Malaria – Microscopy and PCR

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Malaria

Unstained blood slides4

N/A

Slide mailer for unstained slides

Malaria

EDTA blood

2.0 ml

EDTA blood tube

Malaria PCR

EDTA blood

2.0 ml

EDTA blood tube

Submission and Collection Notes

1

Please note on the requisition (under other) if the patient has fever, intravascular hemolysis, hemoglobinuria, renal failure or is immunocompromised.

2

Indicate Country/Region and if the patient is a new immigrant or refugee or returned traveler under ‘Travel’ section of the requisition. It is imperative that the foreign country of exposure be identified.

3

Please complete malaria specific clinical information sheet as well.

4

Submit unstained thick and thin slides AND EDTA blood.

5

Exclusion of malaria as a diagnosis requires a minimum of at least 2 specimens over a 24hr period, each taken greater than or equal to 6-12 hrs apart.

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

Place slide mailer in a biohazard bag and seal. Store specimen at room temperature and ship to the PHO laboratory as soon as possible.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Malaria testing turnaround time is up to 24 hours after receipt by PHO laboratory.

Reporting

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

Test Methods

Blood specimens for Malaria are tested by Microscopy, Rapid Diagnostic test (RDT), and PCR.

  • thick and thin blood smears are stained with Giemsa’s stain
  • rapid diagnostic testing occur via BinaxNOW kit.

Genotyping of drug Resistance: Genotyping is available for testing malaria patients with P. falciparum infection where treatment failure has occurred, and subject to approved by the Medical Microbiologist. The DNA sequencing method allows for rapid detection of markers of drug resistance to commonly used anti-malarial drugs.

Genotyping testing will only be performed following a discussion with the Medical Microbiologist for cases where the physician is concerned that the patient is not responding to standard anti-malarial therapy.

Algorithm

PCR (Polymerase Chain Reaction) will be performed on blood specimens in the following circumstances: The specimen tests negative for malarial organisms by microscopy but RDT is positive or clinical history and symptoms strongly suggest malaria infection or following consultatioin with the Medical Microbiologist/Head Technologist in the Toronto Parasitology lab.

Mis à jour le 21 déc. 2018