Avian Dz

Question 1

Paramyxoviridae causes _____________

Answer 1

Newcastle Dz (APMV-1)/ Avian pneumoencephalitis
genus: avulavirus, 11 serotypes

Question 2

In many countries like ________________, __________ is the biggest threat to food security because of recurring outbreaks and high mortality

Answer 2

Asia, Middle east, Africa, Central and South America
Newcastle Dz

Question 3

International monitoring of Newcastle Dz is done by who?

Answer 3

FAO and OIE

Question 4

Which species show no CS with Newcastle

Answer 4

Ducks and geese
Carrier in Migratory waterfowl

Question 5

Pathotypes of Newcastle

Answer 5

Asymptomatic, enteric: subclinical
Lenthogenic: subclinical to mild resp.
Mesogenic: Resp. or neuro
Velogenic: Neurotropic (resp. or neuro) and vicerotropic (hemorr. intestinal lesions)

Question 6

What is the new classification of Newcastle Dz?

Answer 6

vND, reportable
Mesogenic, velogenic neurotropic (lethal) and velogenic vicerotropic (lethal + hemorr.)

Question 7

CS of Newcastle

Answer 7

Edema of the head (eyes)
Greenish- dark watery diarrhea
Resp. or neruo signs

Question 8

Neuro. signs in protracted cases

Answer 8

Muscle tremors, drooping wings, dragging legs, twisted head and neck, circling, depression, inappetence, paralysis

Question 9

T/F: Vx birds will have less severe signs but not protected against vND viruses

Answer 9

TRUE

Question 10

Newcastle Dz is indistinguishable from _____________

Answer 10

Highly pathogenic avian influenza
Hemorrhagic internal lesions: tracheal and intestinal mucosa and proventriculus

Question 11

Zoonosis of Newcastle Dz

Answer 11

Mild conjunctivitis: sheds ocular secretions for 4-7d (avoid contact)
Lab and vx crews most @ risk
No cases handling or consuming poultry or human-human spread

Question 12

Control of Newcastle

Answer 12

Disinfection of premises
Delay re-intro of new birds for 30d
Control insects and mice
Limit human traffic
Vx

Question 13

Newcastle vx

Answer 13

Live (lentogenic NC virus) for commercial
Inactivated (individual bird)
Recombinant (in ovo)
Combo of live then inactivated

Question 14

What are the 3 R’s with infectius bronchitis

Answer 14

Resp., renal, reproductive

Question 15

Gallid Herpesvirus 2 causes ____________

Answer 15

Marek’s Dz Virus (non-resp.)
genus: mardivirus

Question 16

How does GH1 differ from GH2?

Answer 16

GH1 (Avian Laryngotracheitis) is a resp. dz

Question 17

Marek’s Dz is the most important progressive _____________ of chickens (+ turkeys) causing substantial economic loss worldwide

Answer 17

Lymphoproliferative dz

Question 18

Acute signs of Marek’s Dz

Answer 18

Fowl paralysis in explosive outbreaks in young chicken with depression
Mortality without neuro signs
Enlargement of nerves (most consistent)

Question 18

Classical signs of Marek’s Dz

Answer 18

Lymphoproliferative syndromes
Lymphomas, neuro signs
Vagus nerve: dilation of crop and gasping

Question 19

Ocular Lymphomatosis (Marek’s Dz)

Answer 19

Graying of the iris
Pupil irregular and eccentric (partial or total blindness)

Question 20

Cutaneous Marek’s Dz

Answer 20

Round nodular lesions on feather follicles of young
Redleg
Carcass condemned

Question 21

Epidemiology of Marek’s Dz

Answer 21

Mature chicken have Ab
Protected first weeks of life due to progressive nature of the dz
Epizootic: sexually immature birds (2-5m), high mortality
Commercial flocks in US vx (endemic)

Question 22

Pathogenesis of Marek’s Dz

Answer 22

Inhalation of skin dander/ dust → lung B cells and macros → B cells to T cells → immunesuppression → skin infection lymphos

Question 23

What happens of the second week after infection of Marek’s Dz

Answer 23

Proliferation of T cells then death 1 w layer
T lymphomas

Question 24

Marek's resistance to infection

Answer 24

Genetics: Carry MHC B21 halotype Maternal Abs in chicken up to 3w Bursectomized Life-long carriers and shedders (5-6w after infection)

Question 25

What lesions due to in situ proliferation of T cells of Marek's Dz lead to?

