Anthrax

Anthrax is a bacterial infection caused by the gram-positive, spore-forming bacillus Bacillus anthracis or the related Bacillus cereus biovar anthracis. The disease derives its name from the Greek word for coal, referring to the characteristic black eschar that develops in cutaneous infections. First clinically described by Maret in 1752 and Fournier in 1769, the causative organism was subsequently identified by German scientist Robert Koch, establishing the microbial basis of the disease.

Anthrax manifests in three primary clinical forms depending on the route of spore exposure. Cutaneous anthrax, representing over 90% of naturally occurring cases, presents as a boil-like lesion that evolves into a painless ulcer with a characteristic black necrotic center (eschar), typically appearing 2-5 days after spore penetration through broken skin. Inhalation anthrax develops within one week to two months following spore deposition in the lungs, initially presenting with influenza-like symptoms including fever, chills, fatigue, cough, and chest pain, progressing to severe respiratory distress and systemic toxicity. Gastrointestinal anthrax results from consuming contaminated meat, producing diarrhea (often bloody), abdominal pain, nausea, and vomiting, with lesions documented in both the intestinal tract and oropharynx. An injection-associated form has also been documented, particularly among heroin users, which may spread more rapidly into deep muscle tissue.

Anthrax maintains a global distribution with endemic foci in agricultural regions where livestock come into contact with soil-borne spores. Human cases occur predominantly among individuals with occupational exposure to infected animals or animal products, including farmers, veterinarians, abattoir workers, and those handling wool, hides, and bone meal. Military personnel represent another recognized risk group due to potential biothreat exposure scenarios. A notable non-occupational outbreak occurred in Scotland in 2009 among injecting heroin users, resulting in 14 deaths; epidemiological investigation traced the source to heroin contaminated with bone meal from Afghanistan, marking the first documented non-occupational human anthrax outbreak in the UK since 1960.

Human infection occurs through contact with spores present in infectious animal products or contaminated environmental sources. The primary routes include percutaneous exposure through cuts or abrasions (cutaneous anthrax), inhalation of aerosolized spores (inhalation anthrax), and ingestion of undercooked meat from infected animals (gastrointestinal anthrax). Injection drug users may acquire infection through spore contamination of heroin or cutting agents. Importantly, anthrax does not typically spread directly from person to person, limiting secondary transmission in human populations.

Individuals with occupational exposure to livestock, animal products, or contaminated materials face the highest risk of naturally acquired anthrax, including farmers, veterinarians, abattoir workers, and those processing wool, hides, or bone meal. Military personnel deployed to regions with endemic anthrax or operating in contexts with potential biothreat exposure represent a distinct risk category. Injecting drug users may acquire infection through contaminated heroin supplies, as demonstrated by the 2009 Scottish outbreak.

Source-backed detail is not yet available.

Source-backed detail is not yet available.

1. 1 WHO Fact Sheet. Detail.
2. 2 WHO Q&A. News.
3. 3 Wikidata. Anthrax.
4. 4 Wikipedia. Anthrax - Wikipedia.

ICD-10

A22

ICD-11

1B91

Total cases

6K

Total deaths

43

Peak month

2023-08

Coverage

4 reporting countries · 2000-01-01 → 2026-05-09