Biowar Considerations (from The Law Enforcement Medical Encyclopedia)

Biowar Considerations

Martin Greenberg, MD

This chapter is intended to provide an analysis of the biological weapon (BW) threat. Please use this as a reference guide. Specific descriptions, treatments and drug regimen are provided for completeness purposes only. Please do not be deterred by them unless they are of specific interest. Unlike a Chemical Weapon (CW) attack, here no crime scene generally exists. Rather, tactical containment teams and first responders may likely be present at hospitals and triage/holding areas. Memorizing disease symptoms and antibiotic protocols is not relevant to the law enforcement community. Relevance lies in understanding the magnitude of the threat. Imagine that a terrorist cult or government successfully releases the Ebola virus. Within days, large numbers of people develop fever and joint pains. The tissues connecting our musculoskeletal system and major organs liquefy. If touched, the skin bleeds. We choke on our sloughed tongues. Our eyes fill with blood that leaks down our cheeks. Near death, we convulse, splashing infected blood on anyone in the vicinity. This blood remains contaminated for a month. Ninety percent of us are dead within a week.

Definitions: Biological agents are defined by the United Nations as “living organisms…or infective material derived from them, which are intended to cause disease or death in man, animals and plants, and which depend for their effects on their ability to multiply in the person, animal, or plant attacked.” Toxins are the poisonous by-products of these organisms. Surprisingly, biological agents are more toxic than chemical agents. Microgram (10 to the -6th power) toxin doses are lethal. Picogram (10 to the -12th power) biological agent doses are lethal. BW agents are more specific than CW (Chemical Weapon) agents. They attack a single host class (humans, plants, or animals). They are hard to control, dependent upon weather conditions, geography and vectors (carriers such as birds and insects). BW agents act within days. CW agents act within minutes, while toxins act immediately. Anthrax spores may survive for years in the soil, but aerosolized BW agents are generally nonpersistent. Ideally, a BW agent should be infectious, hearty, and able to reproduce quickly and easily. The target audience defines the appropriateness of the agent. Staphylococcus, for example, is appropriate to infect a salad bar, but inappropriate for widespread aerosol dissemination. Different types of living organisms may be used as biological weapons. Viruses are “a collection of genes wrapped in protein.” A virus enters a cell and usurps the cell’s RNA (ribonucleic acid) forcing it to reproduce the intruder’s genetic material and thus causing infection. Among others, BW viruses include Ebola, Marburg, encephalitis, yellow fever and dengue fever. Most lethal viruses have difficulty surviving outside the host. Generally, a virus’ lethality is inversely proportional to its transmissibility. In other words, it’s more difficult to catch the Ebola virus than a cold. Bacteria are living organisms that can survive outside the body. These include the infection causing organisms with which we are most familiar including anthrax, brucellosis, glanders, plague, and tularemia. Fungi are plantlike organisms that usually attack plants. Toxins are chemical by-products of living organisms. Botulinum toxin is the most toxic substance known. Ricin is a toxin produced from castor beans. Venoms are toxins obtained from reptiles and insects.

The Biological Warfare Convention: The convention on the Prohibition of the Development, Production, and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction (the Biological Warfare Convention or BWC) bans the production, development, transfer, acquisition, and use of BWs. It entered into force on March 26, 1975. 183 countries have signed and/or ratified the BWC. Ten states/countries have neither signed nor ratified it (mostly African nations and Israel.) The U.S. pledged to ban BWs in 1969. The BWC unfortunately lacks verification protocols, but negotiations have been underway to add them to the agreement.

