Health officials in Bulgaria announced that four cows had died from the bacterial disease, anthrax, in Silistra district in northeastern Bulgaria.
Bulgaria reported a number of anthrax outbreaks in humans and animals in 2015.
According to the Merck Veterinary Manual, Anthrax is a zoonotic disease caused by the sporeforming bacterium Bacillus anthracis. Anthrax is most common in wild and domestic herbivores (eg, cattle, sheep, goats, camels, antelopes) but can also be seen in humans exposed to tissue from infected animals, contaminated animal products or directly to B anthracis spores under certain conditions.
Depending on the route of infection, host factors, and potentially strain-specific factors,anthrax can have several different clinical presentations. In herbivores, anthraxcommonly presents as an acute septicemia with a high fatality rate, often accompanied by hemorrhagic lymphadenitis.
B. anthracis spores can remain infective in soil for many years. During this time, they are a potential source of infection for grazing livestock. Grazing animals may become infected when they ingest sufficient quantities of these spores from the soil.In addition to direct transmission, biting flies may mechanically transmit B. anthracis spores from one animal to another.
People can get anthrax by handling contaminated animal or animal products, consuming undercooked meat of infected animals and more recently, intentional release of spores.