Ehrlichia canis

Test code:
B0052 - Ultrasensitive qualitative detection of Ehrlichia canis by real time polymerase chain reaction

Canine ehrlichiosis is a disease of dogs, wolves and other canids. Occurring worldwide, canine ehrlichiosis is also known by other names such as 'tracker dog disease,' 'tropical canine pancytopenia,' 'canine hemorrhagic fever' and 'canine typhus.' The disease is caused by ehrlichieae, tick-transmitted organisms that infect the leukocytes of specific mammalian hosts. There are several ehrlichieae that can infect dogs but Ehrlichia canis is the most common and severe one.

Disease caused by E. canis typically occurs in three phases. The initial acute phase is characterized by fever, malaise, lymphadenomegaly, splenomegaly, thrombocytopenia, leukopenia, and nonregenerative anemia. Symptoms subside in 2 to 4 weeks but are followed by a subclinical phase that persists for 2–3 months to years, during which infected dogs are carriers. Some dogs subsequently enter a chronic phase, a period when severe clinical ehrlichiosis occurs. E. canis causes ocular disease and meningitis during this phase.

Ehrlichia is transmitted by the Brown Dog tick, Rhipicephalus sanguineus. The immature form of the tick feeds on an animal infected with Ehrlichia. When the tick later feeds on another animal, the Ehrlichia is passed on. The disease can occur wherever Brown Dog ticks are found. Almost every state in the United States has reported ehrlichiosis.

Dogs exposed to E. canis infection will develop an antibody response detectable by ELISA, but this immune response does not prevent re-infection. ELISA does not distinguish dogs with prior exposure from those with current infections, and it cannot determine reinfection or current carrier status. Blood smear examination can detect E. canis, but the sensitivity of this technique is very low. Molecular detection by PCR, which is very specific and sensitive, is useful to quickly identify this pathogen and confirm animals’ infection or carrier status.

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Ehrlichia canis infection
• Ensure that dog populations are free of E. canis
• Early prevention of the spread of E. canis among a group of dogs
• Minimize human exposure to E. canis
• Safety monitoring of biological products and vaccines that derive from susceptible animals

Specimen requirement: 0.5 ml whole blood in EDTA (purple top) or ACD (yellow top) tube, shipped overnight at room temperature.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected