In early December 2002, the National Security Council learns of a smallpox outbreak in Oklahoma. Twenty cases are confirmed by the Centers for Disease Control and Prevention (CDC), with 14 more suspected. There are 16 more reported cases in Georgia and Pennsylvania. Federal and state authorities quickly inform the public and implement a vaccine distribution policy to those people most at risk of being exposed to the smallpox virus.

Six days after the initial outbreak, a total of 2,000 smallpox cases are reported in 15 states. Three hundred people have died. All of the cases appear to be related to the initial outbreaks in Oklahoma, Georgia, and Pennsylvania. A public health investigation points to three shopping malls as the initial sites of exposure. Even without evidence to suspect any individual or group, sporadic violence is reported against individuals who appear to be of Arab descent. Seaports are closed, food shortages emerge, schools are closed nationwide, and nonessential travel is discouraged. Misinformation regarding the smallpox outbreak spreads quickly on the Internet and in the media, including false reports of cures for smallpox. Within days, chaos swamps those trying to manage the crisis.

Three days before the Christmas holiday and 13 days after the initial outbreak, a total of 16,000 smallpox cases are reported in 25 states, and 1,000 people are dead. Ten other countries report cases of smallpox, likely caused by visitors from the United States. Canada and Mexico close their borders to the United States. Vaccine supplies are depleted, and health officials predict that by February, there will be three million cases of smallpox, leading to as many as one million deaths.

The New York Times, The Washington Post, and USA Today each receive an anonymous letter demanding the removal of all U.S. forces from Saudi Arabia and all warships from the Persian Gulf within one week. Failure to comply, the letters threaten, will result in new smallpox attacks on the U.S. as well as additional attacks with anthrax and bubonic plague. Each letter contains a genetic fingerprint that matches the fingerprint of the smallpox strain that caused the epidemic, proving the authenticity of these claims and the seriousness of the threats.

GAME OVER.

The above scenario was, in fact, a game. In June 2001, several collaborative groups staged an exercise entitled Dark Winter, which simulated a covert smallpox attack on the United States. This exercise offered insights and lessons for those with responsibility for biological warfare preparedness. Dark Winter also demonstrated the ease with which a motivated group could launch a biological attack.

In years past, the United States and other countries put significant effort into developing biological weapons for offensive purposes. These days, U.S. programs aim to prevent, prepare for and defend against potential attacks. Let's have a look at the science behind offensive and defensive biowarfare techniques.

OFFENSIVE biological warfare - creating harmful biological agents

In their natural state, bacteria, viruses and fungi can make pretty good biological weapons. Throw some genetic engineering into the mix, however, and more harmful agents can emerge.

Each of these organisms maintains its genetic information in the form of DNA or, in some viruses, RNA. This genetic material contains genes, which encode all of the information the organism needs to survive and replicate. Some of these genes govern the organism's pathogenicity, or its ability to infect a cell of a plant or animal. Through genetic engineering, pathogenicity genes may be manipulated to make the organism more infectious or more resistant to a therapy or cure.

During the Cold War, the Soviet Union ran several offensive biowarfare programs to develop so-called "Super Bugs." One such program, Project Bonfire, worked to create bacteria that were resistant to about ten varieties of antibiotics. This was done by identifying and cutting out genes that conferred antibiotic resistance in many different strains of bacteria. By pasting these genes into the DNA of the anthrax bacterium, the Project Bonfire researchers created a strain of anthrax that resisted any existing cure, making it impossible to treat.

The Hunter Program was another Soviet biological warfare research program that focused on combining whole genomes of different viruses to produce completely new hybrid viruses. These artificial viruses could cause unpredictable symptoms that have no known treatment. In an innovative twist, the Hunter Program researchers also created bacteria strains that carried pathogenic viruses inside them. These strains would be double trouble: a person who contracted the bacterial disease would likely be treated with an antibiotic, which would stop the infection by disrupting the bacterial cells. This would release the virus, resulting in an outbreak of viral disease. Such a scenario would confuse medical personnel, making treatment very difficult.

It is not known whether the biological agents developed by the Soviet Union were ever actually used to infect people.

At the same time, the United States was mounting its own offensive biological warfare agenda, focusing on the difficult task of delivering biological weapons such as anthrax to a population. In experiments conducted at sea or at the Dugway Proving Grounds desert facility in western Utah, large populations of animals such as guinea pigs, monkeys, and sheep were exposed to these deadly agents. Even more unsettling was the research performed at Fort Detrick, Maryland, another major site of biological weapons research. To test the dispersal of bacterial spores on human populations, harmless bacterial spores that mimicked anthrax in size and shape were covertly dispersed in the Pentagon ventilation system, over the bay of San Francisco, and in the subways of New York. Results from these experiments revealed not only the difficulty of delivering anthrax to a populace, but also the deadly consequences of a successful distribution.

The existence of these experiments was unknown to the public until the 1970s, and the actual results were not revealed until 1999, when some of the data was declassified by the Department of Defense. Most of the details about the U.S. offensive biological weapons program still remain secret.

