Fowl adenovirus: Using serology to control your flocks
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Transcript of Fowl adenovirus: Using serology to control your flocks
Fowl Adenovirus:Using Serology to Control
Your Flocks
Rafael Monleon DVM, MSpVM, ACPV, PASBusiness Unit Manager (Poultry)
9th September 2014
Adenovirus• Double stranded DNA; Non-enveloped
• Reproduce in nucleus
• Produce intranuclear inclusion bodies
Adenovirus
• Very resistant
• pH changes
• Disinfectants
• 60-70C for 30 minutes
• Formaldehyde and some other disinfectants have been somehow effective
Adenovirus
• Worldwide distribution
• Ubiquitous in poultry farms
• Chicken
• Turkeys,
• Ducks, geese, quail
• Found also in wild birds
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)
Classification FAV
FamilyAdenoviridae
GenusAviadenovirus
AD Group I
A
B
C
D
E
FAV-1
FAV-5
FAV-11
FAV-8b
FAV-2FAV-3FAV-9
FAV-4FAV-10
FAV-6FAV-7FAV-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
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
• 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
Fowl Adenovirus (FAV)Transmission
• Horizontal Transmission• Usually >15-20d• Litter, Equipment, Personnel• Recurrent Problem in Poorly C+D Houses• Commonly related with immunosuppression
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
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
Dynamics of FAV Infection Scenario II
12
16 W 40 W25 W
%Positives
(seroconversion)
8 W
FAVInfection
Point of Lay
TRANSMISSION OF ACTIVE VIRUS TO PROGENY FOR A PERIOD OF ~4 – 8 WEEKS
LOSSES DUE TO LATE SEROCONVERSION
FAV - VERTICAL TRANSMISSIONOffspring Mortality
AGE
FAVOffspring Mortality – Vertical Transmission
FARM Dead% Cum.
Mort. Age of Disease
B9 705 11.73% 0-6 -2-1 wk.
A7 1,155 16.02% 0-6 -2-0 wk.
A8 1,769 24.83% 0-4-1-6 wk.
A2 83 1.43% 0-4-1-1 wk.
A3 291 4.98% 0-4-2-1 wk.
A4 535 9.22% 1-0-2-0 wk.
A5 510 8.56% 0-6-2-0 wk.
Total
5,048 Average10.97%
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
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
Mortality Associated
with FAV(21D)
Dias Mortalidad
1 3
2 5
3 6
4 2
5 5
6 335
7 63
8 26
9 18
10 18
11 12
12 10
13 14
14 16
15 12
16 14
17 7
18 10
19 14
20 10
21 19
Cumulative Mortality5.79%
Caribe @ 21D
India – Mortality >10%
INDIACUMULATIVE MORTALITY
>10%
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
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
Fowl Adenovirus (FAV)Gizzard Erosion and Ulceration (GEU)
Schade, 2013
Fowl Adenovirus (FAV)Diagnostic Tools
• Histopathology – Gold Standard
• Intranuclear Inclusion Bodies
• liver, pancreas, proventiculus or gizzard
Fowl Adenovirus (FAV)Diagnostic Tools
• Virus Isolation / PCR / In-Situ Hybridization
• VI+PCR > Detecting Presence of Virus
• Sequencing > Determine Serotype /Species
• HRM (Alternative)
• PCR+ / VI+ Does not Equal Disease
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
• Launched in 2011• Worldwide distributed FAV ELISA kit• Fowl Adenovirus Serotype 1 • Indirect ELISA, dilution 1:100• Specificity > 98 %• Filter 405 nm• Positive Cuttof S/P ≥ 0.5
• Positive Titer >1070
Biochek FAV ELISA
Detects Different SpeciesS/P RATIO Positive Cut-off >0.5
Biochek, Unpublished
FAV A FAV B FAV D FAV E FAV E0
1
2
3
4
5
6
7
S/P
AGP vs. Histopathology vs. ELISAELISA Positive Titer 1070
BioChek, Unpublished
FAV ELISA SPECIFICITYPOSITIVE CUT-OFF >0.5 (n=102) SPF
0 20 40 60 80 100 120
-0.1
-8.32667268468867E-17
0.0999999999999999
0.2
0.3
0.4
0.5
0.6
100% SPECIFICITY
BioChek, Unpublished
BioChek FAVBreeders
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
BB 26 wks Poor SeroconversionAMT = 15200, CV % 53 AMT = 23467, CV % 20
BB 18 wks Good Seroconversion
FAV ELISA
Flock A Flock B0
5000
10000
15000
20000
25000
30000
0
5
10
15
20
25
30
35
40
AMTCV
FAV ELISAMONITORING SEROCONVERSION BREEDER FLOCKS
POOR SEROCONVERSION
GOOD SEROCONVERSION
FLOCK AT RISK OF INFECTION
BB 17W
BB 10W
BB 29WBB 29W
POOR SEROCONVERSION GOOD SEROCONVERSION
FAV ELISA Challenged BB Flocks (Vertical Transmission)
1 2 30
5000
10000
15000
20000
25000
30000
35000
512 5124096
8192
32768
16384 25 wks29 wks
Adapted Grafl et. al, 2012Titers converted from log2
WEAK SEROCONVERTIONPRE-LAY
WITH SUBSEQUENTINFECTION AND VERTICAL
TRANSMISSION
0w 4w 9w 15w 26w0
5000
10000
15000
20000
25000
30000
35000
0
20
40
60
80
100
120
140
AMTCV
FAV ELISA Vaccinated @ 8 weeks
VACCINATION
FAV ELISA BB 12w old / Vaccinated @ 8 weeks
A B C D E0
5000
10000
15000
20000
25000
30000
0
10
20
30
40
50
60
70
80
90
100
23143 2209823993
22398 22422
AMTCV
Flock
FAV ELISABB Flocks / Vaccinated @ 12-13wks
25w 60w0
2000400060008000
10000120001400016000
1800020000
010203040
50607080
90100
AMTCV
Flock A Flock B
LOW AMT / HIGH CVSEROTYPE?/PRIMING?
BioChek FAVDay 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
FAV ELISAMonitoring MAB DOC
10/20 NEGATIVEDOC AT RISK
BioChek FAVBroilers
• 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
FAV ELISANaturally Infected Broilers 45D-46D
A B C D0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
0
10
20
30
40
50
60
70
80
90
100
AMTCV
FLOCK
Tite
r
(%)
NON-CLINICAL
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
CESAC, SPAIN
FAV ELISANon-clinical vs. Clinically Affected Flocks
Non-Clinical Clinically Affected0
2000
4000
6000
8000
10000
12000
14000
16000
0
10
20
30
40
50
60
70
80
90
100
AMTCV
CESAC, SPAIN
FAV ELISA Clinically Affected Broiler Flock Over Time
16d 38d0
2000
4000
6000
8000
10000
12000
14000
16000
0
20
40
60
80
100
120
140
AMTCV
START CLINICAL SYMPTOMS
SLAUGHTER
Control of Disease
• Prevent Immunosuppression
• IBD, CAV, REV, MD, Others
• Biosecurity• Cleaning and Disinfection + Downtime
• Beware “Clean / New House Syndrome”
• Some benefit with formaldehyde
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
48
Promoting Sero-conversion
49
FAV Inactivated Vaccines
Poultrymed (accessed 5/09/14)
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.
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
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
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
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
THANK YOU