VIRAL DISEASES Presented by EMAD M A SAMARA

VIRAL DISEASES Presented by EMAD M. A. SAMARA, BVM&S

I- Foot and Mouth Disease • • AKA (FMD, Aftosa) Causative agent (Virus; Picornaviridae) History (1921 -29, 1953, 1967 -68, 1981, 1993 -97, and 2001) Public Health Significance (not a public health concern; 40 cases since 1921) • Species Affected (Domestic Cloven-Footed animals) • Animal Transmission (Direct and indirect contact) • Morbidity/ Mortality (100% / 1%; Higher in young animals) • Economic Impact (Direct and indirect costs, Economically Devastating)

I- Foot and Mouth Disease • Diagnosis (Clinical Signs, Laboratory Tests) • Clinical Signs – In Cattle (Fever, Vesicles and Erosions on “feet, mouth, nares, muzzle, teats, hoof”, Excess salivation, Serous nasal discharge, Abortion, Death in young animals) – In sheep and goat (Mild, Fever, Oral lesions, Lameness) • Post Mortem Lesions (indistinguishable from other vesicular diseases, Single or multiple vesicles, Dry Erosions, Tiger heart) • Treatment (No treatment available, Supportive and symptomatic, Vaccine available) • Prevention and Control (Import restrictions, Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, Vaccination)

II- Rinderpest • • AKA (RPV, Cattle Plague) Causative agent (Virus; Paramyxoviridae) History (1184 BC, 1762, 1885, 1960’s, and 1992) Public Health Significance (not a public health concern) • Species Affected (Domestic Cloven-Footed Animals) • Animal Transmission (Direct and indirect contact) • Mortality (100%; Susceptible stock are immature or young adults) • Economic Impact (Direct and indirect costs, Destroys entire populations of cattle)

II- Rinderpest • Clinical Signs (Four forms) – Classic form (Fever, depression, anorexia, Constipation followed by hemorrhagic diarrhea, Serous to mucopurulent nasal/ocular discharge, Necrosis and erosion of the oral mucosa, Enlarged lymph nodes, Death in 6 -12 days) – Peracute form (Young animals, high fever with congested mucous membranes, death in 2 -3 days) – Subacute form (Mild clinical signs with low mortality) – Atypical form (Irregular fever, mild or no diarrhea, Immunosuppression leading to secondary infections) • Post Mortem Lesions – Esophagus (Brown and necrotic foci) – Omasum, Abomasum, Small intestine and cecum ( Tiger striping; Necrosis, edema and congestion ) – Lymph nodes (Swollen and edematous) – Gall Bladder ( Hemorrhagic mucosa) – Lungs (Emphysema, congestion, and areas of pneumonia)

II- Rinderpest • Treatment (No treatment available, Diagnosis usually means slaughter of effected animals, Supportive care with antibiotics in rare cases of valuable animals, Preventative measures are the keys) • Prevention and Control (Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, Vaccination)

III- Peste des Petits Ruminants • AKA (Pest of Small Ruminants, Stomatitis-Pneumoenteritis Syndrome, Pseudorinderpest, Contagious Pustular Stomatitis, Kata) • Causative agent (Virus; Paramyxoviridae) • History (1942, 1972, and 1990’s) • Public Health Significance (not a public health concern) • Species Affected (Principally goats and sheep, reported in captive wild ungulates, Cattle and pigs seroconvert but do not transmit disease) • Animal Transmission (Direct and indirect contact) • Morbidity/ Mortality (80 -90% / 50 -80%, can be up to 100%; More severe in young animals, poor nutrition, concurrent parasitic infections; Goats more susceptible than sheep) • Economic Impact (Direct and indirect costs)

III- Peste des Petits Ruminants • Diagnosis (Clinical Signs, Laboratory Tests) • Clinical Signs (Acute fever, Anorexia, Upper respiratory discharge progressing to catarrhal exudate, Dyspnea Profuse diarrhea, Dehydration, Emaciation, Abortion and Death in 5 -10 days) • Post Mortem Lesions (Similar to Rinderpest; Carcass emaciation, Bronchopneumonia, “Zebra stripe” lesions of congestion in large intestine, Enlarged lymph nodes) • Treatment (No specific treatment, Drugs to control bacterial and parasitic complications may decrease mortality, Supportive care) • Prevention and Control (Import restrictions, Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, Vaccination)

IV- Malignant Catarrhal Fever • AKA (Malignant Head Catarrh, Gangrenous Coryza, Snotsiekte) • Causative agent (Virus; Gamma-herpesviridae) • History (1920’s, 1973, and 2002) • Public Health Significance (not a public health concern) • Species Affected (Domestic and wild Cloven-Footed Animals) • Animal Transmission (Direct and indirect contact; Some species ”Dead end hosts” ) • Morbidity/ Mortality (30 -40% / 1 -100 %; depend on the host; Survival is rare; carrier species asymptomatic) • Economic Impact (Direct and indirect costs; Variable)

IV- Malignant Catarrhal Fever • Clinical Signs (Five forms) – Acute form (High fever, Dyspnea, D. I. C. , and Sudden death) – Head and eye form (Bilateral corneal opacity, Crusty muzzle and nares, Nasal discharge, Salivation, Erosions on the tongue and buccal mucosa) – Intestinal form (Inappetence, Dysphagia, Severe diarrhea) – Nervous form (Depression, Incoordination, head pressing, nystagmus, hyperesthesia) – Mild form (Inoculated animals recover) • Post Mortem Lesions (Erosions on the tongue and soft and hard palate, Multiple erosions of intestinal epithelium, Enlarged lymph node, Diptheritic areas in the larynx, Edematous urinary bladder mucosa )

IV- Malignant Catarrhal Fever • Treatment (Supportive therapy, antibiotics for secondary bacterial infection, Recovered animals will remain virus carriers) • Prevention and Control (Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, No vaccine available)

V- Rift Valley Fever • Causative agent (Virus; Bunyaviridae) • History (1900’s, 1930, 1950 -51, 1977 -78, 1987, 1997 -98, 2000 -01, and 2003) • Public Health Significance (a public health concern; cause Flu-like illness, Retinopathy, Hemorrhagic fever, and Encephalitis; mortality ~1%, Treatment is supportive care) • Species Affected (Domestic and wild Cloven-Footed Animals, pet animals) • Animal Transmission (Direct and indirect contact; ”Dead end hosts” in human) • Morbidity/ Mortality (100% / 10 -100%, More severe in young animals “week vs. over week” ) • Economic Impact (Direct and indirect costs)

V- Rift Valley Fever • Clinical Signs (High fever, Listless, Anorexia, ptyalism, High rate of abortion, Fetid diarrhea, Icterus, Mucopurulent nasal discharge, Acute death ) • Post Mortem Lesions (Necrosis and Petechial hemorrhages in Hepatic, abomasum and peritoneal cavity; yellow, enlarged, friable Liver; aborted fetuses) • Treatment (No specific treatment, Drugs to control bacterial and parasitic complications, Supportive care Preventative measures are keys) • Prevention and Control (Immunization of ruminants, Avoid and control vectors, Personal protective equipment, Avoid contact with infected tissues and blood, Restrict movement of animals, Precautions when traveling)

VI- Bluetongue Virus • AKA (Sore Muzzle, Pseudo Foot-and-Mouth Disease, Muzzle Disease) • Causative agent (Virus; Reoviridae) • History (1997 -2002) • Public Health Significance (Not a significant threat to humans; One human infection documented, Reasonable precautions should be taken, Treatment is supportive care) • Species Affected (Domestic and wild Cloven-Footed Animals) • Animal Transmission (Direct and indirect contact ) • Morbidity/ Mortality (100% / 0 -50% in Domestic Animals, and 80 -90% in wild Animals) • Economic Impact (Direct and indirect costs; Variable)

VI- Bluetongue Virus • Diagnosis (Clinical Signs, Laboratory Tests) • Clinical Signs (Fever, depression, salivation, Facial swelling, Oral erosions and ulcerations, Swollen, protuding, and Cyanotic Tongue “Blue-tongue”, Dyspnea, Panting, Nasal discharge, Hyperemia of muzzle, lips, ears, lameness “Coronitis”, abortion, “dummy” lambs) • Post Mortem Lesions (Edematous face and ears, Dry, crusty exudate on nostrils, Vesicles, ulcers, necrosis in Mouth, Hyperemic coronary bands, Internal hemorrhaging, Hydranencephaly, cerebellar dysplasia) • Treatment (No specific treatment, Supportive care) • Prevention and Control (Control of vectors, Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, )

VII- Viral Encephalitis • Types (Western equine encephalitis (WEE), Eastern equine encephalitis (EEE), St. Louis encephalitis (SLE), La Crosse encephalitis (LAC), Venezuelan equine encephalitis (VEE), West Nile virus (WNV) • Causative agent (Virus; Flaviviridae) • History (1925 -2000, and 2003 -04) • Public Health Significance (a public health concern; 19642002, 182 cases; cause Flu-like illness, Sudden fever, headache, myalgia, malaise, encephalitis, Death, mortality ~ 0. 1%) • Species Affected (Equine species; and other animals) • Animal Transmission (indirect contact; Dead end hosts; equine and human ) • Case-fatality rates (Equine: 90%, Human: 30 -70%, other Variable)

VII- Viral Encephalitis • Diagnosis (Clinical Signs, Laboratory Tests) • Clinical Signs – Neurological (Paralysis of lips, facial muscles, tongue; Dysphagia; Hyperesthesia; Sound sensitive; torticollis; nystagmus; Seizures; Blindness; Ataxia) – Other (Flu-like signs, Fever, Depression, Anorexia, Muscle spasm, Skin twitching, Weakness, and recumbency) • Post Mortem Lesions (Mild to moderate, diffuse, and non-suppurative meningoencephalitis; myocarditis)

VII- Viral Encephalitis • Treatment (No specific treatment, Supportive care, Fully licensed vaccine) • Prevention and Control (Vector Management “Surveillance, Source reduction, Personal protection, Biological control, Larvicide, and Adulticide”; Confirmatory diagnosis, Authorities Notification, Quarantine, Disinfection, Vaccination)

VIII- Other Important Dz • • Bovine Viral Diarrhea Maedi-Visna African Horse Sickness Vesicular Stomatitis Lumpy Skin Disease Sheep and Goat Pox Haemorrhagic Fever Disease

The End