Hepatitis E virus infections in German blood donors: results of 8 years of screening, 2015 to 2022.

BackgroundAwareness of transfusion-transmitted hepatitis E raised in recent years led to the mandatory testing of blood donations in some European countries for hepatitis E virus (HEV) RNA. However, little is known about the epidemiology of HEV infections.AimTo and describe and analyse the epidemiology of HEV infections in blood donors in Germany.MethodsData from routine testing of therapeutic blood products donated between January 2015 and December 2022 at the Uni.Blutspendedienst OWL were analysed at the Institute of Laboratory and Transfusion Medicine, Heart and Diabetes Centre North Rhine-Westphalia. A total of 731,630 allogenic blood donations from 119,610 individual blood donors were tested for HEV RNA in minipools of 96 samples. The HEV RNA-positive donations were analysed for the presence of anti-HEV IgM and IgG. The HEV strains were genotyped and various clinical liver-specific parameters were determined.ResultsA total of 497 HEV-positive blood donations were identified, resulting in a yearly incidence of 1:1,474, from which 78.4% of the donations were RNA-only positive. Increased alanine aminotransferase activity was determined in 26.6% of HEV RNA-positive donors and was associated with the detection of IgG antibodies (1.2% anti-HEV IgM-positive, 11.9% anti-HEV IgM- and IgG-positive and 8.5% anti-HEV IgG-positive). An average incidence of 0.084-0.083% HEV RNA-positive donations in June and July in all years was observed, and a higher proportion of HEV RNA-positive men compared with women. All isolated HEV sequences corresponded to genotype 3.ConclusionOur results underline the necessity of HEV RNA screening in blood donations.

Epidemiology of HEV Infection in Blood Donors in Southern Switzerland.

From 2014 to 2016, the number of hepatitis E virus (HEV) infections in southern Switzerland increased dramatically and suggested food as a potential infection reservoir. We evaluated the effects of food control measures introduced to limit HEV infections, assessing anti-HEV IgG and IgM rates in blood donors before and after the implementation of food control measures in 2017. From 2012 to 2013, we screened 1283, and from 2017 to 2019, we screened 1447 donors for IgG and IgM antibodies. No statistically significant differences were detected for IgG (32.8% from 2012 to 2013 vs. 31.1% from 2017 to 2019, p = 0.337) or IgM rates (2.0% from 2012 to 2013 vs. 2.8% from 2017 to 2019, p = 0.21). Rural provenience and age > 66 are predictors for positive IgG serology. A total of 5.9% of 303 donors included in both groups lost IgG positivity. We also determined nucleic acid testing (NAT) rates after the introduction of this test in 2018, comparing 49,345 donation results from southern Switzerland with those of 625,559 Swiss donor controls, and only 9 NAT-positive donors were found from 2018 to 2023. The high HEV seroprevalence in southern Switzerland may depend on different food supply chains in rural and urban areas. Local preventive measures probably have a limited impact on blood HEV risk; thus, continuous NAT testing is recommended.

Prevalence of HEV RNA in Croatian blood donors.

OBJECTIVES: HEV infection is asymptomatic for immunocompetent blood donors (BD). Transfused HEV-infected blood products may cause potentially hazardous HEV infection in immunocompromised patients. Evaluation of the need for routine BD HEV RNA screening primarily demands the establishment of HEV infection prevalence in Croatian BD. MATERIALS AND METHODS: We tested BD samples in ID-NAT with the Procleix UltrioPlex E screening test for simultaneous detection of HBV DNA, HCV RNA, HIV-1,2 RNA, and HEV RNA (Grifols, Spain). HEV infection was confirmed with HEV RNA quantitative test (Altona Diagnostics, Germany) and HEV IgM and HEV IgG antibody test (DIA.PRO Diagnostic Bioprobes, Italy). We analysed the HEV RNA sequence and performed a phylogenetic analysis. We recorded BD's anamnestic data and dietary habits. BDs gave follow-up samples after two months and did not donate blood for six months. RESULTS: Between December 2021 and March 2022, we tested 8,631 donations and found four HEV RNA-positive donations, which equals to one in 2,158 donations (0.046 %, 95 % confidence interval, 0.018 %-0.119 %). Confirmatory HEV RNA testing gave results from negative to 4.73E + 3 IU/ml HEV RNA. Three donations were in the serological window period. We have genotyped HEV RNA of two infected BD as genotype HEV-3c. Blood donors didn't report any health problems and their diet included pork. Testing on follow-up samples presented seroconversion and no HEV RNA could be detected. CONCLUSION: The incidence of HEV RNA infection in BD in Croatia corresponds with other European data. The decision on implementation of HEV NAT screening in Croatia needs an expert team evaluation of the possible risk of TT-HEV infection.