Answer 25

Leukemia Significant inflamm cell resp. Enlargement of nerves

Question 26

What nerves are enlarged fro Marek's Dz

Answer 26

Abdominal vagus, sciatic plexuses, brachial plexuses, coeliac plexuses, intercostal nerves

Question 27

Dx of Marek's

Answer 27

History, CS and gross lesions (lymphomas and nerve enlargement) Age (not in chicks <3w, older)

Question 28

DD of Marek's DZ

Answer 28

Avian leukosis Neuro symptoms, @ least 3w, T lymphomas, Herpesvirus, several species vx in MD Tumors in bursa, .14w, B lymphomas, acute, chickens, vertical trans, retrovirus in AL

Question 29

Marek’s Dz vx

Answer 29

↓ the incidence of neoplastic lesions in visceral organs and neuro. Dz

Question 30

Marek’s Dz control measures

Answer 30

Building up of flocks carrying B21 alloantigen All-in-all-out Cleaning/ disinfection

Question 31

Retroviridae causes _________

Answer 31

Avian Leukosis Viruses *genus: alpharetrovirus*

Question 32

Lymphoid leukosis (visceral lymphomatosis)

Answer 32

Most common form of avian leukosis in chickens 3-7m

Question 33

Lesions of Lymphoid Leukosis

Answer 33

Non-specific (pale comb, abdominal swelling etc) Multi-centric tumors (discrete nodular lesions in the BF that metastasize)

Question 34

__________ up to 5m of age abrogates formation of tumors for avian leukosis virus

Answer 34

Bursectomy

Question 35

Tumors associated with lymphoid leukosis

Answer 35

Aggregates of B lymphoblasts Transformation the intact bursa Diffuse or nodular lymphoid tumors common in liver, spleen and bursa

Question 36

Avian leukosis virus transmission

Answer 36

Congenital due to virus in oviduct → chicks shed virus in meconium and feces Horizontal by direct contact, saliva and contaminated environ. Transovo (not impt)

Question 37

Dx of Avian leukosis virus

Answer 37

History, CS, histopath Immune assays RT-PCR and sequence analysis

Question 38

Immunity and prevention of Avian leukosis virus

Answer 38

Maternal Abs low and disappear by 4-7w Infected chicks have high levels of Abs (persistently infected) Roosters in germ line transmission of endogenous retroviruses

Question 39

Control of Avian leukosis virus

Answer 39

All-in-all-out Hygiene, single source chicks (genetically resistant animals)

Question 40

Birnaviridae causes ________________

Answer 40

Infectious Bursal Dz/ Gumboro Delaware Dz *genus: avibirnavirus, RNA, reportable*

Question 41

Infectious Bursal Dz

Answer 41

Severe and prolonged immunosuppression Contagious: oral and direct contact 2 serotypes

Question 42

Serotype 1 of IBD

Answer 42

Pathogenic in young Ab- free chickens Classic or standard with 10-50% mortality (worldwide) Variant: no mortality (worldwide) Very virulent: 50-100% mortality (Europe, Asia, SA)

Question 43

What age does IBD affect?

Answer 43

Most severe in chicks 3-6w <3w subclinical infection, >6w rarely develop dz

Question 44

CS of IBD

Answer 44

Distress, depression, ruffled feathers, anorexia, diarrhea, trembling and dehydration Clinical dz starts @ 3-4d and immunodepressed

Question 45

Lesions of IBD

Answer 45

3-4d after infection, BF enlarged up to 5x → edema, hyperemia, prominent longitudinal striations Hemorrhage, necrotic foci through parenchyma Virulent: lymphos in spleen, thymus and BM BF atrophic, kidneys enlarged

Question 46

Pathogenesis of IBD

Answer 46

Replicates in macros and lymphos → viremia 1 in cecum and SI Infects BF lymphos → viremia 2 and systemic dissemination

Question 47

______________ survive without CS or dz with IBD

Answer 47

Bursectomized

Question 48

Why is the stage of B cell differentiation crucial in IBD?

Answer 48

Only IgM bearing B cells of pre- B cells are infected

Question 49

Dx of IBD

Answer 49

IF (smears and secretions of BF) - Ag 3-4d after infection RT-PCR EM of bursal specimens Cell cx: chicken lymphoblastoid cells (14d)

Question 50

How long does the IBD virus last?

Answer 50

>120d in farm environ. >50d in feed, feces and water Resists heat, cleaning and disinfection

Question 51

Control of IBD

Answer 51

Inacvitvated by phenolic-base compounds, iodine complexes, formalin, chloramine compounds Vx primary mode of control