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Incidence and pattern of 12 years of reported transfusion adverse events in Zimbabwe: a retrospective analysis.

BACKGROUND
Haemovigilance hinges on a systematically structured reporting system, which unfortunately does not always exist in resource-limited settings. We determined the incidence and pattern of transfusion-related adverse events reported to the National Blood Service Zimbabwe.


MATERIALS AND METHODS
A retrospective review of the transfusion-event records of the National Blood Service Zimbabwe was conducted covering the period from 1 January 1999 to 31 December 2011. All transfusion-related event reports received during the period were analysed.


RESULTS
A total of 308 transfusion adverse events (0.046%) were reported for 670,625 blood components distributed. The majority (61.6%) of the patients who experienced an adverse event were female. The median age was 36 years (range, 1-89 years). The majority (68.8%) of the adverse events were acute transfusion reactions consisting of febrile non-haemolytic transfusion reactions (58.5%), minor allergies (31.6%), haemolytic reactions (5.2%), severe allergic reactions (2.4%), anaphylaxis (1.4%) and hypotension (0.9%). Two-thirds (66.6%) of the adverse events occurred following administration of whole blood, although only 10.6% of the blood was distributed as whole blood. Packed cells, which accounted for 75% of blood components distributed, were associated with 20.1% of the events.


DISCUSSION
The incidence of suspected transfusion adverse events was generally lower than the incidences reported globally in countries with well-established haemovigilance systems. The administration of whole blood was disproportionately associated with transfusion adverse events. The pattern of the transfusion adverse events reported here highlights the probable differences in practice between different settings. Under-reporting of transfusion events is rife in passive reporting systems.