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Facts
About Anthrax
Anthrax is an acute infectious
disease caused by the spore-forming bacterium Bacillus
anthracis. Anthrax most commonly occurs in hoofed
mammals and can also infect humans. Symptoms of disease
vary depending on how the disease was contracted, but
usually occur within 7 days after exposure. The serious
forms of human anthrax are inhalation anthrax, cutaneous
anthrax, and intestinal anthrax. Initial symptoms of
inhalation anthrax infection may resemble a common cold.
After several days, the symptoms may progress to severe
breathing problems and shock. Inhalation anthrax is
often fatal. The intestinal disease form of
anthrax may follow the consumption of contaminated food
and is characterized by an acute inflammation of the
intestinal tract. Initial signs of nausea, loss of
appetite, vomiting, and fever are followed by abdominal
pain, vomiting of blood, and severe diarrhea. Direct
person-to-person spread of anthrax is extremely
unlikely, if it occurs at all. Therefore, there is no
need to immunize or treat contacts of persons ill with
anthrax, such as household contacts, friends, or
coworkers, unless they also were also exposed to the
same source of infection. In persons exposed
to anthrax, infection can be prevented with antibiotic
treatment. Early antibiotic treatment of anthrax
is essential–delay lessens chances for survival. Anthrax
usually is susceptible to penicillin, doxycycline, and
fluoroquinolones. An anthrax vaccine also can
prevent infection. Vaccination against anthrax is not
recommended for the general public to prevent disease
and is not available.
Facts
About Smallpox
Smallpox infection was eliminated from the world in
1977. Smallpox is caused by variola virus. The
incubation period is about 12 days (range: 7 to 17 days)
following exposure. Initial symptoms include high fever,
fatigue, and head and back aches. A characteristic rash,
most prominent on the face, arms, and legs, follows in
2-3 days. The rash starts with flat red lesions that
evolve at the same rate. Lesions become pus-filled and
begin to crust early in the second week. Scabs develop
and then separate and fall off after about 3-4 weeks.
The majority of patients with smallpox recover, but
death occurs in up to 30% of cases.
Smallpox is spread from one person to another by
infected saliva droplets that expose a susceptible
person having face-to-face contact with the ill person.
Persons with smallpox are most infectious during the
first week of illness, because that is when the largest
amount of virus is present in saliva. However, some risk
of transmission lasts until all scabs have fallen off.
Routine vaccination against smallpox ended in 1972. The
level of immunity, if any, among persons who were
vaccinated before 1972 is uncertain; therefore, these
persons are assumed to be susceptible. Vaccination
against smallpox is not recommended to prevent the
disease in the general public and therefore is not
available.
In people exposed to smallpox, the
vaccine can lessen the severity of or even prevent
illness if given within 4 days after exposure.
Vaccine against smallpox contains another live virus
called vaccinia. The vaccine does not contain smallpox
virus. The United States currently has an
emergency supply of smallpox vaccine. There is no
proven treatment for smallpox but research to evaluate
new antiviral agents is ongoing. Patients with smallpox
can benefit from supportive therapy (intravenous fluids,
medicine to control fever or pain, etc.) and antibiotics
for any secondary bacterial infections that occur.
Facts
About Botulism
Botulism is a muscle-paralyzing disease caused by a
toxin made by a bacterium called Clostridium botulinum.
There are three main kinds of botulism:
- Foodborne botulism occurs when a
person ingests pre-formed toxin that leads to
illness within a few hours to days. Foodborne
botulism is a public health emergency because the
contaminated food may still be available to other
persons besides the patient.
- Infant botulism occurs in a
small number of susceptible infants each year who
harbor C. botulinum in their intestinal tract.
- Wound
botulism occurs when wounds are infected with C.
botulinum that secretes the toxin.With foodborne
botulism, symptoms begin within 6 hours to 2 weeks
(most commonly between 12 and 36 hours) after eating
toxin-containing food. Symptoms of botulism include
double vision, blurred vision, drooping eyelids,
slurred speech, difficulty swallowing, dry mouth,
muscle weakness that always descends through the
body: first shoulders are affected, then upper arms,
lower arms, thighs, calves, etc. Paralysis of
breathing muscles can cause a person to stop
breathing and die, unless assistance with breathing
(mechanical ventilation) is provided.
Botulism
is not spread from one person to another. Foodborne
botulism can occur in all age groups. A supply of
antitoxin against botulism is maintained by CDC. The
antitoxin is effective in reducing the severity of
symptoms if administered early in the course of the
disease. Most patients eventually recover after weeks to
months of supportive care.
Facts About Pneumonic
Plague
Plague is an infectious disease of animals and humans
caused by the bacterium Yersinia pestis. Y. pestis, is
found in rodents and their fleas in many areas around
the world. Pneumonic plague occurs when Y. pestis
infects the lungs. The first signs of illness in
pneumonic plague are fever, headache, weakness, and
cough productive of bloody or watery sputum. The
pneumonia progresses over 2 to 4 days and may cause
septic shock and, without early treatment, death.
Person-to-person transmission of pneumonic plague
occurs through respiratory droplets, which can only
infect those who have face-to-face contact with the ill
patient. Early treatment of pneumonic plague is
essential. Several antibiotics are effective, including
streptomycin, tetracycline, and chloramphenicol. There
is no vaccine against plague. Prophylactic antibiotic
treatment for 7 days will protect persons who have had
face-to-face contact with infected patients.
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