A presentation about Fowl Adenovirus in chickens. It provides insights on: etiology, pathology, monitoring and control among others.
Presented globally on September 9th 2014 via Watt Ag-Net Webinar by Dr. Rafael Monleon
Contact me in LinkedIn for any question: www.linkedin.com/rafaelmonleon
5. Familiy Adenoviridae
• Genus Aviadenovirus: Group I Avian Adenoviruses
• Fowl Adenovirus - 12 Serotypes / 5 Species
• Inclusion Body Hepatitis (IBH)
• Hydropericardium Syndrome (Angara Disease)
• Gizzard Erosion and Proventiculitis
• Genus Siadenovirus: Group II Avian Adenoviruses
• Hemorraghic Enterititis (turkeys), Marble Spleen Disease
(pheasants), Splenomegaly (chickens)
• Genus Atadenovirus: Group III Avian Adenoviruses
• Egg Drop Syndrome (EDS)
6. Classification FAV
Family
Adenoviridae
Genus
Aviadenovirus
AD Group I
A
B
C
D
E
FAV-1
FAV-5
FAV-11
FAV-8b
FAV-2
FAV-3
FAV-9
FAV-4
FAV-10
FAV-6
FAV-7
FAV-8a
CELO, 112, QBV, Ote, H1
340, TR22, M2, Tipton, IBH-2A
KR5, 506, H2, K31, 61, J2-A
C2B, M11, CFA20, SA2, C-2B
SR48, 685, H3, P7-A, GA1-1, Z7
SR49, 75, H5, 75-1A-1
A02, 90, CFA19, A2-A
CR119, 168
UF71, 380
YR36, X11, X11-A, 122
TR59, 58, CFA40, T8-A
764, VRI-33, B-3A
ICTV Classification
7. Fowl Adenovirus (FAV)
Epidemiology
• Antibodies to FAV can be found in many
poultry flocks
• FAV can be isolated from healthy as well as
clinical birds
• Vertical transmission important in spread or
“seeding” farms with several serotypes
8. • Birds can be infected with more than one
serotype
• Protection is primarily serotype specific
• Some Cross-protection Between Serotypes
•3&4 / 2&11
• Birds can shed a serotype while having
antibodies to another serotype
Fowl Adenovirus (FAV)
Epidemiology
9. Fowl Adenovirus (FAV)
Transmission
• Horizontal Transmission
• Usually >15-20d
• Litter, Equipment, Personnel
• Recurrent Problem in Poorly C+D Houses
• Commonly related with immunosuppression
10. Fowl Adenovirus (FAV)
Transmission
• Vertical Transmission
• Approx. >3d – 18-20d
• Breeders not seroconverted before lay
• Infection During Lay > Virus shedding for 4-8 weeks
• When ALL breeders seroconvert shedding stops –
Vertical transmission stops
• Reactivation of latent virus might occur with stress
• “Clean House Syndrome”
• Generally Seen High Levels Biosecurity
• “Dirty” Houses – Re-used litter – Less Problems
11. Dynamics of FAV Infection
Scenario I
16 W 40 W25 W8 W
FAV
Infection
Point of
Lay
NO TRANSMISSION OF ACTIVE
VIRUS TO PROGENY
%
Positives
(seroconversion)
VERY IMPORTANT TO ACHIEVE
SEROCONVERSION BEFORE LAY
12. Dynamics of FAV Infection
Scenario II
12
16 W 40 W25 W
%
Positives
(seroconversion)
8 W
FAV
Infection
Point of
Lay
TRANSMISSION OF ACTIVE
VIRUS TO PROGENY FOR A
PERIOD OF ~4 – 8 WEEKS
LOSSES DUE TO LATE SEROCONVERSION
15. Fowl Adenovirus (FAV)
Inclusion Body Hepatitis
• First Described in 1960’s in USA
• “the 3 days disease”
• 3d ↑ mortality, 3d plateau, and 3d drop in mortality
• Depression, Weakness, Jaundice, Convulsions, Anorexia, Death
• Enlarged, dystrophic friable liver with redish-yellowish color
• Pale necrotic pancreas, muscle hemorrhages, bursal atrophy
• Breeder Mortality, Drops in Egg Production & Hatchability Reported
16. Fowl Adenovirus (FAV)
Inclusion Body Hepatitis
• Multiple serotypes involved
• Serotype 2, 8b, 9, 11 common
• Traditionally Associated with IBD/CAV (ImS)
• Now Considered Primary As Well
20. Fowl Adenovirus (FAV)
Hepatitis-Hydropericardium Syndrome
•
•
• Mainly Serotype 4 (FAV-4 / Species C)
• Broilers / Breeders
• Increase of pericardial fluid (hydropericardium); hepatitis
• Generally 3 weeks or older
• Variable mortality but can be very high 40%+
• Sometimes associated with Immunosuppression
21. Fowl Adenovirus (FAV)
Gizzard Erosion and Ulceration (GEU)
• Excessive erosion and ulceration of gizzard lining
• Mostly Species A (FAV-1) – Also reported FAV-8
• GEU experimentally reproduced
• Low mortality, uneven growth, increased FCR
• Also seen pancreatitis, proventiculitis, Hepatitis
• Rule-outs / Comorbidity: Mycotoxins, Biogenic Amines (Histamine,
Gizzerosine, etc.), Vitamine B6 deficiency
25. Fowl Adenovirus (FAV)
Diagnostic Tools
• Serology
• VN - serotype specific antibody detection
• Serotype specific
• Tedious, expensive, complicated, few places to perform
• ELISA – group specific antibody detection
• Fowl adenovirus specific (Avian Adenovirus Group I)
• CANNOT DIFFERENCIATE BETWEEN SEROTYPES
• Easy to reproduce, inexpensive, automation, mass testing
• Interpretation of ELISA meaningful when comparing healthy vs.
