Download Newcastle disease virus

 Presented To:
Dr. Madiha Salah Ebrahim.
 Edit by:
1. Mai Labib Badr.
6. Nehad Ahmed Saleh.
2. Nesma Khatan.
7. Maha Tantawy.
3. Maha El.Ansary.
8. Amina El.Nagar.
4. Amira Abd El.Naser.
9. Hadeer Fouad Shams.
5. Lamiaa Gamal.
10. Amal Samy.
Newcastle disease virus
 NDV also called (avian paramyxovirus type I,
pneumoencephalitis virus & pseudo-fowl pest).
 ND is contagious and fatal viral disease affecting most species
of birds (chickens, turkeys, pigeons ,parrots ,ducks, geese,
quails)and human.
Taxonomy of the NDV :
 Family: Paramyxoviridae.
 Subfamily: Paramyxovirinae.
 Genus: Avulavirus.
Characteristics:
 Spherical virus with diameter of 100-300 nm.
 Enveloped virus (containing lipid, CHO & protein).
 It has segmented & single stranded negative sense RNA.
 Two specific virus proteins (hemagglutinin-neuraminidase &
fusion protein) are the main proteins found in the outer coat
of the virus.
 Replication occurs in the cytoplasm of the host cell.
 Affected species; birds & human.
 Morbidity; Up to100% & Mortality; 90%.
Fig1; Diagrammatic representation of Newcastle disease virus.
Inactivation of the virus:
 Minimum core temperature of 80°C for one minute, 75°C for 5
minutes or 70°C for 30 minutes - completely destroys the virus
in meat.
 Ether sensitive and inactivated by formalin, phenol & acid pH.
 Destroyed rapidly by dehydration and ultraviolet rays.
CPE of NDV:
 Syncytia formation.
 Production of inclusion bodies.
 Haemadsorption of G.pig RBCs by infected cell culture.
Haemagglutination:
 All strains of NDV agglutinate (Chicken, G.pig, human group
O)RBCs.
 Most strains agglutinate (OX & sheep)RBCs.
 Horse RBCs agglutinated by lentogenic strain.
 NDV cause haemadsorption.
Antigenic properties:
 NDV is immunologically distinct from orthomyxoviruses & from
other members of paramyxoviruses.
 Mumps may develop HI antibodies to NDV.
Cultivation:
 NDV is inoculated into 10-12 days hen embryonated eggs via
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chorioallantoic membrane or allantoic sac.
It produces haemorrhagic lesions and encephalitis & embryo
dies within 34-72 hours.
NDV grows well in chicken embryo fibroblast cell culture.
Maximum titer is obtained after 24-36 hours.
Titer of the virus in tissue culture is one log lower than that in
embryonated egg.
Strains of NDV classified according to their
pathogenicity into:
1. Viscerotropic velogenic NDV (Doyle's form).
2. Neurotropic velogenic NDV (Beache's form).
3. Mesogenic NDV (Beaudett's form).
4. Lentogenic NDV (Hitchner form).
5. Asymptomatic enteric NDV.
Transmission:
 Direct contact between healthy birds and the infected bird
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discharges.
Contaminated feed, water, equipment and clothing.
Virus can be picked up on shoes and clothing and carried
from an infected flock to a healthy one.
Airborne spread.
Contaminated poultry vaccines.
Other animals and birds transporting the virus from farm to
farm.
Pathogenicity:
 the virulence of NDV Can be determined by the following
techniques:
1. The mean death time in chicken egg embryo (MDT).
2. Intracerebral Pathogenicity index (ICPI) in day-old chick.
3. Intravenous Pathogenicity index (IVPI) in 6 week old chickens.
4. Intracloacal Pathogenicity test in 6-8 week old chickens.
Incubation period:
 It varies from (2 to 15) days in poultry depending on the
virulence of the strain.
 In chickens infected with velogenic isolates; (2 to 6) days.
 In some avian species; 25 days.
Pathogenesis:
 The virus replicates in the mucosa of the upper respiratory and
intestinal tracts.
 Virus spreads via blood to spleen and bone marrow (viremia)
causing infection of other organs: lung ,intestines & C.N.S.
Immune response against NDV:
 Antibody production is rapid.
 HI antibody can be detected within 4-6 days of infection.
 The level of HI antibody is a measure of immunity.
 Serum antibodies of the hen are transferred to chicks through
yolk, and protect chicks for 3-4 weeks after hatching.
 Serum IgG does not prevent respiratory infection.
 Locally produced IgA prevent respiratory and the intestinal
infection.
Clinical Signs and Symptoms:
 Respiratory symptoms.
 Nervous signs.
 Digestive symptoms.
 Drop in egg production with thin, rough-shelled eggs.
 Swelling of tissues around eyes and in the neck.
 Sudden death.
 In human;(Mild conjunctivitis, influenza-like symptoms and
laryngitis).
Fig2; Coughing and gasping.
Fig3; Mouth discharges.
Fig4; The bird displays torticollis.
Fig5; Twisting and circling of head and
neck.
Fig6; Paralysis of the legs
Fig7; The chicken stand on its hock joints, a sign of generalized
depression.
