Trichinella – Serology

Timing of Specimen Collection

An acute (collected early after the onset of symptoms) and a convalescent (collected 2-3 weeks later) may be required for laboratory diagnosis.

Limitations

Haemolysed, icteric, lipemic or microbial contamination of the sera or plasma are not recommended for testing.

Manufacturer's reported performance characteristics are as follows: sensitivity 94-95% in those who are symptomatic during an outbreak, and specificity 94%. Accuracy of trichinella serology may be limited by cross-reactivity with other helminths, particularly other nematodes.

In an outbreak of trichinosis due to Trichinella nativa in Ontario, the sensitivity of this assay was 40% in acute illness, and 87.5% in convalescence [Clin Infect Dis 2017;64(10):1367-73]. Compared to the former complement fixation assay used at PHOL, sensitivity of this assay is 100%.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Special Instructions

Centrifuge if using SST. Place specimen in biohazard bag and seal.

Test Frequency and Turnaround Time (TAT)

Trichinosis serology testing is performed once per week. 

Turnaround time is up to 10 days from receipt by PHO laboratory.

Reporting

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

Specimens that are positive for Trichinella serology are reported to the Medical Officer of Health as per Health Protection and Promotion Act.  

Interpretation

Results should be interpreted in the clinical context of the patient.

Labstracts

LAB-SD-008, Blood Collection using Serum Separator Tubes