Anti-A and Anti-B Haemolysins amongst Group “O” Voluntary Blood Donors in Northeastern Nigeria

Background and Objective. The aim of this study was to determine the prevalence and haemolytic significance of alpha- and beta-haemolysins in our voluntary group “O” donor population. Methods. This was a prospective study carried out at North-East Zonal Centre, the National Blood Transfusion Service, Maiduguri, Nigeria from April 2007 to April 2009. One thousand nine hundred and twenty nine voluntary group “O” blood donors (1609 males and 320 females, median age 26 years ± 7.6 SD) were screened for alpha- (anti-A) and beta- (anti-B) haemolysins using the standard tube technique at 37 degrees C for 1 hour. All samples showing haemolysis were titrated for anti-A and anti-B haemolysins. Results. The overall prevalence of haemolysins in group O donors was 55.4%. Prevalence of alpha- and beta-haemolysins only was 10.3% and 12.6%, respectively, while that of donors having both alpha- and beta-haemolysins in their sera was 32.5%. Visual titre of 8 was seen in 0.4% of lytic alpha-haemolysin and 0.2% of lytic beta-haemolysin whereas donors with both alpha- and beta-haemolysins had a titre of 1.8%. Lytic titre of 16 and 32 was very low in our donor population. Conclusion. This study has shown that although the prevalence of haemolysins is high in our voluntary group “O” donor population, the strength of the lytic antibodies is low. Therefore, despite the labour intensiveness of our haemolysis titration technique and the frequent transfusion of group O blood to certain recipients of blood group A, B, and AB in our environments, there is the need to routinely screen our donors for haemolysins in order to identify those posing the greatest risk to recipients. Further studies to determine episodes of clinically significant haemolysis in recipients of blood group O may be necessary.

Comparison of Epidemiological Methods for Estimation of Hepatitis B Incidence and Residual Risk for Blood Donors in Southern Brazil

Background and Objective. The objective of this work was to compare three methods for estimating hepatitis B virus (HBV) incidence and residual risk. Methods. Computerized blood donor records in southern Brazil were examined for the period 2004–2006. The methods for estimating HBV incidence included stand-alone HBsAg, HBsAg yield method, and an extension of the latter which added recent anti-HBc seroconversions as incident HBV cases. Results. HBV incidences for the above methods were 9.91, 20.09, and 22.93 per 100000 repeat donors, respectively. In the same order, corresponding residual risks were 1 : 62482, 1 : 30821, and 1 : 47559, respectively. First-time donors had 52 higher HBV incidence compared to repeat donors. Conclusion. Although the three methods compared produced overlapping 95% confidence intervals, their variation was considerably lower for the method which included recent anti-HBc seroconversions. First-time donors are primary cause for concern regarding HBV transmission via blood transfusion in southern Brazil.

An Audit on Near-Miss Events in Transfusion Medicine: The Experience of the Teaching Hospital in Northeastern Malaysia

The rate of near misses in transfusion is important as it indicates situations with the potential of adverse outcome. The aim of this study was to assess the frequency of mislabeled and miscollected samples received by our transfusion medicine unit. This study was conducted from January to December 2009 in Transfusion Medicine Unit, Hospital Universiti Sains Malaysia. The total number of near-miss events reported and analysed over the 1-year period was 178 (0.40%). All mislabeled and miscollected samples and its location cases were identified. Mislabeled and miscollected (WBIT) samples were 66.3% and 33.7%, respectively. The highest number of mislabeled and miscollected samples was from accident and emergency unit and medical ward, respectively. Continuous monitoring and analysis of near misses data should be mandatory in order to improve the safety of transfusion.