Institute of Tropical Medicine

Trypanosoma evansi

Which test do we use?

  • Card Agglutination Test (CATT) for antibodies.
  • Immuno trypanolysis (confirmation test for positive CATT)
  • Microscopic examination of a smear after Giemsa staining.
  • PCR for parasite DNA
  • ELISA for antibodies (only Equidae and Camelidae)

Sampling instructions

  • CATT:
    Minimum 1-ml serum
  • Immuno trypanolysis:
    Minimum 1-ml serum or plasma (EDTA/heparin), or 2-ml blood (EDTA/heparin)
  • Microscopic examination
    Unstained good quality smears made from fresh blood
  • PCR
    1-ml blood (EDTA/heparin)
  • ELISA
    Minimum 1-ml serum or plasma (EDTA/heparin), or 2-ml blood (EDTA/heparin)

Storage conditions

  • Serum/plasma: -20°C to +30°C
  • Blood: 2-30°C
  • Smears: ambient temperature

Important advice

Preparing a smear

Wipe the slide with alcohol. Handle slides by edges only. (Any grease on the slide will cause the dried blood to flake off during staining.)

Dispense a small drop (5 µl) of blood near one end of a slide. As shown in the picture, bring the edge of another slide in contact with the drop and allow the drop to bank evenly behind the spreader. The angle between the two slides has to be 30-40 degrees. Now, push to the other end of the slide in a smooth, quick motion.

smear.jpgIt is important that the volume of blood is not excessive. So, if you succeed in making a gradual transition from thick to thin in your smear, you should get a zone with a satisfactory distribution of cells.

It's a good idea to prepare several smears. In fact, they aren't always successful, and with several attempts, your chances of getting a well-prepared one increase.

Let the smears dry at ambient temperature for at leas 30 minutes. Observe the smears with the microscope to check whether they are properly made. The red cells must not overlap each other, nor be so scarce as to be too spread out.

Serology

Maternal antibodies may be present until 6 months after birth

Consignee for T.evansi samples
Institute of Tropical Medicine
Applied Technology & Production Unit
Nationalestraat 155
B-2000 Antwerp
Tel: 32 (0)3 247 63 51 or 32 (0)3 247 63 68

Information
Practical questions about sampling and shipment: surra@itg.be
Questions about diagnosis and interpretation of results: pbuscher@itg.be
Managament: Diane Jacquet and Philippe Büscher

Submission form

Which laboratory performs the test?

  • CATT: Applied Technology & Production Unit
  • Microscopic examination: Applied Technology & Production Unit
  • PCR: Unit of Parasite Diagnostics
  • ELISA: Unit of Parasite Diagnostics

How frequently do we perform this analysis?

  • CATT: Once a week on Thursday
  • Immuno trypanolysis: on demand
  • Microscopic examination: Once a week (≥10 slides delivery delay 2 to 3 weeks)
  • PCR: on demand
  • ELISA: on demand

Reference values

  • CATT: < ¼
  • Immuno trypanolysis: Percent lysis 0%
  • Microscopic examination: No trypanosomes detected.
  • PCR:
  • ELISA: Percent Positivity < 30%

How soon can you expect results?

  • CATT: one week
  • Immuno trypanolysis: 3 weeks
  • Microscopic examination: one to two weeks depending on the number of tests.
  • PCR: one week
  • ELISA: one week

For CATT test and microscopic examination urgent testing is possible. An extra costs of 10% will be charged.

Is this test accredited?

CATT & microscopic examination
Certificate 147-TEST

RIZIV/INAMI code