An outbreak of naturally occurring anthrax has killed at least 50 animals, including cattle and a moose, in Wyoming. This marks the first confirmed case of anthrax in Wyoming cattle since the 1970s and the first in wildlife since the 1950s. The Wyoming Livestock Board confirmed the outbreak in multiple beef herds in Carbon County, near Elk Mountain, on September 3rd. The Wyoming Game and Fish Department also confirmed a case of anthrax in a dead moose in the same county on the same day.
Anthrax is an infectious disease caused by the bacterium *Bacillus anthracis*. This bacterium forms spores that can remain dormant in the environment for decades, potentially causing outbreaks after heavy rainfall or flooding following a drought. While naturally occurring, anthrax has also been developed as a biological weapon by militaries around the world and has been used in terrorist attacks, such as the 2001 anthrax mailings in the United States.
Anthrax typically affects livestock and wild animals like cattle, sheep, and deer. Animals contract the disease by breathing in or ingesting spores from contaminated soil, plants, or water. Human infection is rare, but can occur through contact with infected animals or contaminated animal products such as wool, bone, or hair. During the 2001 anthrax attacks, 22 people were infected and five died.
There are four types of anthrax, each named according to how the *B. anthracis* spores enter the body. Cutaneous anthrax occurs when spores enter through a cut or scratch on the skin. Inhalation anthrax results from breathing in the spores, causing infection in the lungs. Gastrointestinal anthrax occurs from ingesting the spores, possibly through consuming infected meat or milk. Injection anthrax has been reported in heroin-injecting drug users in Europe, occurring when the spores enter the body through an injection site. Human-to-human transmission of anthrax has not been reported.
Symptoms of anthrax in humans vary depending on the type of infection. Cutaneous anthrax often causes itchy blisters or bumps that develop into painless sores with black centers. Inhalation and gastrointestinal anthrax share symptoms like fever, chills, and nausea, but inhalation anthrax can also cause chest pain and shortness of breath, while gastrointestinal anthrax can trigger neck swelling. Symptoms typically develop within one to seven days after exposure, but can take up to two months to appear.
Anthrax can be fatal if left untreated, but antibiotics are effective in treating the disease. A vaccine is also available for high-risk individuals, such as those who work with potentially infected animals or related products or in laboratories handling *B. anthracis*.
While anthrax is rare in developed countries due to vaccination programs, authorities are urging caution. The Wyoming Livestock Board is working with producers and veterinarians to limit human exposure during the outbreak. The Wyoming Game and Fish Department is monitoring the outbreak in wildlife. Anyone who suspects exposure to anthrax-infected animals should contact the state health department and seek medical attention.
