Anthrax symptoms puzzle doctors

Officials have confirmed 18 infections since October

WASHINGTON (CNN) -- Doctors say they're intrigued and baffled by the case of a postal inspector who worked at an anthrax-contaminated office here, was admitted to a hospital with symptoms of the inhaled form of the disease, but never tested positive for the bacterium.

Physicians wrote about the case in the latest issue of the The Journal of the American Osteopathic Association.

As a postal inspector, the patient was responsible for removing air filters in the part of the Brentwood Post Office that was contaminated with anthrax. Two other employees who worked at that office died of inhalation anthrax and another two were diagnosed with the disease.

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The patient cited in the article was never diagnosed with inhalation anthrax. The patient said he was wearing only a store-bought face mask while removing and changing the filters and said he inhaled large quantities of dust particles. The patient also reportedly inspected about 10 packages at high risk for containing anthrax.

Three days after that initial exposure, the patient was given a 10-day course of the antibiotic Cipro after a nasal swab. The patient took the medicine for one day and then missed two doses before he continued with the prescription. He went on to develop headaches and a cough.

When the headache, cough and a severe chest pain continued for two days, the patient -- who had previously been healthy -- sought medical attention and was admitted to intensive care at Sinai Hospital of Baltimore. When the symptoms abated over two days, the patient was discharged to continue with a 60-day treatment of Cipro.

The patient's symptoms returned. He was switched from Cipro to doxycycline, but the symptoms persisted and worsened. A month after the initial hospital admission, the patient was re-admitted.

He didn't test positive for the presence of bacteria in his blood when he arrived at the hospital and never received a positive test the entire time he was there, about two months. He was discharged this past Friday and is continuing treatment at home.

"Our patient clearly had a significant exposure to the weaponized form of anthrax," wrote Dr. Tyler Cymet, one of the attending physicians, in the journal article. "We strongly believe that there is a relation between the patient's exposure to anthrax and the symptoms displayed. In the absence of an alternative diagnosis for this patient, and because an anthrax diagnosis was not made definitively, we suggest that there may exist a clinical entity of 'aborted anthrax infection.' "

It's the missed doses of Cipro that have the doctors intrigued.

The initial doses may have killed most of the bacteria, but allowed a small number of spores to hide out in a lymph node, allowing the toxins the spores produce to do damage, Cymet said.

Although they may never know if this patient was indeed infected with anthrax, Cymet said, "It's important not to miss doses of an antibiotic in general, but it's even more important if you have a life-threatening condition like anthrax."

Cymet said there's a chance that cases like this could just be coincidental. Cymet said he saw a similar case yesterday where someone who worked at Brentwood presented anthrax-like symptoms. That patient turned out to have a problem with her thyroid.

He said he has talked to other doctors who think they have something similar, but they haven't done the complete work-up yet because the patients are not sick enough.

Federal health officials have confirmed 18 anthrax infections -- including five fatalities -- since anthrax-tainted letters began showing up in the mail in early October.

No one has been arrested in connection with the deadly missives, which were sent to Senate offices in Washington and news media outlets.