1. Sampling procedures:
1.1. Diagnosis in disease situations
The recommended minimum numbers of specimens to collect for diagnostic testing are 100 for the larval stages of most crustaceans; 50 for the postlarval stages; and 10 for juveniles and adults. Sample numbers may be greater if clinically diseased specimens are readily apparent and collected.
Nonetheless, these recommended ¡®minimum¡¯ sample numbers are provided as guidelines, and it must be emphasized that carefully selected, quality specimens are far more valuable (and cost-effective) diagnostic specimens than dozens or hundreds of specimens taken at random to ¡®fill out¡¯ the sample.
1.2. Diagnosis in asymptomatic crustaceans
The minimum sample size for each lot tested should provide a 95% level of confidence that infected specimens, if present, will be in the sample, assuming a defined minimum prevalence of infection equal or greater than 2%, 5% or 10%.
Samples taken for molecular or antibody-based tests for OIE-listed crustacean diseases may be combined as pooled samples of no more than five specimens per pooled sample
Table
1. Sample size based on assumed
pathogen prevalence in lot
|
Lot size
|
At 2% prevalence,
size of sample
|
At 5% prevalence,
size of sample
|
At 10% prevalence,
size of sample
|
|
50
|
50
|
35
|
20
|
|
100
|
75
|
45
|
23
|
|
250
|
110
|
50
|
25
|
|
500
|
130
|
55
|
26
|
|
1000
|
140
|
55
|
27
|
|
1500
|
140
|
55
|
27
|
|
2000
|
145
|
60
|
27
|
|
4000
|
145
|
60
|
27
|
|
10,000
|
145
|
60
|
27
|
|
100,000
or more
|
150
|
60
|
30
|
|
WSSV?
Sampling
Prevention
Speedo
|
