It was the perfect biological crime—almost. The year was 1978. A man stood waiting for a bus in London when someone jabbed the back of his thigh with an umbrella tip. Georgi Markov, a Bulgarian dissident, was known for broadcasting anti-Communist messages on BBC radio. The umbrella tip breached his initial line of defense, the skin. He felt immediate pain at the puncture site. Inside his body ricin toxin, delivered in a poison pellet by the umbrella’s sophisticated, hidden air-injection mechanism, began killing him silently.
Although not one of the six top threat agents (Chessmen), ricin toxin is the perfect weapon for a Cold War spy. Easily made from inexpensive, accessible ingredients—castor beans—it is potent and lethal. Most doctors wouldn’t think of it, so the cause of death would be missed. An injection of only half a milligram, just enough to fit on the head of a pin, could have been enough to kill Markov. There is no antidote. The toxin binds to cells, which invite this Trojan horse in. Once inside it blocks protein production, throwing a wrench into the cell’s cogwheel, and overwhelming its repair mechanisms. The cells begin to die.
Death by ricin is agonizing. Cells near the injection site in Markov’s leg would die first, causing severe pain. Local lymph nodes, the body’s next line of defense, attempt, unsuccessfully, to block further invasion. Other cells throughout the body start to die. The small intestine lining disintegrates, leaving a raw, denuded surface that oozes blood into the bowel. Victims can bleed into their brain, heart, and chest.
Within five hours Markov felt weak. The next day he developed a fever, nausea, and vomiting. He sought care within thirty-six hours of the attack, but the swollen lymph nodes in his groin and the thigh lesion baffled his physicians. Within two days his pulse climbed to 160 beats per minute, and the bottom fell out of his blood pressure. On day three Markov’s kidneys shut down, and he vomited blood. His heart’s electrical conduction pathways short-circuited, and he died an agonizing death.1
Ten days before Markov’s attack, another Bulgarian dissident, Vladimir Kostov, felt a jab in his lower back while walking in a Paris metro station. He also turned to see an attacker with an umbrella, but he only developed a fever. When he learned of Markov’s death, he became suspicious and visited his doctor, who found buried in Kostov’s back a tiny hollowed-out platinum-iridium ball the size of a ballpoint pen tip. It was filled with ricin. The assassination weapon, hidden inside an umbrella like something “Q” would develop for James Bond, was created by the Bulgarian Secret Service and the Soviet KGB. Spring-loaded and powered by a carbon dioxide canister, it injected the poison pellets coated with a waxy substance into the flesh of its victims. At body temperature the wax melted and released the toxin. Unlike Markov, Vladimir Kostov dodged the “bullet.” The thicker tissue in his back may have kept the poisoned pellet from penetrating deep enough to fully melt the pellet’s coating.
Biological weapons have a range of potential uses, from the individual assassination to the next level, targeting tens to hundreds of victims. We fear most the well-funded terrorist or the military adversary with access to the highest threat agents, like the six Chessmen, the ability to produce them in large quantities, and the intent to kill or incapacitate hundreds to thousands.
The Aum Shinrikyo, a doomsday cult in Japan, presents such a frightening worst-case scenario. Armed with millions of dollars, scientific personnel, and the intent to kill thousands, the cult was enamored of biological weapons. Its adherents first sprayed a cloud of anthrax slurry from the roof of an eight-story building in Tokyo. No one got sick. Next they tried to disperse the agent by driving through the city with trucks emitting anthrax through vents. Again, nothing. It turns out they had chosen the wrong anthrax strain: one developed to vaccinate cattle. After they made similar, unsuccessful, attempts with botulinum toxin, they shifted to chemical weapons. In 1994 they had a vendetta against some judges over a real-estate lawsuit in Matsumoto, Japan. They used the opportunity to test a homemade chemical weapon and released the nerve agent sarin on an apartment complex where the judges resided, killing seven and injuring over three hundred. After this successful attack, they sought a much larger target in 1995: Tokyo. Using plastic bags filled with liquid sarin, they poked holes in the bags with umbrellas. The agent spilled onto the floors of subways headed toward central Tokyo, killing twelve and injuring thousands.
