Frequently Asked Questions for the Cervid Dual Path Platform (DPP) VetTB Assay® Tests for Bovine Tuberculosis
(June 2020)
The DPP® Antibody Test is a serologic test used to test for bovine TB antibodies in captive cervids.
Yes, the guidance document can be found at DPP Guidance Document.
The DPP test is approved for use in elk, red deer, white tail deer, fallow deer, and reindeer. A pilot project is also being implemented to evaluate the test in Mule and Sika deer.
For each cervid tested, at least 2 ml of refrigerated serum must be submitted in a blood serum collection tube such as a red top tube. The whole blood in the original tube is allowed to clot and centrifuged so the serum can be transferred to a separately labeled clean tube. If a serum separator tube is used it also needs to be centrifuged and the serum transferred to a new clean tube.
Only Designated Accredited Veterinarians who have received supplemental training on TB testing and the DPP testing are authorized to collect and submit samples.
No. You must be a Designated Accredited Veterinarian who has received supplemental DPP test training in order to collect and submit samples using the DPP test on cervids.
Contact your local APHIS Veterinary Services Area office to receive information on the supplemental DPP test training and to become a Designated Accredited Veterinarian.
Yes, either the DPP or the SCT may be selected by the veterinarian. Animals that are non-negative on the DPP will be retested after 30 days with the DPP. Animals that are responders on the SCT will be retested with the Comparative Cervical Test (CCT).
In order to perform bTB testing of any kind (skin testing, serological testing, etc.) in cervids, a veterinarian must be knowledgeable not only in technique, but also in the regulations under the National bTB Eradication Program. Additionally, many tests that are performed must adhere to additional requirements such as for import/export and establishing and maintaining accredited cervid herds. The additional training provides this information.
No. Serum samples must be sent to the National Veterinary Services Laboratory (NVSL) in Ames, Iowa. Be sure to obtain permission from the APHIS VS Area Veterinarian in Charge (AVIC) in your state to submit the sample(s) to NVSL prior to sample shipment.
Samples must be received by NVSL within 5 days of collection. Samples must be received Monday through Friday and must not be shipped to arrive at NVSL on weekends or holidays. Samples received on the weekend will be considered to have been received on the following Monday. Samples received on a federal holiday will be considered received the following day and classified invalid if this exceeds 5 days from collection.
Samples received after 5 days will be processed at NVSL and user fees will be collected for this service. However, the test results will be classified as invalid.
You must verify with the State of residence of the animals, the importing State, or the importing country to determine if their animal health regulations allow the use of the DPP as an official testing method for cervids.
No. When also testing a cervid for brucellosis, an additional tube of whole, clotted blood must be collected and submitted to an approved brucellosis testing laboratory accompanied by the official brucellosis testing chart VS Form 4-33.
If the DPP test has a positive result, the animal will be subject to quarantine and a second DPP test will be perform no sooner than 30 days later. Animals testing positive on the second test will be classified as reactors.
No. The TB skin test and serologic tests cannot be used in combination or interchangeably. Cervids classified as responders by testing positive on the single cervical skin test (SCT) must be retested by regulatory veterinarians using the comparative cervical skin test (CCT).
No. Any tuberculosis test conducted in species under the National TB Eradication Program is an official test as defined in the Title 9 Code of Federal Regulations, Part 77. All results must be reported to State animal health officials within a specified time after the test was administered.
The antibodies detected by the DPP do not cross-react to antibodies for Mycobacterium avium, M. paratuberculosis, or most environmental mycobacteria. However, M. kansasii has certain common antigens with M. bovis, therefore, animals exposed to M. kansasii may have a DPP false positive test result. The final culture results on the animal tissues will determine which Mycobacteria is present. An animal is classified negative to bTB when Mycobacteria other than M. bovis are cultured.
No. Official identification recognized by APHIS must be present on each animal tested with the DPP. Identification numbers must be recorded on the VS 10-4/10-4a and VS 6-22 to correspond to the sample submitted for testing.
Designated Accredited Veterinarians may submit blood samples using their own compliant shipping container using 24-hour delivery service. The US Postal Service does not deliver directly to NVSL. You may also order a DPP test kit that consists of written instructions, a VS 10-4/10-4a Laboratory Submission Form, an ice pack, and a paid shipping label to NVSL. For more information on how to order a DPP test kit or on compliant shipping boxes, please contact NVSL at (515) 337-6200 or email at NVSL_userfee@aphis.usda.gov.
NVSL fees can be accessed through our NVSL Catalog or contact NVSL by email at NVSL_userfee@aphis.usda.gov.
The Designated Accredited Veterinarian submitting the sample will be responsible for test payment. NVSL accepts the following payment methods Check, money order, or bank draft (US dollars) -- make payable to USDA Credit card (Visa, MasterCard, American Express, or Discover) -- include the credit card number and expiration date on the submission form Bill to USDA Account -- write the account number in the designated area on the submission form Contact NVSL at (515) 337-6200 for more information.
Results will be reported to the submitting Veterinarian within 5 business days after samples are received by NVSL.
Test results will be provided to the submitting Veterinarian by email, FAX, or mail. Veterinarians may specify preferred methods for receiving results on the submission form or when they set up their account with NVSL.