The Fear of Disease: Historically, epidemics have killed many more people than those killed in conflicts. It is reasonable to fear this killer. However, exotic illnesses such as the Ebola and Marburg viruses which killed 800 and 10 people respectively are feared more than malaria which routinely kills one million people yearly. Fear of the unknown imbues disease with an almost supernatural horror. The mid-fourteenth century Black Death decimated one-fourth of Europe’s population and was thought to be due to the supernatural. The fear of disease and its actual effects have changed the course of many wars. The Mongols, for example, won the Battle of Caffa (a port city in Crimea) by catapulting plague infested cadavers into the walled city. The Japanese killed 3,000 prisoners of war (including Americans) in WW2 BW experiments. They also attacked eleven Chinese cities with plague and killing 700. Fear, too, is generated by the fact that frequently no specific agent antidote, vaccine, or countermeasure is available. By genetically combining virulent viruses such as Ebola or hemorrhagic fever with an easily spread, common virus such as influenza, it has been hypothesized that viral dissemination would be facilitated.

Planning Considerations: Jane’s Information Group feels that four components are necessary to create a successful BW attack. They include: the agent, the munitions, the delivery system, and target meteorological conditions. These elements must be addressed in any successful strike. The BW agent may be a toxin or an organism. Toxins usually have no, or limited incubation periods. The target area is limited. An organism has a longer incubation period of up to several days with a wider target area of even hundreds of square kilometers. Agents may be deemed “incapacitating” or “lethal” for obvious reasons. As previously mentioned, they should be infectious/toxic, easy to produce in quantity, and stable from production through dissemination. BWs are deployed in liquid or dry form. Liquids are produced easily but are difficult to disseminate in a respirable mist of five microns diameter. Dry agent is difficult to produce, requiring sophisticated drying and milling technology. However, once produced they are easily disseminated. Luckily, no agent is both easy to produce and disseminate and no standard appearance exists. All liquid agents regardless of production techniques should have a viscosity of five to fifteen centipoises. Solid/liquid content should be five to twenty percent. Its viscosity would be between whole milk and light pancake syrup. The colors of liquid agents are variable but those derived from fermentation are colored opaque amber to brown. Agents grown in egg media will be yellow or pink/red. Viruses grown in sophisticated tissue culture technology would likely be processed into a dry powder. They would ideally contain particles one to five microns in diameter. Containing a strong static electric charge, these agents would be difficult to handle. Less sophisticated processing would yield a ten to twenty micron diameter particle that would be easier to manage but would tend not to remain aerosolized. Dried agent has the same color as its liquid counterpart. Dying, however, could effectively change the dry agent’s color. Munitions designed to release BW agent as an infectious, respirable mist may vary widely. They are termed “point source” munitions. Alternatively, “line source” munitions release agent along a line perpendicular to prevailing winds to disseminate agent across a very large downwind target. Domestic terrorists would more likely employ crude garden style sprayers. This single fluid device requires 600 psi to work effectively. A two fluid nozzle is ten times more effective and only requires a working psi of 90. Explosive devices might also be used but would kill much of the agent through blast effects. If the difficult task of producing high concentration, small particle, neutrally charged dry agent was overcome, a simple delivery system such as the ABC fire extinguisher would be highly effective. Meteorological conditions must be considered when attacking an outdoor target. To keep agent at ground level (3-15’) an air inversion is needed where a cold air layer prevents vertical air currents and keeps the agent at ground level. Inversions are present at night, daybreak, and sunset. Sunlight also destroys live organisms, but spores and toxins are not affected. A prevailing wind speed of 5-25 MPH is also an important factor. A lower speed will limit coverage while a higher speed will disperse the agent excessively. Dry agents work best in dry climes: liquid agents work best in a moist/humid environment. Temperature and precipitation may have only minor effects upon BW delivery. The urban outdoor environment may degrade agent effectiveness as vertical air current eddies between buildings create “micrometeorological effects” and disperse agent. Snipers are well aware of these air eddies when firing from an urban location. For about one minute after release, BW agent equilibrates with the atmosphere. Heavy particles of greater than 15 microns diameter fall to the ground while those of one to five micron diameter remain suspended in the aerosol and act as a gas. This gas is termed the “primary aerosol.” Since it acts as a gas, it is unimpeded by objects in its path. It will not adhere to trees, buildings, or clothing. Individuals at risk, breathing at ten to twenty liters per minute are likely to suffer inhalation infection. Biological agent decay will also occur and is expressed in percent death/minute of aerosol age. It is a geometric progression. In Jane’s example, a twenty percent per min. degradation rate implies aerosol content is halved every 3.5 minutes after release. Delivery systems other than inhalation may be effective on a much more limited basis. Ingestion of agent causes only limited damage. Contaminating municipal water supplies is unrealistic due to agent dilution/diffusion. Chlorination is effective in its intended role as a bactericide. Reverse osmosis filtration, coagulation, and flocculation systems are effective against a host of toxins including ricin, microcystin, T-2 mycotoxin, and sagitoxin. Small-scale contamination of a water supply directed at a small target such as a building is possible if the water is contaminated as it enters the target. Isolated attacks on food sources such as salad bars (1984 Rajhneeshee cult Salmonella typhimurium salad bar poisonings) and product tampering (1982 Tylenol scare) have severe psychological effects.