An international comparison of HIV prevalence and incidence in blood donors and general population: a BEST Collaborative study.

BACKGROUND AND OBJECTIVES: Efficiency in mitigating HIV transmission risk by transfusion may vary internationally. We compared HIV prevalence and incidence in blood donors across different jurisdictions in relation to those rates in the general population and differences in deferral practices. MATERIALS AND METHODS: Data from 2007 to 2016 were collected in Australia, Brazil (São Paulo), Canada, England, France, Italy, Ireland, Japan, the Netherlands, New Zealand, Norway, Spain (Basque Country), USA (Vitalant) and Wales. For each country/region, the number of HIV antibody-positive donations and nucleic acid testing (NAT)-only-positive donations was broken down according to first-time or repeat donor status, along with the relevant denominators. RESULTS: There is a modest correlation between HIV prevalence among first-time donors and HIV prevalence in the general population. However, rates of HIV-positive donations in repeat donors, a proxy for incidence, do not correlate with incidence rates in the general population. Rates in donors from Italy and Basque Country, where deferral criteria for men having sex with men are less stringent, are higher compared with most other jurisdictions. Rates of NAT-only-positive donations are extremely low and do not differ significantly after adjustment for multiple comparisons. CONCLUSION: Donor HIV rates are only weakly associated with those observed in the general population. Countries with less stringent deferral criteria have higher HIV rates in their donor population, but the rates remain very low.

An economic reappraisal of hepatitis B virus testing strategy for blood donors in Taiwan.

BACKGROUND AND OBJECTIVES: Taiwan is among the few hepatitis B virus (HBV) high-endemic countries that implement universal mini-pool nucleic acid testing (MP-NAT) and hepatitis B surface antigen (HBsAg) testing together with confirmatory individual donor nucleic acid testing (ID-NAT) for its blood supply since 2013. The aim of this study was to reappraise the value of HBsAg test in Taiwan's HBV testing strategy. MATERIALS AND METHODS: A Markov model was constructed, and cost-effectiveness analysis was conducted in order to reappraise the existing HBV screening strategy in Taiwan. RESULTS: The incremental cost-effectiveness ratio (ICER) for the current testing strategy in Taiwan was estimated to be $US 443 154 per quality-adjusted life year (QALY) gained. This is almost six times the willingness-to-pay (WTP) threshold that reflects local preferences. CONCLUSION: Universal HBsAg and MP-8-NAT together with confirmatory ID-NAT testing prevents a significant amount of HBV infections from entering the Taiwan blood supply. However, this comes at a disproportionate increase in cost.

HIV incidence in South African blood donors from 2012 to 2016: a comparison of estimation methods.

