Children And Anthrax
This article was written on 11/11/01 from resources available on that date.
Please check the CDC Web site for updated information.
Anthrax is making headlines as an agent of biological warfare, and as a weapon
of bioterrorism. The last epidemic of inhalational anthrax occurred in the
former Soviet Union, in the industrial city of Sverdlovsk, in 1979. The 66
deaths were due to inhalation of aerosolized spores of anthrax, which were
accidentally released from the nearby military microbiology laboratory.
Anthrax is an acute infectious disease caused by the bacterium Bacillus
anthracis. B. anthracis is a bacterium which is distributed
worldwide. It exists in contaminated soil in the form of extremely resistant
spores. Anthrax is most prevalent among cattle, horses, sheep, and goats which
have grazed on contaminated land, or which have ingested contaminated feed.
Most cases in industrialized countries are associated with exposure to goat hair
imported from countries where anthrax is common among livestock. In the U.S.
these bacteria remain endemic in the soil of Texas, Oklahoma, and the lower
Mississippi valley.
Anthrax may have been responsible for two of the plagues which afflicted Egypt
in 1491 BC. The Greek poet and scientist Virgil gave a detailed description of
this disease. Around 1877, John Bell first described woolsorters’ disease in
England. This form of inhalational anthrax is linked to processing of infected
hides and wool in enclosed factory spaces.
WHAT IS ANTHRAX?
It is a square-ended, non-motile, aerobic, Gram-positive rod with a
centrally located spore.
The anthrax spores are highly resistant to drying, boiling, and most
disinfectants. Resistant spores can survive in the soil for decades. B.
anthracis spores germinate when exposed to human (or animal) tissue
or blood.
Anthrax is not spread from person to person.
Children may be affected by three forms: inhalational, cutaneous, or
gastrointestinal.
HOW MANY FORMS OF ANTHRAX ARE THERE?
There are three
forms of anthrax: inhalational, cutaneous, and gastrointestinal.
Inhalational Anthrax:
This is the most lethal form of anthrax. It results from the inhalation of
anthrax spores 1-5 microns in diameter. The 8,000 to 50,000 spores needed to
infect someone are smaller than a speck of dust. Dormant spores travel to
tiny sacs in the lungs where they germinate into bacteria. Children develop
symptoms 1-5 days after exposure, with nonspecific respiratory symptoms of
cough associated with low-grade fever, fatigue, malaise, and muscle aches.
Cutaneous
Anthrax:
"Anthrax" means coal in Greek. The cutaneous form eventually
produces skins lesions which resemble the color of coal.
The disease is initiated when spores enter the skin through cuts or
abrasions. Handling wool or other by-products of infected animals can result
in spores lodging in skin cuts. After an incubation period of 12 hours to 7
days the spores germinate, multiply, and produce a toxin that causes an
initial skin lesion which resembles an insect bite or pimple. A painless
ulcer the size of a quarter appears after a few days. It then develops a
black center.
Gastrointestinal and Pharyngeal Anthrax:
This form occurs after ingestion of anthrax spores in contaminated and
undercooked meat. The spores germinate in the abdominal lymph nodes where
they produce a hemorrhagic lymphadenitis and bacteremia.
In oropharyngeal anthrax, fever and neck swelling occur in the presence of
an oral cavity lesion. Soft tissue edema and dramatic cervical lymph node
enlargement follow.
WHAT MAKES ANTHRAX SO DEADLY?
Anthrax is now being used as a biologic weapon for terrorism. Its spores
remain viable for years, and can be easily stored and transported.
Inhaled anthrax spores can produce a lethal infection despite antibiotic
therapy.
Anthrax bacteria produce and release a deadly toxin. The anthrax toxin has
3 components:
edema factor (EF), lethal factor (LF), and protective antigen (PA).
EF is responsible for the edema at the site of infection, as well as the
inhibition of neutrophil function.
LF destroys cells, injures local blood vessels, and causes thrombosis. LF
stimulates the release of tumor necrosis factor alpha and interleukin-1B,
which contribute to sudden death.
PA facilitates the transfer of EF and LF into the body’s cells.
