Anthrax update for health care providers

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:

My patient has no symptoms but is requesting to be tested and/or treated for anthrax. What should I 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 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 useful as an epidemiologic tool in an investigation following a known exposure. If you suspect your patient may have been exposed, then local law enforcement and Public Health must be notified to investigate the situation.

Prophylaxis for anthrax would only be recommended following a confirmed or highly likely exposure to Bacillus anthracis. The decision to prescribe prophylaxis should be made in consultation with Public Health. The duration of antibiotic prophylaxis for anthrax is 60 days.

What should we do if an asymptomatic person recalls past contact with powdery material from a letter or in the environment, but the material is no longer available for testing?

Answer:
Ask the person about the presence of a threatening message. If the letter contained a message suggesting a threat the patient should report the situation to their local law enforcement agency. Also assess if inhalation or skin contact with material occurred.

	If no contact, reassure the person. No exposure, therefore no risk. No further action needed.
	If skin contact or inhalation occurred, reassure person that risk is extremely low in the absence of a threat in or on the letter or package. It would be prudent to watch carefully for respiratory symptoms or fever, or development of skin lesions.

What should we do if an asymptomatic person has had contact with powdery material from a letter or in the environment, and the material is currently available for testing?

Answer:
If you suspect your patient may have been exposed to anthrax, then local law enforcement and Public Health must be notified to investigate the situation. Assess if inhalation or skin contact with material occurred.

	If no contact, reassure the person. No exposure, therefore no risk. No further action needed other than law enforcement investigation.
	If skin contact or inhalation occurred, reassure person that risk is extremely low in the absence of a threat in or on the letter or package. It would be prudent to watch carefully for respiratory symptoms or fever, or development of skin lesions.
	If it is determined that a credible threat of an anthrax exposure is present after an investigation by law enforcement and/or Public Health authorities, Public Health will arrange testing of the substance at the Washington State Public Health Lab.

My patient gives a history of being at a site where anthrax exposures have been confirmed or is currently under active investigation for anthrax exposures (such as FL, D.C. or NYC). Do they need to have prophylaxis?

Answer:
Please consult Public Health by calling 206-296-4774.

My patient has flu-like symptoms and is worried that they may have anthrax. What should I do?

Answer:
Persons with "flu-like" symptoms should know that we are entering the respiratory virus, or "flu season", and these symptoms are caused by naturally occurring viruses and colds in the community. Because of recent events in the news, many persons are requesting to be tested for anthrax. There have been no cases of anthrax in our area. Continuous monitoring in King County by Public Health has found no unusual disease activity in our area. Persons without credible evidence of anthrax exposure should be reassured and the appropriate steps as described above taken if indicated.

There are no useful tests to determine if persons are infected with anthrax before they become ill. Nasal swabs to detect anthrax spores have been used in investigations of known or presumed anthrax exposure as determined by law enforcement and public health authorities, but are not useful in clinical management.

Nasal swabs and other tests that are obtained during investigations help determine how the organism was spread. These tests do not provide useful information about whether a specific individual needs treatment. Persons who have had a confirmed or likely exposure to anthrax as determined by law enforcement and/or public health authorities would be advised to take preventive antibiotics regardless of the results of laboratory screening tests.

I have a high index of suspicion that my patient may have anthrax. What specimens should I obtain for testing?

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

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 (if meningeal signs are present) or pleural fluid; and a chest X-ray
	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 presumptive for Bacillus anthracis. What should they do?

Answer:
Any confirmed or suspected isolate of B. anthracis must be reported Public Health IMMEDIATELY.