Issue link: http://life-technologies.uberflip.com/i/340646
3 Life Technologies | Animal Health Number of samples needed for detection of disease i.e., at least one infected animal has tested positive Group size Percentage of diseased animals within a group 5% 10% 20% Number of samples (95% confidence level) 100 44 25 13 200 50 26 13 300 53 27 13 750 57 28 13 3,000 58 29 13 Sample size Sample sizes may vary based on in-herd prevalence level of a disease, the tested disease itself, confidence level of the outcome, the requested test method, and the purpose of the sampling. Preparation • Do not take samples from animals in overcrowded pens—pigs may panic and hurt each other or the veterinarian during sampling. • Ensure there is enough light in the work area. • Pooling of samples on-farm is not recommended. If detection of Salmonella alone is of interest, pools of up to a maximum of 5 samples can be tested, but mixing of the samples should be performed in the laboratory. • Take naive fecal samples for microscopy and PCR testing. • Take rectal swabs for cultural testing. • Use clean disposable gloves, when feces are sampled from the rectum. • Never collect feces from the floor: this would be a sample of the environment rather than the pigs! • Use new gloves for each pig. • Use a sterile collection tube for each pig (5–12 mL). Tubes should not contain any salts, etc. • Use a sterile swab for each pig. Swabs should be replaced in a tube containing transport medium—especially when isolation of Brachyspira spp. is the aim.