Bioterrorist's Arsenal
BACTERIAL AGENTS
Inhaled anthrax

Brucellosis
Cholera
Glanders
Pneumonic plague
Tularemia
Q fever
VIRAl AGENTS
Smallpox

Venezuelan equine encephalitis
Viral hemorrhagic fever
BIOLOGICAL TOXINS
Botulism

Staphylococcus enterotoxin B
Ricin
T-2 mycotoxins



Inhaled anthrax
General info: Anthrax is caused by bacillus anthracis, a ubiquitous, spore-forming gram-positive bacillus found in soil. The cutaneous anthrax, the most common naturally occurring form, is usually spread through contact with infected livestock or animal products. Inhalational anthrax is the form most likely to be used in a terrorist attack. Patients will present with an febrile influenzal prodrome within 10 days of exposure and followed 2 days later by severe respiratory distress. About half will have meningitis and septic shock and death in 24 to 36 hours.
Historical notes: The earliest mention of anthrax is in the Old Testament story of Moses, in the Book of Exodus, as the fifth plague suffered by Egypt. In the second world war, the Japanese attempted to use it in their war against Manchuria. In 1979, aerosolized spores were inadvertently released in the Ural Mountains region of Soviet Russia, where 66 of 77 infected persons died. Iraq is speculated to have produced approximately 8,000 L of anthrax solution.
Transmission from human to human: NO
Infective quantity (aerosol): 8,000-50,000 spores
Incubation period: 1-6 days
Duration of illness: 3-5 days; usually fatal if untreated
Lethality: High
Stability of organism: Very stable, spores remain viable for >40 years in the soil
Vaccine efficacy (aerosol exposure): 2 doses protective against approximately 1000 LD50 in monkeys
Vaccine: Bioport vaccine (licensed) 0.5 ml SC at 0, 2, 4 weeks, 6, 12, and 18 months, then annual booster.
Chemotherapy: Ciprofloxacin 400 mg IV q 8-12 hours; Doxycycline 200 mg IV, then 100 mg IV every 8-12 hrs; Penicillin 2 million units IV q 2 hours
Chemoprophylaxis: Ciprofloxacin 500 mg PO twice daily for 4 weeks (if not vaccinated, begin initial dose of vaccine); Doxycycline 100 mg PO twice daily for 4 weeks plus vaccination. Potential alternative therapy includes levofloxacin, gatifloxacin, moxifloxacin, gentamicin, erythromycin, and chloramphenicol. Provide prophylaxis for 8 weeks if vaccine is not given.
Comments: A 1993 report by the US Congressional Office of Technology Assessment estimated between 300,000 to 3 million deaths 100 kg of aerosolized anthrax spores is released over a heavily populated area.

Brucellosis
General info:
Brucellosis is a disease caused by zoonotic gram-negative bacteria most often contracted by contact with contaminated livestock; less common througyh ingestion of milk and other infected animal products. Aerosoliized brucella are highly infectious. Patients will present wil an influenza-type prodrome. A pattern of periodic fevers and remissions can last for months or years.
Transmission from human to human:
NO
Infective quantity (aerosol):
10-100 organisms
Incubation period:
5-60 days; usually 1-2 months
Duration of illness:
Weeks or months
Lethality:
< 5% if untreated
Stability of organism:
Very stable
Vaccine:
No human vaccine available
Chemotherapy:
Doxycycline 200 mg/d PO plus rifampin 600-900 mg/d PO for 6 weeks; or, Levofloxacin 250 mg and rifampin 600 mg PO daily for 6 wk.
Chemoprophylaxis:
Doxycycline and rifampin for 3 weeks
Comment:
Trimethoprim-sulfamethoxazole may be substituted for rifampin; however, as many as 30% of patients suffer relapse.