BACKGROUND: Measuring incidence is important for monitoring and maintaining the safety of the blood supply. Blood collected from repeat-donors has provided the opportunity to follow blood donors over time and has been used to estimate the incidence of viral infections. These incidence estimates have been extrapolated to first-time donors using the ratio of NAT yield cases in first-time versus repeat-donors. We describe a model to estimate incidence in first-time donors using the limiting antigen (LAg) avidity assay and compare its results with those from established models. METHODS: HIV-positive first-time donations were tested for recency using the LAg assay. Three models were compared; incidence estimated for (1) first-time donors using LAg avidity, (2) first-time and repeat-donors separately using the NAT yield window period (WP) model and (3) repeat-donors using the incidence/WP model. RESULTS: HIV incidence in first-time donors was estimated at 3·32 (CI 3·11, 3·55) and 3·81 (CI 3·07, 4·73) per 1000 PY using the LAg assay and NAT yield WP models, respectively. Incidence in repeat-donors was between 2·0- and 2·5-fold lower than in first-time donors estimated at 1·56 (CI 1·37, 1·77) and 1·94 (CI 1·86-2·01) per 1000 PY using the NAT yield/WP and incidence/WP models, respectively. CONCLUSION: Testing HIV-positive donations using the LAg assay provides a reliable method to estimate incidence in first-time donors for countries that collect the majority of blood from first-time donors and do not screen with NAT.

Direct comparison of three residual risk models for hepatitis B virus window period infections using updated input parameters.

BACKGROUND AND OBJECTIVES: Comparison of two models for estimating residual transfusion transmission risk by NAT screened window period (WP) donations in South African repeat donors gave identical results for HIV but not for HBV. In order to understand discrepant HBV modelling outcomes, the values of input parameters in three HBV WP risk models were reviewed and subsequently applied to the same South African screening data generated by HBsAg PRISM and two NAT assays (Ultrio and Ultrio Plus). Two of the models were also compared using individual donation (ID)-NAT screening data from different geographical regions. METHODS: Values of input parameters were derived from two published data sources and used in three risk models [(1) the incidence rate-WP risk day equivalent model, (2) the NAT yield WP ratio model and (3) the anti-HBc-negative HBsAg yield period ratio model] and subsequently applied to the same ID-NAT screening data. RESULTS: The HBV WP transmission risk in South African repeat donations during a one-year Ultrio Plus NAT screening period was estimated as 22, 43 and 17 per million, respectively, for the three models, as compared to 56, 117 and 48 per million for HBsAg PRISM screening. The approximate two-fold higher estimate calculated with the NAT yield WP ratio model was corroborated in repeat donations from three of four regions in a multi-regional study. When another set of model input values (with shorter viraemia periods and a higher proportion of acute occult infections) was applied to the South African screening data, the relative difference in risk estimates between the three models became smaller. CONCLUSIONS: Window period risk modelling for HBV is more complex than for HIV. Multiple factors affect the modelling outcomes. These include the values used for the length of transient HBsAg and HBV-DNA-positive phases, the proportion of acute occult and vaccine breakthrough infections and the assumption of random appearance of donors throughout the entire acute resolving infection phase. A substantial proportion of HBV WP NAT yields have very low viral load and lack donor follow-up data calling into question their definitive classification into the early acute (infectious) replication stage. Since these possible WP NAT yields most highly impact the NAT yield WP ratio model, we recommend relying on the more conservative estimates of the incidence rate-WP risk day equivalent model.

Transfusion-Transmitted Hepatitis E: NAT Screening of Blood Donations and Infectious Dose.

The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The infectious dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than 2 years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the infectious dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/mL). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving an HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (<100 IU/mL). Of note, the distribution of viral RNA in blood components depends on the plasma content of the component; nonetheless, HEV RNA could be detected in RBCs even when low viral plasma loads of 100-1,000 IU/mL are present. Comprehensive retrospective studies of TT-HEV infection offered further insights into the infectivity of HEV RNA-positive blood products. Minipool HEV NAT screening (96 samples) of blood donations should be adequate as a routine screening assay to identify high viremic donors and will cover at least a large part of viremic phases.

Transfusion-transmitted hepatitis B virus (HBV) infection from an individual-donation nucleic acid (ID-NAT) non-reactive donor.

Lookback was initiated upon notification of an acute HBV infection in a repeat Irish donor, 108 days post-donation. The donation screened non-reactive by individual-donation nucleic acid testing (ID-NAT) using the Procleix Ultrio Elite multiplex assay and again when the archived sample was retested, but the discriminatory assay for HBV was reactive. The immunocompromised recipient of the implicated red cell component was tested 110 days post-transfusion, revealing a HBV DNA viral load of 470 IU/ml. Genotype C2 sequences identical across two regions of the HBV genome were found in samples from the donor and recipient.

