Seminars 2019


Vector Borne Disease Screening Using Available Diagnostic Panels: What Am I Missing?

Oct 24, 2019
Clinical Theater 3
Internal Medicine

“Tick panels” and “vector borne disease panels” offered by diagnostic laboratories or in house test kits give clinicians the ability to test peripheral blood for multiple agents using serology, polymerase chain reaction (PCR) or a combination of the two. Choosing a panel requires the clinician to consider which organisms to test for, and which methodology (PCR and/or serology) to employ. Knowing the breed and "occupation" risks of the patient and the epidemiology and clinical findings that are most commonly associated with each organism help determine which agents should be included in a diagnostic panel. The sensitivity of serology as compared to PCR varies with characteristics of the host, the assays, and pathophysiologic characteristics of the organism. Therefore, using either PCR or serology exclusively may overlook the presence of infection. Knowing when clinical signs occur in relation to time of infection, when and if organisms circulate in peripheral blood, and whether they circulate in high or low number helps determine whether serology, PCR, and/or acute and convalescent serologic testing are most appropriate for an individual patient. Testing initially using both comprehensive serologic and PCR testing can increase diagnostic sensitivity for vector borne disease agents, and repeated testing should be considered.

  • •Understand how pathophysiology of the organism and host factors affect sensitivity of diagnostic testing for vector-borne disease.
  • •Understand how characteristics of diagnostic tests affect their ability to detect infection in a given patient.
  • •Understand how case context including breed, geographic locale and presenting abnormalities help clinicians ensure relevant agents are included in diagnostic testing for vector-borne disease.
  • •Apply these concepts to optimize vector-borne disease testing in individual patients.
Linda Kidd, , Associate Professor Small Animal Internal Medicine - Western University of Health Sciences