Biological Terrorist Agents Part I – Bacterial Agents

In January 2002, anthrax was covered in detail in the Hazmat Studies column. This column will cover other potential biological agents that could be used by terrorists. Biological terrorist agents are microorganisms or toxins derived from living...


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Treatment of brucellosis involves the administration of the antibiotics tetracycline and streptomycin or TMP-SMX. The disease is resistant to penicillin and cephalosporin. Brucellosis bacteria remains active outside a host in carcasses and organs for up to 135 days, in paper 32 days, in soil for 125 days and in blood for 180 days at 40F. No vaccine is available for use in humans.

Rickettsia are pleomorphic (found in many varying sizes) parasitic microorganisms. A number of strains of these bacteria exist naturally. Rickettsia Canada, also known as louse-borne typhus fever and classical typhus fever, occurs in areas of poor hygiene that are also louse-infected. Outbreaks generally occur in Central America, South America, Asia and Africa. The last epidemic in the United States occurred in 1921. It is primarily a disease of humans and squirrels. The body louse, pediculus humanus, is the primary carrier of the disease. It feeds on the blood of an infected patient with acute typhus fever and becomes infected. Once this occurs, the lice excrete rickettsiae in their feces, which is defecated as they feed.

Infection occurs from feces left on the skin by the lice, which are rubbed in at the site of the bite or other breaks already existing in the skin, or through inhalation of infected dust. Squirrels become infected from the bite of the squirrel flea. The incubation period ranges from one to two weeks, with an average of 12 days. Rickettsia Canada cannot be transmitted directly from human to human, but it is a bloodborne pathogen, and universal precautions should be practiced. Infection remains in the louse for two to six days after biting the source, although it may occur quicker if the louse is crushed.

Symptoms include headache, chills, fever, prostration and general pains. On the fifth or sixth day, a macular eruption (unraised spots on the skin) occurs on the upper trunk and spreads to the entire body (except for the face, palms of the hands and soles of feet). The illness lasts for approximately two weeks. Without treatment, the fatality rate is about 10% to 40%. Treatment involves antibiotic therapy with tetracyclines and chloramphenicol.

Comparison Of Biological Agent Characteristics
DISEASE Dissemination Method Infective Dose Incubation Period Lethality
Cholera Food and water 106 organisms 1 week Low when treated, high when not treated
Brucella Aerosol, food and water Unknown 5 to 30 days Very low
Plague Aerosol Fewer than 100 organisms 1 to 6 days High when not treated, within 12 to 24 hours
Tularemia Aerosol 1 to 50 organisms 1 to 10 days Moderate
Q-Fever Aerosol, food and water 10 organisms 14 to 26 days Very low

Robert Burke, a Firehouse® contributing editor, is the fire marshal for the University of Maryland. He is a Certified Fire Protection Specialist (CFSP), Fire Inspector II, Fire Inspector III, Fire Investigator and Hazardous Materials Specialist, and has served on state and county hazardous materials response teams. Burke is a veteran of 24 years in fire and emergency services, with experience in career and volunteer departments. He has attained the rank of lieutenant, assistant chief and deputy state fire marshal. Burke is an adjunct instructor at the National Fire Academy and the Community College of Baltimore, Catonsville Campus, and the author of the textbooks Hazardous Materials Chemistry for Emergency Responders and Counter-Terrorism for Emergency Responders. He can be reached in the Internet at robert.burke@att.net.