The Agents: It is certainly not necessary to memorize the symptom complex of each potential BW agent as this information has little bearing in the pre-hospital environment. Rather, several agents will be described to demonstrate the most common examples of these organisms.

Anthrax - Anthrax is caused by the gram positively staining (an identification technique) rod shaped bacterium called Bacillus anthracis. Its BW application is as a pulmonary agent. The spore form would be released via sprayer and would be inhaled. The disease incubation period is one to seven days. After two to four days, symptoms of shortness of breath, exhaustion, tachycardia (rapid heart rate) and shock occur. Death occurs after one day. The mortality rate is ninety percent. 8,000-10,000 spores are necessary to cause an infection. There is no effective treatment. The World Health Organization (WHO) estimated in 1970 that if anthrax was sprayed over a city of 500,000 inhabitants, that 125,000 would become infected and that 95,000 would die. No effective treatment is available. In other words, if you develop a symptomatic infection, you will die. No wonder that BWs are called the “poor man’s nuclear weapon.” The dramatic implications for the health care community are that people stricken with anthrax, coming to hospitals for treatment will instead be triaged and observed while asymptomatic (healthy appearing) individuals will require antibiotics. It is likely that a treatment vacuum will occur where the medical community will be unaware that the problem exists for several days and by then treatment would no longer be effective. An anthrax vaccine is available which has recently been the subject of much controversy. A number of troops have refused inoculation under penalty of court martial claiming that it was responsible for Gulf War Syndrome. The vaccine consists of six doses over eighteen months with yearly boosters. Should this vaccination be given to the entire population in the expectation of a BW attack? Non-vaccinated, potentially exposed individuals need ciprofloxin 500 mg. BID (twice a day,) or doxycycline 100 mg. BID for a month and require vaccination with at least three doses prior to discontinuing antibiotics. Effective treatment also assumes that non-genetically modified anthrax has been disseminated.

Plague- Plague is caused by the aerobic, gram-negative rodshaped organism Yersinia pestis (formerly called Pasturella pestis). It is a non-spore forming organism that clinically causes bubonic or pneumonic plague. The latter form would be seen in intentional dissemination first affecting the lungs. It results from inhalation of the organism and causes hemorrhagic pneumonia that is fatal unless treated. Although it is extremely infective as a respirable mist, agent degradation and THE LAW ENFORCEMENT MEDICAL ENCYCLOPEDIA 207 instability are barriers to its successful weaponization. As mentioned, it was termed “the Black Death” and was responsible for killing one-fourth of Europe’s population in the mid-1400s. It can be successfully treated within twenty-four hours of symptom onset with streptomycin 30mg/kg. IM in two divided doses/daily for ten days, or doxycycline 200mg. IV followed by 100mg. IV every twelve hours for ten to fourteen days. Post Exposure Prophylaxis (PEP) for asymptomatic individuals is doxycycline 100mg. by mouth BID (twice a day) for a week or for the exposure duration if longer than seven days. Decontamination is affected by boiling or dry heating above 130 degrees F. steam for fifteen minutes or treatment with Lysol. It is also killed by sunlight exposure for five hours. A vaccine is available administered at zero, three, and six months. Booster doses every six months times three and yearly afterwards are protective for individuals in high-risk settings. Unfortunately, it is not protective against pneumonic plague.

