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Essay on Anthrax!
Meaning of Anthrax:
Anthrax is zoonotic disease. It is primarily an infectious disease of domestic animals and is transmitted to man when he comes in contact with them.
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Bacillus anthracis is the causal agent of anthrax. It is Gram-positive bacillus arranged in chains or in pairs or singly (Fig 42.1). In the blood and tissue, it exhibits a distinct capsule when stained by polychrome methylene blue.
The capsule is stained purplish and bacillus blue. It is called as methylene blue reaction of McFadyean which is very useful to recognise anthrax bacillus in blood films. Its spore, central, oval within the bacillus, can be stained by ordinary staining method.
B. anthracis grows best aerobically at 37°C. Its colonies appear under low power of microscope as lock of hair “medusa head appearance“.
Toxin:
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Anthrax bacillus produces a toxin-“anthrax toxin complex“— which increases the permeability of blood vessels leading to the gelatinous oedema and haemorrhage — particularly in animals. In man, the infection is acquired from animal source, usually through damaged skin or mucous membrane.
The resulting lesion is usually described as “malignant pustule” This starts as papule and becomes a blister within 48 hours and then a pustule with in an increasing area of inflammation — depending upon the resistance of the host.
Infection may also result from inhalation of spores carried in dust or filaments of wool from infected sheep as in wool factories-“Wool sorter’s disease.”
The organisms settle in the lower part of the trachea or in large bronchus and an intense inflammatory lesion results with haemorrhage, oedema, involvement of lungs, spread to the thoracic glands and diffusion into the pericardial and pleural cavities; considerable numbers of organisms are present in the lesion; a septicaemic condition or haemorrhagic meningitis may supervene.
Infection of intestinal route is very uncommon.
Laboratory Diagnosis:
Smears made from the exudate of malignant pustule or sputum of Wool sorter’s disease patient are stained with Gram-stain. The finding of bacillus morphologically similar to B. anthracis is suggestive but not conclusive.
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Chemotherapy:
B. anthracis is sensitive to most antibiotics, hence treatment of malignant pustule and Wool sorter disease is successful.
Application to Nursing:
When taking care of a patient with anthrax, the nurse should wear rubber gloves and a rubber apron. Dressings contaminated with purulent exudates or in fatal cases, fluids exudation from eyes, nose and mouth should be burnt promptly. Autoclaving or exposure to hot air oven at sterilising temperature or exposure to sporicidal gases for sufficient time is effective in destroying the spores.
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Pulmonary thorax requires the same precautions of respiratory infections. In addition to these, the disinfectant resistant spores of the exudates should be completely destroyed.
Besides the public health, nurse should educate in explicit language the community that since the infected animal and dead carcasses are potent source of infection to man the farmers should avoid the contact of infected animals which should be buried very deep with lime. All fomites should be completely burnt.
