Anthrax


A cutaneous anthrax lesion on the arm of
a 50-year old female
This section provides information on one of the nine zoonotic diseases which have been identified by a experts in a national consultation organised by RCZI in June, 2008  as focus or priority diseases for the next five years.

Anthrax is primarily a disease of herbivorous mammals, although other mammals and some birds have been known to contract it. It is an acute disease caused by Bacillus anthracis, a bacterium that forms spores that are able to survive in harsh conditions for extremely long periods of time. Until the introduction and widespread use of effective veterinary vaccines, it was a major cause of fatal disease in cattle, sheep, goats, camels, horses, and pigs throughout the world.

Cases continue to be reported from many countries in domesticated and wild herbivores, especially where livestock vaccination programmes are inadequate or have been disrupted. Virtually all mammals and some birds can contract anthrax, but susceptibility varies widely and most clinical cases occur in wild and domesticated herbivores. Cattle, sheep, and goats are considered to be highly susceptible; horses somewhat less so. Pigs, other omnivores, and carnivores are more resistant to disease, but they may become ill if the dose is high. Birds are highly resistant.

Human cases usually develop after exposure to infected animals and their tissues. In most countries, human anthrax occurs infrequently and sporadically, mainly as an occupational hazard among veterinarians, agricultural workers, and workers who process hides, hair, wool, and bone products. In humans, the three forms of anthrax are cutaneous, gastrointestinal, and inhalational. Cutaneous anthrax accounts for more than 95% of natural infections, and is rarely fatal if treated with antibiotics. The gastrointestinal form is less common but more serious, and can occur in outbreaks associated with contaminated meat. Inhalational anthrax is the most serious form, and has a very high case fatality rate even when treated. Natural cases of inhalational anthrax are rare; however, anthrax has been used as a weapon by bioterrorists, and weaponized anthrax can form aerosols readily.

Effective vaccines against anthrax are available, and some forms of the disease respond well to antibiotic treatment. Anthrax is found worldwide with areas of enzootic and sporadic occurrence.

Global Situation

Regional/ India Situation

Recent Publications and Reviews

Confirmed and Suspected Outbreaks of Anthrax