Welcome back Everyone!
In the previous post, I started to explain how Bacillus anthracis infects animals. But how exactly can humans catch anthrax? Humans come into contact with this microbe in a few different ways, but each way deals with some kind of contact with the endospore of Bacillus anthracis. The first way is by ingesting food that contains the Bacillus anthracis spore, which ultimately leads to gastrointestinal anthrax. The most typical case of ingesting a spore causing anthrax occurs when people consume infected, undercooked meat originating from an animal that was also infected. Once the ingestion happens the spores move to into the human body, specifically into the throat, esophagus, stomach, and intestines. Gastrointestinal anthrax is curable with treatment. The next method of contracting anthrax comes from the skin to produce cutaneous anthrax. Humans can get this version of the disease by handling dead animals infected with the disease, mostly in terms of fashion (with wools, hinds, and animal hair) and in one way or another spore enters through an open wound or cuts on the surface of the skin. The infection can spread to many areas of the body, but it is more common on the hands, neck, and arms. Cutaneous anthrax is also curable and will not cause death if treated correctly.
This image displays subcutaneous anthrax; this specific visual is impacting the skin of the leg.
https://www.mja.com.au/journal/2006/185/5/case-human-cutaneous-anthra
This visual also shows a subcutaneous anthrax infection, directly on the face.
https://www.nejm.org/doi/full/10.1056/NEJMicm0802093
The next version of this disease is more recently discovered only in Europe for the most part, is still being heavily researched, and has so far been seen specifically in individuals that use heroin through needle injection. The site of injection behaves like an open wound, behaving and sometimes even appearing similar to that of cutaneous anthrax. Researchers believe that this kind of anthrax spreads more quickly through the body but it can be difficult to specifically detect. The last type of anthrax, inhalation anthrax, is the deadliest version of the disease. Inhalational anthrax can occur, once again, when handling infected animal products and material. Certain occupations have a higher likelihood of being exposed to the disease if they work in areas like tanneries or slaughterhouses, where dead animals are directly handled. Inhalational anthrax moves from the lymph nodes to the rest of the body, spreading the infection to every area possible along the way. If left untreated, the disease will kill the infected individual. The treatment must be quite aggressive and still, despite the dangers, inhalational anthrax can be cured.
This visual depicts the general movement of spores causing inhalational anthrax. An individual inhales the spores through the nose, causing the spore to move from the trachea to the lymph nodes, and the spores spread throughout the body promoting infection.
https://myhealth.alberta.ca/Health/pages/conditions.aspx?hwid=zm2269
An important thing to remember about anthrax is that it is not necessarily contagious; humans cannot catch the disease from being around other infected humans and animals cannot catch it from other animals. Furthermore, humans cannot get the disease by simply being around an animal with anthrax– there must be an entry of the spore into the body in some kind of way, and without the spore, no disease will occur.
Inhalational anthrax is quite a serious disease– in fact, a few months after the September 11th attacks in New York, inhalational anthrax broke out for the first time in the postal systems as a method of bioterrorism. Envelopes were intentionally prepared to contain Bacillus anthracis spores– they were addressed to specific individuals within the government systems of the United States. The timing of this discovery is crucial, and the simple fact that this event occurred in the same year as 9/11 is alarming in itself. Individuals in the states were genuinely worried about their physical safety after being attacked by global terrorists, but now they were concerned about the safety of their health. The spores were also reported in these same intentionally packaged envelopes to workers of a postal processing system in DC, and they were infected with the Bacillus anthracis spores. To combat the infection, a supply of PEP, or post-exposure prophylaxis, was given to all workers. To avoid this situation again, postal systems derived specific codes on the packages to ensure that there are not foreign packages in the postal systems.
The image to the left displays an image of the envelopes addressed to a senator in Washington DC containing the B. anthracis spores.
Citations-
https://www.cdc.gov/anthrax/basics/types/gastrointestinal.html
https://www.cdc.gov/anthrax/basics/types/cutaneous.html
https://www.cdc.gov/anthrax/basics/types/injection.html