clinical birds and/or having meaningful baseline / guidelines
• Baselines / Guidelines
30. BioChek FAV
Breeders
Birds in production generally positive
Although poor seroconversion often occur
Monitoring is useful to confirm seroconversion,
before entering production in troublesome areas
BB should be 100% positive > 12-18W
High antibody titers do not necessarily correlate
with protection
Protection is SEROTYPE specific
31. BB 26 wks
Poor Seroconversion
AMT = 15200, CV % 53 AMT = 23467, CV % 20
BB 18 wks
Good Seroconversion
FAV ELISA
36. FAV ELISA
BB 12w old / Vaccinated @ 8 weeks
23143
22098
23993
22398 22422
0
10
20
30
40
50
60
70
80
90
100
0
5000
10000
15000
20000
25000
30000
A B C D E
AMT
CV
Flock
37. FAV ELISA
BB Flocks / Vaccinated @ 12-13wks
0
10
20
30
40
50
60
70
80
90
100
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
25w 60w
AMT
CV
Flock A Flock B
LOW AMT / HIGH CV
SEROTYPE?/PRIMING?
38. BioChek FAV
Day Old Chicks
• Biochek FAV ELISA can demonstrate antibodies in DOC
• Samples in group 0 (negative) can be easily infected
• Positive titers do not necessarily correlate with protection
• Protection is SEROTYPE specific – Not GROUP specific
• Some examples of serology of DOC field data
• DOC offspring from vaccinated breeders
• FAV Serotype 4 – Inactivated Vaccine x1/x2
40. BioChek FAV
Broilers
• Limited data available
• Many healthy broiler flocks will test low
positive (MT < 5000) at > 35D
• Clinical flocks have MT > 6500
• Useful to compare healthy non-clinical birds
with clinically affected birds
• Baselines
41. FAV ELISA
Naturally Infected Broilers 45D-46D
0
10
20
30
40
50
60
70
80
90
100
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
A B C D
(%)
Titer
FLOCK
AMT
CV
NON-CLINICAL
42. IBH Broilers
Case History
First symptoms at 13-16D
Depressed, crouching position, lethargic with acute mortality
Peak mortality 3-5D after first symptoms, disappearing after
6-7D.
Total mortality at slaughter between 8 – 30%
Enlarged, dystrophic liver with yellowish color and crumbly
texture
Nephritis
Intracellular Inclusion bodies in liver and kidney tissues
CESAC, SPAIN
46. Control of Disease
• Prevent Immunosuppression
• IBD, CAV, REV, MD, Others
• Biosecurity
• Cleaning and Disinfection + Downtime
• Beware “Clean / New House Syndrome”
• Some benefit with formaldehyde
47. Control of Disease
• Seroconversion of Breeders
• Once neutralizing antibodies are present shedding generally stops
(exceptions in some isolates)
• Natural Exposure – Litter, Faeces
• Beware what you bring in (i.e. Mycoplasma / Salmo)
• Live Un-attenuated Vaccine
• Serotype 8b (Australia)
• Inactivated Vaccines - Serotypes 4, 5 & 8 available
• Autogenous Vaccines
50. Control of Disease
• Supportive Treatment
• BLOOD BIOCHEMICAL CHANGES IN BIRDS WITH
INCLUSION BODY HEPATITIS AND THE EFFECT OF
SUPPORTIVE TREATMENTS DURING OUTBREAKS
• D. VenneA and Y. ChorfiB – Western Poultry Diseases
Conference 2011
• Treatment:
• Treatment consisted in the addition of 125 g of sodium bicarbonate
plus 400 g of sugar in 576 L of drinking water.
51. Application BioChek FAV ELISA
• SPF Monitoring Confirming Negative Status
• Monitoring BREEDERS Natural Seroconversion
• 12-18W of age > 90% POSITIVE
• Vaccination Monitoring of BREEDERS
• After Vaccination with FAV vaccines
• >90% POSITIVE
• Disease Monitoring BREEDERS
52. Application BioChek FAV ELISA
• DOC Titer – Monitoring of Mab Transfer
• Disease Monitoring BROILERS > 35D
• Suggested Horizontal Transmission Protection
• Compare clinical vs non-clinical serology
• AMT > 6500 associatied clinical disease
• Non-clinical flocks have AMT < 5000
• Vaccination Monitoring of BROILERS
53. Baselines BioChek
FAV ELISA Test Kit
Provisional Baselines
Vaccine AMT CV %POS SUSPECT TITER CV
Broiler
Breeders Inactivated / Natural SC 12000-30000 <35% >90% >15000-18000 <35%
Broilers None <5000 >40% >6500 <35%
These guidelines are based on our experience and information from our clients.
BioChek does not accept any responsibility for the results using these guidelines.
These guidelines are subject to change without notice
54. Summary
• FAV are world wide distributed viruses that affect poultry
in a wide array of manifestions that vary from mild to
very severe forms
• FAV diagnosis is attained by combination of: clinical
history, serology, and molecular techniques.
• ELISA has been proved to be an useful tool
• Prevention of FAV starts by achieving seroconversion of
parent flocks prior to lay and avoiding immunosupression