Pathology/Lab Coding Alert

With the threat of bioterrorism becoming a reality, clinicians are often the first line of defense in identifying potential cases of anthrax. As part of both the diagnostic and epidemiological network, pathologists and laboratories are being called on to conduct specific tests to help identify this once-uncommon organism.
 
Anthrax Microbiological Testing
Identifying anthrax from nasal swabs has been widely reported recently. "It is important to realize that the nasal swabs are an epidemiological tool, not a diagnostic test for anthrax," says Ray Kaplan, PhD, clinical scientist for microbiology and serology at Quest Diagnostics Inc. in Atlanta. "Along with environmental testing, the swabs are used to analyze the extent of exposure to a population. If positive, a nasal swab does not indicate that an individual is infected with the disease, but has been exposed to it."
 
Report a nasal swab culture provided to screen for anthrax as CPT 87081 (culture, presumptive, pathogenic organisms, screening only).
 
Rapid field tests for Bacillus anthracis, such as the antibody-based Guardian BTA test strips, are also used for investigative rather than diagnostic purposes. "None of these products are FDA-approved and, to my knowledge, a published assessment of their accuracy is not available," Kaplan says.
Culture
 
For patients with clinical symptoms of anthrax, growing a culture of Bacillus anthracis is the most straightforward and certain method to confirm infection. Depending on the symptoms and apparent route of infection, the culture may be taken from many sources such as blood, tissue biopsy, skin lesion exudate, sputum or cerebrospinal fluid (CSF).
 
"Bacillus anthracis is readily cultured on standard blood agar plates, and colonies may be evident as early as six to eight hours, or nearly always within 18 to 24 hours, depending on the original bacterial concentration and contamination level," Kaplan says. These cultures are reported based on the source: 87040 (culture, bacterial; blood, with isolation and presumptive identification of isolates [includes anaerobic culture, if appropriate]) or 87070 (... culture, bacterial; any other source except urine, blood or stool, with isolation and presumptive identification of isolates).
 
"Beyond the culture morphology, growth on selective media and Gram stain, if a biochemical panel is run to perform a definitive identification, also report 87077 (... culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate)," says William Dettwyler, MT-AMT, coding analyst for Health Systems Concepts, laboratory coding and compliance consultants in Longwood, Fla. CPT defines definitive identification as "identification to the genus or species level that requires additional tests (e.g., biochemical panels, slide cultures)."
 
"Identification involves several tests that point strongly to B. anthracis but do not rule out a few related Bacillus strains," Kaplan says. "Any isolate that is Gram-positive, aerobic, nonmotile, nonhemolytic and nonurease active would be highly suspicious. Labs are required [...]