Herpesvirus Flashcards
Herpesvirus
General Characteristics
- dsDNA
- Icosahedral
- Enveloped
- Replicates in nucleus-> Nuclear inclusion bodies!
- Strongly immunosupressive , strong CPE
- Weak antigenicity-> weak immune response-> Lifelong carriers and latency
- Cross reaction withim the genera - cross protection
- Weak resistance (exc. Marke’s disease virus)
Infectious Bovine Rhinotracheitis
Species affected
Ru
Infectious Bovine Rhinotracheitis
Most susceptible
All age groups
- Respiratory form: 1-6mo
- Calves encephalitis <5mo
- Genital form: adults
Infectious Bovine Rhinotracheitis
Spread
Slow spread
- Carrier animal introduction
- Semen
- contact
- Airborne
Infectious Bovine Rhinotracheitis
Pathogenesis
- Aerogenous: Respiratory Mucosa —> Inflammation —> Viraemia —> Other organs —> Encephalitis in calves and Abortion
- Ascending inflammation in the nose —> nerves —> calf encephalitis
- Genital form —> Degeneration and inflammation of the mucosal epithelium and nodule formation
Infectious Bovine Rhinotracheitis
Primary replication
- Aerogenous: respiratory mucosa
- Genital: genital mucosal epithelium
- Incubation: 2-5d
Infectious Bovine Rhinotracheitis
Target organs
Respiratory & Genital organs
Infectious Bovine Rhinotracheitis
Clinical signs
Febrile disease!
*Respiratory form: conjunctivitis, coughing, nasal discharge, encephalitis, interstitial pneumonia, abortion(in resp form, not genital), red nose disease(necrotic mm), calf encephalitis (<5mo)
*Genital form: adults,
Vulvoginits& Balanoposthitis
Greyish yellow nodules, vaginal discharge
*no fertilization& abortion in acute
Infectious Bovine Rhinotracheitis
Pathology
- Inflammation, hemorrhages and erosions in upper respiratory
- Intranuclear inclusion bodies
Infectious Bovine Rhinotracheitis
Diagnosis
CS
PCR
ELISA
Infectious Bovine Rhinotracheitis
Treatment
No effective treatment
Ab
Infectious Bovine Rhinotracheitis
Prevention and immunity
- AI tested bulls
- closed groups according to age
- Marker vaccines
- Live&inactivated vaccine - inactivated- breeding, cow before parturition, 2-3mo calves, heifers in fertlization
Bovine Herpesmamillits
Species affected
- Cattle, Buffalo (other ru might be seropositive)
* Humans —> Zoonotic!
Bovine Herpesmamillits
Most susceptible
Milking Cows
Bovine Herpesmamillits
Occurrence
- Africa, Australia and USA
* Rare in Europe
Bovine Herpesmamillits
Spread
- Infected animal
- Spread within the herd via milking
- Arthropod vectors
Bovine Herpesmamillits
Clinical Signs
- After first parturition: teat edema, suffusion, pustules
- Hu: lesions on the hands
- Subclincial infection is common
- Secondary infection -> mastitis
- Reduced production
- Teat scarring
Bovine Herpesmamillits
Primary Replication
- Teat epithelium
* Incubation: 3-7d
Bovine Herpesmamillits
Target Organs
Teat
Bovine Herpesmamillits
Pathogenesis
- Epithelial damage, inflammation —> pustules, scabs, lacerations, erosions —> recovery within 1-2 weeks
Bovine Herpesmamillits
Pathology & Histopathology
Intranuclear inclusion bodies
Bovine Herpesmamillits
Diagnosis
Histopathology
Virus isolation
PCR
Serology
Bovine Herpesmamillits
Treatment
Local, symptomatic treatment
Bovine Herpesmamillits
Prevention & Immunity
No vaccine available!
Malignant Catarrhal Fever
Species Affected
- Reserviors: Wildbeest, Sheep (asymptomatic,the only oneswho can infect)
- Ru - dead end hosts
Malignant Catarrhal Fever
Most susceptible
Elderly Animals!
Malignant Catarrhal Fever
Occurrence
- Africa —> Wildebeest associated MCF
* Rest of World —> Sheep associated MCF
Malignant Catarrhal Fever
Spread
- Carrier animal introduction, thier secretion (respiratory)
* Cattle are unable to shed and transmit the virus
Malignant Catarrhal Fever
Pathogenesis
Aerogenous Infection —> Cell associated viraemia —>immunopathological process
- Lifelong infection in surviving animals
- Systemic febrile disease
Malignant Catarrhal Fever
Primary Replication
Latent infection -Incubation: 2w-couple of months
Malignant Catarrhal Fever
Target Organs
- All organs
- Lifelong infection in surviving animals
- Systemic febrile disease
Malignant Catarrhal Fever
Clinical Signs
- Peracute: fever, hemorrhagic enteritis, convulsions, Urinary bladder wall oedema death.
- Acute: keratitis, conjuctivitis, laboured breathing, laminitis, odema, severe hemorrhagic enteritis, CNS
Malignant Catarrhal Fever
Pathology & Histopathology
Peracute:
- Inflamed mucosa, haemorrhages, without erosions
- Urinary bladder wall oedema
Subacute:
- Eye lesions, *Hemorrhagic pneumonia and enteritis
- Arteritis
Malignant Catarrhal
Fever
Diagnosis
History, CS, PM, histopathology, PCR, ELISA
Malignant Catarrhal Fever
Treatment
Poor prognosis
No effective treatment
Malignant Catarrhal Fever
Prevention & Immunity
No vaccine available!
Aujeszky’s Disease (Pseudorabies)
Species Affected
Pigs: natural hosts&reservoir
Other mammals - dead end hosts
Aujeszky’s Disease (Pseudorabies)
Most susceptible
All age groups
Aujeszky’s Disease (Pseudorabies)
Spread
*infected swine, semen (vertical transmission), fomites, mechanical vectors (rodents), raw pork!!
Aujeszky’s Disease (Pseudorabies)
Pathogenesis
PO/inhalational-> haemolymph->nerves->encephalitis> Secondary lung multiplication->fever& respiratory
Pigs may be lifelong carriers& shedders
Aujeszky’s Disease (Pseudorabies )
Primary Replication
Tonsils, Nasal & Pharyngeal mucosa
2-8d incubation
Placental crossing!
Aujeszky’s Disease (Pseudorabies)
Target Organs
All organs (lungs, brain)
Aujeszky’s Disease (Pseudorabies)
Clinical Signs
*Febrile& systemic
*Vertically infected piglets will be asymptomatic
*Piglets usually have febrile general disease, CNS (~100% mortality), sometimes die without CNS cs
*Gilts mostly recover after 5-6d(resp& CNS symp)
*Pregnant: abortion, stillbirth, infertility
*Adults are usually subclinical
*Ru- mad itch disease, acute lethal encephalitis, death in 1-2s, recovery is rare
Ca- febrile& general, acute lethal encephalitis
Aujeszky’s Disease (Pseudorabies)
Pathology & Histopathology
- Lung edema
- suckling piglets- necrotic foci on pharyngeal mucosa& tonsils, spleen and liver
- hemorrhages in Ln
- Nuclear inclusion bodies
- Meningitis
Aujeszky’s Disease (Pseudorabies)
Treatment
No effective treatment
Ab
Aujeszky’s Disease (Pseudorabies )
Prevention & Immunity
Epidemiology measures
- No feeding with raw pork to carnivores
- Maternal protection until 8-14w
- modified live vaccine at 10-121wo, 6mo, at fertilization and 70-904 pregnant
- The virus can maintain in vaccinated pigs!