A clinical hematologist who works for the South African National Blood Transfusion Services writes that despite donor screening processes and the application of deferral periods, the risk of transfusion-transmitted malaria cannot be completely eliminated. The hematologist reports that the current malarial deferral policy in the East Coast Region of South African National Blood Transfusion Services is as follows:

• Following recovery from infection with malaria the donor is deferred for 3 years
• Following a visit to a malaria risk area a prospective donor is excluded from donating in the ensuing 2 weeks
• During the 3 to 12 weeks following a visit to a malaria risk area, whole blood may be donated provided the donor appears healthy, but only the red cell concentrate and plasma are used. The platelets are discarded
• Donations collected during the 3-12 week period following a visit to a malaria risk area are labeled/tagged (see below for details) to indicate that there is an incremental risk of the product possibly transmitting malaria
• Donations made 12 or more weeks after a visit to a malaria risk area are handled as normal, and are not specially labeled/tagged regarding malaria risk.

Apparently, the above policy is out of necessity, due to the need for adequate blood inventories. As mentioned above, one of the ways they currently address an increased risk of transfusion-transmitted malaria associated with a blood product collected during the 3-12 week period following a donor's visit to a malaria risk area is by labeling or tagging the blood product that it has such a risk. In addition, they also provide recommendations on the tag or label for chemoprophylaxis and a warning regarding drug resistance. Units with these tags/labels would preferentially NOT be used for individuals with the following conditions, unless blood inventory fell so low that there was no alternative:

• pregnant women
• neonates and infants
• post-splenectomy
• unconscious patients
• thrombocytopenic or leukopenic patients.

Since they are in a country with varying patterns of anti-malarial drug sensitivity/resistance, she is concerned that mentioning prophylactic drugs and doses on these special blood product labels might lead to a false sense of security.

This hematologist would like input regarding:

• how other blood bankers would approach this issue
• what others consider minimum information for such a special blood product tag
• the appropriate follow-up for recipients of specially tagged units
• whether it is possible to define the obligation of the blood banker in this respect

The following responses have been received.

ADDENDA Dec. 30, 2002

1. A transfusion medicine physician in the UK reports that the following information was acquired during a WHO consultancy in Sri Lanka. Malaria is endemic in many parts of Sri Lanka and it is impossible to maintain a blood supply if donors at risk of transmitting malaria are excluded. Studies have shown that approximately 40% of the population of Sri Lanka have malaria antibodies. Infected donations cannot be excluded with certainty but a thick blood film is examined for malaria parasites and if positive, the donation is discarded. All transfused patients are monitored closely for malaria and treated without delay. There have been no reported deaths (known to the UK blood banker) due to transfusion-acquired malaria.

2. A retired blood center medical director in Palo Alto wonders if either of the above physicians (or others who have followed similar policies in malaria-endemic countries) have any data on the incidence of post-transfusion malaria among recipients of blood from donors screened by measures such as these.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator