The document discusses the monitoring and control of vertically transmitted poultry diseases, particularly focusing on bacterial and viral diseases such as Mycoplasma and Salmonella. It details the types of transmission, challenges in treatment due to antibiotic bans, and methods for monitoring diseases through serology and PCR. The document emphasizes the importance of biosecurity, vaccination, and regular testing to manage these diseases and minimize their impact on poultry production.

1. Monitor and Control of Vertically
Transmitted Poultry Diseases
Rafael Monleon, DVM, MSpVM, ACPV, PAS
Business Unit Manager (Poultry)
Biochek Seminar – Manila, Philippines
29th March 2014

2. OUTLINE
• Types of Transmission
– Horizontal vs. Vertical
• Bacterial Vertically Transmitted Diseases
– Monitor & Control
• Viral Vertically Transmitted Diseases
– Monitor & Control
• Summary

3. HORIZONTAL TRANSMISSION

4. VERTICAL TRANSMISSION

5. Important Poultry Vertically
Transmitted Bacterial Diseases
• Mycoplasma
– Mycoplasma gallisepticum
– Mycoplasma synoviae
• Salmonella
– Salmonella pullorum / S. gallinarum
– Salmonella enteritidis / S. typhimurium

6. Important Poultry Vertically
Transmitted Bacterial Diseases
• Persistent infection (Chronic) makes
bacterial VT diseases dentrimental
• Life long carriers are observed even in
well treated flocks
• Ban on several antibiotic makes treatment
difficult
• Erradication or Vaccination are the most
common options

7. Mycoplasma
• M. gallisepticum / M. synoviae
• Probably the most prevalent vertically
transmitted disease worldwide
• Losses in parents / progeny
• Hard to remove from farms
– Shed rate highest (30%) acute vs. decreases
(to about 5%) chronic phase of the disease.
– Persistent problem. Carriers
7

8. Mycoplasma gallisepticum
• In breeding chickens (GPs/PS)
– Respiratory signs including sinusitis
– Decreased egg production
– Secondary Egg Yolk Peritonitis
– Airsac in embryos
• Causing late dead or first week mortalities/
infections
• In broilers
– Mainly CRD

9. Mycoplasma Losses
9
Hy-line

10. MG/MS in Broilers
Flock Av. Wt. Age % %
Status (grams) FC Days Mort. Cond.
MG/MS
Negative 2525 2.182 51.8 4.23 0.15
MG
Positive 2378 2.205 52.9 7.05 1.47
MS
Positive 2461 2.190 52.7 6.23 0.87
Source: LA Integration, 1991

11. Sinusitis

12. Sinusitis

13. Airsacculitis

14. Airsacculitis/Pericarditis

15. CRD

16. Mycoplasma synoviae (MS)
(Infectious synovitis)
• Mild respiratory disease
• Inflammation of the synovial sheaths.
• Chickens and Turkeys.
– It is common in commercial laying flocks.
– In chickens mostly silent type infections
• Synovitis rarely seen
• Young birds - 4 to 12 weeks of age.
• Can also contribute to CRD in broilers
• Less virulent than MG
• Spreads faster than MG.

17. Swollen
hock
and
foot
pad
Synovi5s

18. Keel bursitis Synovial
exudates
Car5lage
erosions
Chronic
synovi5s

19. Airsacculitis

20. Mycoplasma synoviae
• Some new conditions recently reported
• Eggshell Apex Abnormalities (EAA) since
2000. Also called Top Cone Abnormalities.
– Mostly in Commercial Layers
– Netherlands, South Africa and Japan
– Estimate 2-3 egg losses / bird and
– 5% loss in downgrades
– MS with IBV D1466 > higher incidence

21. MS Egg Effects-EAA or Top Coning

22. • PIP Analysis
• Serology
– RPA
– ELISA
– HI – mainly confirmation
• PCR
– qPCR
Monitoring

23. PIP Analysis
• Routine observation
• Airsacculitis - Baby
Chicks or DIS pips
• When see in DIS or
day old chicks this is
almost a pathognomic
lesion

24. Mycoplasma Monitoring
Farm
MG
MS
Day
Old
X
X
6wks
X
X
16wks
X
X
24wks
X
X
34
wks
X
X
44wks
X
X
54wks
X
X
*testing every 3-4 weeks in production might be necessary

25. Serology
Rapid Plate Agglutination
• Sensitive.
– IgM antibody
• Detects around – 7 to 10 days
• Screening – a flock test.
• Prone to false reactions
• May not detect atypical strains

27. Serology
False Positives with RPA
• Frozen sera.
• Too long in coldest area of refrigerator.
• Killed TC antigens/Oil Emulsion vaccines.
• Use of fetal calf serum – MG/MS antigens.
• Coryza bacterins.

28. Serology
False Positive with RPA
• Antigen too sensitive
• Erysipelas infections
• Staph bacterins and/or infections
• Contaminated sera
• Cross reaction with MS

29. Serology
False Positive with MG RPA
• Dilute serum 1:10.
• Mix serum with equal volume of horse or swine
sera.
• Labs that use 2-fold dilutions consider > 1:8 as
positive

30. Serology
HI Test
• More specific
• Positive 1:80, suspicious 1:40
• Confirmatory
• Antigens not readily available
• Appears later than RPA (14 days)
• Antigen quality and variations
• Atypical strains

32. ELISA
• Becoming the most common form of monitoring
– Mass testing / Affordable (Combo)
• In general a bit less sensitive but more specific
than RPA (IgM vs. IgG)
• Less specific but more sensitive than HI
• However Biochek MS test kit can detect 7d post
infection
– Recombinant antigen

33. ELISA
Ringtrial Results
MS
Field
Isolate
in
4
Wk
Old
SPF
Chickens,
7
DPI*
2010 2011
RPA
Ms** 33% 17%
Mg/Ms(r)
ELISA 100% 100%
Other
Mg/Ms
ELISAs** 17% 44%
%
positives
Assay
GD Deventer

34. Results
(MS WVU1853 Inoculated)
0
20
40
60
80
100
0
7
9
14
16
%
Posi*ve
Days
Post-­‐Challenge
Mg/Ms(r)
ELISA
Mg/Ms
(c)
ELISA
RPA
(1&2)
RPA
(3)

