Post on 14-Jun-2020
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Cav = Chicken AnemIa virus aka
CAA = Chicken Anemia Agent
Causes pancytopenia ( a reduction in both red cells and white cells
including thrombocytes (platelets).
The result of pancytopenia is always immunosuppression and sometimes
hemorrhage
Infection: Transient event unless chick dies
Economic Impact
CAV Immunosupression
Disease
Lost
Profitability Impaired
vaccination
Pathogenesis: CAV Viremia Thymic Atrophy Bone marrow hypoplasia Pancytopenia
Disease: Age and Dose Dependent
The very young are most susceptible , but all ages are affected
IBD infections will prolong chick susceptibility
CAV Clinical Disease A consequence of …….. 1) Maternal shedding in form of gangrenous dermatitis 2) Horizontal transmission in the form of oral and respiratory complications due to secondary pathogens involvement 3) Immunosuppression , CAV found in association with….
Marek’s disease IBD infections Diminished resistance to ILT and NDV Other diseases
Diagnosis: 1) History 2) Signs 3) Gross & microscopic lesions 4) Finding anemia
Measurements in Diagnosis on CAV
Anemia •White and RBC counts
Antibody Detection • Detect maternal antibody * • Detect rise in CAV antibody
* maternal antibody is protective against the disease but not protective against the infections
GPLN utilizes the commercial CAV antibody test from IDEXX which is a
direct or competitive ELISA
CAV Testing at GPLN
1:10 Dilution of Serum
Field exposure: For optimal detection of antibody subsequent to field exposure to Chicken Anemia Virus dilute serum 1:10 Note: GPLN is not currently using the CAV100 test which is at a final serum
dilution of 1:100 and is geared more toward vaccine monitoring
The presence or absence of CAV antibody is determined by the
sample to negative (S/N) ratio for each sample
- 5.0 0.0 +5.0
S/N > 0.60 Negative for CAV antibody S/N < 0.60 Positive for CAV antibody
The S/N cutoff for the ELISA:CAV test is 0.60
S/N Scale
Samples with S/N greater than 0.60 are considered negative for CAV antibody
Samples with S/N less than 0.60 are considered positive for CAV antibody
On the average, 1000 flocks are tested for antibodies to CAV in a
given year at GPLN
These 1,000 flocks represents over 15,000 CAV antibody tests per year
18 - 20 commercial poultry companies tests for CAV antibody on a yearly
basis at GPLN
The average coefficient of variation (CV) for CAV antibody testing averages 62%
for any given year for all ages
Breeders: Average Number Flocks Tested per Year for Each Age Range
228 247
64
287
56
106
41 30 48
31
83
21 46
0
50
100
150
200
250
300
350
1d
5-9
w
10
-14
w
15
-19
w
20
-24
w
25
-29
w
30
-34
w
35
-39
w
40
-44
w
45
-49
w
50
-54
w
55
-59
w
60
+w
Nu
mb
er o
f Fl
ock
s
Bird Age (weeks)
Breeders
Breeders
Breeder CAV Percent Positives and cv’s by age
Sept 2009- Sept 2011
95
51
79
98 98 99 97 95 99 95 99 99 96
0
10
20
30
40
50
60
70
80
90
100
1d
(57
2 flks)
5-9
w (6
18
flks)
10
-14
w (1
60
flks)
15
-19
w (7
18
flks)
20
-24
w (1
40
flks)
25
-29
w (2
67
flks)
30
-34
w (1
03
flks)
35
-39
w (7
6 flks)
40
-44
w (1
19
flks)
45
-49
w (7
8 flks)
50
-54
w (2
06
flks)
55
-59
w (5
3 flks)
60
+w (1
15
flks)
CV 73 44 56 51 68 59 73 77 54 84 58 59 77
Perc
ent
Posi
tive
s (%
)
334
6 12 13 10 12
6 2 1 1 0
50
100
150
200
250
300
350
400
1d
2-6
d
7-1
3d
14
-20
d
21
-27
d
28
-34
d
35
-41
d
42
-48
d
49
-55
d
>56
d
Nu
mb
er
of
Flo
cks
Bird Age (days) CV 75 84 43 17 15 25 44 37 24 35
Broilers: Average Number Flocks Tested per Year for Each Age Range
Broiler CAV Percent Positives and cv’s by age
Sept. 2009 – Sept 2011
93 90
42
5
15
22
84 90
100 100
0
10
20
30
40
50
60
70
80
90
100
1d
(83
6 flks)
2-6
d (1
4 flks)
7-1
3d
(29
flks)
14
-20
d (3
2 flks)
21
-27
d 2
4flks)
28
-34
d (2
9 flks)
35
-41
d (1
5flks)
42
-48
d (5
flks)
49
-55
d (1
flk)
>56
d (3
flks)
Bird Age (days) CV 75 84 43 17 15 25 44 37 24 35
Perc
ent
Po
siti
ve (
%)
Call GPLN If You Have CAV Antibody Testing
Needs