Cholera
Transmission from human to human: Rare
Infective quantity (aerosol):
10-500 organisms
Incubation period:
4 hours - 5 days; usually 2-3 days
Duration of illness:
> 1 week
Lethality:
Low with treatment; high, without
Stability of organism:
Unstable in aerosols and fresh water; stable in salt water
Vaccine efficacy (aerosol exposure):
No data on aerosol
Vaccine: Wyeth-Ayerst vaccine, 2 doses 0.5 ml IM or SC at 0, 7 - 30 days, then booster every 6 months.
Chemotherapy: Oral rehydration therapy during period of high fluid loss; Ciprofloxacin 1 gm PO once or 500 mg twice daily for 3 days; Doxycycline 300 mg once or 100 mg twice daily for 3 days.
Comments:
Vaccine not recommended for routine protection in endemic areas (50% efficacy, short term); Alternate therapy includes erythromycin and trimethoprim-sulfamethoxazole; give quinolones for strains resistant to tetracycline and doxycycline.

Glanders
Transmission from human to human:
Low
Infective quantity (aerosol):
Assumed low
Incubation period:
10-14 days via aerosol
Duration of illness:
With septicemic form, death in 7-10 days
Lethality:
> 50%
Stability of organism:
Very stable
Vaccine efficacy (aerosol exposure):
No vaccine
Vaccine: No vaccine available
Chemotherapy: Antibiotic regimens vary depending on localization and severity of the disease.
Chemoprophylaxis: Postexposure prophylaxis may be tried with trimethoprim-sulfamethoxazole.
Comments: No large therapeutic human trials have been conducted owing to rarity of naturally occurring disease.

Pneumonic plague
General info: Plague is caused by Yersinia pestis, usually spread from rodent to man through the bites of infected fleas. The pneumonic form is spread by by the inhalation of droplets from the cough of afflicted patients. The terrorist mode will be through aerosol inhalation containing the gram-negative bacillus Yersinia pestis. Patients will present with respiratory distress, fulminant pneumonia and death through respiratory failure and circulatory collapse. Primary pneumonic plague is rare in the United States, so a case should raise the suspicion of a biological attack.
Historical notes: Plague has been the cause of several pandemics and millions of deaths. Several countries, including the United States, have experimented with plague as a biological weapon.
Transmission from human to human: High
Infective quantity (aerosol):
100-500 organisms
Incubation period: 2-3 days
Duration of illness: 1-6 days, usually fatal
Lethality: High unless treated within 12-24 hours
Stability of organism: Stable for up to 1 year in soil; 270 days in live tissue
Vaccine efficacy (aerosol exposure): 3 doses not protectiv e against 118 LD50 in monkeys
Vaccine: Greer inactivated vaccine (FDA licensed, no longer available) 1.0 ml IM; 0.2 ml IM 1-3 months later, 0.2 ml 5-6 months after dose 2; 0.2 ml booster at 6, 12, and 18 months after dose 3, then every 1-2 years.
Chemotherapy: Streptomycin (or gentamicin) 30 mg/kg/d IM in 2 divided doses for 10 days; or, Doxycycline, 200 mg IV then 100 mg IV twice daily for 10-14 days; or, Chloramphenicol 1 gm IV 4x daily for 10-14 days.
Chemoprophylaxis: Doxycycline 100 mg PO twice daily for 7 days or duration of exposure; or, Ciprofloxacin 500 mg PO twice daily for 7 days; or, Doxycycline 100 mg PO twice daily for 7 days; or, Tetracycline 500 mg PO 4x daily for 7 days.
Comments: Plaque vaccine not effective against aerosol challenge in animal studies; alternate therapy includes trimethoprim-sulfamethoxazole; give chloramphenicol for plague meningitis.

Tularemia
General info: Known as rabbit or deer fly fever, caused by Francisella tularensis, a gram-negative coccobacillus. It is usually contracted from bites of infected deerflies, mosquitoes and ticks, after contact with infected animals, from ingestion of contaminated food and water, and from inhalation of contaminated air.The most common presentation is ulceroglandular tularemia. Aerosol dispersal will result in typhoidal tularemia with pneumonia.
Transmission from human to human: No
Infective quantity (aerosol):
10-50 organisms
Incubation period:
2-10 days; average, 3-5 days
Duration of illness:
About 2 weeks
Lethality:
Moderate if untreated
Stability of organism:
Stable for months in moist soil or other media
Vaccine efficacy (aerosol exposure):
80% protected against 1-10 LD50
Vaccine: IND live attenuated vaccine, 1 dose by scarification
Chemotherapy: Streptomycin 30 mg/kg IM divided twicde daily for 10-14 days; or, Gentamicin 3-5 mg/kg/d UV for 10-14 days.
Chemoprophylaxis:
Doxycycline 100 mg PO twice daily for 14 days; or, Tetracycline 500 mg PO 4x daily for 14 days.

