Detecting and Responding to Anthrax Bioweapons
Detecting and Responding to Anthrax Bioweapons
On September 18, 2001—a week after the September 11 al-Qaeda terrorist attacks on the Pentagon and World Trade Center—letters containing anthrax spores were sent to Tom Brokaw at NBC news, Peter Jennings at ABC news, Dan Rather at CBS news, and to the editor of the New York Post. The letters passed through a mail-sorting facility in Hamilton, New Jersey. Two employees at the New York Post, two NBC workers, an employee at CBS, six local postal workers, and a baby who had visited ABC all became ill. The illnesses were not immediately recognized as anthrax, but the victims received medical treatment and recovered.
Two weeks later, in early October 2001, Robert Stevens—a photo editor at the Sun (a tabloid newsmagazine) in Boca Raton, Florida—died from an undiagnosed disease. Two other employees in the building also fell ill but were treated and recuperated. The illnesses were later identified as anthrax, and Bacillus anthracis spores were traced to a mail bin in the building.
Soon afterward, in mid-October, anthrax-spore-containing letters were sent to Senator Tom Daschle of South Dakota and Senator Patrick Leahy of Vermont, who work in the Senate office buildings in Washington, D.C. On October 17 anthrax spores were also found in mail bins at the House of Representatives in Washington, D.C. The Capitol Hill buildings were closed for cleaning, and hundreds of congressional workers were told to start taking the antibiotic ciprofloxacin to protect them from anthrax.
The mailed anthrax spores were examined by scientists at the U.S. Army Medical Research Institute of Infectious Disease (USAMRIID) at Fort Detrick, Maryland. The experts found that the anthrax powder in the Senate letters was "professionally done" and "energetic,"41 meaning that the spores wafted into the air to form a spreading cloud. This is a characteristic of weaponized anthrax. In addition, scientists discovered that the strain of anthrax in the letters was identical to a strain being studied at USAMRIID.
Moreover, researchers found that though the letters were tightly sealed and taped, the anthrax spores were small enough to squeeze through pores in the envelopes when the letters passed through mail-sorting machines. Government investigators believe, therefore, that the terrorist (or terrorists) had not meant to infect postal workers or the general public. Nevertheless, in October 2001 five postal workers in Washington, D.C., fell ill. Joseph P. Curseen Jr. and Thomas L. Morris Jr., who worked at the Brentwood mail-sorting facility in Washington, D.C., developed inhalation anthrax and died. The other victims in Washington, D.C., were treated and survived. The Brentwood postal facility was closed soon afterward, and two thousand postal workers were instructed to start taking antibiotics.
About two weeks later, on October 31, a New York City hospital worker named Kathy Nguyen died of inhalation anthrax. She did not work or live near a building where anthrax had been found, and no one knows how she contracted the disease. A similar incident occurred on November 30, when Ottilie Lundgren, a Connecticut resident, died of inhalation anthrax. Researchers speculated that the women may have handled mail that passed through an anthrax-contaminated postal facility.
When law enforcement officials realized the United States was in the midst of an anthrax attack, the Federal Bureau of Investigation (FBI) obtained and analyzed the four anthrax letters that had been found (though more were apparently mailed). The September 2001 letters sent to news outlets in New York City read:
THIS IS NEXT
TAKE PENACILIN NOW
DEATH TO AMERICA
DEATH TO ISRAEL
ALLAH IS GREAT42
The October 2001 letters mailed to senators in Washington, D.C., said:
YOU CAN NOT STOP US.
WE HAVE THIS ANTHRAX.
YOU DIE NOW.
ARE YOU AFRAID?
DEATH TO AMERICA.
DEATH TO ISRAEL.
ALLAH IS GREAT.43
After a massive investigation FBI profilers concluded that the anthrax terrorist was a white, American, male scientist associated with USAMRIID or another U.S. bioweapons laboratory. Experts suspected that the culprit had dated the letters "09-11-01," and included the phrases "Death to America" and "Allah is Great" to cast suspicion on Arabs.
