Peste des petits ruminants (ppr), Biology

Peste des petits ruminants (PPR) is an acute, highly contagious viral disease of goats and sheep caused by peste des petits ruminants (PPR) virus which belongs to the genus Morbillivirus of the family Paramyxoviridae. The disease is characterized by fever, anorexia, necrotic stomatitis, diarrhoea, oculo-nasal purulent discharge and respiratory distress. Infection is mainly transmitted by inhalation or through conjunctiva and oral mucosa. PPR virus penetrates the retropharyngeal mucosa and enters the blood. Virus localizes in alimentary, respiratory and lymphoid system and causes diahorrea, dehydration and death.PPR is rinderpest like disease in Africa and Asia and highly fatal in goats and less so in sheep. Case fatality rate in goats is 55-85% and in sheep it is less than 10%. Goat kids aging between 4 months and 1 year are most susceptible. The disease was first described in West Africa in 1942. In India, it was first reported in Tamilnadu in the year 1989 and subsequently from other states of India. The disease was first confirmed in Andhra Pradesh in 1991 using specific molecular probes. Since then several outbreaks of rinderpest like diseases in sheep have been attributed to this virus. Cattle and pigs can have antibodies against PPR but do not come down with disease upon inoculation of PPR virus.


Epidemiology:
The transmission of virus occurs through contact mainly through inhalation of aerosols produced by sneezing and coughing fomites;    bedding may also contribute to the onset of an outbreak. Ocular, nasal, and oral secretions and feces are potent sources of virus. Infected animals can transmit the disease during the incubation period as well as during the recovery phase.


Clinical signs: Disease occurs in 2 forms; acute form which is common in goats especially in kids and subacute form which is common in sheep with mild clinical symptoms.The disease usually appears in an acute form, with an incubation period of 4 to 5 days followed by a rise in body temperature to 106° F (40-41° C). The temperature usually remains high for about 5 to 8 days before slowly returning to normal. Affected animals appear dull with a dry muzzle, and reduced appetite. From the onset of fever, mo st a nimals have a se rous na sal discha rge , which pr ogre ssively be comes mucopurulent. At this stage, animals suffer from respiratory distress, and there is sneezing in an attempt to clear the nose. The conjunctiva usually becomes congested and there may be profuse catarrhal conjunctivitis resulting in matting of the eyelids. Necrotic stomatitis is common. Death usually occurs after a course of 5 to 10 days. Bronchopneumonia, evidenced by coughing and characterized by consolidation, is a common feature in the later stages of PPR. Pregnant animals usually abort.


Diagnosis: Diagnosis is based upon clinical and necropsy findings supported by viral isolation in Vero and primary cells of ovine origin and characterization using RT- PCR to distinguish from rinderpest virus. Competitive ELISA based on monoclonal antibodies for detection of antigen is used.
Prevention and control: Vaccination; presently live attenuated tissue culture vaccine (Sungri 94 strain virus) produced by IVRI Mukteswar and from Anasur strain by TANUVAS are effective in controlling PPR in the country.

 

Posted Date: 9/18/2012 6:55:16 AM | Location : United States







Related Discussions:- Peste des petits ruminants (ppr), Assignment Help, Ask Question on Peste des petits ruminants (ppr), Get Answer, Expert's Help, Peste des petits ruminants (ppr) Discussions

Write discussion on Peste des petits ruminants (ppr)
Your posts are moderated
Related Questions
Q. What is population growth rate? The Population growth rate (PGR) is the percent variation between the numbers of individuals in a population at two different times. Thus the

Now try to pull the strands apart at the "origin of replication." What happens to the DNA molecule when the ends are restricted

Define the Food System in space? Mercury (1961-1963) astronauts had to eat bite-sized cubes, freeze dried powders, and semi liquids stuffed in aluminium tubes. For most asbonau

What are the antigens and the respective antibodies of the ABO blood group system? The ABO blood system contain the erythrocytic antigens A and B that can be attacked by the an

Bilateral Cleavage In some animals (for example tunicates and nematodes, although in different way), the arrangement of 4 blastomeres after second cleavage is almost radially

Explain the Bio availability of Vitamin A? By now it is clear that vitamin A is supplied in two forms. One form is retinol, from animal foods such as liver, fatty fish, eggs, a

Explain about the Glycoproteins? Most of the naturally occurring conjugated proteins are glycoproteins. Sugar molecules are covalently bound to them, especially those secreted

Explain the Acid Fast Staining? Acid fast staining is a type of differential staining used for identification of certain bacteria, e.g. Mycobacteria which cannot be stained rea


Explain about Listeria monocytogenes infection Listeria monocytogenes is a gram-positive, motile, non-spore forming rod. It is widely distributed in nature and can be found on