Transfusion risk associated with recent arbovirus outbreaks in French Polynesia

International review of blood donation nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

Nucleic acid amplification testing (NAT), in blood services context, is used for the detection of viral and parasite nucleic acids to reduce transfusion-transmitted infections. This project reviewed NAT for screening blood donations globally.

MATERIALS AND METHODS

A survey on NAT usage, developed by the International Society of Blood Transfusion Working Party on Transfusion-transmitted Infectious Diseases (ISBT WP-TTID), was distributed through ISBT WP-TTID members. Data were analysed using descriptive statistics.

RESULTS

Forty-three responses were received from 32 countries. Increased adoption of blood donation viral screening by NAT was observed over the past decade. NAT-positive donations were detected for all viruses tested in 2019 (proportion of donations positive by NAT were 0.0099% for human immunodeficiency virus [HIV], 0.0063% for hepatitis C virus [HCV], 0.0247% for hepatitis B virus [HBV], 0.0323% for hepatitis E virus [HEV], 0.0014% for West Nile virus [WNV] and 0.00005% for Zika virus [ZIKV]). Globally, over 3100 NAT-positive donations were identified as NAT yield or solely by NAT in 2019 and over 22,000 since the introduction of NAT, with HBV accounting for over half. NAT-positivity rate was higher in first-time donors for all viruses tested except WNV. During 2019, a small number of participants performed NAT for parasites (Trypanosoma cruzi, Babesia spp., Plasmodium spp.).

CONCLUSION

This survey captures current use of blood donation NAT globally. There has been increased NAT usage over the last decade. It is clear that NAT contributes to improving blood transfusion safety globally; however, there is a need to overcome economic barriers for regions/countries not performing NAT.

Infectious diseases and the impact on transfusion medicine: A historical review and lessons for the future

Blood transfusion saves millions of lives each year. It is a well-established treatment, and many procedures are applied to avoid transmitted infections. However, throughout the history of transfusion medicine, many infectious diseases arose or were recognised, bringing up an impact on the blood supply, as the difficulties in diagnosing new diseases, the decrease in blood donors, the challenges for the medical team, the risks for the receptor and the related costs. This study aims to review historically the principal infectious diseases transmitted through the blood that circulated worldwide in the 20th and 21st centuries, considering the impact on the blood banks. Despite the current blood bank control of transfusion risks and the hemovigilance improvements, transmitted and emerging infections can still compromise the blood bank supply, as we have witnessed during the first waves of the COVID-19 pandemic. Moreover, new pathogens will continue emerging, and we must be prepared for the future.

Detection of dengue, chikungunya, and Zika RNA in blood donors from Southeast Asia

BACKGROUND

Chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses are of concern due to the potential of transfusion transmission in blood, especially in regions such as Southeast Asia where the viruses are endemic. The recent availability of nucleic acid testing (NAT) to screen blood donations on an automated platform provides the opportunity to detect potentially infectious units in asymptomatic donors.

STUDY DESIGN AND METHODS

Three thousand blood donations from Vietnam and 6000 from Thailand were screened with a real-time polymerase chain reaction (PCR) test (cobas CHIKV/DENV, Roche Diagnostics, Indianapolis, IN) and equal numbers on cobas Zika (Roche Diagnostics). Reactive samples were tested by alternative NAT with resolution of discordant results by heminested PCR. Throughput of simultaneous testing of the two assays on the cobas 8800 system (Roche Diagnostics) was evaluated.

RESULTS

In Vietnam, 9 of 3045 samples were reactive for DENV and all were confirmed, for a prevalence (with 95% confidence interval [CI]) of 0.296% (0.135-0.560). In Thailand, 2 of 6000 samples were reactive for CHIKV, 4 of 6000 for DENV, and 1 of 6005 for ZIKV, and all confirmed. The prevalence of CHIKV is 0.033% (0.004-0.120), DENV 0.067% (0.018-0.171), and ZIKV 0.017% (0.000-0.093). The overall specificity for the cobas CHIKV/DENV and cobas Zika tests was 100% (99.959-100). For the simultaneous assay testing, 960 test results were available in 7 hours and 53 minutes.

CONCLUSION

Detection of CHIKV, DENV, and ZIKV RNA in donor samples in Vietnam and Thailand indicate the presence of the virus in asymptomatic blood donors. The cobas 6800/8800 systems (Roche Molecular Systems, Pleasanton, CA) enable screening blood donations in endemic areas for these viruses together or separately.

Impact on blood safety of the last arboviruses outbreaks in French Polynesia (2012-2018)

BACKGROUND

Several successive arbovirus outbreaks have affected French Polynesia (FP) in the recent past years due to different dengue serotypes (DENV) present for several decades, Zika (ZIKV) (2013-2014) and chikungunya (CHIKV) (2014-2015) viruses with a potential impact on blood safety and blood supply due to the geographical isolation of these islands. This study reports an assessment of the impact of these outbreaks on blood products supply and infectious safety in FP and discuss the effectiveness of implemented preventive measures.

METHODS

To ensure the infectious safety of blood products during outbreaks, several measures have successively been introduced as the selection of donors suspected of infection, the nucleic acid testing (NAT) and the pathogen reduction of platelets and plasmas.

RESULTS

The donor deferral rate increased by 6% between 2012 and 2014 without changes in the number of collected donations. NAT excluded five blood donations reactive for DENV RNA, 42 for ZIKV and 34 for CHIKV. As Zika screening could not been implemented before the third month of the outbreak, 36 blood products from ZIKV-infected donors were transfused to 26 recipients. However, no transfusion-transmitted arbovirus has been reported.

CONCLUSION

The last past arboviruses outbreaks did not have a significant impact on blood supply in FP. The measures introduced to prevent arbovirus transmission by transfusion were able to maintain infectious safety for all blood products without impairing self-sufficiency.