Final Exam - Paramyxoviridae

Question 1

Paramyxoviridae

Answer 1

Causes rinderpest, canine distemper virus, Newcastle disease virus, Nipah, measles and mumps. Impact has been reduced from vaccination.

Question 2

Two genera that come from Paramyxoviridae are:

Answer 2

1. Avulavirus

2. Morbilivirus

Question 3

3 membrane proteins

Answer 3

1. Unglycosylated matrix protein (M)
2. Fusion protein (F) glycosylate envelope protein
3. Hemagglutinin (H) glycosylated envelope protein

Question 4

3 nucleocapsid proteins

Answer 4

1. RNA binding protein (N)
2. Phosphoprotein (P)
3. Large polymerase (L)

Question 5

Antibodies directed against these proteins

Answer 5

Usually neutralizing antibodies - important in protection against paramyxovirus infection

Question 6

Replication - Rubulaviruses, Respiroviruses and Avulaviruses

Answer 6

The HN molecule binds to sialic acid residue - either glycolipids or glycoproteins.

Question 7

Replication - Morbiliviruses

Answer 7

The receptor is located on lymphocytes, dendritic cells or macrophages - CD150

Question 8

Replication - Henipaviruses

Answer 8

The receptor is ephrin B2 and B3 cell surface proteins on endothelial cells or on brain stem neurons

Question 9

Replication - Pneumoviruses

Answer 9

The receptor is heparan sulfate.

Question 10

Paramyoviruses Inclusion Bodies

Answer 10

Cytoplasmic acidophilic inclusion bodies, composed of ribonucleoprotein structure

Question 11

Newcastle Disease

Answer 11

A disease of chickens. 10 serotypes. Avian ParaMyxoViruses. APMV-1 to APMV-10. NDV = APMV-1.

Question 12

Newcastle Disease - 5 Pathotypes

Answer 12

1. Viscerotropic velogenic
2. Neurotropic velogenic
3. Mesogenic
4. Lentogenic (respiratory)
5. Asymptomatic

Question 13

Newcastle Disease Hosts

Answer 13

Chickens are highly susceptible to disease. Turkeys do NOT develop severe signs.

Question 14

Newcastle Disease Transmission

Answer 14

Direct contact with secretions of infected birds via ingestion and inhalation. Fomites feed, water, premises, human clothing, boots, sacks, egg trays/crates. Hatching chicks may be infected through the egg for some NDV strains.

Question 15

Newcastle Disease Occurence

Answer 15

Velogenic NDV is endemic in areas of Mexico, Central and South America. In double crested wild cormorants in the US and Canada. Lentogenic strains of NDV are worldwide in their distribution.

Question 16

Newcastle Disease Diagnosis

Answer 16

Clinical signs are rare. Clinical signs alone do not present a reliable basis for diagnosis of ND.

Question 17

Lentogenic Strains

Answer 17

Usually associated with subclinical disease marked by mild respiratory symptoms; coughing, gasping, sneezing and rales. Morality is negligible.

Question 18

Velogenic Strains

Answer 18

Cause severe disease in chickens with high mortality for unvaccinated chickens. Signs, principally respiratory and/or nervous. Initial clinical signs vary but include: lethargy, inappetence, ruffled feathers, edema. Greenish or white water diarrhea, dyspnoea and inflammation of the head and neck with cyanotic discoloration. Often result in death with few or no signs.

Question 19

Velogenic Strains - Neurological Signs

Answer 19

May be manifested as tremors, tonic/clonic spasms, wing/leg paresis or paralysis, torticollis, and aberrant circling behavior.

Question 20

Velogenic Strains - Lesions

Answer 20

Only velogenic strains produce significant gross lesions such as: swelling of periorbital area of entire head. Edema of interstitial or peritracheal tissues of neck. Edema, hemorrhages or degeneration of ovaries. Edema, hemorrhages, necrosis of ulceration of respiratory/digestive lymphoid tissue.

Question 21

Laboratory Diagnosis

Answer 21

Samples collected from recently dead or moribund birds. Sent to a reference laboratory. Dead birds: oronasal swabs. Live birds: tracheal or oropharyngeal and cloacal swabs. Clotted blood samples or serum for serology. inoculation of embryonated specified pathogen free (SPF) eggs and tested for hemagglutination (HA) activity. ELISA. and Validated xisspecific molecular methods (PCR)

Question 22

Prevention and Control - Medical Prophyla

Answer 22

Vaccination with live vaccines: lentogenic vaccines and mesogenic vaccines. Live virus vaccines administered by incorporation in the drinking water, as a coarse spray (aerosol), or by intranasal or conjunctival instillation.

