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Most of the 233 worldwide cases of variant Creutzfeldt-Jakob disease (vCJD) have been reported in the United Kingdom and 3 have been associated with transfusion-transmission. To mitigate the potential vCJD risk to blood safety, Australian Red Cross Lifeblood imposes restrictions on blood donation from people with prior residency in, or extended travel to, the United Kingdom during the risk period 1980-1996. We have modified a previously published methodology to estimate the transfusion-transmission risk of vCJD associated with fresh component transfusion in Australia if the UK residence deferral was removed.The prevalence of current pre-symptomatic vCJD infection in the United Kingdom by age at infection and genotype was estimated based on risk of exposure to the bovine spongiform encephalopathy agent for the period 1980-1996. These results were used to estimate the age-specific prevalence of undiagnosed, pre-symptomatic vCJD in the Australian population in the current year due to prior UK residency or travel. The primary model outputs were the 2020 vCJD risks/unit of vCJD contamination, transfusion-transmission (infections) and clinical cases.The overall (prior UK residency in and travel to United Kingdom, 1980-1996) mean risk of contamination per unit was 1 in 29,900,000. The risks of resulting vCJD transmission (infection) and clinical case were 1 in 389,000,000 and 1 in 1,450,000,000, respectively.Our modelling suggests that removing the Lifeblood donation deferral for travel to, or UK residence, would result in virtually no increased risk of vCJD transfusion-transmission and would be a safe and effective strategy for increasing the donor base.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus first identified in late 2019 and subsequently declared a worldwide pandemic in March 2020. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Summary: Approximately one-third of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period typically varies from 2 to 11 days, but longer periods up to 22 days have been reported. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. A small number of presymptomatic and asymptomatic blood phase cases have been reported. Transfusion-transmission (TT) of SARS-CoV-2 has not been reported. Therefore, the TT risk associated with SARS-CoV-2 is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centers, blood services can implement donor deferral policies based on travel, disease status, or potential risk of exposure and encourage staff vaccination. Key Messages: The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-2 to donors and staff while donating blood.

Objectives: To determine the motivators and barriers to COVID-19 convalescent plasma donation by those in the United Kingdom who have been diagnosed with or who have had symptoms of SARS-CoV-2 (COVID-19) but who have not donated. Background: Convalescent plasma from people recovered from COVID-19 with sufficient antibody titres is a potential option for the treatment and prevention of COVID-19. However, to date, recruiting and retaining COVID-19 convalescent plasma donors has been challenging. Understanding why those eligible to donate COVID-19 convalescent plasma have not donated is critical to developing recruitment campaigns. Methods/Materials: A total of 419 UK residents who indicated that they had been infected with COVID-19 and who lived within 50 km of sites collecting COVID-19 convalescent plasma completed an online survey between 25th June and 5th July 2020. Respondents completed items assessing their awareness of convalescent plasma, motivations and barriers to donation and intention to donate COVID-19 convalescent plasma. Results: Awareness of COVID-19 convalescent plasma was low. Exploratory factor analysis identified six motivations and seven barriers to donating. A stronger sense of altruism through adversity and moral and civic duty were positively related to intention to donate, whereas generic donation fears was negatively related. Conclusions: Once potential donors are aware of convalescent plasma, interventions should focus on the gratitude and reciprocity that those eligible to donate feel, along with a focus on (potentially) helping family and norms of what people ought to do. Fears associated with donation should not be neglected, and strategies that have been successfully used tor recruit whole-blood donors should be adapted and deployed to recruit COVID-19 convalescent plasma donors.

Background West Nile virus (WNV) is a mosquito-borne virus and transfusion transmission (TT) has been demonstrated. The European Union and neighboring countries experience an annual transmission season. Study design and methods We developed a novel probabilistic model to estimate the WNV TT risk in Australia attributable to returned donors who had travelled to the European Union and neighboring countries during the 2018. We estimated weekly WNV TT risks in Australia for each outbreak country and the cumulative risk for all countries. Results Highest mean weekly TT risk in Australia attributable to donors returning from a specific outbreak country was 1 in 23.3 million (plausible range, 16.8-41.9 million) donations during Week 39 in Croatia. Highest mean weekly cumulative TT risk was 1 in 8.5 million donations (plausible range, 5.1-17.8 million) during Week 35. Conclusions The estimated TT risk in Australia attributable to returning donors from the European Union and neighboring countries in 2018 was very small, and additional risk mitigation strategies were not indicated. In the context of such low TT risks, a simpler but effective approach would be to monitor the number of weekly reported West Nile fever cases and implement risk modeling only when the reported cases reached a predefined number or trigger point.