Eventually, the FBI identified Steven Hatfill, a scientist and former bioweapons researcher at USAMRIID, as a "person of interest" (suspect) in the investigation. However, after two years Hatfill had not been arrested, and in September 2003 the scientist filed a lawsuit against the Justice Department, claiming it had violated his constitutional rights and damaged his reputation. No other suspects in the anthrax attacks were identified, and the case remains unsolved.
Though tragedy resulted from the 2001 anthrax attacks, the damage was minor compared to what might have happened if there had been a massive bioterrorist assault. Moreover, development of biological weapons and terrorist activity has increased alarmingly since the close of World War II. Thus, the United States and its allies have been taking steps to protect themselves from anthrax and other bioweapons.
The Danger of Anthrax Attacks
Military experts have become especially fearful of state-sponsored terrorist organizations. William C. Patrick, who developed anthrax bioweapons at Fort Detrick, Maryland, remarks, "I don't think that Tom, Dick, and Harry terrorists, without significant training and experience … could develop an agent that would cause serious harm to this country. My biggest concern now is a rogue country that supports state terrorism and has the facilities to prepare, for example, a good dry powder of anthrax."44 Patrick speculates that terrorist organizations might disperse anthrax powder in buildings and subway systems, causing serious harm to American civilians.
Because of the danger of anthrax attacks, the United States has been seeking ways to protect its population from Bacillus anthracis and other bioweapons. Military officials believe an anthrax attack would probably involve the release of anthrax spores in the form of a spray, called "aerosolized anthrax," that could spread quickly. The Working Group on Civilian Biodefense, an expert panel assembled by the Center for Civilian Biodefense Studies at the Johns Hopkins University Bloomberg School of Public Health, notes that aerosolized anthrax could be widely dispersed within a few hours to one day. Thus, there would be little time to destroy the spores or provide antibiotics to affected populations. Moreover, aerosolized anthrax is invisible. Therefore, the first evidence of an anthrax strike might be large numbers of people with flulike illnesses that rapidly develop into inhalation anthrax—the most deadly form of the disease.
To prevent such an occurrence, U.S. officials believe the nation needs fast-working, dependable, low-cost microbe detectors. In the event of an anthrax strike, such devices could "sound an alarm," allowing exposed individuals to be treated immediately. James Woolsey, former director of the U.S. Central Intelligence Agency, comments: "With [an] anthrax [attack] there is a period of one to two days before people become symptomatic, when almost all of the people who had been exposed could be treated and treated successfully. If one … had the right types of sensors so that you knew that a biological attack had occurred … you could save a vast share of lives."45
At this time, the United States does not have such germ detectors. However, scientists in government, industry, and universities are looking for ways to develop them.
Researchers at the Center for Environmental Biotechnology (CEB) at the University of Tennessee are developing a germ detector that uses bacteriophage (bacteria-killing viruses) to detect microbes. Scientists at the CEB are creating bacteriophage that give off light when they infect certain bacteria, such as Bacillus anthracis. For example, when a prepared bacteriophage infects an anthrax organism, a device called a luminescent bioreporter that is incorporated into the bacteriophage emits light rays. The light is detected by a tiny photodetector contained in a microchip, which gives off a signal that is sent to a desktop computer. The tiny detection device, composed of the bacteriophage attached to the microchip, is called a microluminometer.
According to the inventors, microluminometers would be inexpensive detectors that could identify microbes instantly. Moreover, microluminometers could be used almost anywhere. Steven Ripp, senior research specialist at CEB, notes: "You could just toss them into air vents or water samples." In addition to activating the light signal, the bacteriophage would kill the microbes. "Since the phage are infecting the pathogen [disease-causing organism], they're ultimately killing it as well," observes Ripp. "So the phage itself could be sprayed onto an infected area to render the pathogens harmless."46 Sample microluminometers are now being tested. The inventors note, however, that an efficient microluminometer against anthrax may take years to develop.
