Human Anthrax as a Re-Emerging Disease

Abstract

Anthrax is primarily a disease of herbivores and the etiological agent is B. anthracis which is a gram-positive, aerobic, spore-forming, and rod shaped bacterium. Bacillus anthracis spores are highly resistant to heat, pressure, ultraviolet and ionizing radiation, chemical agents and disinfectants. For these reasons, B. anthracis spores are an attractive choice as biological agents for the use of bioweapon and/or bioterrorism. Soil is the main reservoir for the infectious agent. The disease most commonly affects wild and domestic mammals. Human are secondarily infected by contact with infected animals and contaminated animal products or directly expose to B. anthracis spores. Anthrax occurs worldwide. This infection is still endemic or hyperendemic in both animals and humans in some part of areas of the world; particularly in Middle East, West Africa, Central Asia, some part of India, South America. However, some countries are claiming free of anthrax, and anthrax has become a re-emerging disease in western countries with the intentional outbreak. Currently, anthrax is classified according to its setting as (1) naturally occurring anthrax, (2) bioterrorism-related anthrax. Vast majority of human anthrax are occurring as naturally occurring anthrax in the world. It is also a threaten disease for western countries. The aim of this paper is to review the relevant patents, short historical perspective, microbiological and epidemiological features, clinical presentations and treatment.

Injectional anthrax in human: A new face of the old disease

“…Resolution is slow (2-6 weeks), regardless of treatment. [10][11][12][13][14][15] Cutaneous anthrax is the most common form of B. anthracis infection. The mortality rate of this form without medical treatment is estimated to be 20%.…”

“…1 However, when the lesion is located on the face, neck or chest, clinical symptoms may be severe, toxic and fatal. 1,2,10 Inhalational anthrax occurs when a person inhales anthrax spores. This form is regarded as the most deadly form of anthrax.…”

“…Less specific findings include pleural effusions and parenchymal infiltrates. 10,[12][13][14][15] Gastrointestinal form of anthrax is a result of consumption of contaminated food (usually meat) or drinking contaminated water. It can present clinically as either oropharyngeal or intestinal infection.…”

Epidemiological and laboratory investigation of a zoonotic anthrax outbreak in West Bengal, India

“…Cutaneous infection usually occurs in herdsmen and butchers in India and also in other developing countries, while other two forms (inhalational and gastrointestinal) are uncommon [8]. Under natural conditions, humans usually acquire cutaneous infection by direct or indirect contact with infected dead animal and animal products [1,9,10]. Human anthrax cases range between 2 000 and 20 000 annually over the world with majority in cutaneous form [8].…”

The putative drug efflux systems of the Bacillus cereus group

“…B . anthracis is endemic in several parts of the world [5]. The three toxin genes ( pag , lef and cya ) are located on a plasmid, pXO1 (189 kb), while the genes necessary for capsule synthesis, capABCD , are located on plasmid pXO2 (95 kb), and fully virulent B .…”