Tularemia- This disease is caused by the gram negative, non-spore forming coccobacillus, Francisella tularensis. The two most common forms of tularemia are the ulceroglandular form (caused by the inoculation of infected mosquitos, ticks, or deerflies,) and the typhoidal form (caused by the inhalation of contaminated dust, or the ingestion of contaminated food or water.) In the former, an ulcer appears at the site of inoculation with local lymph node swelling followed by fever and nonspecific systemic symptoms. The latter presents with weight loss, fever, and collapse. No lymphadenopathy (enlarged lymph nodes) is present, and the diagnosis is difficult due to its nonspecific symptoms. This organism is extremely infective. Even 1 organism may cause clinical infection. The likelihood of contracting this disease is almost 100%. Every exposed unprotected individual would develop clinical disease. The choice route would be an aerosol causing pneumonia. Tularemia is treated with the antibiotic streptomycin 1G every 12h IM (Intra-Muscular) for two weeks. Gentamicin is also effective but runs the risk of kidney damage. An investigational vaccine is also available.

Smallpox-The variola virus causes smallpox. This disease was conquered, or declared eradicated, by the World Health Organization in 1980. Two known virus banks retained variola samples; the Centers for Disease Control (CDC) in Atlanta and Vector in Koltsovo, Russia. However, an unknown number of clandestine banks may possibly retain viral samples. The virus is highly infective. The incubation period is about twelve days; quarantine is required for sixteen days after exposure. Symptoms include fever, headache, muscle pain, and vomiting. Delirium may occur in fifteen percent. About three days later, a rash about the face, forearms, and hands appears. The rash then spreads to the trunk and becomes pustular. After one to two weeks, the pustules form scars. A vaccine is available administered intra-dermally (within the skin) that leaves a permanent scar. This Wyeth brand vaccine is effective if given up to one week post exposure. Immunity lasts between three and ten years and booster injections are recommended for repeat exposures. Vaccine immune globulin (VIG) is given to pregnant or immunosuppressed individuals (0.6mg/kg within 24h).

Toxins- Toxins are effective and specific poisons produced by living organisms such as bacteria, algae, fungi, and plants. Many toxins produced for military purposes were sensitive to heat and light and thus made unstable and impractical weapons. In the late 1970s, development of gene and biotechnology allowed toxins to be produced in larger amounts or even synthetically. Genetic modifications allow them to be less sensitive to light. Using bio-regulators (naturally occurring peptides participating in bodily activities) it is possible to target specific body organs. Microencapsulation technology makes it possible to protect unstable toxins when dispersed. Because most toxins are unstable in alkaline solutions, 1-2% hypochlorite decontamination solutions effectively destroy them. Botulinum toxin is produced by the bacteria clostridium botulinum. It is the most toxic substance known. The organism grows on improperly preserved food and causes the disease botulism. The incubation period is one to three days after which suffocation by respiratory paralysis eventually occurs. If untreated, it is fatal in sixty percent of cases. The toxin occurs in 7 different forms. The most lethal is type A (molecular weight 150,000) with a lethal dose of 1 microgram if ingested. A vaccine is available, but if poisoning occurs no antidote exists. Facial muscles are affected first, followed by symmetric, downward paralysis. When the diaphragm and chest muscles are paralyzed, breathing ceases. The respiratory LD50 is not known (the amount needed to kill fifty percent of subjects) but it is extrapolated from rhesus monkey experiments as 4.88 microns for a 70kg subject. Treatment includes the use of assisted ventilation and antitoxin (20ml IV.) Antitoxin does not reverse paralysis that may take months to resolve. The pentavalent vaccine (types A-E) is an investigational drug. Castor oil seeds can be used to extract ricin which is also classified as a lethal toxin. E. coli bacteria have also been genetically modified to produce this toxin. It is easy to naturally produce in large quantities and became notorious when it was used in the 1978 London “umbrella murder.” A ricin treated bullet was used to kill a Bulgarian defector. In 1995, 4 members of the Minnesota Patriots Council militia were discovered possessing ricin. Its mechanism of action is to block bodily protein synthesis. Death occurs through multi-organ failure. Congestive heart failure is a major feature, and treatment is supportive only. Staphylococcus enterotoxin B (SEB) is produced by the Staphylococcus aureus bacteria and is classified as an incapacitating toxin. It is the bacteria most commonly associated with food poisoning. Because it is very stable and requires only a small dose (ED50=.025 mcg) to cause symptoms via the respiratory route, it is a potential inhalation agent as well. SEB is a protein (molecular weight=28,500D) and is water soluble. It can withstand boiling for several minutes and can survive freeze-dried for over a year. Ingestion of 20-25g causes food poisoning symptoms after a few hours including nausea, cramps, diarrhea, and vomiting. Spontaneous recovery usually occurs within twenty-four hours. Inhalation symptoms occur within one to six hours following exposure including fever, chills, headache, myalgia (muscle pain,) and a cough which may persist for one to four weeks. Nausea, vomiting, and diarrhea may also occur. Despite the more severe symptoms caused by the inhalation route, the mortality rate is only 2%. Fluid replacement therapy may be needed in severe cases.

