HTLV I and II – Serology

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

This page provides serology testing information for human T-lymphotropic virus type 1 (HTLV-I) and type 2 (HTLV-II) at Public Health Ontario (PHO).

*Uncontrolled print copy. Valid only on day of print: 10 July 2025.

Testing Indications

Acceptance/Rejection Criteria

Donor testing is not available through PHO’s laboratory. Specimens from patients being screened as potential donors (e.g. organ, tissue, cells, fertility, etc.) should be referred to a laboratory that performs donor screening assays. Specimens received for donor screening at PHO’s laboratory will be rejected.
Specimens received more than 7 days post collection will not be tested.

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
HTLV l/ll	General Test Requisition	Serum	1.5 ml	Serum Separator Tube (SST)

Submission and Collection Notes

Complete all fields of the requisition form, including:

Test(s) requests and reason for testing
Patient setting, specimen type and site
Relevant clinical information

Label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or health card number. For additional information see: Criteria for Acceptance of Patient Specimens. Failure to provide this information may result in rejection or testing delay.

Submit centrifuged serum separator tubes (SST) for serological assays.

One FULL 5 mL SST is required for testing a combination of hepatitis virus, HTLV, syphilis and rubella. If a full tube cannot be drawn, submit two tubes.

Do not submit glass tubes.

Limitations

Haemolysed, icteric, lipemic or microbially contaminated sera are not recommended for testing.

Storage and Transport

Place specimen tube in biohazard bag and seal. Place completed General Test Requisition in the pouch at the front of the biohazard bag.

Specimen tubes should be stored at 2-8°C following collection and centrifugation, and should be shipped to PHO’s laboratory on ice packs within 3 days of collection. If delayed shipping is anticipated, remove serum from clot and store frozen at -20°C or colder, and ship on dry ice.

All clinical specimens must be shipped in accordance to the Transportation of Dangerous Good Act.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

HTLV-l/-ll screening is performed daily Monday to Friday.

HTLV-I/-II confirmatory testing is performed every two weeks.

Turnaround time is up to 5 business days for negative results, and up to 14 business days from receipt by PHO’s laboratory for positive results.

Test Methods

Specimens for HTLV-l/-ll are screened using a chemiluminescent microparticle immunoassay (CMIA) for the qualitative detection of HTLV-l and HTLV-ll antibodies in human serum. Confirmatory testing is done using a line immunoassay (LIA).

Algorithm

Specimens that are reactive by the CMIA screen are tested with the confirmatory LIA. No further testing is done on specimens that are non-reactive by the CMIA screen.

Requests for HTLV-I/-II confirmatory testing will be re-screened at PHO’s laboratory. Confirmatory testing will only be done on reactive specimens.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.