Background and objectives In 2018, Australian Red Cross Lifeblood changed its plasmapheresis eligibility criteria to allow donors to donate plasma without the requirement of a prior successful whole blood donation. This study evaluated the impact of this policy change on donor retention and donor safety. Materials and methods All donors who had attempted to give their first plasma or whole blood donation from January to June 2018 were included in this retrospective cohort study. Donor characteristics and adverse events were analysed for this index donation, and the cohort was followed for 18 months to analyse time to return, subsequent donation frequency and predictors of return. Results Male and younger donors provided a significantly greater proportion of first donation plasma than females and older donors. New donors who gave plasma had the highest rate of donor adverse events, including vasovagal reactions and phlebotomy injuries. Nevertheless, donor retention was not affected, with more new donors returning and at a greater subsequent donation frequency after a plasma donation compared to new donors donating whole blood. First-time plasma donors who had previously donated whole blood, however, had greater and quicker rates of return, and more subsequent donations. Conclusion Offering new donors the option to give plasma had a positive effect on donor return and subsequent donation frequency. Removing the requirement of a prior whole blood donation is a viable way to increase plasma collections although the combined effect of new donor status and plasmapheresis procedure on adverse event risk needs to be considered.

Aim Donor selection for milk banks is essential to ensure the safety and nutritional quality of the donor milk, and to ensure that the prospective donor and her breastfeeding infant do not come to harm through donating. Australian Red Cross Lifeblood Milk went through a robust process to develop a set of criteria for the selection and screening of potential breast milk donors, which included development of a Donor Questionnaire (DQ), supported by a formal set of Guidelines for the Selection of Milk Donors. Key screening questions from the DQ were made available to prospective donors to self-screen prior to the formal assessment process. The aim of this study was to review the outcomes of milk donor screening at Lifeblood Milk. Methods We reviewed the outcomes of our donor screening process over the first 12-months (July 2018-June 2019) of operations. Results A total of 50 out of 327 donors who responded to the self-screening questions were not able to proceed further; 201 donors were formally screened using the DQ and Guidelines for the Selection of Milk Donors, with 9 of 201 deferred based on their responses. An additional two donors were deferred (failed phlebotomy (n = 1) and reactive infectious disease serology (n = 1)), with 190 of 201 (95%) of prospective donors accepted after screening. Conclusions Our experience highlighted international differences in practice between milk banks and lack of strong research to inform milk donor selection. Making a set of key screening questions available to donors for self-screening resulted in a high acceptance rate (95%) for donors who began the formal screening process. Further work is needed to better understand the impact of deferral on prospective milk donors.

International audience

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus–cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)–confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of “high responders” maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design.

Serological testing for SARS-CoV-2-specific antibodies provides important research and diagnostic information relating to COVID-19 prevalence, incidence and host immune response. A greater understanding of the relationship between functionally neutralising antibodies detected using microneutralisation assays and binding antibodies detected using scalable enzyme immunoassays (EIA) is needed in order to address protective immunity post-infection or vaccination, and assess EIA suitability as a surrogate test for screening of convalescent plasma donors. We assessed whether neutralising antibody titres correlated with signal cut-off ratios in five commercially available EIAs, and one in-house assay based on expressed spike protein targets. Sera from recovered patients or convalescent plasma donors who reported laboratory-confirmed SARS-CoV-2 infection (n = 200), and negative control sera collected prior to the COVID-19 pandemic (n = 100), were assessed in parallel. Performance was assessed by calculating EIA sensitivity and specificity with reference to microneutralisation. Neutralising antibodies were detected in 166 (83%) samples. Compared with this, the most sensitive EIAs were the Cobas Elecsys Anti-SARS-CoV-2 (98%) and Vitros Immunodiagnostic Anti-SARS-CoV-2 (100%), which detect total antibody targeting the N and S1 antigens, respectively. The assay with the best quantitative relationship with microneutralisation was the Euroimmun IgG. These results suggest the marker used (total Ab vs. IgG vs. IgA) and the target antigen are important determinants of assay performance. The strong correlation between microneutralisation and some commercially available assays demonstrates their potential for clinical and research use in assessing protection following infection or vaccination, and use as a surrogate test to assess donor suitability for convalescent plasma donation.

