Rickettsia can be used as a weapon because

Rickettsia
prowazekii is gram-negative coccobacillus bacteria belonging to the
Genus Rickettsia. It is the agent causing epidemic typhus, or louse borne
typhus. Lice are the vectors of the bacteria, and are strictly human parasites (3).
Epidemic typhus is spread through contact with body lice infected with rickettsia prowazekii. Within two weeks
of contact with infected body lice, individuals typically begin exhibiting
symptoms. Symptoms include: fever, chills, headache, rapid breathing, muscle
aches, rash, cough, nausea, vomiting, and/or confusion. Certain individuals can
remain infected, without any symptoms, for up to years after they first exhibit
initial symptoms. Occasionally, these individuals can relapse in disease, up to
months or years following their first bout of illness. This relapse is called
Brill-Zinsser disease. It normally occurs because the body’s immune system has
been weakened due to medication, advanced age, or other illness. Brill-Zinsser
disease exhibits symptoms much like the original disease, but typically much
milder (4).

Epidemic typhus is
diagnosed based on clinical features and symptoms present, a biopsy of any
present rashes with fluorescent antibody staining (which detects the organism),
serologic testing, and a polymerase chain reaction. The treatment for epidemic
typhus primarily involves administering doxycycline, or in some cases
chloramphenicol. These antibiotics are most effective when given shortly after
symptoms appear (2). If treated early, most individuals recover quickly.

There is no
vaccine to prevent epidemic typhus. However, improved sanitary conditions,
insecticides, and antibiotics have been extremely effective in decreasing the
incidence of the disease (2). Furthermore, leading health organizations
recommend several hygienic and preventative practices to prevent the spread of epidemic
typhus. Individuals should avoid overcrowded areas and areas where people
cannot change clothes or bathe on a regular basis. Lice may be prevalent in
these areas. If lice are suspected on bedding or clothing, they should be
treated with permethrin which kills lice and offer long-lasting protection from
lice infestation (4).

Additionally, because of the presence of lice around the globe, rickettsia prowazekii is considered an
agent of bioterrorism. It can be used as a weapon because of many key traits. It
is environmentally stable, small in size, uses aerosol transmission, has a low infectious
dose, and high morbidity and mortality if not treated quickly or correctly (1).