No diagnostic sample submission is complete without including the tonsil. Because of their location in the oropharynx, the tonsils are exposed to a variety of viral and bacterial pathogens. Advances in diagnostic capabilities have made analysis of the tonsils an increasingly important tool in diagnosing a number of endemic swine diseases. United States Department of Agriculture (USDA) Animal and Plant Health Inspection Services (APHIS) now has funding to use the tonsil as part of a routine surveillance program to detect classical swine fever (CSF) and is offering incentives to encourage practitioners to submit samples for surveillance.
Tests using the tonsil have been developed by the Foreign Animal Disease Diagnostic Laboratory (FADDL) at USDA‘s Plum Island Animal Disease Center to aid in detection and diagnosis of CSF. USDA‘s Classical Swine Fever (CSF) Surveillance Procedure Manual1 includes tonsil, tonsil scrapings, and nasal swabs as appropriate samples for CSF detection if collected and submitted properly. Submission of tonsil scrapings and nasal swabs requires a special transport media, Dulbecco‘s Modified Eagle Medium, which is available from the National Veterinary Services Laboratory in Ames, Iowa. As an incentive for producers and veterinarians to submit tonsils, the USDA will credit the submitter with $50 to be applied to the diagnostic workup for cases tested by one of the following National Animal Health Laboratory Network (NAHLN) laboratories: Arizona, California, Florida, Georgia, Iowa, New York, North Carolina, Texas, and Washington.
The USDA has designated 18 states and Puerto Rico as “high risk” for CSF introduction. The designated high-risk states for CSF introduction are Arizona, California, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Minnesota, Nebraska, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Texas, and Washington. Surveillance efforts will focus on these locations. With the exception of submissions from Iowa and Minnesota, all tonsil and nasal-swab samples sent to a participating NAHLN laboratory in or from these states are eligible to be tested.
Due to the large number of swine cases submitted to the NAHLN diagnostic laboratories in Iowa and Minnesota, samples from these states will be eligible for testing if at least one of the following lesions is observed: dramatic acute septicemia, abortion, congenital deformity, dermatitis or nephritis (porcine dermatitis-nephritis syndrome), undiagnosed CNS cases, or other undefined cases the pathologist wishes to submit. In cases where, on the basis of history, clinical signs, or other indicators, the veterinarian suspects that CSF might have infected the herd, then the veterinarian should immediately call the State Veterinarian or USDA Area Veterinarian in Charge to request a foreign animal disease investigation, with submission of diagnostic samples to FADDL.
For a complete description of sample collection and submission techniques, please visit the USDA‘s CSF Surveillance Web site at www.aphis.usda.gov/vs/nahss/swine/csf/index.htm, contact the program managers at USDA-APHIS-VS-NAHPS (David Pyburn: Tel: 515-284-4122; E-mail: David.G.Pyburn@aphis.usda.gov; John Korslund: Tel: 301-734-5914; E-mail: John.A.Korslund@aphis.usda.gov), or contact FADDL: Tel: 631-323-3256; E-mail: firstname.lastname@example.org.
1. USDA. Classical Swine Fever (CSF) Surveillance Procedure Manual. 2005. Available at: www.aphis.usda.gov/vs/nahss/swine/csf/CSF_Procedure_Manual.pdf. Last accessed July 6, 2006.