The SARS-CoV-2 antibody neutralization response and its evasion by emerging viral variants are unknown. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus-cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 RT-PCR-confirmed COVID-19 individuals with detailed demographics and followed up to seven months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization were associated with COVID-19 severity. A subgroup of ‘high responders’ maintained high neutralizing responses over time, representing ideal convalescent plasma therapy donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal plasma donors and vaccine monitoring and design.One Sentence SummaryNeutralizing antibody responses to SARS-CoV-2 are sustained, associated with COVID19 severity, and evaded by emerging viral variants

BackgroundSerological testing for SARS-CoV-2 specific antibodies provides important research and diagnostic information relating to COVID-19 prevalence, incidence, and host immune response. A greater understanding of the relationship between functionally neutralising antibodies detected using microneutralisation assays and binding antibodies detected using scalable enzyme immunoassays (EIA) is needed in order to address protective immunity post-infection or vaccination, and assess EIA suitability as a surrogate test for screening of convalescent plasma donors. We assessed whether neutralising antibody titres correlated with signal cut-off ratios in five commercially available EIAs, and one in-house assay based on expressed spike protein targets.MethodsSera from individuals recovered from patients or convalescent plasma donors who reported laboratory-confirmed SARS-CoV-2 infection (n=200), and negative control sera collected prior to the COVID-19 pandemic (n=100) were assessed in parallel. Performance was assessed by calculating EIA sensitivity and specificity with reference to microneutralisation.ResultsNeutralising antibodies were detected in 166 (83%) samples. Compared with this, the most sensitive EIAs were the Cobas Elecsys Anti-SARS-CoV-2 (98%) and Vitros Immunodiagnostic Anti-SARS-CoV-2 (100%), which detect total antibody targeting the N and S1 antigens, respectively. The assay with the best quantitative relationship with microneutralisation was the Euroimmun IgG.ConclusionsThese results suggest the marker used (total Ab vs IgG vs IgA), and the target antigen are important determinants of assay performance. The strong correlation between microneutralisation and some commercially available assays demonstrate their potential for clinical and research use in assessing protection following infection or vaccination, and use as a surrogate test to assess donor suitability for convalescent plasma donation.

Background and objective Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus, first identified in China at the end of 2019 and has now caused a worldwide pandemic. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Material and method We searched the PubMed database, the preprint sites bioRxiv and medRxiv, the websites of the World Health Organization, European Centre for Disease Prevention and Control, the US Communicable Diseases Center and monitored ProMed updates. Results An estimated 15%-46% of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period is 3 to 7 days with a range of 1-14 days. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. An asymptomatic blood phase has not been demonstrated. Given these characteristics of SARS-CoV-2 infection and the absence of reported transfusion transmission (TT), the TT risk is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centres, blood centres can implement donor deferral policies based on travel, disease status or potential risk of exposure. Conclusion The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-19 to donors and staff while donating blood.

Background and objectives Based on the Council of Europe directive which dictates regulatory requirements in Australia, blood donors are currently deferred from donating for 4 months after an endoscopic procedure if either polyps were removed or a biopsy sample was taken. We aimed to assess the incidence of blood-borne viruses (BBVs) (HIV, hepatitis B and C) in blood donors who donated after an endoscopic procedure and evaluate the risk to blood safety through risk modelling. Materials and methods Donors from 1/1/2013 to 31/12/2017 with an endoscopy deferral on their blood donor file with pre- and post-BBV testing were analysed to determine an incidence of BBVs using standard methods. The standard blood donor cohort was used as a comparator group. Using the incidence of endoscopies and BBV risk, the total residual risk estimate of allowing donors to return postendoscopy without restriction was calculated. Results The incidence of a BBV postendoscopy in this large cohort of 16,283 where testing has been confirmed postendoscopy was zero (95% CI 0-0·000105). The upper confidence interval of the zero events is 10·5 per 100 000 donations. Total positive donations from 2017 repeat donors were 1·87 per 100 000 (95% CI 0·0000117-0·0000277). Sensitivity analysis demonstrated that the residual risk remained negligible under realistic worst-case scenarios. Conclusion A BBV endoscopy deferral is not required for blood safety in Australia. The presented data has enabled us to submit a request for an exemption to our regulator, which has been approved and the policy change subsequently implemented by Lifeblood on 4/4/2020.

Background Men who have sex with men in Australia are currently ineligible to donate blood (are "deferred") for 12 months since last oral or anal sexual contact with another man. In Australia and overseas, there has been limited research on attitudes and perceptions related to blood donation in this population. Study design and methods Questions on blood donation histories and attitudes toward the deferral policy were included in the questionnaire of an online prospective cohort of gay and bisexual men (GBM) living in Australia. Results In 2018, 1595 GBM responded to the survey. In this sample, 28.7% reported previously donating blood. Among the remaining men who had never donated blood, 64.5% expressed an interest in doing so. Nearly all men indicated they were not willing to abstain from sex with another man for 12 months in order to donate, and the vast majority believed the rule was unfair, too strict, and homophobic. Three-quarters (77.7%) said that if the policy changed, they would likely donate blood. Age and openness about one's sexuality were independently associated with one's willingness to donate blood in the absence of the deferral. Conclusion There was a high level of willingness and desire to donate blood among GBM. However, rather than abstaining from sex in order to donate, many men comply with the deferral policy and do not donate. A less conservative deferral policy may increase donations from GBM.