Although the mistakes made by a well-funded organization like the Aum demonstrate that executing a large-scale bioweapon attack is not simple, it is not hard to understand the appeal of bioweapons. The incubation period of microbes (the delay between exposure and when victims become ill) allows the perpetrator to escape halfway around the world and sit on the beach nursing a gin and tonic before anyone knows what hit him. Some of the agents have vaccines, so the perpetrators can protect themselves. And with disease to cover their tracks, the perpetrators may throw off the scent of public health authorities who may assume the deaths and illnesses occurred naturally. It’s hard to figure out when illnesses are not due to natural causes.
That’s what happened in the Dalles, Oregon.
The Baghwan Shree Rajneesh, a spiritual leader with a long white beard and a penchant for Cadillacs, established a commune in 1981 on a ranch near the sparsely populated (<50) town of Antelope, Oregon. In the ensuing years, the “Rajneesh Purim” commune grew to over seven thousand members and developed escalating tensions and legal battles with its neighbors and the town.
Armed with a microbe weapon created by nature and using a laboratory on the compound, the commune’s chief nurse grew Salmonella typhimurium—a cousin to the agent that causes typhoid fever. This was a strategic decision—to pick an agent that would cause severe diarrhea but not kill people. Typhoid fever kills. A rare and deadly agent like typhoid might raise too many alarm bells.
In a series of attacks in the fall of 1984, commune members secretly contaminated food and salad bars at ten restaurants in the local community. Then they sat back to watch the results: 751 people became sick with salmonella infection. Local public-health authorities recognized the outbreak and investigated. Some foodborne outbreaks can be linked to a sick employee. None could be found. When an outbreak occurs at multiple restaurants, the contaminated foods at each restaurant should be the same or come from a common supplier. They didn’t.2 The investigators knew the outbreak didn’t match the normal pattern of a foodborne outbreak, but they couldn’t pinpoint the cause.
A year later a cult member confessed to the crime, but what was the cult’s motivation? The commune had hoped to keep nearby residents away from the ballot box to manipulate the local elections in a unique and sinister way—by making them sick. It was a tactical victory but a strategic defeat. The cult succeeded in making people sick, but it didn’t win the election. An internal schism drove some leaders to flee the compound. The nurse who orchestrated the attack was arrested and jailed. The Baghwan fled the country, and the other members disbanded. Today, the compound serves as a religious summer camp.
Sometimes the terrorists aren’t quite as sophisticated. In October 1996 someone brought donuts and pastries to share in the microbiology laboratory at a Texas hospital. A couple of days later, twelve out of forty-five lab staff came down with severe diarrhea, caused by Shigella dysenteriae, a bacterium that causes bloody diarrhea. When authorities investigated the outbreak, they linked it to the pastries, but they identified some odd aspects. They found no other local shigella outbreaks, so they couldn’t blame the commercial pastry vendor. The strain of shigella that caused the outbreak was rare—with no cases in the community for years—but they found the microbial “smoking gun”: a sample in the lab refrigerator that matched the strain isolated from the victims and the pastries exactly. There was no reason for that control strain to be out of the fridge, so accidental contamination from lab error was unlikely.
It helped that authorities caught one of the hospital lab workers, Dianne Thompson, on video bringing the pastries into the lab, which required a combination for entry known only to the lab workers. Oh, and she used her boss’s account to email her coworkers, inviting them to enjoy the pastries.3
Using a strict definition, Dianne Thompson perpetrated a biocrime, rather than bioterrorism, because no one could identify a specific political, religious, or ideological motivation for her crime. We still don’t know why she wanted to make her coworkers sick.
We can’t peer into the mind of a terrorist. Sometimes the terrorist wants to gain a little publicity or just scare people. Whether it’s leprosy, HIV, plague, or Ebola, infectious diseases frighten us, can create panic, make us want to run and hide, and can turn neighbor against neighbor.