Fig8; Diarrhea with green bile
pigment and white urates.
Fig9; Square appearance of the head
due to bilateral facial edema.
Fig10; Swelling of the lower eyelid
and conjunctivitis.
Fig11; Reddening of periocular
region and corneal edema.
Fig12; Conjunctivitis in human.
PM and gross lesions:
 Inflammation with Petechial hemorrhages on proventriculus
mucosa.
 Edematous, hemorrhagic, necrotic, and ulcerative areas on
Peyer's patches, caecal tonsils.
 Edematous, hemorrhagic, or degenerated ovaries.
Fig13; subconjunctival haemorrhages with
external lesions.
Fig14; Odema and hemorrhages in the
conjunctiva and infraorbital sinus.
Fig15; Accumulation of mucus in the
respiratory tract.
Fig16; Mild haemorrhagic lesions
in the mucosa of trachea.
Fig17; Congestion and haemorrhages
in the pharynx and proximal trachea.
Fig18; Sever thymus atrophy with
extensive haemorrhages.
Fig19; Inflammation with pinpoint heamorrhagic lesions in the proventriculus
mucosa.
Fig20; Necrosis of lymphoid tissue at the caecal
tonsils.
Fig21; Extensive haemorrahges and
ulcers of caecal tonsils mucosa.
Fig22; Acute focal lymphoid necrosis in the
duodenum.
Fig23; Focal ulceration and haemorrahge in
the small intestine.
Fig24; Haemorrhagic lesions along the entire
length of the intestine.
Fig25; Sever haemorrhages in the rectal
mucosa.
Fig26; Ulcers with fibrin accumulation in the
mucosa of the cloaca .
Fig27; Pulmonary congestion and
edema.
Fig28; The spleen is enlarged with numerous
white lesions.
Fig29; Extensive haemorrhages on the
liver.
Fig30; Odema and haemorrahges
within the mucosa of bursa of
fabricius.
Fig31;Sever acute haemorrahges and
congestion in the ovarian follicles.
Fig32; Sever acute haemorrhages and congestion.
Diagnosis:
It includes:
1. Clinical signs and symptoms.
2. Lab tests include;
 Serological tests: Haemagglutination inhibition test, Enzyme
Linked Immunosorbant Assay (ELISA), PCR & Sequence technology.
 Pathogenicity assessment:
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Plaque test in chicken embryo fibroblast cultures.
Mean death time.
Intracerebral pathogenicity index.
Intravenous pathogenicity index.
Diagnostic Samples:
 Samples from live birds:
 Tracheal swabs.
 Cloacal swabs.
 Faecal swabs.
 Serum.
 Samples from dead birds:
 Lung, kidneys, intestine, spleen, brain, liver, and heart
tissues.
Differential diagnosis:
 Pathogenic avian influenza.
 Infectious laryngotracheitis.
 Salmonellosis & Mycoplasmosis.
 Vit. E and Selenium deficiency.
 Avian encephalomyelitis.
 Infectious bronchitis.
 Fowl cholera.
 Fowl pox.
 Coryza.
Treatment:
 There is no known treatment for Newcastle Disease.
Prevention:
 Quarantine & isolation of all newly purchased birds for at
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least 30 days.
Transportation of birds in new or disinfected containers.
Restrict personnel movement between new and old birds.
Disinfection of all surfaces and equipment.
Disposal of any destroyed birds and contaminated products.
Removal of insects and mice (vectors).
Control handling of bird carcasses, litter and manure.
Vaccination:
 Vaccines are administrated at 2 to 4 weeks of age or at 1 day
of age via conjunctival instillation.
 Vaccine-induced immunity is short-lived (8–10) weeks.
Live vaccine.
Inactivated vaccine.
Newplex (a proprietary virus antibody complex vaccine).
REFERENCES:
 http://www.fst.osu.edu/li/research.htm
 http://www.spc.int/rahs/Manual/AVIAN/NEWCASTLE.htm
 http://www.daff.gov.au/animal-plant-health/pests-diseases
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weeds/animal/newcastle
http://www.cfsph.iastate.edu/DiseaseInfo/clinical-signsphotos.php?name=newcastle-disease
www.webconferences.com/.../ppt/Newcastle%20Disease%20Virus_Samal.pdf
www.fao.org/docrep/003/t0756e/T0756E08.htm
Clubb, S. Laws and Regulations Affecting Aviculture and the Pet Bird Industry.
Altman, R; Clubb, S; Dorrestein, G; Quesenberry, K. (eds.). Avian Medicine and
Surgery. W.B. Saunders. Philadelphia, PA; 1997.
Gallerstein, G; Acker, H. The Complete Bird Owner's Handbook. Simon &
Schuster Macmillan. New York, New York; 1994.
Olsen, G; Orosz, S. Manual of Avian Medicine. Mosby, Inc. St. Louis, MO; 2000.
Rupley, A. Manual of Avian Practice. W.B. Saunders. Philadelphia, PA; 1997.
USDA Department of Agriculture. Veterinary Services. Exotic Newcastle
Disease. May, 2001.