35. Results
(MS K5664 Inoculated)
0
20
40
60
80
100
0
7
9
14
16
%
Posi*ve
Days
Post-­‐Challenge
Mg/Ms(r)
ELISA
Mg/Ms
(c)
ELISA
RPA
(all
3)

36. Mycoplasma gallisepticum
Day-old Chick Monitoring
36
0
2
4
6
8
10
12
14
16
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples Lot:
Mean Titer:
G.M.T.:
Titer Range Ref. Controls:
TiterS/P Ratio Titer Group
2 09/11/2007
Name : R1-IMPORTF.3-1
ROSSCompany :
Code : S07-370
Age : 01D
Type : GP
House No. : L-1
Mg FS4633
05/11/2007 09/11/2007
56
1
5
282
R6 (700-2000)
Titer Group
ARBOR ACRES THAILAND CO.,LTD.
10/3 Soi Chuemsumphan25 Chuemsumphan Rd.
Nongjok Bangkok 10530 THAILAND
A01 0.098
A02 0.098
613
- 0.000
- 0.000
R6= 803Mean Titer Ref. Controls:
15 0 0150.50Positive Cutoff S/P >=
Histogram/BlockDiagram Page : Date :Report:
.
Assay :
Bleeding Date : Testing Date:
Min. - Max Titer : -
%CV :
.
.
.
.
.
.
.
.
Neg/Sus/Pos = / /Total No. Samples:
.
Sample ID Raw O.D. ResultWellVery low amount of false positives in DOC

37. Mycoplasma synoviae
Day-old Chick Monitoring
37
0
2
4
6
8
10
12
14
16
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples Lot:
Mean Titer:
G.M.T.:
Titer Range Ref. Controls:
1 09/11/2007
Name : R1-IMPORTF.3-1
ROSSCompany :
Code : S07-370
Age : 01D
Type : GP
House No. : L-1
MS FS4646
05/11/2007 09/11/2007
2
1
1
110
R6 (700-2000)
Titer Group
ARBOR ACRES THAILAND CO.,LTD.
10/3 Soi Chuemsumphan25 Chuemsumphan Rd.
Nongjok Bangkok 10530 THAILAND
9
R6= 1365Mean Titer Ref. Controls:
15 0 0150.50Positive Cutoff S/P >=
Histogram/BlockDiagram Page : Date :Report:
.
Assay :
Bleeding Date : Testing Date:
Min. - Max Titer : -
%CV :
.
.
.
.
.
.
.
.
Neg/Sus/Pos = / /Total No. Samples:
.
Very low amount of false positives in DOC

38. Mycoplasma Monitoring
MG Positive
0
1
2
3
4
5
6
7
8
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples
Age : 34W
Type : BB
Birth Date : 10/10/2008
House No. : 2 NO
Reason for Testing : PROBLEM
Mean Titer:
G.M.T.:
0
Mg CH4350
11/06/2009 12/06/2009
4 280
2 012 6 818
4 077
30
Titer Group
Lot:
S/P Ratio Titer Titer Group
BioChek B.V. Service Laboratory
Burg. Bracklaan 57, 2811 BP , Reeuwijk, Holland
Tel: +31 182 582 592 - Fax: +31 182 599 360
0 15150.50Positive Cutoff S/P >=
VI Index: 143
189 21/09/2010Histogram/BlockDiagram Page : Date :Report:
.
Assay :
Bleeding Date : Testing Date:
Min. - Max Titer : -
%CV :
.
.
.
.
.
.
.
.
.
.
/ /Total No. Samples: Neg/Sus/Pos =
.
Sample ID Well Raw O.D. Result

39. Case History 1 Respiratory Infection BR
serology test at 42D
Mycoplasma Monitoring
Mg Suspect / MS Positive

40. PCR (qPCR)
• Kits commercially available
– Biochek MG/MS qPCR Q2 2014
• Excellent, rapid method
• No interference with non-pathogenic
Mycoplasma
• Sensitive – Specific
• Very low % of false positives

41. PCR – False Positives
• Laboratory contamination.
• Other Mycoplasma or bacteria with
similar DNA sequences.
• Reactions may be real.

42. PCR – False Positives
• Laboratory contamination.
• Other Mycoplasma or bacteria with similar
DNA sequences.
• Reactions may be real.

43. Role of PCR
• Confirm diagnosis in serologically positive
flocks
• Check DOC for vertical transmission
• Test spike males or other bird moves
• Rapid ID of strains: vaccines vs. field
• May reduce need to culture
• Research

44. Control Mycoplasma
• Biosecurity
• Antibiotics
• Live vaccines
• Bacterins

45. Control - Biosecurity
Hatchery People
Source Flock
Insects
Rodents
Wild Birds
Housing
Litter
Water
Feed
Equipment

46. Eradication
• Serological testing and elimination.
• Strict biosecurity
• Heating eggs to 41ºC
• Antibiotic injection.
• Antibiotic dip

47. Mycoplasma Eradication
• Most economical in certain scenarios
– Long term consequences are far too high
• Easily done if truly desired
• Commitment / education.

48. Antibiotics
Tetracyclines Macrolides Quinolones Others
Oxyletracycline Tylosin Enrofloxacin Tiamulin
Chlortetracycline Lincomycin Danofloxacin
Tetracycline Kitasamicyn Sarafloxacin
Doxycycline Josamycin
Which one works?

49. Control – Antibiotics
Native broiler chickens
• Day 0 – MS Ab positive
• Tylosin @ 3d for 5 days
• Tylosin @ 3 wks every 4 weeks
• Results seems to have eliminated
serological evidence by 3 & 10 weeks

50. National Chiayi University
Report: Histogram/Blockdiagram
Dr. Kuo Lab
ResultSample ID Well Raw OD S/P Ratio Titer Titer Group
下午
2013/10/8
Ms
2013/10/8
2/0/18
204218
403 -­ 12478
2691
93
45
RF10 (2148)Meantiter Ref.Controls
RF10 (1500-­4500)Titer Range Ref.Controls
Positive Cuttoff S/P: 0.5>=
4 pos
3 pos
1 pos
1 pos
0 neg
1 pos
0 neg
8 pos
Control on native broiler chickens DOC

51. National Chiayi University
Report: Histogram/Blockdiagram
Dr. Kuo Lab
ResultSample ID Well Raw OD S/P Ratio Titer Titer Group
Reason :
Housenumber :
smallCode :
Type :
21 Day(s)Age :
2013/10/30Samplingdate :
Company :
G.P.Customer-­Name :
2013/10/30 07:24:37Lab code :
Assay:
Bleedingdate:
Lotnumber:
Testdate:
0
2013/10/30
Ms
2013/10/30
10/0/0Neg/Sus/Pos:
10Mean Titer:
Min-­Max Titer:
GMT:
%CV:
50
1 -­ 138
23
88
No. Samples:
Target Titer:
Target %CV:
VI Index: 0
Target Range VI:
Interpretation VI:
RF10 (2910)Meantiter Ref.Controls
RF10 (1500-­4500)Titer Range Ref.Controls
Positive Cuttoff S/P: 0.5>=
0.584D01+
0.608C01+
0.125B01-­
0.104A01-­
01 F01 0.191 0.159 138 0 neg
02 G01 0.157 0.088 65 0 neg
03 H01 0.164 0.103 79 0 neg
04 A02 0.170 0.115 91 0 neg
05 B02 0.141 0.055 35 0 neg
06 C02 0.129 0.030 16 0 neg
Control on native broiler chickens 3wks

52. Control on native broiler chickens 10wks

53. Control – Antibiotics
• Still WIP
– Need more data
• We see decrease in titers following a
succesful use of antibiotics
• Delay of 4-6 weeks

54. Serological Profile Following Treatment

55. Serological Profile Following Treatment

56. Serological Profile Following Treatment

57. Antibiotics Use
• Loading dose
• Maintenance
– Every 4-8 weeks
• Helps egg
production
• It ill not stop
shedding 100%
First three days.
During vaccine
reactions.
Production Broilers

58. Vaccination
• Commercial Egg // Multiple Age
Complexes
– Currently also sometimes in single age
farms
• Live
• Killed (Bacterins)

59. Killed F 6/85 ts-11
Route s/c or i/m Various Spray Eye-drop
Safety +++ ± +++ +++
Persistence - +++ - ++
Antibodies ++ ++ - ±
Spread - ++ - ±
Displacement - +++ + +
Vaccines for Mg

60. Vaccines for Ms
Killed MS-H
Route s/c or i/m Eye-drop
Safety +++ +++
Persistence - ++
Antibodies ++ ++
Spread - +
Displacement - +

61. Baselines Live Mycoplasma vaccines
Differentiation of Vaccination Serology vs. Field Challenge Serology
based on evaluation mean flock titers with baselines and evaluating %
positives. Flocks are suspect of infection when mean titers > baseline
and 100% positive.

62. Killed Vaccines
Bacterins
• Various manufacturers.
• Some combinations.
• MG
• MS

63. Killed Vaccines
Bacterins
• Expensive
• Two applications
• Need to inject every chicken
• Protects partially against production losses
• Decreases shed considerably
– Vertical Transmission
• Does not spread

64. Salmonella
• S. pullorum / S. gallinarum
– Non-motile salmonella
– Ser. Gr. D
• S. enteritidis / S. typhimurium
– Motile salmonella
– Ser. Gr. D / Ser. Gr. B
• Substantial losses due to mortality, egg
contamination, public health significance
64

65. Salmonella pullorum
65
R.Monleon

66. Salmonella pullorum
66

67. Salmonella gallinarum
67

68. Salmonella gallinarum
68

69. Salmonella enteritidis
69
Type 2 Livers
Ruptured Tendons
R.Monleon

70. Monitoring
• Serology
– Agglutination (WBA, RPA)
– ELISA
• Bacterial Culture
– Enrichment – RV (soy peptone broth) & MK
(tetrathionate broth) / MSRV / Others
– Brilliant Green / MacConkey / XLT / Others
– Biochemistry
– API Strips (RAPID ID 20 E)

71. Salmonella Monitoring
Farm
SP/SG
S.
Enteri*dis
S.
typhimurium
Day
Old
X
X
6wks
X
X
16wks
X
X
X
24wks
X
X
34
wks
X
X
44wks
X
X
54wks
X
X
* Additional sampling might be needed on circumstances

72. Common Group B & D Salmonella spp.
Serotyping Antigens
Serovar
Group
“O”
Soma*c
“O”
An*gens
Flagellar
“H”
An*gens
Heidelberg
B
1,
4,
12
r
Agona
B
1,
4,
12
r,
g,
s
Derby
B
1,
4,
12
f,
g
Typhimurium
B
1,
4,
12
i
Kingston
B
1,4,12,27
g,
s,
t
Gallinarum
D
1,
9,
12
-­‐
Pullorum
D
1,
9,
12
-­‐
Enteri5dis
D
1,
9,
12
g,
m
Berta
D
1,
9,
12
f,
g,
t
Panama
D
1,
9,
12
l,
v
As “O” antigens 1 & 12 are common in both Group B & D, any representatives of either
group may cause cross reactions when high amounts of antibodies are present.

73. Salmonella WBA

74. Pullorum Agglutination Test
Salmonella P/G RPA

75. ELISA
Specificity Results-Group B, D
Commercial Broiler Breeders
Specificity
>99.8%

76. ELISA Specificity Results –
Group D
Commercial Layers

77. Sensitivity BioChek SE/ST ELISA
Temporal Panel with samples of infected SPF birds with S. enteritidis
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
1.2000
1.4000
1.6000
00D 07D 14D 21D 28D 35D 42D
S/P>0.5=positive
DAYS P.I.
BIOCHEK SE/ST. ORAL S. enteritidis INFECTION
at Day 00
MEAN S/P 10 CHICKENS
AHS Deventer Salmonella validation serum Panel

78. Salmonella Typhimurium Monitoring
Negative Flock
0
5
10
15
20
25
30
35
40
45
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples Lot:
Mean Titer:
G.M.T.:
TiterS/P Ratio Titer Group
Name : R2F.2
ROSSCompany :
Code : S07-360
Age : 40W
Type : GP
House No. : 01
St FS4583
03/11/2007 04/11/2007
51
9
42
59
ARBOR ACRES THAILAND CO.,LTD.
10/3 Soi Chuemsumphan25 Chuemsumphan Rd.
Nongjok Bangkok 10530 THAILAND
Titer Group
129
45 0 0450.50Positive Cutoff S/P >=
1 04/11/2007Histogram/BlockDiagram Page : Date :Report:
.
Assay :
Bleeding Date : Testing Date:
Min. - Max Titer : -
%CV :
.
.
.
.
.
.
.
.
Neg/Sus/Pos = / /Total No. Samples:
.
Sample ID Raw O.D. ResultWell

79. Salmonella Typhimurium Monitoring
Recently Contaminated Flock
0
5
10
15
20
25
30
35
40
45
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples Lot:
Mean Titer:
G.M.T.:
TiterS/P Ratio Titer Group
Name : R4F.1
ROSSCompany :
Code : S07-361
Age : 58W
Type : GP
House No. : 02
St FS4583
03/11/2007 04/11/2007
142
8
80
131
ARBOR ACRES THAILAND CO.,LTD.
10/3 Soi Chuemsumphan25 Chuemsumphan Rd.
Nongjok Bangkok 10530 THAILAND
Titer Group
828
42 1 2450.50Positive Cutoff S/P >=
3 04/11/2007Histogram/BlockDiagram Page : Date :Report:
.
Assay :
Bleeding Date : Testing Date:
Min. - Max Titer : -
%CV :
.
.
.
.
.
.
.
.
Neg/Sus/Pos = / /Total No. Samples:
.
Sample ID Raw O.D. ResultWell
Salmonella isolate from AA,Ross 14 - 25 October 2007
Lab code Date Farm Flock House Age(Wks.) Sock Dust Feces Remark
B07-2014 14 Oct 07 R3 2 1-2 24 2( C) - - Gr.C=S.Mbandaka
B07-2015 " R3 2 1-2 24 - 1(I),2(E) -
B07-2053 21 Oct 07 KB 29 5 40 -ve - -
B07-2055 " KB 29 5 40 - -ve -
B07-2054 " KB 30 1-2 28 -ve - -
B07-2056 " KB 30 1-2 28 - 1(B) - Gr.B=S.Stanley
B07-2062 " A1 36 4-6 52 4(B),5(G),6(E) - - Gr.B=S.Derby
B07-2063 " A1 36 4-6 52 - -ve -
B07-2074 " A3 1 1-3 8 3(B) - - Gr.B=S.Stanley
B07-2075 " A3 1 1-3 8 - -ve -
B07-2091 " R4 1 1-2 56 1(E) - -
B07-2092 " R4 1 1-2 56 - 1(C),2(B) - Gr.C=S.Albany,Gr.B=Typhimurium
B07-2085 " R2 2 1-2 38 - - 1,2(B) H1-Gr.B=S.Stanley,H2-Gr.B=S.Typhimurium
Salmonella isolate from AA,Ross 14 - 25 October 2007
Lab code Date Farm Flock House Age(Wks.) Sock Dust Feces Remark
B07-2014 14 Oct 07 R3 2 1-2 24 2( C) - - Gr.C=S.Mbandaka
B07-2015 " R3 2 1-2 24 - 1(I),2(E) -
B07-2053 21 Oct 07 KB 29 5 40 -ve - -
B07-2055 29 5 40 - -ve -

81. Control
• SP/SG
– HOST SPECIFIC – REQUIRES CHICKENS
• SE/ST
– Wide Range of hosts
– Can come to the farm by multiple ways
• Biosecurity is the most effective means to
control disease
• BESTEST – CULL PARENT FLOCK
• Stop Vertical Transmission
– Do not Use Infected Parent Stock

82. Salmonella Control
• Biosecurity
• Vaccination
– Live Vaccines
• SG
• SE / ST
– Killed Vaccines
• ST / SE / Others
• Treatment

83. Control - Biosecurity
Hatchery People
Source Flock
Insects
Rodents
Wild Birds
Housing
Litter
Water
Feed
Equipment

84. Control
Biosecurity
• Chicks must be obtained from flocks free of Salmonellas
• Salmonella Free flocks should not be mixed with other
birds
• C+D of premises should be done stringently – Houses
must be easy to be cleaned
• Use pelletized feed (thermal treatment) / Raw materials
free of Salmonella
• Avoid introduction of salmonellas by:
– Poultry houses should be bird proof
– Houses must be vermin (Rats, mice, rabbits, cats, dogs) proof
– Insect control (flies, poultry mites, and the lesser mealworm) as
they may provide a means of survival in the environment

85. Control
Biosecurity
• Water should be sanitized
– (i.e. chlorinated water)
• Control mechanical carriers
– footwear and clothing of humans, as well as
poultry equipment, processing trucks, and
poultry crates
• Effective disposal of dead birds is a must
as they can be sources of infection to other
birds

86. Control
• Treatment
– Not recommended, not 100% effective
• Carriers - Shedding
– Enrofloxacin, Furazolidone, Sulfas, others
– Treatment of eggs possile
– After antibiotics C.E. possible

87. Control
• Vaccination
– SG9R (S. gallinarum)
• Relative value
• 6w / 14-16wk
• Safety / Potency
– SE / ST
• Multiple applications (DOC + x2)
• Early protection
• Safe
– Bacterins

88. Live Vaccines
• Attenuated by modifications in genes coding for
metabolic/virulence functions
• Administration
– Coarse spray or drinking water (most, SG 9R exception)
– Guidelines: day of age, 4-6 wks and 10-12 wks
• Manufacturers/Products (most common)

89. Inactivated Vaccines
• Utilized in layers, broiler breeders, and
turkey breeders
– Approx. 90% shell egg producers
utilizing
– Layers utilize in combination with NDV
and IBV
• Manufacturers: Ceva, Lohman, Pfizer,
Merial (not US); Merck (not US)
– Gallimune – Merial
– Immunovac – BioVet Poland
– Nobilis Salenvac - Merck
– Poulvac SE - Pfizer

90. Baselines
Test
Vaccine
Type
Mean
Titer
Range
Wks
aKer
Vaccina*on
to
Test
D
Inac5vated
(2X)
3000-­‐10000
4-­‐6
wks
a[er
2nd
Salenvac
T,
Gallimune
Se+St
1000-­‐5000
10-­‐12
wks
a[er
2nd
1X
SE4
(preliminary)
1500-­‐4000
4-­‐6
wks
a[er
inact.
B&D
Inac5vated
(2X)
3000-­‐12000
4-­‐6
wks
a[er
2nd
Salenvac
T,
Gallimune
Se+St
1000-­‐5000
10-­‐12
wks
a[er
2nd
1x
SE4
(preliminary)
2500-­‐5000
4-­‐6
wk
a[er
inact.

91. Salmonella Serology and Vaccination –
experiences to date and expected results
Vaccines Application
ELISA KIT
SE/ST SE ST
SE inac + + -
SE+ST inac + + +
SG live + + -
SE live
Oral +/- +/- -
+ + -
ST live
Oral +/- +/- -
+ - +

92. EXAMPLE OF EXPECTED
RESULTS

93. Se/St Results:
Periodic Monitoring of Vaccinated Layers
Vaccinated with live S. typhimurium vaccine at 2 & 20 d, and
inactivated S. enteritidis vaccine at 16 wk of age

94. SE/ST ELISA GMT Results
Broiler breeders vaccinated with an autogenous salmonella vaccine
A- well vaccinated complex; B-poorly vaccinated complex
0
1000
2000
3000
4000
5000
6000
7000
A A A A B B B
GMT
10W 30W 48W

95. Se/St ELISA Results
Broiler Breeders – comparison of non-vaccinated with vaccinated
(autogenous S. typhimurium, S. kentucky, and S. enteritidis at 10-12 wk,
and 17-18 wk SQ)

96. Typical Vaccination Curve 2x Inactivation:
Peak response 4-6 wks post 2nd vaccination 100% positive
End of production 50- 85% positive
0
1000
2000
3000
4000
5000
6000
7000
19 24 31 38 46 61
MEANELISATITER
AGE IN WEEKS
SE/ST: BROILER BREEDERS VACCINATED WITH
INACTIVATED SE+ST VACINE
at 10W and 15W

97. Group B/D ELISA Results –
Commercial Layers
Flock
Age
Mean
Titer
GMT
%
CV
%
Pos
VacA
(0.25
ml)
17
wk
8300
7879
27
100
Vac
(0.5
ml)
17
wk
7937
7710
24
100
Control
17
wk
67
53
84
0
A Vaccinated flocks received an inactivated Se vaccine at 13 wks
of age. Data provided by AviServe

98. Vaccination Programs
• Layers
– SE bacterin
• Usually 1x at 13 – 15 wk in layers
– Live ST vaccines
• 3 applications-2, 6, and 12 weeks
• Bacterin + Live vaccine
– Live vaccine – 2 & 6 weeks
– Bacterin – 13-15 weeks
– Vaccine costs
• 0.5 cents for live
• 8 cents for bacterin (5 cents for handling and 2.5 cents
for vaccine)

99. Factors to Consider in
Interpreting Serological Results
• Use to identify infected flocks and not individual
birds
• Unvaccinated positive flocks may no longer be
infected or excreting
• Actively excreting flocks may be negative
serologically
• Chickens may acquire anti-Salmonella
antibodies from parents via the yolk sac
• Many live vaccines given orally do not provoke a
significant antibody response

100. Commercial Layer Breeders (LB) vaccinated with 2 live ST vaccines at D7 and D28, and
inactivated SE4 bacterin at 12W, and of 1D progeny (PR) derived from those flocks.
Samples provided by LAHI

101. Important Poultry Vertically
Transmitted Viral Diseases
• Chicken Anemia Virus
• Avian Encephalomyelitis
• Fowl Adenovirus
• Chicken Astrovirus
• Lymphoid Leukosis (Not Covered Today)
• Newcastle Disease (Not Covered Today)
• ReoVirus (Not Covered Today)

102. Dynamics of VT Viral Infections
Scenario I
16 W 40 W25 W8 W
Viral
Infection
Point
of Lay
NO SHEDDING OF ACTIVE
VIRUS TO PROGENY
%
Positives
(seroconversion)

103. Dynamics of VT Viral Infections
Scenario II
16 W 40 W25 W
%
Positives
(seroconversion)
8 W
Viral
Infection
Point
of Lay
SHEDDING OF ACTIVE VIRUS
TO PROGENY FOR A PERIOD
OF ~4 – 8 WEEKS

104. Chicken Anemia Virus
• Discovered in late 70s
• CAA / CAV
– Circoviridae - Avian Gyrovirus 1
• Induces vertical transmission in non-
seroconverted flocks
• Lesions on the bone marrow, thymus, etc
• Potent Immunosupressive Disease
– Blue-wing disease (Clostridium)
104

105. Post Mortem Findings
• Pale organs
• Pale fatty bone marrow (yellow or pink)
• Anaemic condition > low PCV (heamatogrit) scores ≤ 27
• Thymus atrophy / Bursal atrophy
• Watery blood
• Subcutaneous and intramuscular hemorrhages
• Proventricular hemorrhages
• Skin lesions are prone to secondary bacterial infection leading
to gangrenous dermatitis > blue-wing disease

106. Post Mortem Findings
Anorectic, lethargic,
depressed, and pale
Gangrenous
dermatitis

107. Post Mortem Findings
Atrophy of Thymus
Pale fatty bone
marrow

108. Post Mortem Findings
Pale fatty bone marrow and bursal atrophy

109. Post Mortem Findings
Subcutaneous and intramuscular hemorrhages, gangrenous
dermatitis

110. Post Mortem Findings
Anaemic condition indicated by low PCV
(heamatogrit) scores ≤ 27

111. Post Mortem Findings
Blood results of an field infected broiler flock,
indicating anemic condition of birds by low
PCV (hematocrit) scores ≤ 27

112. Monitoring
• Histopathology
• Serology
– VN, ELISA
• PCR
– Thymus / Bone Marrow

113. Virus Neutralization
• VN is “gold standard”
• Interpretation VN:
§ Log 2 VN < 5 negative result
§ Log 2 VN titers of ≥ 5 positive result
• Log 2 VN titers of ≥ 8 prevent CAV infection / re-isolation
• Log 2 VN titers of ≥ 11 are protective against clinical CAV
• High MAB titers protect against clinical disease in broilers for
2-3 weeks
• Once positive, naturally infected adult birds will seroconvert
to protective VN ≥ 8 titers in 4-6 weeks post infection

114. CAV VN Serology
• Once positive, naturally infected adult birds will seroconvert
to protective VN ≥ 8 titers in 4-6 weeks post infection
Data courtesy of MSD, Boxmeer, Holland
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11.0
12.0
14 21 31 38 49 55
Meanlog2CAVVNantibodytitre
Weeks of age
Protective log 2 VN Titer

115. ELISA
• Accurate and inexpensive
• Easy interpretation
• Possibility of test a large number of samples
and flocks in short periods of time
• Correlation of ELISA vs. VN is critical

116. ELISA (BioChek)
– Detects antibodies against CAV in serum of chickens
– Indirect ELISA, dilution 1:500
– Specificity > 98 %
– Sensitivity: will give positive results 10-20 days p.i
– Filter 405 nm
– Positive Cuttof S/P ≥ 0.35
– Log 10 titer = 1.1 x log (s/p) + 3.361
S/P Titer Interpretation
≤ 0.349 ≤ 724 NEGATIVE
≥ 0.350 ≥ 725 POSITIVE

117. ELISA (BioChek) vs. VN
– Biochek ELISA correlates well with VN
– Interpretation of results when compared to VN
Positive BC Titers > 2296 correspond to protective VN titers ≥ 11
Positive BC Titers > 724-2295 correspond to VN titers ≥ 8-10

118. CAV ELISA KITS ON MARKET
BIOCHEK Comp. I Comp. S
DILUTION 1:500 1:10 detection 1:100
1:100 vaccine
response
Interpretation 3000-8000
80-100%
(positive)
Complicated 3000-5000
CV <50%

119. Application of CAV ELISA
• SPF Screening for Negative CAV status
• Vaccination Monitoring
§ Confirm success of vaccination prior to lay and during Lay.
• Non-vaccinated breeders:
§ Check at 12-16W to determine need of vaccination.
- Criteria: vaccinate when birds have < 80% positive titers
• Disease Monitoring BR > 35D of age

120. PCR

121. Control
• Biosecurity
• Induced Exposure
• Vaccination

122. Biosecurity
• Virus Ubiquitous
• Cleaning and Disinfection + Downtime
– Beware “Clean / New House Syndrome”
– Some benefit with formaldehyde
• Prevent Immunosuppressive Disease
§ IBD, MDV, REV, Others

123. Induced Exposure
• Seroconversion
§ Once neutralizing antibodies are present shedding
generally stops
• Natural Exposure – Litter, Faeces
§ Beware what you bring in (i.e. Mycoplasma / Salmo)
• Liver Homogenates

124. Promoting Sero-conversion
124

125. Vaccination CAV
• Live Vaccines
§ Circomune, CAV-Vac, P4, Thymovac
• WW / Injection / Drinking Water
§ Rate of spread minimize ->
Missed bird might be negative

126. Vaccination CAV
• Initial vaccination between 8 and 12 weeks
§ Monitoring (14-16 weeks) >
Seroconversion
§ Revaccination if needed
§ High uniform levels of antibody to CAV are
detected from 4 weeks post vaccination
onwards and are maintained throughout
the laying period

127. BioChek CAV ELISA
Vaccination Monitoring
• Objective: Confirm vaccination success
• Test 4 - 6 weeks after vaccination
• Vaccinate at age ( 8-12 W) so that confirmation
testing and revaccination can be done
• Test at an age (14-16W) that revaccination is
possible (revaccination during lay not possible)

128. Vaccination and Serological
Confirmation
Criteria for successful vaccination
§ 80- 100 % of birds must have positive
protective titers > 2000 at least 4 weeks prior
to onset of lay
§ When < 80% positive protective titers
revaccinate immediately

129. CAV
Vaccination Baselines BioChek
BIOCHEK VACCINATION BASELINES LAYERS/BREEDERS (Continued)
Titer values may vary according to age & type of bird , vaccine type, vaccination program, and other factors such as placement programs. You may find
different results under different circumstances.
TEST VACCINE MEAN TITER WKS AFTER VAC. SUSPECT TITER
TYPE RANGE TO TEST % POS VI Index INFECTION
MS live MS-H (eye drop) 500 - 3 000 6 -12 wks 30- 70% Pos > 5000 and > 90%
AI Inact 2x H5N2 1 000 - 4 000 6 – 10 wks 100% Pos
Inact 2x H9N2 2 000 - 6 000 6 – 10 wks 100% Pos
EDS inact. 1x 1 000 - 4 000 4 – 6 wks
SE live 3x DW (Salmonella Vac E) 100 - 500 5 - 6 wks < 15% Pos
(Salm D)
inact. 2x 3 000 - 10 000 4 - 6 wks after 2nd
90-100% Pos 50 - 500
Salenvac T, Gallimune Se +St
Talovac 109 SE, Poulvac SE, 1 000 - 5 000 10 -12 wks after 2nd
50-100% Pos 10 - 100
Layermune SE, Avipro SE4
SE/ST live 3x DW (Salmonella Vac E+T) 500 - 1 500 5 - 6 wks < 70% Pos
(Salm B&D)
inact. 2x 3 000 - 12 000 4 - 6 wks after 2nd
90-100% Pos 50 - 500
Salenvac T, Gallimune Se +St
Talovac 109 SE, Poulvac SE, 1000 - 6 000 10 -12 wks after 2nd
50-100% Pos 10 - 100
Layermune SE, Avipro SE4
CAV live (Tymovac, PG4, CAV-Vac, 3 000 - 8 000 4 - 6 wks 80-100% Pos 100 - 300
Circomune)
* ORT: Titers > 10 000 often correlate with clinical disease
These guidelines are based on our experience and information from our clients.

130. CAV: Case History
Serological profile of vaccinated BB flock
BB vaccinated at 15W (IM) with live Nobilis CAV P4 CAV vaccine
Vaccinated flocks have persistant high and uniform protective titers

131. CAV: Case History
Serological profile of vaccinated BB flock
98% Seroconversion 4 W post vac.

132. CAV: Case History
Serological profile of vaccinated BB flock
98% Seroconversion 9W post vac.

133. CAV: Case History
Serological profile of vaccinated BB flock
100% Seroconversion 16W post vac.

134. CAV: Case History
Monitoring of immune status of non-vaccinated BB flocks at 13W
Poor immune status
36% POS
Poor uniformity
Vaccination needed
Good immune status
100% POS
Good Uniformity
No vaccination
necessary

135. CAV: MAB transfer
Parent to Progeny 01D
AGE W Parent 01D ChickMA Transfer Rate
49 5188 3254 63%
49 5013 2570 51%
Average 57%
MEAN BIOCHEK CAV ELISA TITER (n=20)

136. CAV: MAB Transfer Parent – Chick 01D
Parent 49W
100% POS
40 wks post vac
Chick 01D
100% POS
51% transfer
Parent to
Chick
100% POS
100% POS

137. MDA Negative Broilers: Field Case
Intervet

138. MDA Negative Broilers: Field Case
Intervet

139. Vaccination CAV
Broilers
• Seroconversion of parents induce transfer of
antibodies (MAB)
• Progeny with high level MAB is protected against
clinical CAV
• High MAB titers protect against clinical disease in
broilers for 2-3 weeks
• UNIFORMITY of titers is KEY for PROTECTION

140. CAV
BioChek Serology Broilers
• Limited data available
• Most healthy broiler flocks will test negative
to low positive (MT < 2000) at > 35D
• Clinical flocks have MT > 5000
• Serology only meaningful when comparing
healthy non-clinical birds with clinical birds

141. CAV BioChek Serology Broilers
Non-Clinical BR 42D
Clinical CAV BR 42D

142. CAV
Vaccination Baselines BioChek

143. Avian Encephalomyelitis
• Old Disease; Hard to See in the Field
– Vaccine (Vaccination) failures
• Picornavirus
• Epidemic Tremor
• Drops in egg production in affected
parents
• Up to 100% mortality in affected vertically
transmitted chicks
143

144. Avian Encephalomyelitis
144
Karki

145. AE:
Clinical
Signs
Adult
Birds
Egg and hatchability drop during 2-5 wks of production due
to AE infection of BB

146. Avian Encephalomyelitis
146
Hong, 2012

147. Hatchability Loss (AE)
9/12 9/15 9/19 9/22 9/26 9/29
Diff
(Candling – Setting)
0 3.9 2.9 3.3 2.3 4.1
Hatchability after setting and candling
0.0
20.0
40.0
60.0
80.0
100.0
9/12 9/15 9/19 9/22 9/26 9/29
Date
Hatchbility(%)
-10.0
0.0
10.0
20.0
30.0
40.0 Hatchability
from the setting
Hatchability
after candling
Diff(Setting)
Diff(Candling)
Hong, 2012

148. ELISA found AE –ve at
33 weeks old
Farm manager forgot to
vaccinate
Vaccination carried out at
34 weeks old
(Calnek 1143 strain)
Sample
Titer
1
120
2
115
3
209
4
115
5
279
6
307
7
151
8
188
9
318
10
220
11
241
12
198
13
258
14
374
15
105
양성율
0/15
평균
213
BioChek kit, cutoff
1071

149. Losses in Broiler
Hong, 2012
Date Customer
No of chicks from
affected B
No of total chic
ks
No of dead
bird
Mortality
(%)
12 J 29,500 29,500 21,500 73
12 P 11,700 30,000 3,454 30
15 K 10,600 29,000 10,600 100
15 P 13,600 36,500 2,283 17
19 J 27,000 27,000 20,000 74
19 K 2,800 8,000 1,400 50
19 P 7,400 38,000 5,206 70
22 M 20,800 32,000 20,800 100
26 J 6,000 13,000 4,000 67
26 J 4,200 17,000 2,000 48
Total 133,600 260,000 91,243 68(Ave)

150. Diagnosis
Histology and serology
• Clinical signs if present
• Histology : microscopic lesions in gut and brain
tissues and brain
• Non vaccinated birds: positive serology
• Vaccinated birds: detection of abnormal serology
through Monitoring

151. AE ELISA (BioChek)
– Indirect ELISA, dilution 1:500
– Specificity > 98 %
– Sensitivity 10-14 days post
infection
– Filter 405 nm
– Positive Cuttof S/P ≥ 0.5
– Log 10 titer = 1.1 x log (s/p) +
3.361
S/P Titer Interpretation
≤ 0.499 ≤ 1070 NEGATIVE
≥ 0.5 ≥ 1071 POSITIVE

152. AE and Immunity
§ Humoral immunity but not cellular immunity is the
most important factor for protection
§ Immunized Adults with positive serology are
effectively protected from egg drops and vertical
transmission.
§ Young birds with maternal immunity are effectively
protected against clinical AE.
§ Vaccination goal is to prevent AE outbreak by
making sure 100% of birds are positive prior to
entering production

153. AE Prevention
Vaccination
Breeders
§ Vaccination with live or inactivated vaccine
§ Live vaccination at least 4 weeks prior to onset of
lay
§ Inactivated vaccination possibly during
production period
§ Lifetime immunity is acquired through vaccination
Young chicks
§ protection through maternal antibodies

154. AE Prevention
Vaccination and Serological Confirmation
§ Live vaccines application through drinking water or
wing web method
§ Wing-web more prone to misapplication
§ Most AE outbreaks of vaccinated flocks due to poor
vaccine handling and/or vaccine application.
§ Vaccination must give at least 80% or more positives
before lay to provide effective 100% immunity during
lay
§ Application methods never give 100% delivery,
monitoring of success of vaccination with ELISA is
recommended

155. AE Prevention
Vaccination and Serological Confirmation
§ Serological test to confirm vaccine take
§ Test 4 - 6 weeks after vaccination
§ Vaccinate at age ( 8-12 W) so that confirmation
testing and revaccination can be done
§ Test at an age (14-16W) that revaccination is
possible
§ Inactivated vaccination possibly during production
period

156. Prevention
Vaccination and Serological Confirmation
Criteria for successful vaccination
• 80% of birds must have positive titers at
least 4 weeks prior to onset of lay
• When < 80% positive titers revaccinate
immediately
• 1x confirmation testing and taking action
on results can prevent AE infection ever
from occurring !

