Peste-des-petits-ruminants virus
Encyclopedia
Ovine rinderpest, also commonly known as peste des petits ruminants (PPR), is a contagious disease affecting goats and sheep in Africa
(from the Tropic of Cancer
to the Equator
), the Middle-East and the Indian subcontinent
. But since June 2008, the disease invaded Morocco
, which indicates a crossing of the natural barrier of the Sahara
. It is caused by a species of the Morbillivirus
genus of virus
es. The disease is highly contagious, and has roughly an 80 percent mortality rate in acute
cases.
and pneumoenteritis of the Nigerian dwarf goat. Peste des Petits Ruminants was the French name of a similar disease of sheep and goats first described in the Ivory Coast in 1942. These diseases have been shown to be very close to each other.
Many authors prefer the name "Ovine Rinderpest". But official agencies such as the FAO
and OIE use the French name "Peste des Petits Ruminants", "Peste Des Petits Ruminants", "Peste-des-Petits-Ruminants" or "Peste-des-petits-ruminants", even in English, although the phrase Goat Plague is becoming more widely used in the popular press. The French acronym, PPR, is commonly used among veterinary professionals in East Africa.
, part of Central Africa
(Gabon
, Central African Republic
), East Africa
(north of the Equator), Middle East
and Indian subcontinent
including Nepal
and Myanmar
.
In North Africa
, only Egypt
was once hit. But since summer 2008, Morocco
is suffering a generalized outbreak with 133 known cases in 129 provinces, mostly affecting sheep. The outbreak has precipitated the vaccination of a large number of the 17 million sheep and five million goats in the country.
In an affected flock, even in pest-free regions, the disease do not progress very rapidly, although close contact between animals. New clinical cases may be oberved daily for a one-month period.
in cattle
. They vary following the previous immunitary status of sheep (enzootic or newly infected country). They also vary following sheep breed.
Incubation period is two to six days.
Body temperature is high (40.5 to 41°C.) in the beginning of the onset in acute cases.
The most typical signs are seen in the digestive tract. When entering an affected flock, one sees many animals with hind limbs stained by sticky faeces. Some sheep have an arched back and show pain to defecate. Tenesmus may be noticed when taking rectal temperature. Fluid faeces are olive green to brown.
Examination of the mouth shows ulceration of the buccal mucosae, especially on the inner face of the lips, and neighboring gum. They can be periodontitis.
There is serous nasal exudate and conjunctivitis
.
A dry, fitful coughing develops.
Death occurs from 5 to 10 days after the onset of the fever.
Some animals may recover, but a dry, stertorous
coughing often persists for some days. Besides coughing, there is a intensive labial dermatitis with scab formation, resembling orf
.
Abortions may occur.
Erosions and inflammation is widespread on buccal mucosa. The same lesions are also present in pharynx, oesophagus, and on mucus-producing epithelia of the gut
, from abomasum
to rectum. Zebra-striped lesions on coecum and colon
are said to be typical in some cases. Rarely, they are also petechiae on the rumen
mucosa.
. Antibodies can also be detected via ELISA.
, penicillin
and streptomycin
can be used and supportive treatment may be helpful.
A vaccine
has been developed that may decrease death in the flock.
According to the country's policy, there may be movement restrictions, slaughter of affected flocks in an attempt to eradicate the disease.
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
(from the Tropic of Cancer
Tropic of Cancer
The Tropic of Cancer, also referred to as the Northern tropic, is the circle of latitude on the Earth that marks the most northerly position at which the Sun may appear directly overhead at its zenith...
to the Equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
), the Middle-East and the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
. But since June 2008, the disease invaded Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, which indicates a crossing of the natural barrier of the Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
. It is caused by a species of the Morbillivirus
Morbillivirus
Morbillivirus is a genus belonging to the Paramyxoviridae family of viruses in the order Mononegavirales. Many members of the genus cause diseases, such as rinderpest and measles, and are highly infectious.- External links :* *...
genus of virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es. The disease is highly contagious, and has roughly an 80 percent mortality rate in acute
Acute
Acute may refer to:* Acute accent* Acute angle* Acute * Acute * Acute toxicity...
cases.
Disease appellations
Traditionally, the name kata was given to stomatitisStomatitis
Stomatitis is an inflammation of the mucous lining of any of the structures in the mouth, which may involve the cheeks, gums, tongue, lips, throat, and roof or floor of the mouth...
and pneumoenteritis of the Nigerian dwarf goat. Peste des Petits Ruminants was the French name of a similar disease of sheep and goats first described in the Ivory Coast in 1942. These diseases have been shown to be very close to each other.
Many authors prefer the name "Ovine Rinderpest". But official agencies such as the FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
and OIE use the French name "Peste des Petits Ruminants", "Peste Des Petits Ruminants", "Peste-des-Petits-Ruminants" or "Peste-des-petits-ruminants", even in English, although the phrase Goat Plague is becoming more widely used in the popular press. The French acronym, PPR, is commonly used among veterinary professionals in East Africa.
Geographical repartition
The disease is present in West AfricaWest Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
, part of Central Africa
Central Africa
Central Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda....
(Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
, Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...
), East Africa
East Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
(north of the Equator), Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
and Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
including Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
and Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
.
In North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
, only Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
was once hit. But since summer 2008, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
is suffering a generalized outbreak with 133 known cases in 129 provinces, mostly affecting sheep. The outbreak has precipitated the vaccination of a large number of the 17 million sheep and five million goats in the country.
Contamination
The disease is spread from a region to another by sick animals. As virus is early inactivated outside the body, indirect contamination is generally limited.In an affected flock, even in pest-free regions, the disease do not progress very rapidly, although close contact between animals. New clinical cases may be oberved daily for a one-month period.
Symptoms
They are similar to those of rinderpestRinderpest
Rinderpest was an infectious viral disease of cattle, domestic buffalo, and some other species of even-toed ungulates, including buffaloes, large antelopes and deer, giraffes, wildebeests and warthogs. After a global eradication campaign, the last confirmed case of rinderpest was diagnosed in 2001...
in cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
. They vary following the previous immunitary status of sheep (enzootic or newly infected country). They also vary following sheep breed.
Incubation period is two to six days.
Hyperacute cases
Hyperacute cases are found dead without previous symptoms. They die with a serous, foamy or haemorrhagic discharge coming out of the nose.Acute cases at onset
In acute cases, animals are recumbent, sometimes in self-auscultation position.Body temperature is high (40.5 to 41°C.) in the beginning of the onset in acute cases.
The most typical signs are seen in the digestive tract. When entering an affected flock, one sees many animals with hind limbs stained by sticky faeces. Some sheep have an arched back and show pain to defecate. Tenesmus may be noticed when taking rectal temperature. Fluid faeces are olive green to brown.
Examination of the mouth shows ulceration of the buccal mucosae, especially on the inner face of the lips, and neighboring gum. They can be periodontitis.
There is serous nasal exudate and conjunctivitis
Conjunctivitis
Conjunctivitis refers to inflammation of the conjunctiva...
.
Evolution of acute cases
Nasal discharge becomes mucopurulent and may obstruct the nose.A dry, fitful coughing develops.
Death occurs from 5 to 10 days after the onset of the fever.
Some animals may recover, but a dry, stertorous
Stertorous
Stertorous is a medical used word used to express respiration characterized by a heavy snoring or gasping sound, i.e hoarsely breathing. It occurs in common with mouth breathing due to chronic nasal obstruction. The patient is said to suffer from stertor....
coughing often persists for some days. Besides coughing, there is a intensive labial dermatitis with scab formation, resembling orf
ORF
ORF may refer to:* ORF , the Austrian public service broadcaster.* Open reading frame, a portion of the genome.* The IATA airport code for Norfolk International Airport in Norfolk, Virginia.* ORF format , Olympus raw image file format....
.
Abortions may occur.
Post-mortem lesions
The pathognomonic lesions are situated in the digestive tract. Quick post-mortem examination will lead to the discovery of many haemorrhagic patches on the serous membranes, and intense pneumonia. There is a risk that it may conclude with enzootic pneumonia, inability to open the mouth, and problems with the oesophagus and different parts of the intestine.Erosions and inflammation is widespread on buccal mucosa. The same lesions are also present in pharynx, oesophagus, and on mucus-producing epithelia of the gut
Gut (zoology)
In zoology, the gut, also known as the alimentary canal or alimentary tract, is a tube by which bilaterian animals transfer food to the digestion organs. In large bilaterians the gut generally also has an exit, the anus, by which the animal disposes of solid wastes...
, from abomasum
Abomasum
The abomasum, also known as the maw, and the rennet-bag, and the read, is the fourth and final stomach compartment in ruminants. It secretes rennin - the artificial form of which is called rennet, and is used in cheese creation....
to rectum. Zebra-striped lesions on coecum and colon
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
are said to be typical in some cases. Rarely, they are also petechiae on the rumen
Rumen
The rumen, also known as a paunch, forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed...
mucosa.
Diagnosis
History and clinical signs will enable a presumptive diagnosis to be made in endemic regions. The virus can be detected in acute cases from various swabs and blood samples, using PCR and ELISAELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
. Antibodies can also be detected via ELISA.
Treatment and control
Antibiotics such as chloramphenicolChloramphenicol
Chloramphenicol is a bacteriostatic antimicrobial that became available in 1949. It is considered a prototypical broad-spectrum antibiotic, alongside the tetracyclines, and as it is both cheap and easy to manufacture it is frequently found as a drug of choice in the third world.Chloramphenicol is...
, penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
and streptomycin
Streptomycin
Streptomycin is an antibiotic drug, the first of a class of drugs called aminoglycosides to be discovered, and was the first antibiotic remedy for tuberculosis. It is derived from the actinobacterium Streptomyces griseus. Streptomycin is a bactericidal antibiotic. Streptomycin cannot be given...
can be used and supportive treatment may be helpful.
A vaccine
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...
has been developed that may decrease death in the flock.
According to the country's policy, there may be movement restrictions, slaughter of affected flocks in an attempt to eradicate the disease.