False positive (FP) viral marker results in blood donors continue to pose many challenges. Informing donors of FP results and subsequent deferral can result in stress and anxiety for donors and additional complexity and workload for blood services. Donor management strategies need to balance the requirement to minimise donor anxiety and inconvenience while maintaining sufficiency of supply. Decisions about how and when to inform donors of FP results and determine deferral periods can be difficult as FP results, while often transitory, can take up to several years to resolve. Additional complexities include the interpretation of indeterminate serological confirmatory testing without detectable viral RNA or non-discriminated NAT results with concomitant anti-HBc reactivity - both may be due to FP results, but the former may also represent past infection and the later may represent occult hepatitis B infection. In this review we discuss strategies to minimise indeterminate serological confirmatory results, possible donor deferral policies and the impact on donors when notified of FP results. We also provide some new data from Australia that address the challenge of interpreting non-discriminated NAT results with concomitant anti-HBc reactivity. Ultimately, the challenge is for each blood service to develop appropriate strategies for donor management, taking into account local information and requirements.

BACKGROUND Emerging transfusion-transmissible pathogens, including arboviruses such as West Nile, Zika, dengue, and Ross River viruses, are potential threats to transfusion safety. The most prevalent arbovirus in humans in Australia is Ross River virus (RRV); however, prevalence varies substantially around the country. Modeling estimated a yearly risk of 8 to 11 potentially RRV-viremic fresh blood components nationwide. This study aimed to measure the occurrence of RRV viremia among donors who donated at Australian collection centers located in areas with significant RRV transmission during one peak season. STUDY DESIGN AND METHODS Plasma samples were collected from donors (n = 7500) who donated at the selected collection centers during one peak season. Viral RNA was extracted from individual samples, and quantitative reverse transcription-polymerase chain reaction was performed. RESULTS Regions with the highest rates of RRV transmission were not areas where donor centers were located. We did not detect RRV RNA among 7500 donations collected at the selected centers, resulting in a zero risk estimate with a one-sided 95% confidence interval of 0 to 1 in 2019 donations. CONCLUSION Our results suggest that the yearly risk of collecting a RRV-infected blood donation in Australia is low and is at the lower range of previous risk modeling. The majority of Australian donor centers were not in areas known to be at the highest risk for RRV transmission, which was not taken into account in previous models based on notification data. Therefore, we believe that the risk of RRV transfusion transmission in Australia is acceptably low and appropriately managed through existing risk management, including donation restrictions and recall policies.

Background and Objectives Universal testing of blood donations for human T-cell lymphotropic virus (HTLV) in Australia may no longer be appropriate given the low prevalence of HTLV infection and the mitigating effect of universal leucodepletion for cellular components. This study aimed to determine the most appropriate HTLV testing strategy using the Risk-Based Decision-Making Framework for Blood Safety. Materials and Methods The risk of HTLV transfusion–transmission using three testing strategies (universal, new-donor and no testing) and cost-effectiveness of the first two strategies were assessed using adaptations of published mathematical models. Results The overall prevalence for 2004–2014 was three HTLV-positives per million donations. It was estimated that annually, universal testing incurred a cost of approximately AUD $3 million and prevented 83 HTLV-positive cellular components from being issued, and new-donor testing cost approximately $225 000 and prevented 81 components. The number of cases of transfusion-transmitted HTLV and HTLV-associated disease prevented per year by universal and new-donor testing was essentially equivalent. According to preset risk thresholds, the risk of transfusion–transmission was negligible for universal and new-donor testing, and minimal without testing. Conclusion Transfusion–transmission of HTLV is a minimal risk in Australia even without testing. However, any revision of testing strategy must consider not only risk and cost-effectiveness, but also stakeholder, ethical and regulatory perspectives. Considering all relevant criteria, new-donor testing is judged the optimal strategy because it is able to achieve almost the same outcomes as universal testing, at a fraction of the cost.