Q fever
General info: Q fever is zoonotic disease caused by inhalation of air contaminated with the rickettsial organism Coxiella burnetti. It causes a mild, rarely fatal, long lasting illness.
Transmission from human to human:
Rare
Infective quantity (aerosol):
1-10 organisms
Incubation period:
10-40 days
Duration of illness:
2-14 days
Lethality:
Very low
Stability of organism:
For months on wood and sand
Vaccine efficacy (aerosol exposure):
94% protective against 3500 LD50 in guinea pigs
Vaccine: IND 610 inactivated whole cell vaccine given as a single 0.5 ml SC injection
Chemotherapy: Tetracycline 500 mg PO 4x daily for 5-7 days; Doxycycline 100 mg PO twice daily for 5-7 days
Chemoprophylaxis:
Start tetracycline 8-12 days after exposure for 5 days; or, doxycycline 8-12 days after exposure for 5 days.
Comments:
Vaccine currently undergoing evaluation to determine necessity of skin testing prior to use.

Smallpox
General info: It is caused by the variola virus, an agent eradicated through an aggressive worldwide program of vaccination. It is one of the most feared agent that can possibly be used in a biological attack. If an initial outbreak is not contained, it will probably necessitate a long eradication effort to begin anew.
Transmission from human to human:
High
Infective quantity (aerosol):
Assumed low, 10-100 organisms
Incubation period:
7-17 days; average, 12
Duration of illness:
4 weeks
Lethality:
High to moderate
Stability of organism:
Very stable
Vaccine efficacy (aerosol exposure):
Vaccine protective against large quantities in primates
Vaccine: Wyeth calf lymph vaccinia vaccine (licensed) 1 dose by scarification
Chemotherapy:
No pharmacologic therapy available; cidofovir is effective in vitro and is undergoing animal studies.
Chemoprophylaxis:
Vaccinia immune globulin 0.6 mg/kg UM within 3 days of exposure (best within 24 hours)
Comment:
Because immunity wanes over time. those vaccinated as children are likely to be susceptible. Vaccination recommended before and after exposure vaccination if >3 years since last vaccine.

Venezuelan equine encephalitis
Transmission from human to human:
Low
Infective quantity (aerosol): 1
0-100 organisms
Incubation period:
2-6 days
Duration of illness:
Days or weeks
Lethality:
Low
Stability of organism:
Relatively unstable
Vaccine efficacy (aerosol exposure):
TC 83 protects against 30-500 LD50 in hamsters

Viral hemorrhagic fevers
General info: Viral hemorrhagic fevers include Lassa fever, Ebola and Marburg disease. They are rapidly progressive with high mortality rates. Transmitted in humans through a variety of ways: through contaminated food, human-to-human through urine, saliva or feces, or through terrorist aerosol dispersal. Patients present with a nonspecific prodrome of fever, myalgia, prostration, rapidly deteriorating into multisystem involvement, mucous membrane hemorrhage and shock.
Transmission from human to human: Moderate
Infective quantity (aerosol): 1-10 organisms
Incubation period: 4-21 days, shorter for ebola
Duration of illness: Death within 7-16 days
Lethality: High with the Zaire strain; moderate with Sudan
Stability of organism: Relatively unstable depending on the agent
Vaccine efficacy (aerosol exposure): No vaccine
Vaccine: AHF Candid #1 vaccine (x-protection for BHF) (IND); RVF inactivated vaccine (IND)
Chemotherapy: Ribavirin (CCHF/arena-viruses) 30 mg/kg IV initial dose, 15 mg/kg IV 4x daily for 4 days, 7.5 mg/kg IV 3x daily for 6 days; or, Passive antibody for AHF, BHF, Lassa fever and CCHF.
Chemoprophylaxis: N/A
Comment: Aggressive supportive care and management of hypotension very important

