but here’s the trick: once the human-transmission strain emerges, it will take months to ramp up production of the corresponding cure.

Flu strains enter the United States in the bodies of sick travelers, so the key here will be our efficient and effective screening of in-bound passengers at international airports. According to Oak Ridge National Laboratory scientists currently investigating pandemic response procedures for the Department of Homeland Security, for every flu carrier who –unwittingly or not– eludes that envisioned net, as many as 10,000 Americans could suffer exposure within three weeks time.

Consider the sheer volume: over 25,000 passengers arrive through Los Angeles’ international terminals on a daily basis. In August, when a software glitch struck U.S. Customs’ computers there, 20,000 passengers were stranded for up to 18 hours.

Even if we can quickly screen all passengers while pulling aside the suspected sick, tough questions abound.

For each potential carrier, how many diagnostics can DHS reasonably pursue? The current gold standard involves a swab that gets sent off to a lab for testing, resulting in a six-hour turnaround. How would that relatively short quarantine impact flight operations? And who would pay?

If one passenger is clearly sick, does everyone else on that plane get tested? Who would receive prophylactic meds like Tamiflu? And what follow-up tracking is warranted?

Ideally, any systemic approach would include initial diagnostic screens conducted overseas at originating airports. Since virtually all international flights are lengthy, passive diagnostic screening at points of embarkation and debarkation would offer authorities the opportunity to compare and contrast readings over time. For example, additional measures would be warranted if a passenger’s symptoms worsened during the flight or if those symptoms spread to other passengers.

In the summer of 2004 my wife and I got a preview of this sort of screening at Honk Kong’s international airport during a localized outbreak of avian flu cases. As we walked through the terminal with our youngest child, just then adopted from China, I noticed a large computer screen along the wall where our ghostly images were being displayed in real time. It turned out that airport authorities were scanning our body temperatures passively as we passed through a chokepoint.

I walked over to the technicians and asked about the procedure, only to be told that if any of us had registered an above normal temperature, our entire family would have been required to spend at least 48 hours in Hong Kong — at our own cost! — before we could again attempt departure on an outbound flight. Fortunately for us, what turned out to be our infant daughter’s impending ear infection didn’t kick in fully until we were several hours into our cross-Pacific flight. Had we been again screened at our American port of entry, we would have been nabbed, preventing — for all we knew at the time — something far worse from unfolding.

Where do you draw the lines in all of this? I can’t begin to say.

I just know it’s important that our Department of Homeland Security think through all realistic scenarios and gear up for the real-world tests that inevitably lie ahead.

(Thomas P.M. Barnett is a distinguished strategist at the Oak Ridge Center for Advanced Studies and senior managing director of Enterra Solutions LLC. Contact him at tom(at)