Background and objectives Until recently, people in Australia with a history of injection drug use (IDU) were deferred indefinitely from donating blood. Knowledge gaps regarding policy non-compliance and the prevalence of blood donation practices amongst people who inject drugs (PWID) precluded changes to this policy. We sought to address these gaps and to estimate the additional risk to Australia's blood supply associated with changing the indefinite deferral policy to 1 or 5 years since last injecting episode. Materials and methods Data on blood donation amongst PWID were collected from 1853 interviews across two Australian studies of PWID conducted during 2015/16. Mathematical modelling was used to estimate the additional risk of hepatitis C (HCV)-infected window period collections as a result of changing the deferral policy. Results A very few (2-4%) study participants reported ever donating blood after ≥1 IDU episode. Changing the deferral policy from indefinite to 1 or 5 years was estimated to result in an additional 0·00000070 (95%CI: 0·00000033-0·00000165) or 0·00000020 (95%CI: 0·00000008-0·00000041) HCV-positive window period collections per year, respectively. Conclusion Changing Australia's indefinite deferral period to 1 or 5 years since last injecting episode poses a negligible increase in the risk of HCV-infected window period collections from blood donors with a history of IDU. Our results informed a successful submission to the Australian regulator to change the deferral period from indefinite to 5 years since last injecting episode, a policy which came into effect in September 2018.

BACKGROUND Foodborne hepatitis A virus (HAV) outbreaks are becoming more common in high-income countries with low HAV incidence, and the associated blood safety risk may not be adequately mitigated by routine HAV risk mitigation strategies. This study describes the rapid risk modeling undertaken in response to a 2018 HAV outbreak in Australia associated with imported frozen pomegranate arils. STUDY DESIGN AND METHODS The input parameters used in the modeling were the outbreak-associated HAV incidence, duration of viremia, population seroprevalence, and rate of symptomatic infection in adults. The number and risk of viremic components issued, cases of transfusion transmission, and symptomatic infections among recipients were estimated. RESULTS The incidence of pomegranate-associated HAV infection among donors was very low, with fewer than 0.1 viremic fresh components estimated to have been released during the risk period. The risk of this event was less than one in 500,000, and the risks of transfusion transmission and symptomatic illness in recipients were less than one in one million. When considering only donors who had consumed the pomegranate product, the risk was much higher, with approximately one in 1000 components estimated to be viremic. CONCLUSION Rapid risk assessment indicated that the overall risk to blood safety associated with a small foodborne outbreak of HAV was negligible. Because fresh components collected from donors known to have consumed the affected product were at high risk, these donors were identified via signage in donor centers and deferred. The contribution of factors other than outbreak size to risk management decisions is discussed.

International audience

Background and objectives There is conflicting evidence in the literature as to whether there is a blood-borne virus (BBV) risk associated with tattoos in licensed premises. However, blood donors are currently deferred from blood donation in Australia for 4 months after any tattoo. We aimed to assess the incidence of BBVs in blood donors who declared tattoos and evaluate the risk to blood safety through risk modelling. Materials and methods Donors from 2013 to 2016 with a tattoo deferral on their blood donor file with pre- and post-BBV testing were analysed to determine an incidence of BBVs using standard methods. This was compared to a 2014 cohort of whole blood donors with a deferral of 4 months due to travel to a malaria-endemic area. Using the incidence of tattoos and BBV risk, the total residual risk estimate of allowing tattooed donors to return without restriction was calculated. Results The incidence rate of BBVs in blood donors following tattoo deferral was 13·26 (95% CI 2·67-38·75) per 100 000 person-years (all were hepatitis C infections in males compared to 9·26 (95% CI 2·49-23·71) per 100 000 in blood donors following malaria deferral. If other risk factors were accounted for the risk in tattoo donors decreased to 4·4 per 100 000 person-years. The total residual risk calculation if donors with a tattoo were allowed to donate without restriction was estimated at 1 in 34 million. Conclusions This residual risk indicates BBV deferral for donors post-tattoo in Australia is not required for blood safety.

BACKGROUND: Hepatitis E virus (HEV) poses a risk to transfusion safety. In Australia, locally acquired HEV is rare and cases are mainly reported in travelers returning from countries endemic for HEV. The risk posed by HEV to transfusion safety in Australia is unknown; therefore, we aimed to measure the rate of current HEV infection in Australian blood donations. STUDY DESIGN AND METHODS: A total of 14,799 blood donations were tested for HEV RNA by transcription-mediated amplification, with confirmatory testing by reverse transcription–polymerase chain reaction. Viral load quantification and phylogenetic analysis was performed on HEV RNA–positive samples. RESULTS: One (0.0068%; 95% confidence interval [CI], 0.0002%-0.0376%) sample was confirmed positive for HEV RNA, resulting in a risk of collecting a HEV-viremic donation of 1 in 14,799 (95% CI, 1 in 584,530 to 1 in 2,657). The viral load in this sample was approximately 15,000 IU/mL, and it was determined to be Genotype 3. DISCUSSION: Our finding of 1 in 14,799 Australian donations positive for HEV RNA is lower than that from many other developed countries; this is consistent with the relatively low seroprevalence in Australia. As this HEV RNA–positive sample was Genotype 3, it seems likely that this infection was acquired through zoonotic transmission, either within Australia or overseas in a developed nation. HEV has the potential to pose a risk to transfusion safety in Australia; however, additional, larger studies are required to quantify the magnitude of this risk.

