Anthrax
In 1875, German physician Robert Koch took a blood sample from an infected cow in Wollstein. He isolated the rod-shaped bacterium Bacillus anthracis and injected it into mice to prove it caused disease. This experiment marked one of the first demonstrations that microbes could cause illness rather than spontaneous generation. The bacteria exist as spores in soil for decades or even centuries. These hardy spores wait for herbivores grazing on rough vegetation to ingest them. Once inside the host, oxygen levels drop and nutrients vanish, triggering germination. A single vegetative bacterium produces exactly one spore when conditions turn hostile again. This cycle allows the pathogen to survive harsh environments while waiting for new hosts.
A small blister appears on the skin within two to five days after exposure to cutaneous anthrax. It evolves into a painless ulcer with a black center known as an eschar. Surrounding redness and swelling often accompany this lesion without causing significant pain. Nearby lymph nodes may swell and become tender. Without treatment, about 23.7% of these cases result in death. Inhalation anthrax presents differently with fever, chest pain, and shortness of breath appearing within a week. Early symptoms mimic influenza but progress rapidly to bloody fluid accumulation in the chest cavity. Respiratory failure follows quickly, leading to death within 48 hours if untreated. Gastrointestinal infection causes diarrhea containing blood, abdominal pains, nausea, and vomiting. Mortality rates for intestinal forms range from 25% to 75% depending on how soon treatment begins.
French scientist Louis Pasteur conducted a public experiment at Pouilly-le-Fort in May 1881. He prepared two groups of animals including 25 sheep, one goat, and several cattle. One group received injections of his vaccine while the other remained unvaccinated. Thirty days later both groups received live anthrax bacteria. All animals in the unvaccinated group died while every animal in the vaccinated group survived. This triumph led to the establishment of Pasteur Institutes across Europe and Asia. Human vaccines became available much later starting in 1954. The current FDA-approved American product BioThrax was formulated in the 1960s as an acellular subunit vaccine.
Nordic rebels supplied by the German General Staff used anthrax against the Imperial Russian Army in Finland during 1916. Unit 731 of the Japanese Kwantung Army tested anthrax as Agent N on prisoners of war in Manchuria throughout the 1930s. British scientists at Porton Down developed Operation Vegetarian in 1942 which planned to drop linseed pellets infected with Vollum-14578 strain over Nazi Germany. Five million pellets were created but plans were scrapped after Allied liberation of France. Soviet Union facilities stored hundreds of tons of spores at Kantubek on Vozrozhdeniya Island until abandonment in 1992. These programs operated despite international treaties signed in 1972 prohibiting production and stockpiling.
Concentrated anthrax spores were mailed to news media offices and two Democratic senators in October 2001. Letters sent to Tom Daschle of South Dakota and Patrick Leahy of Vermont resulted in 22 infections and five deaths. Only a few grams of material were required for these attacks. The United States Postal Service installed biodetection systems in large mail processing facilities following this event. Bruce Ivins, a senior biodefense researcher employed by the government, was identified as responsible in August 2008. Cleaning the Brentwood postal facility cost $130 million and took 26 months to complete. As of 2020 no positive alerts have occurred from these detection systems.
At least 2,000 cases occur globally each year with about two cases annually in the United States. Skin infections represent more than 95% of all reported human cases. Russian researchers estimate arctic permafrost contains around 1.5 million anthrax-infected reindeer carcasses. Spores may survive in frozen ground for up to 105 years. A 2016 outbreak linked to a 75-year-old defrosted carcass demonstrated risks posed by global warming. In July 2022 dozens of cattle died in Lonjsko Polje nature park near the Sava river in Croatia. Six people were hospitalized with light skin-related symptoms during that incident. Disturbed grave sites of infected animals can cause infection even after 70 years.
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Common questions
Who discovered the bacterium Bacillus anthracis and when did this happen?
German physician Robert Koch isolated the rod-shaped bacterium Bacillus anthracis in 1875. He took a blood sample from an infected cow in Wollstein to prove that microbes cause illness.
What are the symptoms of cutaneous anthrax and how long does it take for them to appear?
A small blister appears on the skin within two to five days after exposure to cutaneous anthrax. It evolves into a painless ulcer with a black center known as an eschar surrounded by redness and swelling.
When did Louis Pasteur conduct his public experiment at Pouilly-le-Fort involving sheep and cattle?
French scientist Louis Pasteur conducted a public experiment at Pouilly-le-Fort in May 1881. He prepared groups of animals including 25 sheep, one goat, and several cattle to test his vaccine.
Which countries developed anthrax weapons programs during the twentieth century?
Nordic rebels supplied by the German General Staff used anthrax against the Imperial Russian Army in Finland during 1916. Unit 731 of the Japanese Kwantung Army tested anthrax as Agent N on prisoners of war in Manchuria throughout the 1930s while British scientists developed Operation Vegetarian in 1942.
Who was identified as responsible for the anthrax attacks that occurred in October 2001?
Bruce Ivins, a senior biodefense researcher employed by the government, was identified as responsible in August 2008. Letters sent to Tom Daschle of South Dakota and Patrick Leahy of Vermont resulted in 22 infections and five deaths.
How many cases of anthrax occur globally each year and what percentage are skin infections?
At least 2,000 cases occur globally each year with about two cases annually in the United States. Skin infections represent more than 95% of all reported human cases.