Botulism
General info: Caused by the bacillus Clostridium botulinum, it produces the botulinum toxins, among the most potent in existence, 100,000 times more toxic than the nerve agent sarin used by the cult Aum Shinri Kyo in the Tokyo subway terrorist attack of 1995. Most cases come from ingestion of improperly prepared or canned foods; rarely, from abscesses or wounds associated with intravenous drug use. The toxins may be dispersed via aerosol mode over a vast area. The clinical presentation is neurologic with bulbar palsies and effects (dysarthria and dysphagia), ocular signs (diplopia and mydriasis), progressive weakness, skeletal paralysis, and death from respiratory failure.
Transmission from human to human: No
Infective quantity (aerosol): 0.001 ug/kg is LD50 for type A
Incubation period: 1-5 days
Duration of illness: Death in 24-72 hours; may last months if not lethal
Lethality: High without respiratory support
Stability of organism: Stable for weeks in nonmoving water and food
Vaccine efficacy (aerosol exposure): 3 dose efficacy 100% against 25-250 LD50 in primates
Vaccine: DOD pentavalent toxoid for serotypes A-E (IND), 0.5 ml deep SC, at 0, 2, and 12 weeks, then yearly booster.
Chemotherapy: DOD heptavalent equine despeciated antitoxin for serotypes A-G (IND), 1 vial (10 ml) IV; or, CDC trivalent equine antitoxin for serotypes A, B, E (licensed)
Chemoprophylaxis: N/A
Comment: Do skin test for hypersensitivity before equine antitoxin administration.

Staphylococcus enterotoxin B
Transmission from human to human:
No
Infective quantity (aerosol):
0.03 ug/ person incapacitated
Incubation period:
3-12 hours after inhalation
Duration of illness:
Hours
Lethality:
< 1%
Stability of organism:
Resistant to freezing
Vaccine efficacy (aerosol exposure):
No vaccine
Vaccine: No vaccine available
Chemotherapy:
Ventilatory support for inhaled exposure

Ricin
General info: An extract from castor beans, ricin is a potent cytotoxin that inhibits protein synthesis. It has been manufactured and stored as a potential chemical weapon by Iraq. Inhalation exposure causes respiratory distress followed by airway necrosis and lung injury manifested as hemoptysis and pulmonary edema. Ingestion of ricin-contaminated food will result in hemorrhagic gastroenteritis, shock and death.
Transmission from human to human: No
Infective quantity (aerosol): 3-5 ug/kg is LD50 in mice
Incubation period: 18-24 hours
Duration of illness: Days; death within 10-12 days after ingestion
Lethality: High
Stability of organism: Stable
Vaccine efficacy (aerosol exposure): No vaccine
Vaccine: No vaccine available
Chemotherapy: There is no specific antidote. If inhaled, supportive therapy; if ingested, aggresive gut decontamination through gastric lavage and cathartics. Superactivated charcoal may be tried but is of little value for large molecules such as ricin.
Isolation and Decontamination: Standard Precautions for healthcare workers. Ricin is non-volatile, and secondary aerosols are not expected to be a danger to health care providers. Decontaminate with soap and water. Hypochlorite solutions (0.1% sodium hypochlorite) can inactivate ricin.

T-2 mycotoxins
Transmission from human to human:
No
Infective quantity (aerosol):
Moderate
Incubation period:
2-4 hours
Duration of illness:
Days or months
Lethality:
Moderate
Stability of organism:
Stable for years at room temperature
Vaccine efficacy (aerosol exposure):
No vaccine
Comment: Decontaminate clothing and skin



Sources:
Biological Terrorism: Are We Prepared? Emergency Medicine, November 2001
Medical Management of Biological Casualties Handbook, 4th Edition, Maryland U.S. Army Medical Research Institute of Infectious Disease
Anthrax: Bioterrorism Update, Dr. Mark Graber, Emergency Medicine, December 2001