BACKGROUND It has been suggested that blood donors with hereditary hemochromatosis may pose an increased infectious disease risk and adversely affect recipient outcomes. This study compares the infectious disease risk of whole blood (WB) donors enrolled as therapeutic (T) donors to voluntary WB donors to evaluate the safety of blood products provided by the T donors. STUDY DESIGN AND METHODS This was a retrospective cohort study of all WB donations at the Australian Red Cross Blood Service who donated between January 1, 2011, and December 31, 2013, comparing a yearly mean of 11,789 T donors with 107,773 total donations and a yearly mean of 468,889 voluntary WB donors with 2,584,705 total donations. We compared postdonation notification of infectious illnesses, bacterial contamination screening results, and positive tests for blood borne viruses in T and WB donors. RESULTS Rates of transfusion-transmissible infections in donations destined for component manufacture were significantly lower in therapeutic donations compared to voluntary donations (8.4 vs. 21.6 per 100,000 donations). Bacterial contamination (43.0 vs. 45.9 per 100,000 donations) and postdonation illness reporting (136.2 vs. 110.8 per 100,000 donations) were similar in both cohorts. CONCLUSIONS The Australian therapeutic venisection program enables T donors to provide a safe and acceptable source of donated WB that has a low infectious disease risk profile.

Background and objectives Ross River virus (RRV) is an enveloped, RNA alphavirus in the same antigenic group as chikungunya virus. Australia records an annual average of 5000 laboratory-confirmed RRV infections. While RRV is currently geographically restricted to the Western Pacific, the capacity of arboviruses for rapid expansion is well established. The first case of RRV transfusion-transmission was recently described prompting a comprehensive risk assessment. Materials and methods To estimate the RRV residual risk, we applied laboratory-confirmed RRV notifications to two published models. This modelling generated point estimates for the risk of viraemia in the donor population, the risk of collecting a viraemic donation and the predicted number of infected components. Results The EUFRAT model estimated the risk of infection in donors as one in 95 039 (one in 311 328 to one in 32 399) to one in 14 943 (one in 48 593 to one in 5094). The point estimate for collecting a RRV viraemic donation varied from one in 166 486 (one in 659 078 to one in 49 158) (annualized national risk) to one in 26 117 (one in 103 628 to one in 7729) (area of high transmission). The modelling predicted 8–11 RRV-infected labile blood components issued in Australia during a 1-year period. Conclusion Considering the uncertainty in the modelled estimates, the unknown rate of RRV donor viraemia and the low severity of any recipient RRV infection, additional risk management for RRV in Australia will initially be restricted to strengthening the messaging to donors regarding prompt reporting of any postdonation illnesses.

BACKGROUND Three probable cases of transfusion-transmitted (TT) parvovirus B19 (B19V) occurred in Australia between 2014 and 2017. This study aimed to determine the B19V DNA prevalence among blood donors, to model the risk to recipients of fresh components, and to assess risk management options. STUDY DESIGN AND METHODS Plasma samples from 4232 donors were tested for B19V DNA by polymerase chain reaction. Reactive samples were confirmed and viral load determined. A transmission-risk model was used to estimate recipient risk, and the risk from community exposure was estimated using seroprevalence data. RESULTS Two samples (0.0473%, 95% confidence interval [CI] 0.0130-0.172) confirmed positive for B19V DNA had a potentially infectious viral load of 105 IU/mL or higher. The estimated risk of a TT-B19V-associated significant complication was low overall at approximately 1 in 300,000 (95% CI, 1 in 82,000 to 1 in 1 million) fresh components transfused, with 3.1 (95% CI, 0.85-11.3) complications modeled per year. Among vulnerable recipient groups, the risk was higher than 1 in 15,000 patients, but the risk from community exposure far exceeded the transfusion risk for all patient and age groups. CONCLUSION In the context of the small contribution of transfusion to the burden of B19V disease, the significant costs that would be incurred by any strategy to reduce the risk, and given the significant uncertainties and likely overestimation of the risk, we conclude TT-B19V is a tolerable risk to blood safety, despite being high for some vulnerable recipient groups.

Repeat donors in Australia will shortly cease to be tested for human T-lymphotropic virus (HTLV), removing the ability to measure repeat donor incidence. A risk threshold for repeat donors was investigated based on previous modelling and a conservative ratio between prevalent and incident infections. It was estimated that 26 infections per 100 000 new-donor donations would be associated with an incidence in repeat donors approaching the tolerable risk threshold if sustained over several years. We propose to trigger formal risk assessment at this point, and believe this solution may be useful for other blood services that reduce their HTLV testing requirements.

BACKGROUND AND OBJECTIVES Donor syphilis testing began in the 1940s amidst widespread transfusion-transmitted syphilis (TTS). Since then, the introduction of penicillin, pre-donation screening questionnaires and improved storage conditions have contributed to reducing transmission risk. Consequently, universal testing may no longer be cost-effective. This study analysed alternative options for donor syphilis testing to determine the optimal strategy. MATERIALS AND METHODS A model was developed using conservative parameter estimates for factors affecting TTS and 2009-2015 Australian donations to calculate risk outcomes (TTS infections, tertiary syphilis in recipients and transfusion-associated congenital syphilis) and cost-effectiveness of alternative testing strategies. The strategies modelled were as follows: universal testing, targeted-testing of high-risk groups (males ≤50 years old and first-time donors) and no testing. RESULTS The estimated risk of TTS is one in 49·5 million transfusions for universal testing, one in 6 million for targeted-testing of males ≤50 years old, one in 4 million for targeted-testing of first-time donors and one in 2·8 million for no testing. For all strategies, the risk of tertiary and congenital syphilis is

Emerging transfusion-transmissible pathogens, including arboviruses such as West Nile, Zika, dengue, and Ross River viruses, are potential threats to transfusion safety. The most prevalent arbovirus in humans in Australia is Ross River virus (RRV); however, prevalence varies substantially around the country. Modeling estimated a yearly risk of 8 to 11 potentially RRV-viremic fresh blood components nationwide. This study aimed to measure the occurrence of RRV viremia among donors who donated at Australian collection centers located in areas with significant RRV transmission during one peak season.Plasma samples were collected from donors (n = 7500) who donated at the selected collection centers during one peak season. Viral RNA was extracted from individual samples, and quantitative reverse transcription-polymerase chain reaction was performed.Regions with the highest rates of RRV transmission were not areas where donor centers were located. We did not detect RRV RNA among 7500 donations collected at the selected centers, resulting in a zero risk estimate with a one-sided 95% confidence interval of 0 to 1 in 2019 donations.Our results suggest that the yearly risk of collecting a RRV-infected blood donation in Australia is low and is at the lower range of previous risk modeling. The majority of Australian donor centers were not in areas known to be at the highest risk for RRV transmission, which was not taken into account in previous models based on notification data. Therefore, we believe that the risk of RRV transfusion transmission in Australia is acceptably low and appropriately managed through existing risk management, including donation restrictions and recall policies.

Background and Objectives Hepatitis E virus (HEV) is a known transfusion-transmissible agent. HEV infection has increased in prevalence in many developed nations with RNA detection in donors as high as 1 in 600. A high proportion of HEV infections are asymptomatic and therefore not interdicted by donor exclusion criteria. To manage the HEV transfusion-transmission (TT) risk some developed nations have implemented HEV RNA screening. In Australia, HEV is rarely notified; although locally acquired infections have been reported, and the burden of disease is unknown. The purpose of this study was to determine the frequency of HEV infection in Australian donors and associated TT risk. Materials and Methods Plasma samples (n = 74 131) were collected from whole blood donors during 2016 and screened for HEV RNA by transcription-mediated amplification (TMA) in pools of six. Individual TMA reactive samples were confirmed by RT-PCR and, if positive, viral load determined. Prevalence data from the study were used to model the HEV-TT risk. Results One sample in 74 131 (95% CI: 1 in 1 481 781 to 1 in 15 031) was confirmed positive for HEV RNA, with an estimated viral load of 180 IU/ml, which is below that typically associated with TT. Using a transmission-risk model, we estimated the risk of an adverse outcome associated with TT-HEV of approximately 1 in 3·5 million components transfused. Conclusion Hepatitis E virus viremia is rare in Australia and lower than the published RNA prevalence estimates of other developed countries. The risk of TT-HEV adverse outcomes is negligible, and HEV RNA donor screening is not currently indicated.

