Malaria Screening

[angeu]

In the past we have screened our own Blood parasite specimens and then sent them to our public health department for confirmation.  We did this for both positive and negative screens.  Recently they have stopped offering the screening on negative samples.  Does anyone have a process for how they screen for blood parasites?  Do you do both a wright giemsa and a giemsa stain.  Do you have multiple staff screen the specimen?

[Auntie-D]

We do a 2 thick films stained with Field's stain. 5ul spread with the edge of a slide into a 1cm square. Dried on a hot plate for 5 minutes or air dried for half an hour. 4-5 seconds in stain A (blue), 6-7 seconds in B (red) then rinsed for 20-30 seconds to allow all the lysed red cells to wash away. The whole slide is then examined under x50 oil and the second by another person. All this can be done before the thin films are stained (1:10 dilution of MGG for 30 minutes after a 5 minute alcohol fixation). The thin films are only looked at for speciation and parisitaemia if it is a falciparum.

[Alan Neal]

Suggest review recent BSCH Malaria parasite guideline,,also RCPA HAematology best practice guidleines.

Essentially, we are compliant to these guidelines, in that we do:

Malarial antigen screen

Thick & thick films (Giesma stained), reviewed by two people.

We only would consider refering positive cases ONLY, if difficult cases - images sent to CDC for confirmation (Now thinking about differentiation between Malariae and Knowlesi - may need to locate molecular technique & always notify clinicain if patient from area with Knowlesi & morphology Malariae like).

 

Alan NZ