Question 23

Newcastle Disease Vaccinations

Answer 23

Inactivated vaccines and new recombinants vaccines (fowlpox virus, vaccinia virus, pigeonpox virus, turkey herpesvirus and avian cells in whicht eh HN gene, the F gene or both, of NDV are expressed)

Question 24

Sanitary Prophylaxis

Answer 24

NO TREATMENT! One age group per farm (“all in-all out) breeding is recommended.

Question 25

Nipah Virus

Answer 25

A newly emerging zoonosis that causes severe disease in both animals and humans. Causes encephalitis and respiratory illness.

Question 26

Nipah Virus SYNONYMS in pigs

Answer 26

Barking pig syndrome, porcine respiratory and encephalitis syndrome, porcine respiratory and neurologic syndrome.

Question 27

Nipah Virus - Agent

Answer 27

Genus Henipavirus. Rapidly progressive encephalitis in humans. High mortality rate. Severe, respiratory disease in pigs.

Question 28

Nipah Virus - Transmission (Reservoir)

Answer 28

Flying foxes (fruit bats). Virus found in urine and maybe saliva from partially eaten fruit.

Question 29

Nipah Virus - Clinical signs - Suckling pigs and piglets (

Answer 29

Labored breathing and muscle tremors with limb weakness. Mortality in piglets can be high.

Question 30

Nipah Virus - Clinical signs - Young swine (1 to 6 months old)

Answer 30

Acute fever with respiratory signs. Labored breathing, nasal discharge and loud non-productive cough ("barking pig syndrome" or "one-mile cough"). Neurological signs. High morbidity and low mortality .

Question 31

Nipah Virus Clinical signs - Older animals ( > 6 months old)

Answer 31

Acute febrile, with marked neurological signs. respiratory signs: open mouthed breathing, nasal discharge and sialorrhea (possibly due to pharyngeal paralysis). Morbidity in confined animals is ~100%. First trimester abortions may occur.

Question 32

Nipah Virus - REMEMBER

Answer 32

Classified as a BSL4 agent!

Question 33

Nipah Virus - Identification of agent

Answer 33

Virus isolation and characterization. Virus neutralization. RT-PCR. Immunohistochemistry.

Question 34

Nipah Virus Prevention and Control - Sanitary prophylaxis

Answer 34

Strict biosecurity of swine installations to avoid contact with fruit bats and their secretions. Culling of seropositive swine.

Question 35

Nipah Virus Prevention and Control - Medical prophylaxis

Answer 35

No vaccine yet!

Question 36

Nipah as a biological weapon

Answer 36

Potentially high morbidity and mortality. Aerosolization potential.

Question 37

Canine Distemper Virus

Answer 37

Belongs to Mobilivirus genus. Highly contagious, acute febrile disease of dogs. Currently a rare disease in dogs in the developed world.

Question 38

Canine Distemper Virus - Host

Answer 38

Canidae (dogs, dingo, fox, coyotes), Procyonidae (raccoon, panda), Mustelidae (ferrets, mink, skunk) and Felidae (lions, tigers, leopards, cheetah).

Question 39

Canine Distemper Virus - Clinical Features - Mild

Answer 39

At least 50% of infections are subclinical or mild. Inappetence, fever, respiratory tract infection such as bilateral nasal discharges, serous or mucopurulent, coughing, labored breathing.

Question 40

Canine Distemper Virus - Clinical Features - Severe

Answer 40

Fever, followed by systemic spread of virus, anorexia, inflammation of the upper respiratory tract (serous or mucopurulent nasal discharges), conjunctivitis, depression, leukopenia. Some GI signs such as vomiting and watery diarrhea.

Question 41

Canine Distemper Virus - Clinical Features - in puppies

Answer 41

Develop pneumonia, enteritis, conjunctivitis, rhinitis, and tracheitis. Secondary bacterial infections lead to bronchopneumonia.

Question 42

Canine Distemper Virus - Clinical Features - Other signs

Answer 42

Develop CNS such as seizures, paraparesis or tetraparesis. Hyperkeratosis of footpads and nose.

Question 43

Canine Distemper Virus - Pathogenesis

Answer 43

Replicates in the upper respiratory tract macrophages. Spreads to tonsils and lymph nodes. Virus infects all cells expressing CD150. The virus enters the blood stream and infects T and B cells.

Question 44

Canine Distemper Virus - Diagnosis

Answer 44

Virus isolation. Immunofluorescence test. RT-PCR

Question 45

Canine Distemper Virus - Control

Answer 45

Vaccination only in Canidae. Modified live vaccine available. Vaccinate puppies only after maternal antibody level has gone down. Hyperimmune serum administered immediately after exposure to the virus may help protect against infection.