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Malignant Catarrhal Fever . Jeffrey Musser, DVM, PhD Professor Moritz van Vuuren Suzanne Burnham, DVM Texas A&M University University of Pretoria
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Malignant Catarrhal Fever Jeffrey Musser, DVM, PhD Professor Moritz van Vuuren Suzanne Burnham, DVM Texas A&M University University of Pretoria College of Veterinary Medicine Department of Veterinary Tropical Diseases Malignant Catarrhal Fever
Notes For additional information, download this presentation and read the notes attached to each slide. Malignant Catarrhal Fever
Malignant CatarrhalFever In this presentation the authors especially drew from the first hand experience of their colleagues in South Africa. Personal interviews as well as standard research sources provide the insights we bring you for the recognition of this exotic disease. Jeffrey Musser Suzanne Burnham Malignant Catarrhal Fever
Malignant Catarrhal Fever Another word of thanks to Dr Corrie Brown who believes that sharing information will make the world a better place. Dr Brown generously has shared her work on this subject to add to the depth of this work. MALIGNANT CATARRHAL FEVER Dr Corrie Brown Malignant Catarrhal Fever
Diseases Notifiable to the OIE • Cattle diseases Bovine anaplasmosisBovine babesiosisBovine genital campylobacteriosisBovine spongiform encephalopathy Bovine tuberculosisBovine viral diarrhoeaContagious bovine pleuropneumonia Enzootic bovine leukosisHaemorrhagic septicaemiaInfectious bovine rhinotracheitis/infectious pustular vulvovaginitisLumpky skin diseaseMalignant catarrhal feverTheileriosisTrichomonosisTrypanosomosis (tsetse-transmitted) Malignant Catarrhal Fever
Malignant Catarrhal Fever Malignant catarrhal fever, is an infectious disease of ruminants. It is also referred to as malignant catarrh, malignant head catarrh, and gangrenous coryza. In South Africa it may also be called “snotsiekte” which means “snotting sickness” Malignant Catarrhal Fever
Malignant Catarrhal Fever Malignant catarrhal fever is a sporadic, usually fatal, pansystemic disease of cattle and deer characterized by low morbidity but high mortality, high fever, catarrhal inflammation of the upper respiratory tract and the digestive tract, dehydration, conjunctivitis, generalized lymphadenopathy and epithelial lesions. Malignant Catarrhal Fever
Malignant Catarrhal FeverContents • Etiology • Host range • Transmission • Incubation • Clinical signs • Diagnosis • Differential Diagnosis Malignant Catarrhal Fever
Etiology • Wildebeest derived MCF is caused by Alcelaphine herpesvirus type 1(AHV-1) • Sheep associated MCF is caused by Ovine herpesvirus-2 (OVH-2) Malignant Catarrhal Fever
Etiology and • Caprine herpesvirus type 2 • All are Lymphotropic Cell-associated Gamma family herpesviruses Malignant Catarrhal Fever
Etiology • Wildebeest-derived • Occurs wherever wildebeest live • Alcelaphine herpesvirus-1 • Sheep-associated • Endemic, worldwide; sheep is the natural reservoir host • Ovine herpesvirus-2 • Goat-derived • Goats are the natural reservoir host. • Caprine herpesvirus-2 • Seen in deer as alopecia, weight loss syndrome Malignant Catarrhal Fever
Etiology All varieties of domestic sheep in North America are carriers of ovine herpesvirus-2 (OVH-2). Malignant Catarrhal fever in these natural hosts does not produce clinical disease. Likewise, goats are endemically infected with caprine herpesvirus-2 (CpHV-2) which apparently only causes clinical disease in deer. Malignant Catarrhal Fever
Etiology The disease expression in “sheep-associated” MCF and “wildebeest-derived” MCF is very similar. Malignant Catarrhal Fever
Host Range • The disease can occur in cattle, domesticated buffaloes, a wide range of captive antelopes and deer, and free-living deer. Malignant Catarrhal Fever
Host Range • Under natural conditions only domestic cattle and deer develop clinical signs • MCF has never been reported in free-living wild animals in Africa Malignant Catarrhal Fever
Host Range • In zoological collections a wide variety of ruminant species have been reported to develop clinical signs • Rabbits can be infected experimentally Malignant Catarrhal Fever
Host Range • It was recently confirmed in pigs in Scandinavia Malignant Catarrhal Fever
Reservoir ruminant species • Blue wildebeest • Black wildebeest • Domestic sheep • Goats Malignant Catarrhal Fever
Blue Wildebeest Malignant Catarrhal Fever
Black Wildebeest Malignant Catarrhal Fever
Transmission Neonatal and adolescent wildebeest shed virus Malignant Catarrhal Fever
