Anthrax screening refers to the practice of testing people for the disease who may have been exposed to Bacillus anthracis, even though they have no anthrax symptoms. Nasal swab tests are not typically recommended for anthrax screening. At this point, an effective anthrax screening test has not yet been developed.
Anthrax Screening: An OverviewAnthrax screening is the practice of testing people who may have been exposed to anthrax for the disease, even though they exhibit no symptoms. At this point, a routine, effective anthrax screening test has not yet been developed. The only way an exposure can be determined is through a public health investigation.
Nasal swabs and environmental tests are not tests to determine whether an individual should begin anthrax treatment. These kinds of tests are used only to determine the extent of exposure in a given building or workplace.
A nasal swab test involves placing a swab inside the nostrils and taking a culture. The Center for Disease Control and Prevention (CDC) and the US Department of Health and Human Services do not recommend the use of nasal swab testing to determine whether a person has been exposed to anthrax bacteria (Bacillus anthracis) or as a means of diagnosing anthrax. At best, a positive result may be interpreted only to indicate exposure; a negative result does not exclude the possibility of exposure. Also, the presence of spores in the nose does not mean that the person has inhalation anthrax. The nose naturally filters out many things that a person breathes, which can include bacterial spores. To have inhalation anthrax, a person must have the bacteria deep in the lungs, and also have symptoms of the disease.
Another reason that nasal swabs are not recommended is that most hospital laboratories cannot fully identify anthrax spores from nasal swabs. They are only able to tell that bacteria which resemble anthrax bacteria are present.