Viruses- Ebola is a viral infection that causes death in fifty to ninety percent of cases. It is transmitted through contact with any infected organs or body fluids. The virus has a variable incubation period of up to twenty-one days. Symptoms include sudden weakness, fever, headache, and sore throat followed by kidney and liver failure, a rash, vomiting and diarrhea, and internal/external bleeding. The bleeding begins on about the fifth day. Because of its virility, Ebola is assigned a likely status as a BW. The Marburg virus is a cousin of the Ebola virus and was first described when an epidemic severe hemorrhagic illness occurred in Germany at the same time as the importation of African green monkeys to where the disease was traced. Cases have also been reported in sub-Saharan Africa. Little else is known about the virus. Symptoms develop about a week after exposure and are similar to Ebola. They also include conjunctivitis (irritated eyes) and photophobia (light sensitivity). There is no vaccine or effective anti-viral therapy available to treat these infections. The Marburg mortality rate is twenty-five percent.

Putting it all together; a biological warfare treatment scenario.

A BW attack may be overt or covert. A crime scene will exist only in the overt scenario. In a covert (unwitnessed) attack, evidence it has taken place will initially be epidemiological, or retrospective, as large numbers of similarly affected casualties flood medical facilities over the first few days. Unfortunately, this initial, asymptomatic time interval may also be the “golden period” during which treatment may have been effective. Cross contamination also occurs with a number of BW agents, and we thus unwittingly may become “the vectors of our own destruction.” Such a real time reenactment was aired on the ABC News show Nightline episode production “Biowar” on 10/1- 8/99. It dramatically and realistically portrays the panic and social disintegration that is the “true force multiplier effect” surrounding an unfolding BW incident. Sidell, Patrick, and Dashiell also relate the following scenario: “An intermediate-sized strategic hypothetical target could be represented by the typical city and its surrounding network of suburbs-about 400 to 800 square miles. One jet fighter could disseminate 100 gallons of Francisella tularensis (the causative organism of tularemia) along a fifty-mile line starting northwest of Rockville, MD, and ending southwest of Vienna, VA. The attack would be expected to produce fifty percent casualties in four to seven days in metropolitan Washington, D.C., and could result in severe pneumonia in 1.9 million people, of whom twenty percent would be expected to die without antibiotic treatment. This level of casualties would destroy the ability to function of a significant and vital section of the U.S. and would severely stress the remainder of the country to provide the resources needed to limit the biological disaster.” (JAVMA, Vol. 190, No.6, 1987, p.716) Over an average of the first 3 days, casualties of inhalational tularemia would experience the sudden onset of chills, fever, headache, muscle aches, extreme fatigue (prostration), and loss of body fluids. The diffuse nature of symptoms would significantly delay diagnosis. The conventional diagnosis would rest upon a sputum/blood gram stain of small, non-spore forming, non-motile, aerobic, gram stain negative coccobacilli and positive blood cultures and sensitivities. Advances in polymerase chain reaction (PCR) detection technology identify organisms within minutes. The Navy Medical Research Unit has developed a mobile, 4 box, 300# portable lab combining immune-analysis, PCR, and traditional techniques that can provide onsite BW agent identification in fifteen to twenty minutes. New miniaturization techniques may have already created