Transmission from reservoir animals to domestic cattle, deer contact with calving wildebeest contact with lambing sheep Malignant Catarrhal Fever
Cattle are more susceptible to Wildebeest derived MCF than to the sheep or goat MCF Malignant Catarrhal Fever
Transmission • Transmission of the virus is associated with lambing time of sheep or calving season of wildebeest when the virus can be shed from nasal secretions. • After this period the virus occurs only as cell-associated, not free virus Malignant Catarrhal Fever
Transmission • Droplets and aerosol dispersal of free virus may contaminate feed and water sources • Transmission to cattle mostly occurs by inhalation of droplets shed from ewes that are lambing Malignant Catarrhal Fever
Natural transmission of the virus • Wildebeest to cattle • Wildebeest to other ruminants • Wildebeest to deer • Sheep to cattle • Sheep to other ruminants • Sheep to deer • Deer to susceptible species ? • Deer to deer • Goats to susceptible species ? Quite likely • Cattle to cattle X Malignant Catarrhal Fever
Congenital Transmission Cow will die then later calf will die Malignant Catarrhal Fever
Pathogenesis Virus infects “natural killer” lymphocytes and transforms them. Transformed cells then replicate as if they were neoplastic and attack host. Terminal necrotizing lesions are believed to be the result of an autoimmune type phenomenon. Vessels and stratified squamous mucosal surfaces are attacked. Malignant Catarrhal Fever
Incubation • Unknown for natural infections. Some animals are subclinically infected and only demonstrate symptoms when stressed. Some evidence indicates up to 200 days • Experimentally incubation periods may be from 7 to 77 days Malignant Catarrhal Fever
Malignant Catarrhal Fever: Clinical Signs • In some cases MCF presents as chronic alopecia and weight loss as with deer infected with the Caprine herpesvirus. • However, MCF is typically fatal. Malignant Catarrhal Fever
Clinical Signs • There are many factors that affect the duration of the disease in different species • The severity of the clinical symptoms will depend on those factors. Mortality is usually 100% but some animals face weeks of progressive disease • For this reasons, once the disease is identified, most elect to euthanized the affected animal. Malignant Catarrhal Fever
Clinical Signs • High fever 106-107°F (41-41.5°C) • Depression • In deer - sudden death • Deer and bison that survive 2-3 days: • Hemorrhagic diarrhea • Bloody urine • Corneal opacity • Then death Malignant Catarrhal Fever
Clinical Signs • The longer the animal survives the course of the disease the more severe the signs become. • For example, animals that die acutely may not develop lymphadenopathy or corneal opacity Malignant Catarrhal Fever
As the disease progresses: • Catarrhal inflammation • Erosions and exudates in upper respiratory tract, ocular and oral mucosa • Swollen lymph nodes • Lameness • CNS signs (depression, tremors, stupor, hypo-responsive, aggression, convulsions Malignant Catarrhal Fever
Clinical Signs • On average the time to death for European cattle is longer than for deer, bison and water buffalo; usually 7-17 days after the appearance of clinical signs • In cattle the swollen lymph nodes and severe eye lesions are more frequent Malignant Catarrhal Fever
Clinical Signs • Hemorrhagic enteritis and cystitis are more frequently seen in bison and deer than in cattle • Skin lesions are common in animals that do not succumb quickly • Most eventually die, about 5% recover clinically Malignant Catarrhal Fever
Clinical signs • Depressed and VERY SICK • Stertorous respiration • Enlarged lymph nodes Malignant Catarrhal Fever
Clinical Signs Animals suffer, are painful and breathe with difficulty Malignant Catarrhal Fever
Clinical Signs Secondary bacterial bronchopneumonia may be eventual cause of death if not euthanized first Malignant Catarrhal Fever
Clinical Signs Painful swollen eyes Malignant Catarrhal Fever
Clinical Signs Ocular and nasal discharge Malignant Catarrhal Fever
Clinical Signs “snotsiekte” Malignant Catarrhal Fever
Mucopurulent discharge, crusting occludes the nostril; animal begins open mouth breathing. Malignant Catarrhal Fever
Characteristic of MCF Early corneal opacity begins at the limbus Progresses to total opacity Malignant Catarrhal Fever
Clinical Signs Severe panophthalmitis, hypopion, corneal erosions are more frequent in cattle Malignant Catarrhal Fever
Severe Ocular lesions Painful Conjunctivitis Malignant Catarrhal Fever
Severe Ocular lesions Progresses to corneal opacity beginning at Limbus Malignant Catarrhal Fever
Severe Ocular lesions Characteristic eye lesions Malignant Catarrhal Fever