Lab Information Manual

Laboratory:

Clinical Microbiology

Test Name:

MYCOBACTERIA LEPRAE, SKIN SLITS

Test Code: None

Clinical Information:

Test Indications:
Skin slit smears and PCR of fluid or tissue samples are used as part of the diagnosis and management of a patient with leprosy (Hansen's Disease).

Recommendations:
Diagnosis of M. leprae can be made by PCR on fluid and tissue samples or by skin slit smears.
The recommendations from the National Hansen's Disease Program to which the smears are referred recommend that initial skin smears be taken from 6 “routine sites” (both earlobes, elbows, and knees) and several typical lesions from the patient. In order to evaluate progress, repeat smears are obtained from 3 to 4 of the most active sites.

Patient Preparation Instructions:
The procedure for obtaining skin-slits for smears is detailed at
https://www.hrsa.gov/hansens-disease/diagnosis/skin-smears.html

Collection Devices:

3-6 pre-cleaned slides for skin slit smears - Pre-cleaned slides (cleaned with 70% alcohol, acetone or alcohol-acetone)
For fluid and tissue: 1 Sterile Specimen Container 100 mL

Specimen Required:

Skin slit smears - Skin-slits, typically 6+ initially and 3 - 4 for follow-up
Fluid and tissue samples 5 mL (fluid), 4-5 mm (tissue)
PCR testing is available on clinical samples that are positive for AFB such as fresh tissue and CSF. Formalin fixed tissues and/or paraffin-embedded samples are not recommended.

Referral:

PCR: National Reference Centre for Mycobacteriology-National Microbiology Laboratory (NRCM-NML)
Skin slit smears: National Hansen's Disease Program, Baton Rouge, Louisiana
Ensure samples that are being sent to a referral laboratory are packaged in accordance with Transport of Dangerous Goods recommendations for diagnostic samples.

Requisition:

Reference Values:

The results of skin slit smears are reported on a 0 (none found) to 6+ (very numerous) semi-logarithmic scale.
PCR results are reported as positive or negative for M. leprae.

Availability:

Weekdays

Weekdays (Monday - Friday). Samples to be sent to the National Hansen's Disease Program are to be referred to the Health Sciences Centre for shipment.