157. AE Prevention
Vaccination Baselines BioChek
50 - 500
VI Index

158. AE: Case History
Serological profile of a natural infection in BB
24W 0% POS
28W 64% POS
31W 73% POS

159. AE: Case History
Serological profile of vaccinated BB flock
BB vaccinated at 14W with live AE vaccine through drinking water

160. Vaccination monitoring and revaccination
could have prevented this AE outbreak !
No
vaccinati
on
monitori
ng at
16W

161. Example Natural Infection
0
1
2
3
4
5
6
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples
0
1
2
3
4
5
6
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples
0
2
4
6
8
10
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# Samples
AE 2 038
24-08-2010 1 584
30-09-2010 57
15
GREECE
CEVA
MONITORING
D50
BB 31WTiter Group
AE 1 449
06-08-2010 1 157
30-09-2010 58
14
GREECE
CEVA
MONITORING
D50
BB 28WTiter Group
AE 348
09-07-2010 223
30-09-2010 87
10
GREECE
CEVA
MONITORING
D50
BB 24WTiter Group
G.M.T.:
G.M.T.:
G.M.T.:
BioChek B.V. Service Laboratory
Burg. Bracklaan 57, 2811 BP , Reeuwijk, Holland
Tel: +31 182 582 592 - Fax: +31 182 599 360
24-08-20121 Date :Page :
Assay : Mean Titer
Bleeding Date
%CV :Testing Date:
#Samples :
Name:
Company:
Code:
Reason:
House:Complex:
Type: Age:.
Assay : Mean Titer
Bleeding Date
%CV :Testing Date:
#Samples :
Name:
Company:
Code:
Reason:
House:Complex:
Type: Age:.
Assay : Mean Titer
Bleeding Date
%CV :Testing Date:
#Samples :
Name:
Company:
Code:
Reason:
House:Complex:
Type: Age:.
24 WKS
28 WKS
31 WKS

162. Fowl Adenovirus
• Inclusion Body Hepatitis / Gizzard Erosion
• Hydropericardium Syndrome
• 12 serotypes / 5 species
• Generally no drop in egg production
– However some reports mortality and drops
• Vertically infected chicks develop disease
in first 3 weeks
• Severe morbidity / Mortality
162

163. Fowl Adenovirus (FAdV)

164. 308 Production Производство к.20
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
22 27 32 37 42 47 52 57 62
Weeks of Age
%Production
0
50
100
150
200
250
300
hw%
hh%
hh std
cum fert
норма вывода,
Std H %
hh std СПК
норма инк.яйц,
CV
Средний вывод
АВИАГЕН
He HH
Px feed
He Std СПК
Klausz, 2009

165. Weekly hen mortality %
0.00
5.00
10.00
15.00
20.00
25.00
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
Age / weeks
%mortality
Weekly hen mortality %
Klausz, 2009

166. Hen mortality
0
20
40
60
80
100
120
140
160
129
133
137
141
145
149
153
157
161
165
169
173
177
181
185
189
193
197
201
205
209
213
217
221
225
229
233
237
241
245
249
253
257
261
Age, days
mortality,birds
Klausz, 2009

167. 0
1
2
3
4
5
6
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
อายุไก่(วัน)
%Mortality
B9
A7
A8
A2
A3
A4
A5
FAdV
Offspring Mortality – Vertical
Transmission
AGE

168. Chicken Astrovirus
• New Emerging Disease
• Worldwide Distribution
• Chick Nephropathy
– “Gout”
• White Chicks
– Green Livers
• Astrovirus suspected
– Affected chicks have same source flocks
168

169. CAstV-B
• Chicken Astrovirus
– Subgroup B
• Middle East / India
• Visceral gout in very young chicks aged 4
– 7 days
• 5-15% mortality
• Flocks coming from same source in
multiple occasions
169

170. Chicken Astrovirus
170
Klausz, 2012

171. Chicken Astrovirus
171
Bulbule, 2013

172. Chicken Astrovirus
172
Bulbule, 2013
not shown). Water deprivation, nutritional factors and other
management errors were ruled out as being the causes of
this outbreak of gout. The kidney samples from this
particular flock were positive for CAstV and negative for
IBV, ANV, chicken anaemia virus (CAV) and IBDV, as
detected by qRT-PCR and qPCR and confirmed by nucle-
IBV (Table 3). Overall 717 (80.2%) samples were positive
for CAstV. All samples were negative for IBDV and CAV.
Virus isolation. Kidney samples that were only positive for
CAstV were randomly selected for virus isolation and
Figure 1. Gross and histopathological lesions from a gout-affected commercial broiler chick. 1a: Prominent ureter and urate deposition in
the kidney. 1b: Urate deposition on the heart. 1c: Interstitial nephritis and urate deposits in the kidney (arrows). 1d: Infiltration of
inflammatory cells in the myocardium (arrow). 1c and 1d: bar =100 µm, haematoxylin and eosin staining.

173. White Chick Syndrome
• Astrovirus related disease
– Todd, 2013
• Sporadic Worldwide Distribution
• Drops in egg production, hatchability
• Severe lesions in baby chicks
173

174. Chicken Astrovirus
White Chick Syndrome
174

175. Chicken Astrovirus
White Chick Syndrome
175
Soares, 2012

176. Chicken Astrovirus
White Chick Syndrome
176
White chick syndrome 30-34 week flock October 2011
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0 9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/02/11
10/04/11
10/06/11
10/08/11
10/10/11
10/12/11
10/14/11
10/16/11
percent
Pen1 eggs
Pen2 eggs
hatch %
Soares, 2012

177. Chicken Astrovirus
White Chick Syndrome( Green Livers)
177
Soares, 2012

178. Chicken Astrovirus
White Chick Syndrome( Green Livers)
178
Undisclosed, 2010
Compare Normal chick (Left side) and affected chick.

179. Chicken Astrovirus
White Chick Syndrome (Green Livers)
179
Soares, 2012

180. Chicken Astrovirus
Green Livers
180
Todd, 2013

181. • IFA
• VN
• ELISA
– Commercially Available from Biochek Soon
• PCR
Monitoring

182. • Vertically transmitted diseases represent a great
threat to any poultry operation due to its
economic significance
• Monitoring of VT diseases allows to take
preventive measures that improve productivity
and generates return of invest.
• Among others ELISA is one of the tools of choice
for its relatively low cost / performance ratio
Summary

183. THANK YOU
rafaelmonleon@biochek.com