DEFENSIVE biological warfare - vaccines and detection methods

In 1969, President Richard M. Nixon terminated the U.S. offensive biological warfare program and ordered stockpiles destroyed. The biological warfare research focus shifted from offensive to defensive techniques. Three years later, at the 1972 Biological and Toxin Weapons Convention, more than 100 nations signed a treaty prohibiting the possession of deadly biological agents, except for purposes of defensive research. Nations around the world concentrated on developing vaccines as well as enhancing detection of biological agents. The Soviet Union signed the treaty, but instead of dismantling their offensive program, they stepped up their pace. The Soviet program was not terminated until after the collapse of the Soviet Union in 1992, when Russian President Boris Yeltsin banned all offensive biological weapons-related activity. All biological weapons stockpiles were destroyed and research was considerably downsized, but it is unknown if Russia has completely dissolved the old Soviet program.

Vaccines

Traditionally, vaccines consisted of a preparation of the infectious agent itself - either living, weakened or killed. Introducing the vaccine into the body activates the immune system, resulting in the production of antibodies against that particular agent. If a vaccinated person is later exposed to the infectious agent, he or she will already have built up immunity against it.

More recently, researchers have started using fragments of the pathogen's DNA genome as a vaccine, rather than the entire organism. This approach helps eliminate the risk of infection that comes with using traditional vaccines.

Detection methods

While vaccination helps protect a population from known infectious agents, rapid detection of a suspected act of biowarfare allows fast action to be taken to control the spread of disease. Current detection methods take advantage of the fact that each biological agent maintains its own unique DNA signature. Rapid detection methods use a technique called Polymerase Chain Reaction (PCR) to make a billion copies of a single DNA strand within minutes. This method allows researchers to positively identify an infectious agent, by means of its DNA signature, using even the tiniest samples.

Putting it all together

The Dark Winter project gave us a glimpse of how a biowarfare scenario might unfold. But what is the government's planned response to such a scenario?

• Although it may be difficult to confirm right away that an unusual illness in a community is caused by a biological attack, the local health officer is immediately notified. It is this person's responsibility to inform the state health department, which in turn notifies the federal Centers for Disease Control and Prevention (CDC).
• The state health department conducts a full investigation to determine whether the incident is an act of biological warfare. To protect themselves from any potentially harmful biological or chemical agents, investigators at the scene are outfitted in protective suits and self-contained breathing apparatus (SCBA) respirators (same as the "SCUBA" gear used underwater).
• Investigators collect samples from patients and the surrounding environment, then test them for the presence of harmful biological agents. In order to know which agents to test for, investigators evaluate all of the evidence they collect at the scene, including signs and symptoms shown by patients and patterns of disease transmission. Through a process of deduction, investigators can narrow the list of suspected pathogens to just a few candidates.
  
  While testing can take place in existing laboratories, it can be performed more quickly in temporary field laboratories, using compact, portable detection units such as Idaho Technology's R.A.P.I.D.®, which stands for "Ruggedized Advanced Pathogen Identification Device." The R.A.P.I.D., detection unit uses PCR to identify the unique DNA signatures of suspected pathogens. Genomic DNA or RNA extracted from collected samples is added to a cocktail of reagents that will amplify a particular pathogen's DNA signature. If that specific pathogen is present in the sample collected, it will be positively identified using this approach. The entire process from sample preparation to detection takes less than 60 minutes.
• If a biowarfare incident is confirmed or thought to be probable, the state investigators notify the FBI and local law enforcement agencies immediately. Law enforcement and health officials work together to implement a plan to contain the site of contamination, clean it up and pinpoint the source of the attack.

Biowarfare over the years

Historically, biological warfare is nothing new:

• In the 14th and 15th centuries, warring parties used decomposing corpses as catapult ammunition, which could spread disease among enemy troops.
• During the French-Indian war, it is believed that a British general ordered that blankets and handkerchiefs be taken from smallpox patients in Fort Pitt, Pennsylvania's infirmary, and given to the Indians surrounding the fort.
• Throughout the 20th century, bacterial agents such as anthrax, plague, typhoid, tularemia, and Salmonella were used as bioweapons.

Dispelling the myths

Presently, biological attacks on the U.S. are of utmost concern to government officials. Besides defense, one of the main challenges they face is making sure that the public is informed and prepared for potential incidents. When Homeland Security Secretary Tom Ridge recently declared an elevated risk of terrorist attacks, putting the country on heightened alert, much false information was generated and perpetuated. Here are some of the myths that emerged:

• Myth #1: All agents used for biological warfare are contagious.
  Most biowarfare agents are NOT contagious. Diseases such as anthrax can only be transmitted by exposure to the actual bacteria and cannot spread from person to person. Exceptions include smallpox, pneumonic plague and Marburg/Ebola virus.
• Myth #2: Biological weapons are easily spread throughout a population.
  Creating "weaponized" biological agents is extremely difficult because the organisms need to be processed in such a way that they are small enough to be inhaled, but not so small as to be exhaled. A "dirty bomb" containing biological agents is unlikely to distribute the organisms because they would not survive the heat and force of the blast. Even if a cloud of weaponized anthrax were released over a city block, windy or wet weather would greatly decrease the likelihood of infection.
• Myth #3: A mask, plastic sheeting, and some duct tape will save you from a biological attack.
  Weaponized biological agents are typically one to five microns (0.0001 cm or 0.00003937 inch) in diameter. The Department of Homeland Security suggests wearing a dense-weave cotton mask to help filter contaminants. Such a mask is a barrier only to particles thousands of microns or larger in size. In addition, partitioning off a room with plastic sheeting and duct tape can slow the movement of air from outside to inside, but it will by no means seal the area from outside air.

Funding for this feature was provided by the Educational Resources Development Council, University of Utah.

Author: Katy Andrews