palm, and even dog tag sized detectors. Although genetic engineering may allow BWs to evade traditional detection, new “canary on a chip” technology will detect classes of organisms (bacilli, cocci, etc.) and warn those in the vicinity to obtain treatment. Once a diagnosis of tularemia was reached, antibiotics would need to be administered on a massive scale, probably overwhelming even national stockpiles. Manning triage sites, warehousing large numbers of casualties, and disposing of the dead would all be challenging logistic issues. Except for respiratory paralyzing toxins, it is unlikely that specialized equipment or surgical services will be needed. The specific agent will dictate subsequent triage. For example, if the agent is in the incapacitating group, home care may be recommended. If an untreatable lethal class BW agent is disseminated (anthrax), supportive care by non-medical personnel may unfortunately be mandatory. With the exception of rapidly acting toxins (SEB), a bell shaped curve of symptom onset would be expected. Casualties might return home during the incubation period, unless this is contraindicated by cross contamination fears (smallpox, pneumonic plague). As medical care would be spread thin, an information campaign would be necessary to allow casualties to initiate their own care. Large-scale decontamination of materiel would be challenging to impossible (high-rise buildings). A soap and water shower with clothing decontamination by boiling and soaking in hypochlorite seems to be a bare minimum recommendation. Insecticides will be needed to control secondary insect vectors. Many deaths would be expected, especially among the young, the old, and the immunocompromised. A mandatory educational campaign to inform the public that the agent has been identified and that treatment plans are underway would be needed to avoid panic, the true “force multiplier” and goal of the terrorist. Neutralization of the BW munition, if found, is a necessary but risky task. All munitions have a reservoir of agent and they may still be armed in some manner to continue dissemination. Bomb squad or military munition and BW agent experience is useful here. The response team should be in level A gear (SCBA suit with positive pressure and communications; NFPA 1993). 2 prime functions of the responding team are to sample the agent and to neutralize the threat. Sampling gear is needed while decontamination can frequently be performed with the standard 5% hypochlorite solution delivered from a 10-20psi garden sprayer. Hi pressure sprayers are not recommended as they may aerosolize residual dried agent. Because of the high level of knowledge needed regarding munitions and agents, it is recommended that dedicated teams such as the FBI Hazardous Materials Response Unit (HMRU) or the Chem-Bio Incident Response Force (CBIRF), phone number (301)744-1092, assume munition neutralization responsibilities.

Summary: It is overwhelming to consider the comprehensive picture of a bio-war incident. However, a high index of suspicion and Col. Jeff Cooper’s Condition Yellow (relaxed awareness or head on a swivel) mentality will be needed to become aware of a large group of patients with common symptoms to initiate a response plan as soon as possible. Truly, this is one situation where we hear hoof beats and seek zebras.

REFERENCES

1 Jane’s Chem-Bio Handbook- Sidell, F. R., Patrick, W. C. lll, and Dashiell, T. R., Jane’s Information Group, Alexandria, Va. 1998

2 The Ultimate Terrorists- Stern, Jessica, Harvard University Press, Cambridge, Mass. 1999

3 Consequence Management: Domestic Response to Weapons of Mass Destruction- Chris Seiple, PARAMETERS, US Army War College Quarterly, Autumn-1997

4 Emergency Action for Chemical and Biological Warfare Agents- Ellison, D.H., CRC Press, Boca Raton, FL 1999 pp. 117-12