Last week, Andrew Speaker – an Atlanta, Ga., personal injury lawyer with XDR-TB, a form of tuberculosis that is resistant to almost all antibiotics – created a big health scare by exposing fellow travelers to a dangerous infection. Speaker flew from Atlanta to Paris on Air France on May 12 for his wedding and honeymoon, then from Prague to Montreal on Czech Air on May 24 (and subsequently drove back into the United States despite border officials having orders to detain him). As a result, Speaker set off an ongoing international hunt for people who may had come into contact with him during his two weeks in Europe and on both transatlantic flights (some 80 passengers and crew members were thought to be most at risk to exposure).
Speaker’s odyssey demonstrates how ill-prepared the United States is to deal with the potential threat of bioterrorism. Instead of being a tuberculosis patient, imagine if Speaker had been a terrorist infected with smallpox. Smallpox is considered a particularly serious threat because of its high fatality rate (30 percent or more of unvaccinated persons) and transmissibility – a suicide terrorist with the smallpox virus could infect people simply by coughing and sneezing, which can release millions of virus particles into the air.
Speaker was thought to put at least 80 people at risk to exposure to XDR-TB. A study by the Center for Disease Control (CDC) estimated that a smallpox victim would infect about three other people before authorities could administer vaccinations and implement other countermeasures (one of the problems with smallpox is that the initial symptoms are flu-like and thus not likely to be correctly diagnosed as smallpox immediately, so there would be a lag of days to weeks between infection and knowing there was an outbreak). So if Speaker had smallpox and infected 80 people, those 80 people would infect another 240, who would, in turn, infect another 720 people, and so on (it’s worth noting that a British study estimated that a person who contracted smallpox would spread the disease to as many as 12 other people). According to the CDC estimate, if 100 people in a city of 403,000 were exposed to the smallpox virus, the result would be 4,200 smallpox cases and it would take a year to control. But in the case of Speaker, the people infected wouldn’t necessarily all be from one city. In a highly mobile society, the passengers on the same flights as Speaker could have been connecting to other flights destined for a number of different cities.
Because smallpox was considered eradicated in the 1970s (the last known case in the United States was in 1949), people are no longer routinely vaccinated for the disease – which means the population is vulnerable if infected. But since there is also no known effective treatment for smallpox, the only way to protect against infection is by vaccination. However, waiting until there is a confirmed outbreak may be too late – especially if it is an intentional release of the smallpox virus.
Dark Winter was an exercise conducted in June 2001 to understand the implications (not likelihood) of a bioterrorist attack using smallpox released via aerosol at three shopping malls in Oklahoma, Georgia, and Pennsylvania. On day one of the fictional crisis (nine days after initial "exposure"), all that was known was that some two dozen people reported to hospitals in Oklahoma City with flu-like symptoms of a strange illness (there were no similar signs of potential outbreak in Georgia and Pennsylvania, where the dispersion was not as effective but nonetheless resulted in infected people), which was later confirmed by CDC as smallpox. Assuming that each "victim" had infected at least 10 other people, on day six of the crisis there were 2,000 known cases of smallpox and 300 deaths. With only 12 million doses on hand, the reserve of smallpox vaccine was effectively used up on day six. By day 12 of the crisis, there were 3,000 cases and 1,000 dead in 25 states. With the vaccine supply exhausted, the smallpox virus was projected to explode as follows:
Currently, the U.S. government is stockpiling smallpox vaccine to be used in the event of an outbreak or bioterrorist attack. A Food and Drug Administration (FDA) panel of medical experts recently recommended a smallpox vaccine manufactured by UK-based Acambis for approval (Acambis has been making the vaccine for the U.S. strategic stockpile since 2001). And the Department of Health and Human Services (HHS) just announced that it was purchasing 20 million doses of a smallpox vaccine manufactured by Bavarian Nordic (a Dutch pharmaceutical company) to treat people with compromised immune systems. In both cases, however, the vaccine would not be made available to the public (even though it is being paid for by the public).
But if the Andrew Speaker episode is any indication of the government’s ability to respond to a potential bioterror attack using a contagious pathogen, a more effective approach than leaving the entire population at risk and responding only in the event of an actual smallpox attack would be to make the smallpox vaccine available to the general public for voluntary vaccination. Even if only a fraction of the population chose to be vaccinated, there would be a community immunity effect that would lower the rate of transmission of the disease in the event of an outbreak or attack and significantly increase the effectiveness of post-infection vaccination.
If the paramount obligation of the federal government is to protect the United States and its population, when it comes to the potential threat of bioterrorism such as smallpox, an ounce of prevention beforehand is better than hoping a pound of cure will work after the fact.
