Anthrax

Primary reference(s)

CDC, 2020. Anthrax. Centres for Disease Control and Prevention (CDC). Accessed 11 October 2020.

WHO, FAO and OIE, 2008. Anthrax in Humans and Animals. 4th Ed. World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO), World Organisation for Animal Health (OiE). Accessed 11 October 2020.

Additional scientific description

Until the introduction and widespread use of effective veterinary vaccines, Anthrax was a major cause of fatal disease in cattle, sheep, goats, camels, horses, and pigs throughout the world. Anthrax continues to be reported from many countries in domesticated and wild herbivores, especially where livestock vaccination programmes are inadequate or have been disrupted (WHO, no date).

Humans generally acquire the disease directly or indirectly from infected animals, or occupational exposure to infected or contaminated animal products. Control in livestock is therefore the key to reduced incidence in humans. The disease is generally regarded as being non-contagious (WHO, no date).

The infected host sheds the vegetative bacilli onto the ground and these sporulate on exposure to the air. The spores, which can persist in soil for decades, may displace up to the topsoil, following grass growth or flooding, creating favourable conditions for anthrax. Grazing animals may take up the spore and get infected, when germination and multiplication can again take place upon the site of infection. Flies appear to play an important role in large outbreaks in endemic areas. Humans acquire anthrax from handling carcasses, hides, bones, etc. from animals that died of the disease (WHO, FAO and OIE, 2008).

More than 95% of human anthrax cases take the cutaneous form and result from handling infected carcasses or hides, hair, meat or bones from such carcasses. All three forms (cutaneous, gastrointestinal, inhalational) are potentially fatal if untreated, but the cutaneous form is more often self-limiting. Data from pre-antibiotic and vaccine days indicate that 10%–40% of untreated cutaneous cases may be expected to result in death with some geographical and temporal variations (WHO, FAO and OIE, 2008).

Bacillus anthracis has always been high on the list of potential agents with respect to biological warfare and bioterrorism. It has been used in that context on at least two occasions, prepared for use on several other occasions and been the named agent in many threats and hoaxes (WHO, FAO and OIE, 2008).

Metrics and numeric limits

Not available.

Examples of drivers, outcomes and risk management

The Food and Agriculture Organization of the United Nations provides information on anthrax outbreaks via its guidance on for improved prevention, control and heightened awareness (FAO, 2018). Anthrax provides a good platform for a ‘One Health’ approach which can be operationalised through locally adapted approaches for prevention and control. These efforts should be supported by enhanced intersectoral collaboration and coordination between the veterinary and medical authorities, particularly at the field level, for information and report exchange, integration of surveillance data, joint case investigations, coordination of community awareness messaging and implementation, and effective delivery of vaccination campaigns (FAO, 2018).

In the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code chapter on anthrax, it is reported that there is no evidence that anthrax is transmitted by animals before the onset of clinical and pathological signs. It provides guidance on early detection of outbreaks, quarantine of affected premises, destruction of diseased animals and fomites, and implementation of appropriate sanitary procedures at abattoirs and dairy factories will ensure the safety of products of animal origin intended for human consumption (OIE, 2019).