WHAT ARE THE SIGNS AND SYMPTOMS OF ANTHRAX INFECTION?
Inhalational Anthrax:
Inhalational anthrax has two phases.
In the initial phase, it appears as a nonspecific illness – similar to
influenza. It is characterized by: mild fever, malaise, muscle soreness, dry
cough, and chest or abdominal pain.
The second phase of inhalation anthrax begins abruptly within 2 or 3 days.
It involves additional fever, severe difficulty breathing, sweating,
cyanosis, and occasionally stridor. Death occurs within 24 to 36 hours after
the start of the second phase of the illness.
Cutaneous Anthrax:
The first sign of cutaneous anthrax is a painless pruritic papule. Within
one or two days, a large vesicle develops. A gelatinous swelling surrounds
the lesion. The vesicle ruptures, forming an ulcer which is covered by a
characteristic black eschar. The eschar dries and falls off in a week or
two.
Gastrointestinal Anthrax:
The symptoms of GI anthrax appear 2 to 5 days after the ingestion of
undercooked meat containing spores. The symptoms start out with nausea,
fever, vomiting, and abdominal pain. They rapidly progress to severe, bloody
diarrhea. Oropharyngeal anthrax may also occur.
HOW IS ANTHRAX DIAGNOSED IN CHILDREN?
The physician first needs to determine if there has been a credible
“known” exposure to anthrax.
Second, the physician obtains vital signs, examines the child, and
assesses the neurologic, circulatory, and respiratory status. Signs of
altered mental status which may suggest shock, sepsis, or meningitis are
noted.
Third, the physician notes any erythema, edema, or skin lesions (papules,
vessicles).
Nasal swab cultures should not be used to diagnose cases of anthrax. The
reason is that nasal swab cultures are not very sensitive, so a negative
swab culture result will not rule out exposure to anthrax.
Initial, presumptive, laboratory identification is done using a direct
Gram’s-stained smear of skin lesion fluid, cerebrospinal fluid, or blood.
Microscopic examination will show large, non-encapsulated, broad,
gram-positive rods. In a Gram’s stain preparation, the spore appears as an
unstained area. Anthrax forms non-hemolytic colonies when grown on
sheep’s-blood-agar nutrient.
The physician may consider performing a PCR test on clinical specimens to
document the presence of anthrax.
Confirming tests are done a level B laboratory of the Laboratory Response
Network for Bioterrorism.
WHAT IS THE TREATMENT FOR ANTHRAX IN CHILDREN?
It is important to stress that giving antibiotics to a child who has not
been examined by a physician could mask symptoms of the illnesses, as well
as lead to drug-resistant bacteria.
On the other hand, a high index of clinical suspicion, and rapid
administration of antimicrobial therapy by a physician are necessary for
prompt diagnosis and treatment of anthrax.
Start therapy with IV antibiotics:
Ciprofloxacin 10-15 mg/kg/dose every 12 hours.
OR
Doxycylcline 2.2 mg/kg/dose every 12 hours.
AND
One or two additional antimicrobials.
The physician may then switch to oral antimicrobial therapy when
appropriate. Antimicrobial therapy should be continued for a total of 60
days to ensure that all spores have germinated and that they have been
eradicated.
HOW CAN ANTHRAX INFECTION BE PREVENTED?
Simple measures such as handwashing can prevent skin (cutaneous) anthrax,
just by washing away the spores.
At this time, anthrax vaccine is not recommended for children under 18
years of age.
Drugs and medical supplies which are used to fight anthrax are kept in eight
guarded warehouses in the U.S. Each stockpile holds 50 tons of supplies.
Push packages can reach any American city, if needed, within 12 hours.
This information was developed on 11/11/01 from resources available on that
date. Please check the CDC Web site for
updates. Lecture
material on anthrax is also available.
The
New England Journal of Medicine has published an article on
anthrax. It described the bacteriology, pathogenesis, epidemiology, clinical
features, diagnosis, antimicrobial therapy, and hospital infection control
of anthrax.
Swartz MN: Recognition and management of anthrax – an update. The
New England Journal of Medicine. November 29, 2001; 345(22).