Pox diseases, Biology

Pox diseases

Small-pox in human beings and pox in a few animal species are closely related to each other. It is shown by the fact that the vaccine for the prevention of small pox consists of the virus of cow-pox collected from calves artificially infected with the disease. However, small pox has since been globally eradicated. Its other forms of animal pox viruses, viz. swine pox, horse pox, fowl pox and sheep pox with the possible exception of buffalo pox and campe pox are not transmissible to human beings. Pox diseases affecting human beings and animals have in all probability their origin in a virus analogous to cow pox.

The pox viruses belong to the family Poxviridae and are classified into different genera, viz. Orthopoxvirus including vaccinia, cow-pox, camel-pox, buffalo-pox, ectromelia, horse-pox , monkey-pox and rabbit-pox viruses: Avipoxvirus including fowl-pox, canary-pox, pigeon-pox, quail-pox and turkey-pox; Capripoxvirus including sheep-pox, goat-pox and lumpy skin disease viruses; Leporipox including myxoma, rabbit fibroma, hare fibroma and squirrel fibroma viruses; Parapox including contagious ecthyma pseudo-cow-pox and Milker's nodule viruses. These viruses exhibit cross- reactivity with the production of cytoplasmic inclusion bodies.

Pox is transmitted by cutaneous inoculation or by smearing the infected material on an abraded surface of skin or on mucous membrane. In sheep, the infection is believed to be transmitted by inhalation since it is the lungs that are mostly affected. Pox viruses in a dry state can maintain their infectivity and virulence for several years at 4oC. In a wet state, the viruses are killed when exposed to 60oC for 10 min. The most effective and inexpensive chemical for inactivating pox viruses is potassium permanganate in a dilution of 1:1000. The majority of pox viruses can be grown on the chorio-allantoic membrane of fertile hen eggs. The lesions produced on the membrane are characteristic of a particular pox virus. Pox diseases can be easily reproduced in monkeys and rabbits.

The period of incubation in pox disease is 2 to 5 days. In cows, buffaloes, sheep and goats the disease usually commences with a rise in body temperature accompanied by marked constitutional disturbance. Five well marked stages of lesions viz. roseola stage consisting of diffused redness due to congestion and resembles a flea bite, which later turns into a raised hard area, the so-called  popular  stage. From the congested blood vessels in the papules, lymph exudes and vesicles are formed. The disease is now regarded as having reached the vesicular stage. In the next or the popular stage, the serous fluid becomes turbid with pus-producing organisms and the lesions are light yellow in appearance. The pustules dry up and form scabs in the last or the crust stage. The successive stages mentioned above appear at intervals of about 3 days and the full course run by the disease is of about 2 to 3 weeks. Recovered animals are usually resistant to further attacks of the disease.

Suitable vaccines are available or in offing against sheep pox, goat pox, swine pox, fowl pox, buffalo pox and camel pox.

Posted Date: 9/18/2012 8:17:48 AM | Location : United States







Related Discussions:- Pox diseases, Assignment Help, Ask Question on Pox diseases, Get Answer, Expert's Help, Pox diseases Discussions

Write discussion on Pox diseases
Your posts are moderated
Related Questions
What is Ecology? Ecology is the field of Biology that studies the relationship among living beings and among living beings and the environment.

Aim: To prove that oxygen is evolved during photosynthesis. Apparatus: Beaker, funnel, test tube, water, Hydrilla plants. Procedure: Take a few pieces of Hydrilla plant. Keep a

Describe what is Circulatory Support and Inotropes ? Colloid or Crystalloids: Hypotension after PGEl infusion is common. It is the result of relative intravascular volume deple

Foot as Burrowing Organ The Scaphopoda that usually have burrowing habit, possess foot suitably modified for burrowing purpose. The conical and protrusible foot of Dentalium

CODOMINANCE The alleles which do not show dominance-recessive relationship and are able to express themselves independently when present together are called codominant alleles.

What is Vertebrates ? Vertebrates are animals that have vertebral columns, and include the following classes: Agnatha - jawless fishes (ex. lampreys) Chrondirichthyes - cart

Explain about the Nucleoproteins? Nucleoproteins are combinations of nucleic acids land simple proteins, which usually consists of a large number of basic amino acids. Nucleopr

Prevention   You as nurse needs to ensure that iron supplementation  is given to children who are at risk for iron deficiency.  Iron supplementation  should start between 4 and

Define Dietary and Non Dietary Factors - Causation of Cancer? Several dietary and non-dietary factors (including genetics) can increase the risk in the causation of cancer. Som

List out Points about the Traditional Food Preservation? 1. The traditional food preservation methods like drying, pickling, salting, smoking, canning and freezing have been wi