This is an official CDC HEALTH UPDATE
Distributed via Health Alert Network
Wednesday, February 22, 2006, 15:58 EST (03:58 PM EST)
CDCHAN-00241-2006-02-22-UPD-N
Inhalation Anthrax Case
in Pennsylvania
On February 16, a 44 year old male presented to a hospital
in Pennsylvania with respiratory symptoms including dry cough, shortness of
breath and general malaise. Laboratory Response Network (LRN) and Polymerase
Chain Reaction (PCR) on 2/21 and gamma phage lysis on 2/22 from blood culture
isolate were positive for Bacillus anthracis.
Patient resides in New York City and makes drums from
unprocessed domestic and imported (Africa) animal hides (cow and goat). Patient
reports frequent travel to Africa (most recent travel 12/4/05 – 12/21/05).
Patient reports last work with animal hides on 2/15. Process includes cleaning
and removal of hair from hides without chemical fixatives. While traveling to Pennsylvania on 2/16, the patient collapsed with rigors and was transported and admitted to
a small local hospital.
Patient transferred to a tertiary care center on 2/18.
Patient is reported to be stable on antibiotic therapy in the ICU without
mechanical ventilation. No signs of cutaneous or pharyngeal anthrax lesions.
Preliminary clinical impression suggests anthrax sepsis secondary to inhalation
route of exposure due to spores from contaminated animal hides.
Ongoing investigation by PA and NYC departments of health in
coordination with law enforcement includes environmental assessment of
patient’s storage/work facility and home, and identification of individuals who
may have had contact with unprocessed hides.
Anthrax causes and transmission
Anthrax is caused by exposure to B. anthracis an
encapsulated, aerobic, gram-positive, spore-forming, rod-shaped bacterium.
Depending on the route of infection, human anthrax can occur in three clinical
forms: cutaneous, inhalational, and gastrointestinal. Direct skin contact with
contaminated animal products can result in cutaneous anthrax. Inhalation of
aerosolized spores, such as through industrial processing of contaminated wool,
hair, or hides, can result in inhalational anthrax. Hemorrhagic meningitis can
result from hematogenous spread of the organism following any form of the
disease.
The incubation period for anthrax is generally <2 weeks.
However, due to spore dormancy and slow clearance from the lungs, the
incubation period for inhalational anthrax may be prolonged. This phenomenon of
delayed onset of disease is not recognized to occur with cutaneous or
gastrointestinal exposures.
Skin/cutaneous anthrax
Skin or cutaneous anthrax is the most common type
of naturally-acquired infection. Infection begins as a pruritic papule or
vesicle that enlarges and erodes (1-2 days) leaving a necrotic ulcer with
subsequent formation of a central black eschar (Images at http://www.bt.cdc.gov/Agent/cutaneous.asp.) The lesion is usually painless with surrounding edema,
hyperemia, and regional lymphadenopathy. Patients may have associated fever,
malaise and headache. Historically, the case-fatality rate for cutaneous
anthrax has been <1% with antibiotic treatment and 20% without antibiotic
treatment. There are rare case reports of person-to-person transmission of
cutaneous disease.
See http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5042a1.htm#tab2
for specific treatment of cutaneous anthrax.
Inhalational anthrax
Inhalational anthrax is rare but is the most lethal
form of the disease. Disease may initially involve a prodrome of fever,
chills, nonproductive cough, chest pain, headache, myalgias, and
malaise. However, more distinctive clinical hallmarks include hemorrhagic
mediastinal lymphadenitis, hemorrhagic pleural effusions, bacteremia and
toxemia resulting in severe dyspnea, hypoxia and septic shock. Widened
mediastinum is the classic finding on imaging of the chest, but may initially
be subtle (Images at http://www.bt.cdc.gov/Agent/inhalational.asp and in the appendices). Case-fatality rates for
inhalational anthrax are high, even with appropriate antibiotics, and
supportive care. Following the bioterrorist attack in fall 2001, the
case-fatality rate among patients with inhalational disease was 45%
(5/11). Person-to person spread of inhalational anthrax has not been
documented.
For case definitions, treatment guidelines, laboratory
testing procedures, etc, see Anthrax Information for Health Care Providers
http://www.bt.cdc.gov/agent/anthrax/anthrax-hcp-factsheet.asp
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