Nucleic Acid Analyzer
Researchers at Lawrence Livermore National Laboratory (LLNL) in California have been developing a device that detects microbes such as anthrax bacteria by means of their genetic material, composed of compounds called nucleic acids. Using anthrax as an example, the process works as follows: First, the investigators map the genetic material of the Bacillus anthracis bacteria. The scientists then make artificial pieces of DNA that will bind to the anthrax organism's genetic material. When the human-made DNA and the anthrax organism's genetic material unite, a bit of fluorescent dye is released from the artificial DNA. With the proper lighting, the fluorescent dye glows. Theoretically, artificial segments of DNA matched to Bacillus anthracis could be used in anthrax detection devices. A "glowing reaction" would signal the presence of anthrax bacteria.
By 2001 LLNL scientists had fashioned a microbe detector that could identify germs in seven to ten minutes and is small enough to fit into a handheld device or the pants pocket of some special forces uniforms. Called a Handheld Advanced Nucleic Acid Analyzer (HANAA), the apparatus has been tested at various sites, including the Food and Drug Administration, the Centers for Disease Control and Prevention in Atlanta, and Los Angeles County's emergency operations office. However, Pat Fitch, who heads the team developing the microbe detector, notes that setting up the device is a "non-trivial [complicated] exercise,"47 and that HANAA requires a highly trained operator to process samples.
Christopher Woolverton at Kent State University in Ohio and his colleagues at Northeastern Ohio University's College of Medicine and Kent State's Liquid Crystal Institute have also designed a hand-held germ detector, called a microbial biosensor. MicroDiagnosis, a Washington State company, is marketing the device.
Woolverton's microbial biosensors have been successfully tested on several microorganisms, and an anthrax version is being developed. It will work like this: The microbial biosensor contains a liquid crystal layer that blocks light. Anthrax organisms, when present, combine with specific antibodies (substances that attack germs) in the device. The anthrax-antibody clusters disrupt the liquid crystal layer, allowing light to pass through. The light is detected by an optical scanner that sends a signal to a small computer. According to the developers, the microbial biosensor will be able to detect anthrax germs in about five minutes.
Biological Integrated Detection System
For some time, the U.S. military has had a relatively crude, bulky microbe detector, meant to be used on the battlefield. The apparatus, which looks like a small house with three chimneys, is called the Biological Integrated Detection System (BIDS). Mounted on a Humvee vehicle, BIDS uses a number of technologies to detect biological organisms, including bioluminescence (the production of light by living organisms), flow cytometry (identification of organisms by light-absorbing or fluorescing properties), mass spectrometry (weight determination), and immunological assays (using antibodies to identify organisms). BIDS, which can identify a broad range of microorganisms, requires two expert operators and takes forty-five minutes to complete an analysis.
Scientists at LLNL and Los Alamos National Laboratory in New Mexico have developed a more compact microbe detector, about the size of an automated teller machine (ATM). The device is designed to be used in locations like airports, sports arenas, and convention centers. The apparatus, which analyzes air samples within one hour, can report the presence of anthrax and other deadly germs.
The U.S. government hopes to develop a more efficient germ detector, connected to a remote-controlled vehicle. The new device, called a point detector, would "sniff" air samples. Within fifteen minutes the detector would determine if any of twenty-six dangerous microbes, including anthrax bacteria, was present. This new invention, however, may take years to perfect.
Because rapid, easy-to-use detection devices for deadly microbes are not yet available, the U.S. government uses other means to monitor dangerous germs. One method involves a network of veterinarians. The federal government trains veterinarians, recruited by county and state health departments across the nation, to recognize animal illnesses that could indicate a biological attack.
In the case of anthrax, for example, a bioweapons strike would probably affect animals as well as people. Thus, veterinarians might be among the first doctors to see the disease. This is especially true because small animals like cats and dogs have relatively fast metabolisms. They could, therefore, be among the first victims to display anthrax symptoms. Jean Feldman, a veterinarian who specializes in treating horses, cattle, sheep, and goats, observes: "Pets could be the sentinels of a bioterrorism attack.… Certain diseases would be unusual in dogs and cats and if they show up, vets should think that there may have been a deliberate infection and notify the appropriate public health and veterinarian authorities of it."48 Federal authorities hope that veterinarians, along with farmers, ranchers, and other people that work with animals, might function as an "early warning system" if an anthrax strike occurs.
Preparations for a Possible Anthrax Attack
In spring 1998 New York City officials conducted simulated anthrax attacks as part of the DoD's Domestic Preparedness Program, established by a 1996 act of Congress. Under this program, the U.S. Army's Chemical and Biological Defense Command (CBDC) is helping city and state governments prepare for a terrorist attack. Suzanne Fournier, a spokeswoman for the CBDC, explains: "We're using New York City as a special city to work on biological incidents.… I can't give a lot of specifics, but you actually have the response teams go out and act out what they would do.… You also have a person playing a terrorist acting out what he would do."49 The exercise demonstrated that a bioterrorist attack in New York could be devastating. Consequently, New York officials drew up plans, usable in many urban areas, to prepare for a biological weapons strike.
Jerome Hauer, New York City's emergency management director, describes steps the city has taken to deal with a germ weapon attack. First, to detect a sudden increase in the number of sick residents, New York monitors hospital admissions, emergency room visits, unusual deaths, and sales of over-the-counter medications. Second, the city has established many "points of distribution" for dispensing drugs in an emergency. Third, New York has taught large numbers of doctors, nurses, police, firefighters, and other emergency workers what to do during a germ weapon emergency. And last, New York stockpiled large quantities of medication for immediate treatment of bioterrorism victims.
In addition to New York, the Domestic Preparedness Program—now under the jurisdiction of the Department of Justice—has helped Baltimore and other cities develop plans to deal with bioweapon attacks. The program trains various kinds of emergency workers to detect deadly microbes, furnish medical treatment, decontaminate affected areas, and provide law enforcement in a crisis situation.
To minimize the devastation an anthrax attack might cause, the U.S. government is also sponsoring the development of new and better human anthrax vaccines.
Future Anthrax Vaccines
Misgivings about the safety and efficiency of the currently used anthrax vaccine, MDPH-AVA, as well as the large number of injections required for immunity, have stimulated research into alternative human anthrax vaccines. Since the 1980s U.S. scientists have been trying to develop either a purer cell-free vaccine or a live-organism vaccine. Their aim is to produce a vaccine that requires only one or two shots, has few adverse effects, and provides protection against all strains of anthrax. Several live-organism anthrax vaccines have been tested, but the United States has not yet approved any for use in people.
More recently, in the 1990s, scientists started researching experimental vaccines called "gene vaccines." These vaccines are composed of a mixture of genes (genetic material) from different bacteria. Researchers at Maxygen, a company in Redwood, California, are trying to develop two gene vaccines using a procedure called "gene shuffling." In the past, Maxygen mixed up thousands of genes from various microorganisms to produce an enzyme, used in laundry detergents, that dissolves grass stains. Maxygen hopes to make an even stronger enzyme that can dissolve anthrax organisms. Maxygen is also researching another gene vaccine that would stimulate a huge immune response. They hope this will induce "superimmunity" to anthrax bacteria.
Vical, a vaccine producer in San Diego, California, is also researching gene vaccines. In 2003 Vical announced that it had successfully used a gene vaccine to protect rabbits from anthrax. Vical plans to experiment on another animal species, then move on to human trials. The company hopes to develop a human anthrax vaccine that will require just two injections.
In the early 2000s another pharmaceutical company, DynPort, in Frederick, Maryland, developed an anthrax vaccine that acts faster than MDPH-AVA. DynPort hopes to market the vaccine after human clinical trials are completed.
Vaccine producers are also studying the possibility of producing aerosol vaccines, which would be inhaled. These vaccines could be sprayed over many square miles, providing rapid protection to a large population.
In addition to creating new vaccines, scientists are also developing new medicines to treat people who come in contact with anthrax.
Broad Spectrum Medical Defense
During an interview in 2001, Ken Alibek, an anthrax expert, was asked how the United States could best defend itself against biological weapons. Alibek replied that, in his opinion, vaccines did not provide the best protection. He notes that broad spectrum medications (medicines that work against many microbes) would work better. "There are too many biological agents that could be used in biological weapons," observes Alibek. "It is impossible to imagine how to develop this number of vaccines.… The best approach is to develop a broad spectrum medical defense."50 Alibek is researching broad spectrum medicines and hopes to develop them within five years.