It doesn’t take much for a terrorist to prompt that natural, visceral fear of contagion. In April 1997 the B’nai B’rith mail room in Washington DC received a suspicious package leaking a red liquid. Inside was a petri dish with a threatening note, warning of the presence of anthrax and plague bacteria. Some employees complained of headaches, prompting fear of a chemical weapon attack in addition to bioterrorism. The security director called 911.
Within view of rolling CNN cameras, emergency response crews had approximately thirty employees strip to their underwear and hosed them down outside the building. The package was later deemed to be free of chemical and biological weapons, but that didn’t matter. The damage had been done. The hyper-response was a terrorist’s dream come true, making the national headlines, complete with the vivid video footage. Numerous similar hoaxes followed over the next several years after my arrival at USAMRIID, until local law enforcement and health departments learned how to handle them in a more measured fashion.
The six bioweapon Chessmen at the top of the threat list possess different qualities that a terrorist may find attractive. Only the “bishop” (plague) and King Smallpox spread easily from person to person through a cough or a sneeze. Ebola and other “knights” (viral hemorrhagic fevers) can spread too, but not without very close personal contact. All these transmissible agents can give the “gift” that keeps on giving. Once the infection is started, nature does the work for the terrorist, as one family member infects another, who then transmits it to a coworker, who coughs on someone at the mall, who spreads it on a plane, who brings the contagion home to another family on the other side of the world. The downside for the terrorists: they might catch the contagion they started, unless they have a way to protect themselves.
Some agents kill better than others. Ebola and Marburg sit atop the bioweapon “pyramid,” killing up to 90 percent of victims in African outbreaks. We have no licensed countermeasures for either one. Plague and anthrax can kill just as efficiently, but if recognized early, we have effective antibiotics that can significantly improve victims’ chances of survival. The death rate for botulism is highly variable, but like on a chessboard, a strike by the meager “pawn” can surprise. The first victims to become intoxicated (i.e., affected by the toxin) and paralyzed in a naturally occurring outbreak have the highest death rates because physicians may not immediately recognize the cause. Once diagnosed, though, quick treatment with the botulism antitoxin can limit the extent of the paralysis and save lives.
The human body has great protective shields against deadly pathogens. The skin provides a significant armor barrier. Our stomachs secrete acid to block entry into the digestive tract, and mucus and the cilia in our windpipes protect us against inhaling an organism. The problem is that these barriers can be breached or bypassed.
Organisms sprayed into the air may or may not infect us, depending on their size. This is a significant technical hurdle for “weaponizing” an agent: making it the ideal particle size to create an efficient killer. Anything below about one to two microns (10–6 micrometers) acts like a gas and floats in and out of our lungs without landing. Anything greater than about ten microns is too large to get into the deep recesses of the lungs. The mucus lining the air passages will capture the pathogen, and the cilia will push it out, like crew racers rhythmically beating their oars against the water. Eventually, the individual coughs up or swallows the invading pathogen. Particles between two and five microns are the deadliest because they can fly past the mucociliary blanket, land deep in the lungs, and start their deadly cascade.
Bioweapons don’t do so well when released by an explosive device because living organisms die in the heat and light of the explosion. But that shouldn’t provide any reassurance. Common crop dusters or other spray devices can be configured to release the particles in the “ideal” two- to five-micron range.
Some agents can infect farther downwind than others. If we had sufficient warning of a bioweapon attack, we could significantly reduce the number of ill and dead, but unlike bombs, chemical agents, or nuclear weapons, attacks with bioagents can occur covertly. We only find out sometime after the attack, when sick people seek out their doctors.
Some agents are harder to make than others. It’s a lot easier to grow bacteria than viruses, like making beer, wine, or yogurt. Just swab some bacteria on a petri dish or squirt them into a nutrient soup. Add the right ingredients, some oxygen (or not, in the case of botulinum toxin), turn the incubator to the right temperature, and nature goes to town churning out instruments of death.
Viruses take a little more finesse. They can’t grow by themselves, so they hijack a living cell to crank out their progeny—a much more temperamental process. Some viruses can also grow in chicken eggs. That’s how the raw material for the flu vaccine is made every year.
