What's New

Implementation of Malarial Antibody Testing

Malaria is an infection caused by the protozoa of the genus Plasmodium which is transmitted by the bite of the female Anopheles mosquito. It can also be transmitted by transfusion of blood infected with the protozoa. There have been no documented cases of transfusion associated malaria in New Zealand, however there have been some cases reported overseas and these reported transmissions have usually involved semi-immune individuals (residents or former residents of malarial areas).

As of 2^nd April 2007, NZBS has implemented malarial antibody testing of all donations from donors who have been exposed to malaria. The introduction of new algorithms based on malarial antibody testing should reduce the likelihood of cases of transfusion transmitted malaria occurring since these semi-immune individuals will automatically be selected for testing irrespective of recent travel history.

Donor assessment of malarial risk is based on an assessment of three criteria. This applies irrespective of whether malarial antibody testing is utilised. The criteria are:

Whether the donor has a history of malaria
Whether the donor is a resident or former resident of a malarial area
Whether the donor has returned from a malarial area within a defined period.

The introduction of malarial antibody testing removes much of the complexity around malarial decision rules. In the context of recent overseas travel, all “at risk” donors are excluded from cellular component donation for a period of 4 months which contrasts with the variable time periods utilised before the introduction of testing.

Historically, NZBS has relied on making fractionated blood products from the plasma of donors who are designated as a potential malarial risk. However, as more donors travel to malarial risk areas and immigrants from malarial risk countries present for donation , the number of donors who are at risk of exposure to malaria is increasing. Correspondingly, the number of fresh components that are being discarded is also increasing.

By introducing malarial antibody testing, NZBS is now, on the basis of a negative test result able to utilise the cellular components from these donors without additional risk to the recipient. The introduction of testing will reduce the period of exclusion from cellular component manufacture from 12 to 4 months for visitors and should therefore result in the increased availability of red cell and platelet components from within current collection. Based on an annual collection level of 150000 donations it is anticipated that approximately 3000 red cells units will be saved each year.

The implementation of Malarial Antibody Testing represents a significant change to NZBS processes. The changes that have been made to standards, policies and procedures have all been carried out using established NZBS systems that have been approved by Medsafe and are compliant with Good Manufacturing Practice. All staff have been highly trained and assessed as competent in the new procedures prior to implementation of malarial antibody testing.

Transfusion Medicine Section Of Website Updated

A review of the Transfusion Medicine section of the website means that a number new or updated documents are now available.

In particular you are recommended to check the following pages: