Table 2:

Human specimen types for which ante-mortem rabies virus testing is available in Canada

	Nuchal skin biopsy	Saliva	Cerebrospinal fluid		Serum
Collection	Full thickness biopsy at least 5 mm with several hair follicles	Multiple collections at least 12 hours apart, 2–3 mL/sample	1–2 mL	1–2 mL	2 mL
Testing	Fluorescent antibody test, RT-qPCR*	RT-qPCR*	RT-qPCR*	Rabies serum neutralization test†	Rabies serum neutralization test†
Detects	Virus	Virus	Virus	Antibody	Antibody
Relative diagnostic sensitivity	High	High	Low-average	Low-average	Low-average
Notes	Necessary to submit specimen of adequate size	Highest sensitivity is achieved by testing serial samples. Bile or blood may interfere with testing	Requires detection of patient DNA as a control for successful sample extraction and amplification. If absent sample not valid for testing	Antibody generally appears 7–8 d following symptom onset	Antibody generally appears 7–8 d following symptom onset. No diagnostic value if patient has received vaccination for rabies

Adapted with permission of the Canadian Food Inspection Agency (CFIA). For further details of specimen handling, refer to original document (2).

Note: No single test is sufficient to “rule out” rabies, and early in disease course the predictive value of a negative test is uncertain. It is recommended to submit all samples for ante-mortem testing. Repeat testing may be required, depending on the length of illness.

* Location of testing: Canadian Food Inspection Agency (CFIA), Ottawa, Ontario

† Location of testing: Public Health Agency of Canada (PHAC), Winnipeg, Manitoba

RT-qPCR = Quantitative real time polymerase chain reaction