The French haemovigilance system.

Haemovigilance is a national system of surveillance and alarm, from blood collection to the follow-up of the recipients, gathering and analysing all untoward effects of blood transfusion in order to correct their cause and prevent recurrence. In France haemovigilance was created by law and notification of transfusion incidents is a legal obligation. The haemovigilance network associates local correspondents in each hospital and blood centre with regional co-ordinators and is centralised by the Agence Française du Sang. After 4 years the incident reporting rate is 2.3 per 1,000 allogeneic blood components transfused, justifying for example increased efforts in the prevention of bacteria-associated transfusion reactions, haemolytic transfusion reactions or vascular overload. However, haemovigilance still has to be strenghtened by improved information management or further progress in standardisation from one region to the other. The most important factor of success is collaboration between blood centres and hospitals. Haemovigilance clearly is the ultimate quality indicator of a transfusion service.

The French haemovigilance system.

Haemovigilance was part of the reform of the French transfusion system. The haemovigilance network is now operational with approximately 4600 transfusion incidents reported annually. Immediate incidents observed within 8 days after transfusion account for 85% of the reports. A cause cannot be identified in 41% of these, usually concerning minor clinical incidents with transient fever and/or shivers. An allergic reaction is described in 31% of transfusion reactions. Immunological conflicts account for 18% and bacteria associated transfusion reactions for 6%. The importance of bacteria associated transfusion reactions, the first identified cause of death associated with transfusion is one of the findings of haemovigilance. Improvement in the haemovigilance systems aims at obtaining better descriptions of transfusion incidents, standardisation of severity and imputability assessment and definitions of denominators such as the actual number of recipients. Delayed incidents will ultimately provide a true vision of post transfusion immunisation and infection The improvement of haemovigilance now considered as part of transfusion medicine practice is a continuous process.

[Transfusion incidents related to bacterial contamination: review of the literature and hemovigilance data. For the working group Bacterial incidents of French Blood Agency, scientific advice of Bacthem and the French hemovigilance network]. / Les incidents transfusionnels par contamination bactérienne: synthèse de la littérature et des données d'hémovigilance. Travail Incidents bactériens de L'AFS, le conseil scientifique de Bacthem et le Réseau français d'hémovigilance.

The impact of transfusion reactions related to bacterial contamination (TRBC) of labile blood products (LBP) was identified in France soon after the implementation of the haemovigilance system. The aims of our communication were: 1) to confront published data on TRBC with available French data; 2) to describe measures implemented in France to prevent TRBC. Bacterial contamination of whole blood at the collection stage is found in 0.6 to 3% of blood donations. Systematic bacteriological controls detect frequent contaminations of LBP that vary according to studies and the nature of the product. The incidence of clinical TRBC was only estimated in recipients with malignant diseases. Based on French haemovigilance data, the incidence was estimated to two per 100,000 delivered units. The measures taken were the diffusion of information and recommendations and the implementation of studies. In the framework of the Bacthem study (a national case-control study on LBP-related bacterial contamination), standardised diagnostic criteria are applied to suspected TRBC notified to the Centre National d'Hémovigilance. Expected results should allow us to estimate the incidence of TRBC in France and to determine the recipients or situations at risk more precisely, in order to target additional preventive measures. Preliminary results, 11 months after the beginning of the study, show the feasibility and the relevance of completing the surveillance with specific studies within the haemovigilance network.