Zoonoses disease-anthrax, Biology

Anthrax


Anthrax is primarily a disease of the herbivores and occurs in almost all parts of the world. The disease has declined recently throughout the world as a result of the development of an effective vaccine and the use of antibiotics. As per the World Health Organization (WHO) 20,000-100,000 cases of human anthrax are reported annually throughout the world.The causative agent of anthrax is Bacillus anthracis. The organism forms spores in contact with air, which are resistant to heat, low temperature, many disinfectants and prolonged drying; thus survive for long periods in soil, feed, animal products, etc.


Epidemiology:
In comparison to the herbivores, man is moderately resistant to anthrax. Human anthrax has been classified as non-industrial anthrax and occurs in butchers, farmers, pathologists and veterinarians as a result of close contact with infected animals. Industrial anthrax occurs in those employed in the processing of wool, hair, hides, bones or other animals products.
Non-industrial anthrax results from handling of infected carcasses and usually manifests as cutaneous form. Water-borne and insect –transmitted anthrax also take the cutaneous form. Intestinal anthrax resulting from the consumption of infected meat also belongs to the non-industrial category. Industrial anthrax may be cutaneous but generally occurs as pulmonary form due to inhalation of spore-laden dust. Man almost invariably acquires anthrax directly or indirectly from infected animals. Laboratory-acquired infections have been reported. The occurrence of anthrax appears to be unrelated to age or sex.


Clinical features:
Anthrax occurs in 3 forms in man – the cutaneous form, the intestinal and the pulmonary form. Cutaneous form accounts for most human cases throughout the world. All the three forms are potentially fatal but the cutaneous types are often self – limiting.


Cutaneous anthrax: The incubation period is usually 2-3 days. The infection occurs via a cut, abrasion or insect bite. The lesion develops as a papule which turns black and may contain pus if secondarily infected with pyogenic organisms. The lesion may remain small but occasionally becomes very extensive. It is always surrounded by oedema and the black eschar firmly adherent to the underlying tissues. In cases that become septicaemic, temperature rises to 40oC and then may fall to below normal within a few hours. The patient becomes toxaemic and shocked. Dyspnoea, cyanosis and collapse precede death.


Intestinal anthrax: The incubation period is usually 2-5 days. The lesions develop after the ingestion of B. anthracis spores in infected meat, milk, or other food stuffs. The characteristic eschar, or malignant carbuncle occurs in most part of the duodenum. Nausea, vomiting, anorexia, fever, abdominal pain and bloody diarrhoea are often seen. This form of anthrax is more fatal than cutaneous anthrax.


Pulmonary anthrax:
This form of anthrax is almost always caused by industrial exposure to spores (Woolsorter’s disease). Illness begins 2-5 days after exposure with mild fever, fatigue and malaise. The patient may vomit or cough up a little blood. There is rapid development of dysponoea, cyanosis and severe pyrexia followed by coma and death. The disease is usually fatal.


Laboratory diagnosis: The organism may be seen in smears of exudates stained with polychrome methylene blue (McFadyean reaction) and may tentatively be identified by their characteristic morphology. Anthrax bacilli may be readily cultured from the skin lesions.


Susceptibility of B. anthracis to a specific gamma bacteriophage is helpful for confirmation of the organism. Immunofluorescence and enzyme-linked immunosorbent assay may be conducted for diagnosis. Nucleic acid based diagnosis like PCR may be used for rapid and accurate diagnosis.


Control and prevention: These methods are discussed here.
1.  Avoiding contact with infected animals.
2.  Proper disposal of dead animals.
3.  Prevention of development of anthrax in farm animals through the use of anthrax vaccine.
4.  Vaccination of workers at risk.

Posted Date: 9/20/2012 2:34:34 AM | Location : United States







Related Discussions:- Zoonoses disease-anthrax, Assignment Help, Ask Question on Zoonoses disease-anthrax, Get Answer, Expert's Help, Zoonoses disease-anthrax Discussions

Write discussion on Zoonoses disease-anthrax
Your posts are moderated
Related Questions
SERENDIPIDIT Y - Sometimes discoveries are made unexpectedly matter of chance. This is serendipidity. Examples - 1.       Structural formula of benzene - It was dreamt by

how we attempt a question of phylum mollusca in exame?

Define Intra enterocyte transport - non-haem iron absorption? Intra enterocyte transport: In the enterocyte, the absorbed iron can have one of the following metabolic fates:

Q. What is the pollination? What are the major forms of pollination? The procedure in which pollen grains (the male gametophytes of phanerogamic plants) reach the female gameto

Define Molisch's Test or alpha naphthol reaction? The Molisch test is a common test for the existence of carbohydrates. Principle The reaction is due to the formation of

Define the Food Sources of Thiamin? Thiamin is present in many food products and depending on the amount of vitamin present, we have categorized the foods as rich, good or fair

Heliozoans - Protozoan Heliozoans are spherical protozoan that occur in the sea or in still bodies of fresh water. They are mainly located in the bottom debris. Fine needle li


Advantage of solar energy: 1.         It is renewable: it produce comes from sun, so it is plentiful and will always be there   as long we need it . 2.         Solar

How Vitamin E provide Synthesis of enzymes and proteins? 1) Synthesis of enzymes and proteins: It serves as a co-repressor in the synthesis of certain enzymes and plays a speci