Anthrax: A Domestic Threat

Anthrax may be closer than we think...
Anthrax may be closer than we think…

When most Americans hear the word ‘anthrax’, bioterrorism comes to mind. However, anthrax may be much closer to home than anyone may realize. According to an article (“Investigation of Inhalation Anthrax Case, United States”) in the journal Emerging Infectious Diseases, there has been an incident of inhalation anthrax involving a man who traveled through four U.S. states (North Dakota, Wyoming, Montana, and South Dakota), where animal anthrax may be sporadic or enzootic.

Anthrax is a zoonotic disease caused by the bacteria Bacillus anthracis. It persists in a the form of a spore when dormant (i.e., not living inside of an animal), which can be found within soil (“The Importance of Zoonotic Diseases”). It is important to note that these spores are highly resistant to weather extremes and may last in soil for decades, which may later be consumed by herbivores grazing in contaminated soil. Anthrax is commonly passed on to humans working in wool and goat hair mills and tanneries. Recently, it has been spread to humans via the hides used to cover African drums as well as by bioterrorism attacks in the form of powder. There are four different routes of entry into a host animal:

  1. Cutaneous: This is the most common form of anthrax in humans (approximately 95% of all cases). The infection enters through an abrasion on the skin and results in tissue death and ulceration. 
  2. Pulmonary: The anthrax spore can be ingested into the lungs and transported to the lymph nodes. This is the most fatal form of anthrax. 
  3. Gastrointestinal: If undercooked/contaminated meat is consumed, lesions and ulcers similar to the cutaneous form can occur within the intestines. Humans with B. anthracis in the intestinal tract experience fever, vomiting, severe abdominal pain, and bloody diarrhea. Approximately 50% of cases are fatal.
  4. Oropharyngeal: Anthrax may also enter the body via nasal or oral mucosa resulting in lesions and edema of the throat and oral cavity.

So, how exactly did the 61-year-old Florida man contract anthrax? Jayne Griffith, David Blaney, Sean Shadomy, et al. conducted an investigation in the form of blood tests, genome testing, and interviews with the man and his wife in order to determine the source of infection. Their research reveals many important clues as to just how the man may have ingested anthrax.

Firstly, the blood test and genome sequencing provided scientific evidence that the strain of anthrax in the man most closely resembled strains found within imported animal products containing anthrax. Secondly, he ensured investigators that he had not traveled out of the country or been exposed to any common sources of anthrax (e.g., tanneries, wool/goat hair mills, bone meal, African drums, illicit drugs) within the previous year. Finally, he and his wife described their vacation, explaining they had walked through many national parks, purchased elk antlers, and drove through herds of bison and burros, stopping frequently. This evidence points to contraction of the disease via an animal vector. It is most likely that the man may have received the anthrax in the midst of the dust kicked up by the herds through which he had traveled; however, a specific source was never isolated. Miraculously, the man was treated using antimicrobial drugs and made a full recovery. His wife was also vaccinated as a precaution.

This article provides critical insight to the hidden dangers posed by anthrax – a silent killer. It is imperative that screening for anthrax is performed in areas of recorded cases in order to prevent further infection.

Naturally occurring recorded cases of anthrax throughout the world.
Naturally occurring recorded cases of anthrax throughout the world.

Anthrax is not only a bioterrorism threat, but it is also a domestic threat that can be found within our own U.S. soil.

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