Other medical researchers are also searching for new ways to treat anthrax, because disease-causing microorganisms like Bacillus anthracis can become resistant to commonly used medications.
Investigating New Treatments
A number of scientists and pharmaceutical companies in the United States are searching for ways to improve the nation's defenses against anthrax and other infectious diseases. Beginning in the early 2000s, U.S. legislators planned to fund these efforts through Project Bioshield. This program provides money for the federal government to purchase large quantities of vaccines and medicines to fight potential bioterrorism.
Anacor Pharmaceuticals, a company in Palo Alto, California, is conducting animal trials for new antibiotics to treat anthrax. However, antibiotics—which work by killing bacteria—cannot eliminate Bacillus anthracis toxins from the human body. Moreover, no currently available medication can counteract anthrax toxins. For this reason, scientists have been trying to develop two new medications for treating anthrax victims. One new medicine would prevent the formation of anthrax toxins. The other new treatment, an antitoxin, would neutralize anthrax toxins that are already present. The U.S.-based company Human Genome Sciences Incorporated (HGSI) has developed a new type of antibody drug, called Abthrax, that counteracts anthrax toxins. HGSI has successfully tested the medicine on animals and hopes to begin human trials soon. According to HGSI, a single dose of Abthrax, administered soon after exposure, might protect a person from anthrax; and Abthrax could also be used to safeguard firefighters and police who enter contaminated buildings, soldiers exposed to anthrax bioweapons, or civilians after a terrorist attack.
Medical researchers have also been studying the possibility of using bacteriophage (viruses that kill bacteria) to control anthrax infections. In the laboratory, bacteriophage have been able to kill Bacillus anthracis cells as well as germinating spores. Scientists believe that someday these viruses may provide a new treatment for anthrax. Taking steps to avoid contact with biological weapons is another defense recommended by some bioterrorism experts.
U.S. senator Bill Frist is a physician as well as an authority on bioterrorism. Frist recommends that every American home have a "safe room" where families can stay in the event of an attack with a bioweapon like anthrax. According to Frist, a safe room should be windowless, have a strong door, and contain a radio, telephone, medical supplies, and food and water to last several days. Other useful supplies include flashlights, cell phones, and facemasks with filters. Koken Ltd., a Japanese company that makes hazard masks, recently developed a child-size version to be used against biological weapons. Fumikazu Tanaka, a manager at the company, notes: "With the [terrorist] attacks … and the anthrax scare, people began to get nervous … and for parents, a priority is to protect their children."51 In Frist's opinion, every family should be prepared "when, not if, America is hit by another biological attack … like [the] anthrax scare [of 2001]."52
Aerial Spraying to Kill Anthrax Spores
One method of counteracting an attack with aerosolized anthrax would be to destroy the anthrax spores. Fearing bioterrorist attacks on the United States for many years, Mitch Fadem, a scientist at Kent State University, has been studying ways to kill airborne spores. "I've been telling people for a long time it [bioterrorism] is going to happen here," observes Fadem. "The climate was right. I knew how open the United States was and how easy it would be to get the materials."53
Fadem's background in toxicology (the study of poisonous substances) led him to think of using chemicals to kill Bacillus anthracis. The scientist tested an antimicrobial foam pesticide that can destroy anthrax spores. The pesticide, invented by Sandia National Laboratories, is composed of two disinfectants: alkyl dimethyl benzyl ammonium chloride and concentrated hydrogen peroxide. Fadem tested the foam in his laboratory to find concentrations that would destroy anthrax spores without harming people or property.
Fadem plans to use low-flying military airplanes during field trials to spray the toxic foam over areas contaminated with non-deadly organisms, such as Bacillus globigii, that are similar to anthrax germs. If Fadem succeeds, this method may be used to neutralize aerosolized anthrax in the future.
Defense Against Anthrax Attacks
The anthrax-letter attacks of 2001 demonstrated the terror and damage the disease can cause in the wrong hands. It also demonstrated that better methods of detection and treatment are needed to effectively combat the disease in the event it is used as a weapon by rogue nations or terrorists. Scientists are devising a number of promising new technologies to counter the anthrax threat and hope to be able to deploy them in the next few years. If they are successful, the result will be a safer world.