Health Advisory: Anthrax update for laboratory personnel

Despite multiple "scares," there is currently no evidence that any person, business, or organization in Washington State has been the target of an anthrax threat. There are no clinically useful tests to diagnose exposure to anthrax before disease develops. Testing for exposure to anthrax (nasal swabs or serologic testing) should only be done in the setting of an epidemiologic investigation following a known exposure to anthrax.

Prescribing antibiotics for a presumed exposure to anthrax should only occur after consultation with Public Health - Seattle & King County to determine the likelihood that the situation represents an exposure to anthrax. The Washington State Public Health Laboratory has not found any evidence of anthrax in any of the numerous specimens of "suspicious powder" tested to-date.

Frequently Asked Questions:

A clinician calls about a patient with no symptoms but is requesting to be tested for anthrax. What should the lab do?

Answer:
WE STRONGLY ADVISE AGAINST PRESCRIBING PROPHYLAXIS OR ORDERING NASAL SWABS OR ANY DIAGNOSTIC TESTING ON ASYMPTOMATIC PATIENTS WITHOUT EVIDENCE OF CONFIRMED OR HIGHLY LIKELY ANTHRAX EXPOSURE. There are no clinically useful tests to determine if persons are infected with anthrax before they become ill. A negative nasal swab and/or serologic testing cannot rule out exposure to anthrax and these tests are only used as an epidemiologic tool in an investigation following a known exposure.

Please advise the clinician that the Washington State Public Health Laboratory will not test specimens from asymptomatic persons unless ordered by Public Health as part of a current epidemiologic investigation..

A clinician has requested testing for a suspected case of anthrax. What should the lab do?

Answer:
Any confirmed or suspected case of B. anthracis must be reported Public Health IMMEDIATELY by calling 206-296-4774 at any time.

Instruct the clinician to obtain the appropriate laboratory specimens for culture based on the clinical form of anthrax that is suspected (inhalational, gastrointestinal, or cutaneous).

	Inhalational anthrax: blood (CSF and plueral fluid can also be cultured if disease is present at these sites)
	Gastrointestinal anthrax: blood
	Cutaneous anthrax: vesicular fluid and blood

Evaluation of possible anthrax infection for individuals should be performed through standard laboratory tests, following the Laboratory Response Network (LRN) Level A Clinical Guidelines for rule-out and presumptive testing www.bt.cdc.gov (follow the link for Resources: Agents/Diseases - Bacillus anthracis)

The microbiology laboratory has isolated an organism that is presumptively identified as Bacillus anthracis. What should the lab do next?

Answer:
Any confirmed or suspected isolate of B. anthracis must be reported Public Health IMMEDIATELY by calling 206-296-4774 at any time. Packaging and labeling specimens is the same as for any infectious substance. See diagram showing Packaging and Labeling of Infectious Substances at: www.cdc.gov/od/ohs/biosfty/bmbl4/b4acf1.htm