Table 1.

Suggested diagnostic laboratory tests for the detection of PI infected animals (Larson et al., 2004 ▶)

Test	Cost	Advantages	Disvantages	Specimens/shipping
Virus isolation 1-3 week turnaround	Moderate to high cost	-Gold standard for BVDV -High specificity -Virus is available for study at a later date	-Slow procedure -Labor-intensive -Potential false negative due to interference by maternal Ab -Retest positive animals in 3-4 weeks to distinguish between PI and TI	-Whole blood (10 ml) or serum (2-3 ml) and tissue samples -Send in container with cold packs -Do not freeze the samples
Immunohistochemistry (IHC) 2-5 day turnaround	Low cost	-High sensitivity -Usually identifies only PI -TI animals usually test negative	-Labour-intensive -Formalin usage -Will not generally identify generally identify TI animals	-Skin samples-ear notch and tissue samples -Send fresh on wet ice or stored in 1:10 volume of 10% neutral buffered formalin -Sample can be held in formalin for several weeks
Antigen-Capture ELISA of serum 1-2 day turnaround	Low cost	-High sensitivity -Easy to carry out	-Potential false negative due to the interference by maternal antibodies -Variation of viremia -To distinguish between PI and TI animals, retest 3 weeks later	-Serum (2 ml) -Send in insulated container with cold packs
Antigen-Capture ELISA of skin 1-2 day turnaround	Low cost	-High sensitivity -Usually identifies only PI animals -TI animals usually test negative	-Will generally not identify TI animals	-Skin samples-ear notches -Send in insulated container with cold packs -Do not allow to dry out
Antigen-Capture ELISA of tissue/leukocytes 1-3 day turnaround	Low cost	-High sensitivity	-Labor-intensive to prepare buffy coat -Not used in a large screening	-Whole blood (10 ml) using EDTA or heparin -Tissues -Send in insulated container with cold packs
Polymerase chain reaction (PCR) 1-3 day turnaround	Moderate to high cost (can be reduced pooling samples)	-High sensitivity -Can detect 1 ng/ml BVDV RNA	-Potential of false positive due to laboratory contamination -Retest samples in 3 weeks to distinguish between PI and TI animals	-Whole blood (10 ml) or serum (2-3 ml) -Ear notches in red top tubes -Milk, semen and tissues -Send in insulated container with cold packs