High prevalence and poor linkage to care of transfusion‐transmitted infections among blood donors in Dar‐es‐Salaam,Tanzania

Blood transfusion is one of the most commonly relied upon therapies in sub‐Saharan Africa. Existing safeguards recommended include systematic screening for transfusion‐transmitted infections and restricted voluntary nonremunerated blood donor selection. We report the transfusion‐transmitted infection screening and notification practice at a large urban blood transfusion centre in Dar‐es‐Salaam, Tanzania. Between October 2016 and March 2017 anonymized records of all donors registered at the blood transfusion unit were accessed to retrospectively note demographic information, donor status, first‐time status, transfusion‐transmitted infection result and notification. 6402 consecutive donors were screened for transfusion‐transmitted infections; the majority were family/replacement blood donors (88.0%) and male (83.8%). Overall transfusion‐transmitted infections prevalence was 8.4% (95% CI 7.8‐9.1), with hepatitis B being the most prevalent infection (4.1% (95% CI 3.6‐4.6)). Transfusion‐transmitted infections were more common in family/replacement blood donors (9.0% (95% CI 8.3‐9.8)) as compared to voluntary nonremunerated blood donor (4.1% (95% CI 2.8‐5.7)). A minority of infected‐donors were notified of a positive result (8.5% (95% CI 6.3‐11.2)). Although transfusion‐transmitted infections are more prevalent among family/replacement blood donors, overall risk of transfusion‐transmitted infections across all groups is considerable. In addition, existing efforts to notify donors of a positive transfusion‐transmitted infection are poor. Future policies must focus on improving linkage to care for newly diagnosed patients with transfusion‐transmitted infections.     

Reduction of the risk of transfusion‐transmitted viral infection by nucleic acid amplification testing in the Western Cape of South Africa: a 5‐year review

Background and Objectives In October 2005, individual donation nucleic acid amplification testing (ID‐NAT) for HIV, HBV and HCV was introduced in the Western Cape Province of South Africa. After 5 years, the impact on HIV, HBV and HCV transmission risk was assessed. Materials and Methods A total of 649 745 donations were tested by ID‐NAT using the Ultrio assay on the Tigris instrument (Novartis Diagnostics) and for anti‐HIV, HBsAg and anti‐HCV (Abbott Prism). Initial reactive samples were repeated in duplicate. Discrepant repeat reactive samples were subjected to confirmatory assays. ID‐NAT nonrepeat reactive donations were further screened for occult HBV infection (OBI) by anti‐HBc assay. Results ID‐NAT yielded 6 HIV‐RNA‐positive donations in the anti‐HIV‐negative window period (WP) but only 2 were p24 Ag nonreactive (1:325 000). Mathematical modelling estimated a similar HIV transmission risk for lapsed and repeat donations, in the order of 3 per million. The WP risk for HBV was 13 per million. Eight acute (1:81 000) and 13 chronic OBI yield cases (1:50 000) were interdicted. There were significantly more anti‐HBc‐positive donors in the Ultrio initial reactive/nonrepeat reactive group (12%) than in an Ultrio nonreactive control group (6%). Conclusion ID‐NAT in the Western Cape Province of South Africa has contributed significantly to enhancing blood safety, particularly for HBV transmission risk and to a lesser extent for HIV. Anti‐HBc testing of NAT nonrepeat reactive donations seems useful in identifying a subgroup of donors with OBI who may be at risk of transmitting HBV.     

Significant background rates of HBV and HCV infections in patients and risks of blood transfusion from donors with low anti-HBc titres or high anti-HBc titres with high anti-HBs titres in Japan: a prospective, individual NAT study of transfusion-transmitted HBV, HCV and HIV infections

Background The Japanese Red Cross (JRC) conducted a prospective study to evaluate the frequency of transfusion‐transmitted HBV, HCV and HIV infections to assess the risk of transfusion of blood components routinely supplied to hospitals. Study Design and Methods Post‐transfusion specimens from patients at eight medical institutes were examined for evidence of infection with HBV (2139 cases), HCV (2091) and HIV (2040) using individual nucleic acid amplification testing (NAT). If these specimens were reactive, pre‐transfusion specimens were also examined for the virus concerned by individual NAT. In the event that the pre‐transfusion specimen was non‐reactive, then all repository specimens from implicated donors were tested for the viruses by individual donation NAT. In addition, a further study was carried out to evaluate the risk of transfusion of components from donors with low anti‐HBc titres or high anti‐HBc with high anti‐HBs titres. Results Transfusion‐transmitted HCV and HIV infections were not observed. One case of post‐transfusion HBV infection was identified (rate, 0·0004675; 95% CI for the risk of transmission, 1 in 451–41 841). The background rates of HBV, HCV and HIV infections in patients prior to transfusion were 3·4% (72/2139), 7·2% (150/2091) and 0% (0/2040), respectively. Sixty‐four anti‐HBc‐ and/or anti‐HBs‐reactive blood components were transfused to 52 patients non‐reactive for anti‐HBc or anti‐HBs before and after transfusion (rate, 0; 95% CI for the risk of transmission, <1 in 22). Conclusion This study demonstrated that the current criteria employed by JRC have a low risk, but the background rates of HBV and HCV infections in Japanese patients are significant.     

External quality assessment programmes for detection of HCV RNA,HIV RNA and HBV DNA in plasma: improved proficiency of the participants observed over a 2‐year period

Background and Objectives Two External Quality Assessment Programmes (EQAPs) were run in 2008 and 2009 to evaluate the proficiency of blood centres in detecting, by nucleic acid amplification techniques (NAT), the possible contamination of plasma with hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV). Materials and Methods In the EQAP‐2008, three customized panels were designed; each containing positive samples with a viral nominal concentration for the three viruses of about three times the 95% DL of the respective commercial NAT assay. In the EQAP‐2009, the proficiency of the participants was evaluated with a single panel, independently on the NAT method used. Results While 84% (10 2 /12 2 ) of the participants in the EQAP‐2008 correctly identified the positive and negative samples of the panels, in the EQAP‐2009 the percentage of proficient laboratories increased to 97% (118/122). Most importantly, in this 2‐year experience, we observed a decrease in the number of pre‐/postanalytical errors, from 14 in 2008 to two in 2009. Conclusions The design of these two EQAPs allowed participants to assess the performance of the NAT methods applied in their routine screening of blood donations, not only with respect to analytical errors but also to human errors that, despite the high level of automation reached by NAT methods, can still occur.