International travel assists spread of infectious pathogens. Australians regularly travel to South-eastern Asia and the isles of the South Pacific, where they may become infected with infectious agents, such as dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses that pose a potential risk to transfusion safety. In Australia, donors are temporarily restricted from donating for fresh component manufacture following travel to many countries, including those in this study. We aimed to estimate the unmitigated transfusion-transmission (TT) risk from donors travelling internationally to areas affected by emerging infectious diseases.We used the European Up-Front Risk Assessment Tool, with travel and notification data, to estimate the TT risk from donors travelling to areas affected by disease outbreaks: Fiji (DENV), Bali (DENV), Phuket (DENV), Indonesia (CHIKV) and French Polynesia (ZIKV).We predict minimal risk from travel, with the annual unmitigated risk of an infected component being released varying from 1 in 1·43 million to1 in one billion and the risk of severe consequences ranging from 1 in 130 million to1 in one billion.The predicted unmitigated likelihood of infection in blood components manufactured from donors travelling to the above-mentioned areas was very low, with the possibility of severe consequences in a transfusion recipient even smaller. Given the increasing demand for plasma products in Australia, the current strategy of restricting donors returning from select infectious disease outbreak areas to source plasma collection provides a simple and effective risk management approach.

OBJECTIVE To quantify the risk of transmission of measles associated with infectious people who travelled on aeroplane flights to or within Australia. DESIGN, SETTING AND SUBJECTS Data were obtained from state and territory health authorities on all measles notifications from January 2007 to June 2011 for people who were likely to have been infectious or infected while travelling on aeroplanes in Australia. RESULTS Forty-five infectious people travelled on aeroplanes. Twenty secondary infections occurred in people on seven of 49 flights (14%; 95% CI, 6%-29%), comprising 19% (95% CI, 8%-40%) of the 36 international flights and none of 13 (95% CI, 0-28%) domestic flights that carried infectious people. Secondary infections occurred in nine people who were seated within two rows of the index case and in 11 people who were seated outside of two rows. Secondary transmission was more likely to occur with younger index cases (P = 0.025) and when there were multiple infectious people travelling (P = 0.018). About a third(15/49) of flight manifests were available to health authorities within 5 days oftravel. CONCLUSION Despite secondary measles transmission occurring on 19% of international flights carrying infectious people, risk was not clearly related to seating proximity, and contact tracing was ineffective, especially given delays in diagnosis, notification and accessing flight manifests. We recommend that direct contact tracing to identify susceptible people exposed to people infected with measles on aeroplane flights should not be undertaken routinely, and other strategies should be considered.

Background and Objectives We previously published a model to estimate the residual risk (RR) for occult hepatitis B infection (OBI) in the absence of universal anti-HBc testing. To incorporate new information on the epidemiology of OBI, we describe model refinements and estimate a more accurate HBV RR due to OBI in Australia. Materials and Methods In our original model, the OBI risk, p(OBI), was defined by the rate of ‘non-detection’ by the HBV DNA screening test in use, p(NAT non-detection), and the average infectivity of blood components from OBI donors, p(transmission). We revised the model by integrating three refinements: that donations with anti-HBs levels of >10 IU/l, or donations solely for manufactured plasma products, be excluded from the risk calculation, and an updated estimate of p(transmission). Results Refining our OBI RR model resulted in a more than 10-fold reduction in the reported RR risk to recipients from OBI in our donor population. Based on the use of a common data set, the mean OBI RR risk decreased from 1 in 374 354 donations (95% CI: 1 in 191 940–1 072 681) to 1 in 3 984 033 (95% CI: 1 in 1 146 188–65 268 257) for the refined model. Conclusion Our model refinements provide a more realistic measure of the HBV RR in the donor population. Unlike the previous model, the new model demonstrates that the risk of HBV due to OBI in the Australian blood donor population is negligible, and further potentially cost-ineffective risk management strategies are not currently warranted.

OBJECTIVES To document the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae in the refugee population settling in Western Australia from 1 January 2006 to 31 December 2009 and make recommendations for future screening for chlamydia and gonorrhoea in the refugee population. DESIGN AND PARTICIPANTS A prevalence and quality assurance study of 2610 refugees aged 15 years and older who attended the Humanitarian Entrant Health Service in Western Australia and were screened for chlamydia and gonorrhoea. MAIN OUTCOME MEASURES Demographic details and results of C. trachomatis and N. gonorrhoeae tests on first void urine. RESULTS The prevalence of chlamydia was found to be 0.8% (n = 21) in the refugee population. No gonorrhoea infections were detected. The prevalence of chlamydia was low (0.19%-1.23%) when analysed by sex, ethnicity or age and was considerably lower than other subpopulations considered high risk in Australia. CONCLUSION The low prevalence rates of chlamydia and gonorrhoea found in the refugee population suggest that current screening guidelines should be updated. We recommend screening all refugees who are sexually active up to age 39 years, taking into account an appropriate sexual history; otherwise, screening guidelines should be as for the general Australian population.