Perceived risk of HIV transmission by blood transfusion among gay, bisexual, and other men who have sex with men (gbMSM) in Australia.

BACKGROUND: In Australia, men who have sex with men (MSM) are deferred from blood donation for 3 months from last sexual contact. Internationally, deferral policies for MSM are evolving in the direction of expanded inclusivity in response to community expectations. To inform future policy options, we assessed perceptions of the risk of HIV transmission from blood transfusion among Australian MSM. STUDY DESIGN AND METHODS: Flux is an online prospective cohort of Australian gay and bisexual men (cis or trans, regardless of their sexual history) and other men who have had sex with men (gbMSM). We included questions on blood donation rules, window period (WP) duration, infectivity of blood from people with HIV on treatment and attitudes to more detailed questioning of sexual practices in the regular survey of Flux participants and conducted a descriptive analysis of responses. RESULTS: Of 716 Flux participants in 2019, 703 responded to the blood donation questions. The mean age was 43.7 years (SD 13.6 years). Overall, 74% were willing to confidentially respond to specific sexual behavior questions, such as the last time they had sex and the type of sex they had, in order to be considered eligible to donate blood. The majority (92%) of participants correctly assessed the duration of the WP as less than 1 month. When asked whether transfusion of blood from a donor with HIV and an undetectable viral load could transmit HIV, just under half (48%) correctly said yes. CONCLUSION: Our study suggests Australian gbMSM are generally comfortable with answering more detailed questions regarding sexual activity during the assessment to donate, indicating they would do so honestly. gbMSM are knowledgeable about the WP duration, important for their ability to correctly self-assess their HIV risk. However, half of participants incorrectly assessed the transmissibility by blood transfusion from an HIV positive person with an undetectable viral load, suggesting the need for a targeted education campaign.

Removal of UK-donor deferral for variant Creutzfeldt-Jakob disease: A large donation gain in Australia.

BACKGROUND AND OBJECTIVES: Until 25 July 2022, people who spent more than 6 months in the United Kingdom during the variant Creutzfeldt-Jakob disease (vCJD) risk period 1980-1996 (UK donors) were deferred from blood donation in Australia. Regulatory approval to remove the deferral was underpinned by published mathematical modelling predicting negligible vCJD transmission risk increase with a gain of 58,000 donations. MATERIALS AND METHODS: The donor questionnaire retained the UK deferral screening question until a version update effective 12 February 2023, which enabled identification of the newly eligible cohort of UK donors. Their donations were tracked for a 6-month period (25 July 2022-24 January 2023) and compared with baseline Lifeblood donation metrics and predicted gains. RESULTS: A total of 38,462 UK donors attended to donate 78,762 times in the 6 months. Of these, 32,358 donors (females = 19,456, males = 12,902) successfully donated 67,914 times representing 8.4% of total collections. CONCLUSION: Cessation of the UK deferral resulted in donation gains exceeding modelled predictions because of a higher than predicted number of donors who donated at a higher rate. Had these newly eligible donors not donated, overall donation numbers would have been 88% of target rather than the 96% achieved.

Removing hepatitis C antibody testing for Australian blood donations: A cost-effectiveness analysis.

BACKGROUND AND OBJECTIVES: The risk of transfusion-transmitted hepatitis C virus (HCV) infections is extremely low in Australia. This study aims to conduct a cost-effectiveness analysis of different testing strategies for HCV infection in blood donations. MATERIALS AND METHODS: The four testing strategies evaluated in this study were universal testing with both HCV antibody (anti-HCV) and nucleic acid testing (NAT); anti-HCV and NAT for first-time donations and NAT only for repeat donations; anti-HCV and NAT for transfusible component donations and NAT only for plasma for further manufacture; and universal testing with NAT only. A decision-analytical model was developed to assess the cost-effectiveness of alternative HCV testing strategies. Sensitivity analysis and threshold analysis were conducted to account for data uncertainty. RESULTS: The number of potential transfusion-transmitted cases of acute hepatitis C and chronic hepatitis C was approximately zero in all four strategies. Universal testing with NAT only was the most cost-effective strategy due to the lowest testing cost. The threshold analysis showed that for the current practice to be cost-effective, the residual risks of other testing strategies would have to be at least 1 HCV infection in 2424 donations, which is over 60,000 times the baseline residual risk (1 in 151 million donations). CONCLUSION: The screening strategy for HCV in blood donations currently implemented in Australia is not cost-effective compared with targeted testing or universal testing with NAT only. Partial or total removal of anti-HCV testing would bring significant cost savings without compromising blood recipient safety.

West Nile virus transfusion-transmission risk in Australia associated with a seasonal outbreak in the United States.

BACKGROUND: West Nile virus (WNV) is a potentially transfusion-transmissible virus endemic in the US. The aim of this study was to estimate the monthly WNV transfusion transmission (TT) risk in Australia associated with donors returning from the US in 2018 and consider the implications for mitigation strategies. STUDY DESIGN AND METHODS: We used a probabilistic risk model to estimate the monthly WNV TT risks for each outbreak state/district in the US for the 2018 transmission season and the cumulative monthly risk for all US states/districts. RESULTS: The highest monthly cumulative transfusion risk in Australia occurred in August 2018 when 746 West Nile neuroinvasive disease cases were reported in the US and the estimated mean WNV TT risk in Australia was 1 in 1.0 × 108 donations (95% confidence interval [CI]: 1.6 × 108 -7.0 × 107 ). The highest risk during August was associated with California, with a mean risk of 1 in 4.1 × 108 donations (95% CI: 2.9 × 108 -6.6 × 108 ), representing 24% of the total risk in Australia. The cumulative TT risk in Australia for the other 11 months varied from 1 in 1.5 × 108 donations (95% CI: 2.3 × 108 -1.0 × 108 ) in September to 1 in 3.9 × 1010 donations (95% CI: 6.1 × 1010 -2.7 × 1010 ) in February. DISCUSSION: Our modeling indicates that the WNV TT risk in Australia associated with seasonal outbreaks in the US is extremely small and may not warrant donation restrictions for donors returning from the US.

Risk of variant Creutzfeldt-Jakob disease transmission by blood transfusion in Australia.

BACKGROUND AND OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Current challenges of severe acute respiratory syndrome coronavirus 2 seroprevalence studies among blood donors: A scoping review.

BACKGROUND AND OBJECTIVES: Blood donors are increasingly being recognized as an informative resource for surveillance. We aimed to review severe acute respiratory syndrome coronavirus 2 seroprevalence studies conducted among blood donors to investigate methodological biases and provide guidance for future research. MATERIALS AND METHODS: We conducted a scoping review of peer-reviewed and preprint publications between January 2020 and January 2021. Two reviewers used standardized forms to extract seroprevalence estimates and data on methodology pertaining to population sampling, periodicity, assay characteristics, and antibody kinetics. National data on cumulative incidence and social distancing policies were extracted from publicly available sources and summarized. RESULTS: Thirty-three studies representing 1,323,307 blood donations from 20 countries worldwide were included (sample sizes ranged from 22 to 953,926 donations). The majority of the studies (79%) reported seroprevalence rates <10% (ranging from 0% to 76% [after adjusting for waning antibodies]). Overall, less than 1 in 5 studies reported standardized seroprevalence rates to reflect the demographics of the general population. Stratification by age and sex were most common (64% of studies), followed by region (48%). A total of 52% of studies reported seroprevalence at a single time point. Overall, 27 unique assay combinations were identified, 55% of studies used a single assay and only 39% adjusted seroprevalence rates for imperfect test characteristics. Among the nationally representative studies, case detection was most underrepresented in Kenya (1:1264). CONCLUSION: By the end of 2020, seroprevalence rates were far from reaching herd immunity. In addition to differences in community transmission and diverse public health policies, study designs and methodology were likely contributing factors to seroprevalence heterogeneity.

HIV residual risk in Canada for apheresis source plasma donation without deferral for men who have sex with men.

BACKGROUND AND OBJECTIVES: In Canada, men having sex with men (MSM) are deferred for 3 months from last sexual contact to reduce human immunodeficiency virus (HIV) risk to recipients. The aim of this paper was to model the Canadian residual risk of HIV-positive source plasma incorporating pathogen inactivation (PI) under no MSM deferral scenarios for apheresis plasma donations. MATERIALS AND METHODS: A combined Bayesian network (BN) and Monte Carlo approach were implemented to estimate the HIV residual risk under 3-month deferral compared with no deferral without quarantine scenarios for MSM donors. Models involve the stochastic generation of donation and its infection status based on its corresponding simulated donor profile. Viral load reduction conferred by PI used by source plasma fractionators was simulated. Model parameters were derived from Héma-Québec and Canadian Blood Services data, viral loads in a large sample of HIV-positive US blood donors, CSL Behring documentation and from published data. RESULTS: In the most likely scenario for the 3-month deferral model, there were 2.71 positive donations per 1,000,000 donations (95% confidence interval [CI] 2.63-2.78). For the no-deferral model, there were 3.01 positive donations per 1,000,000 donations (95% CI 2.94-3.09). For both scenarios, the risk of having an infectious pool was 0 in 300,000 pools (95% CI 0-0.0000123) after consideration of PI. CONCLUSION: Based on simulation results, there would be a negligible HIV residual risk associated with the removal of a time-based MSM deferral without quarantine for source plasma incorporating PI.

Severe Acute Respiratory Syndrome Coronavirus 2 and Blood Safety: An Updated Review.

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.

Severe acute respiratory syndrome coronavirus-2: implications for blood safety and sufficiency.

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.

Endoscopies, blood-borne viruses and blood donors: time to move on from precaution.

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.

Effect of HIV pre-exposure prophylaxis (PrEP) on detection of early infection and its impact on the appropriate post-PrEP deferral period.

INTRODUCTION: HIV antivirals for pre-exposure prophylaxis (PrEP) are known to affect detection of early HIV infection through suppression of viral load and delayed seroconversion. To cover potential delay in HIV detection associated with PrEP use by blood donors in the context of international reductions in sexual activity-based deferral periods, we analysed the available data to determine the appropriate minimum post-PrEP deferral period for blood donation. MATERIALS AND METHODS: Published cases of incident HIV infection when PrEP use was objectively demonstrable were identified, consisting principally of seroconverters from the Partners PrEP study (a clinical trial of PrEP efficacy). Data were reviewed to determine the impact of PrEP on the detection of HIV RNA, p24 Ag and seroconversion delay. RESULTS: Nucleic acid testing (NAT) detected early HIV infection in the presence of PrEP prior to or in concordance with serological testing in approximately 90% of cases. Undetectable HIV RNA would rebound to detectable levels within two months of PrEP cessation. PrEP delayed p24 antigen detection and antibody seroconversion by about 7 days. CONCLUSION: Even when daily PrEP is continued, it is likely that the majority of early HIV infections are detectable by individual donation (ID)-NAT, with p24 Ag or antibody seroconversion occurring conservatively within four weeks of exposure. HIV RNA levels also rebound rapidly in the absence of PrEP. In Australia, a three-month deferral period for blood donation after the last dose of PrEP provides an appropriate safety margin to mitigate the residual risk of transfusion-transmitted HIV.

A Systematic Review of Interventions Used to Increase Blood Donor Compliance with Deferral Criteria.

BACKGROUND AND OBJECTIVES: Pre-donation screening of potential blood donors is critical for ensuring the safety of the donor blood supply, and donor deferral as a result of risk factors is practised worldwide. This systematic review was conducted in the context of an expert review convened by the Australian Red Cross Lifeblood in 2013 to consider Lifeblood's injecting drug use (IDU)-related policies and aimed to identify studies assessing interventions to improve compliance with deferral criteria in blood donation settings. MATERIALS AND METHODS: MEDLINE/PubMed, OVID Medline, OVID Embase, LILACS, and the Cochrane Library (CENTRAL and DARE) databases were searched for studies conducted within blood donation settings that examined interventions to increase blood donor compliance with deferral criteria. Observational and experimental studies from all geographical areas were considered. RESULTS: Ten studies were identified that tested at least one intervention to improve blood donor compliance with deferral criteria, including computerized interviews or questionnaires, direct and indirect oral questioning, educational materials, and a combination of a tickbox questionnaire and a personal donor interview. High-quality evidence from a single study was provided for the effectiveness of a computerized interview in improving detection of HIV risk behaviour. Low-quality evidence for the effectiveness of computerized interviews was provided by 3 additional studies. Two studies reported a moderate effect of direct questioning in increasing donor deferral, but the quality of the evidence was low. CONCLUSION: This review identified several interventions to improve donor compliance that have been tested in blood donation settings and provided evidence for the effectiveness of computerized interviews in improving detection of risk factors.

Modeling the West Nile virus transfusion transmission risk in a nonoutbreak country associated with traveling 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.

Attitudes and willingness to donate blood among gay and bisexual men in Australia.

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.

HIV residual risk in Canada under a three-month deferral for men who have sex with men.

BACKGROUND AND OBJECTIVES: In Canada, the deferral for men who have sex with men (MSM) was decreased from a permanent deferral to a 5-year then a 12-month deferral. Current HIV testing can detect an HIV infection in donated blood within 2 weeks of exposure; thus, a 12-month deferral may be unnecessarily restrictive. We aimed to estimate the residual risk of HIV if the deferral were further decreased to 3 months. MATERIALS AND METHODS: Using a deterministic model with stochastic Monte Carlo simulation, residual risk of HIV was the sum of testing error, assay sensitivity and window-period risks. Data inputs were estimated from donor surveillance, donor surveys and published data. Residual risk was modelled at baseline and using three scenarios: (1) most likely - non-compliance, HIV prevalence and incidence rates of MSM are unchanged; (2) optimistic - non-compliance improves by 50%; and (3) pessimistic - non-compliance, HIV prevalence and incidence rates of MSM all double. RESULTS: HIV residual risk at baseline was 1 in 36·0 million donations (95% CI 1 in 1 504 907 million, 10·5 million); in the most likely scenario 1 in 34·2 million (1 in 225 534 million, 8·7 million); in the optimistic scenario 1 in 36·0 million (1 in 282 618 million, 9·5 million); in the pessimistic scenario 1 in 16·7 million (1 in 39 469 million, 6·0 million). All confidence intervals overlapped. CONCLUSION: With very low modelled risk under a 12-month deferral, the additional risk with a 3-month deferral is very low. This is true even with a pessimistic scenario.

Blood safety assessment of hepatitis A outbreak linked to frozen pomegranate arils: are foodborne outbreaks an emerging blood safety risk?

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.

No evidence for widespread Babesia microti transmission in Australia.

BACKGROUND: A fatal case of autochthonous Babesia microti infection was reported in Australia in 2012. This has implications for Australian public health and, given that babesiosis is transfusion transmissible, has possible implications for Australian blood transfusion recipients. We investigated the seroprevalence of antibodies to B. microti in Australian blood donors and in patients with clinically suspected babesiosis. STUDY DESIGN AND METHODS: Plasma samples (n = 7,000) from donors donating in at-risk areas and clinical specimens from patients with clinically suspected babesiosis (n = 29) were tested for B. microti IgG by immunofluorescence assay (IFA). IFA initially reactive samples were tested for B. microti IgG and IgM by immunoblot and B. microti DNA by polymerase chain reaction. RESULTS: Although five donors were initially reactive for B. microti IgG by IFA, none was confirmed for B. microti IgG (zero estimate; 95% confidence interval, 0%-0.05%) and all were negative for B. microti DNA. None of the patient samples had B. microti IgG, IgM, or DNA. CONCLUSIONS: This study does not provide evidence for widespread exposure to B. microti in Australian blood donors at local theoretical risk, nor does it provide evidence of B. microti infection in Australian patients with clinically suspected babesiosis. Given that confirmed evidence of previous exposure to B. microti was not seen, these data suggest that transmission of this pathogen is currently uncommon in Australia and unlikely to pose a risk to transfusion safety at present.

Tattoos, blood-borne viruses and blood donors: a blood donor cohort and risk assessment.

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.

Changing the deferral for men who have sex with men - an improved model to estimate HIV residual risk.

BACKGROUND AND OBJECTIVES: Eight published studies modelled the impact of changing from a lifetime to time-limited deferral for men who have sex with men (MSM); each predicted greater risk impact than has been observed. This study uses these previous efforts to develop an 'optimized' model to inform future changes to MSM deferrals. MATERIALS AND METHODS: HIV residual risk was calculated using observed HIV incidence/prevalence prior to the change in MSM deferral, then with the additional MSM expected under a 12-month deferral for five compliance scenarios, and finally using data observed after implementation of the deferral. Monte Carlo simulation calculated 95% confidence intervals (CI). RESULTS: The architecture of reviewed models was sound, and two were selected for combination into the optimized model. HIV risk estimated by this in the UK under MSM lifetime deferral was 0·102 (95% CI: 0·050-0·172) per million. The model predicted from a 27·8% decrease to a 47·6% increase depending upon compliance pre-implementation of the 12-month deferral. A decrease of 0·9% was observed post-implementation. For Canada, HIV risk under a 5-year deferral was 0·050 (95% CI: 0·00003-0·122) per million. Pre-implementation of the 12-month deferral, the model predicted from 30·2% decrease to 10-fold increase. A decrease of 47·0% was observed after implementation. CONCLUSION: The optimized model predicted HIV risk under 12-month MSM deferral in UK and Canada would remain low, and this was confirmed post-implementation. While the model is adaptable to other deferral scenarios, improved data quality would improve precision, particularly estimates of incidence in individuals likely to donate.

Ross River virus in Australian blood donors: possible implications for blood transfusion safety.

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.