Some agents are easier to obtain than others. You can scoop up some dirt outside your house to get Clostridium botulinum spores to make botulinum toxin, and you can find castor beans just about anywhere to make ricin. The multicolored, black-dotted beans are frequently used to make jewelry. It’s a lot harder to get a sample of Ebola virus—you’d have to fly to sub-Saharan Africa during an outbreak and take some blood from a victim, or isolate it from a fruit bat flying around the forest canopy—not so easy. In fact no one has isolated Ebola from bats yet, even though we think it spreads between fruit bats when humans aren’t spreading it. Plague or anthrax may be easier to obtain. You could look for anthrax spores in the soil, if you knew where cattle had died from anthrax along the old Chisholm Trail stretching from Texas to Kansas. Fleas spread plague among small rodents, prairie dogs, and ground squirrels in the four corner states of Colorado, Arizona, New Mexico, and Nevada. Catch some infected fleas, grind them up, and try to grow plague. The bacteria that causes tularemia also lives among small rodents or wild rabbits in several parts of the country, particularly Arkansas. Smallpox virus only lives in humans. Since its eradication from human populations, you won’t find it in the natural setting anymore. It is kept locked behind multiple layers of security at the CDC in Atlanta and the Vektor Institute in Russia. Breaking in to get it would be an undertaking, like trying to steal the Crown jewels or Tom Cruise stealing the “NOC” (nonofficial cover) list in Mission Impossible.
Chemical and biological agents are frequently lumped together as “weapons of mass destruction,” but they have significant differences regarding how many people they can affect and how we defend against them. Mother Nature made bio agents. Humans dreamed up chemicals. They kill in different ways.
Although commonly called “gases” (i.e., mustard “gas” and nerve “gas”), many chemical warfare agents are really liquids. Sarin is approximately the consistency of water, whereas VX is more like corn syrup, but both nerve agents are volatile and evaporate. The vapors kill even if you don’t get the liquid on you, hence the confusion with gases. That is why liquid sarin nerve agent spilled on the floor of the Tokyo subways killed people. If someone spills a chemical agent on the floor, it volatilizes quickly. By the time you smell the characteristic fruity odor of a nerve agent (Tabun, Soman) or the mustard or garlic odors of some of the blister agents, it may be too late.4 You’ve been exposed. Bio agents don’t get into the air that way. They need an energy source: a cough, a sneeze, a spray device, or a fan to make them airborne. If you spill them on the counter without such a source, they usually just sit there, harmless.
The other major difference is that your skin shields you against most bio agents, unless you give them an entry by scratching, cutting, or piercing it with an umbrella tip or other sharp object. Not so with chemical agents. They go through intact skin, like shit through a goose, straight into the bloodstream rapidly. That’s why a mask and goggles may prevent exposures to bio agents, but chemical agents require heavy clothing lined with charcoal to absorb the chemicals and keep them away from your skin. Unfortunately, the protective gear for chemical agents makes you sweat like a pig. Soldiers are all too familiar with wearing this heavy “MOPP” gear (for mission oriented protective posture). Those scary-looking gas masks seen in World War I photos look that way for a reason. Chemical protection requires a fully encapsulating face shield along with specialized air canisters with extra layers to absorb the chemicals to protect the eyes, nose, and airways.
Because chemical agents are volatile, they don’t spread very far downwind. Instead, once released, they evaporate into the atmosphere. When I teach about the differences between chem and bio, I show a picture of the Washington Monument, in Washington DC. Then I overlay the “footprint” from release of sarin nerve agent at the base of the monument. Like explosive devices, its impact zone stretches only a couple of city blocks. Compare that to anthrax, which can spread over the entire Washington DC metro area.
Understanding how the agents make us sick or how they might be used is only a small piece of defense. We need to exploit that knowledge to find ways to protect against them. As we saw with the Rajneesh salmonella attack, unfortunately we can’t predict which agent a terrorist might choose, and we’ll never have countermeasures for everything.
After 9/11 we had some experimental vaccines in the freezers for several of the agents, but we didn’t have the luxury of time to develop new countermeasures. We needed to use the tools we had because war was approaching faster than I imagined.