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): 10-100
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