Amustaline (S-303) treatment inactivates high levels of Chikungunya virus in red-blood-cell components.

BACKGROUND AND OBJECTIVES: Chikungunya virus (CHIKV) infections have been reported in all continents, and the potential risk for CHIKV transfusion-transmitted infections (TTIs) was demonstrated by the detection of CHIKV RNA-positive donations in several countries. TTIs can be reduced by pathogen inactivation (PI) of blood products. In this study, we evaluated the efficacy of amustaline and glutathione (S-303/GSH) to inactivate CHIKV in red-blood-cell concentrates (RBCs). MATERIAL AND METHODS: Red-blood-cells were spiked with high level of CHIKV. Infectious titres and RNA loads were measured before and after PI treatment. Residual CHIKV infectivity was also assessed after five successive cell culture passages. RESULTS: The mean CHIKV titres in RBCs before inactivation was 5·81 ± 0·18 log10 50% tissue culture infectious dose (TCID50 )/mL, and the mean viral RNA load was 10·49 ± 0·15 log10 genome equivalent (GEq)/mL. No CHIKV TCID was detected after S-303 treatment nor was replicative CHIKV particles and viral RNA present after five cell culture passages of samples obtained immediately after S-303 treatment. CONCLUSION: Chikungunya virus was previously shown to be inactivated by the PI technology using amotosalen and ultraviolet A light for the treatment of plasma and platelets. This new study demonstrates that S-303/GSH can inactivate high titres of CHIKV in RBCs.

Organ utilization from increased infectious risk donors: An observational study.

BACKGROUND: Donors with an increased risk of transmitting human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV) (increased risk donors [IRDs]) are a potential source of organs for transplant. Organs from IRDs can be utilized with appropriate recipient consent and post-transplant follow-up. We reviewed the characteristics and utilization of IRDs in our Organ Procurement Organization (OPO) over a 2-year period. METHODS: Donor information from April 1, 2013 to March 31, 2015 was obtained through the OPO database. Only consented donors were included. Donors were categorized as IRDs according to Health Canada/Canadian Standards Association (CSA) criteria. RESULTS: A total of 494 potential donors were identified, of which 92 (18.6%) were IRDs. Of these, at least one organ was transplanted from 76 (82.6%). Risk factors for IRDs included injection drug user (IDU) (12%), men having sex with men (MSM) (7%), commercial sex worker (CSW) (4%), and incarceration (24%). Fifty-nine percent (253/429) of IRD organs were utilized. The most frequently used organ was kidney, followed by liver. Median number of organs recovered per IRD was 3 (interquartile range: 2-5). Nucleic acid testing (NAT) was performed in 18.5% (17/92) of IRDs. Reasons for NAT were IDU (n = 2), MSM (n = 2), CSW (n = 2), and previous incarceration (n = 7). Organ utilization from donors that had NAT was similar to donors who did not (94% vs 80%, P = .29). Follow-up NAT was done in <5% of recipients from IRDs. CONCLUSIONS: In our cohort, IRDs comprised a significant proportion of donors. Utilization of IRD organs occurred at a significant rate regardless of pre-transplant NAT. These data suggest that multiple factors contribute to the perception of infectious risk from such organs.

NAT positivity in seronegative voluntary blood donors from western India.

BACKGROUND AND OBJECTIVES: Prevalence and composition of Hepatitis B, Hepatitis C and HIV-1, NAT positive but seronegative voluntary blood donors from western part of India is yet to be documented. MATERIAL AND METHODS: Over last 2 1/2 years all the seronegative voluntary blood donors were tested using 10 minipools on a semiautomated NAT testing platform. The positively tested donors were followed up for at least five months for development of seropositivity. RESULTS: 79532 seronegative donations were tested by 10 minipool (MP) NAT leading to 51 positive sample (44 Hep B, 5 HIV 1 and Hep C positive). All the HIV and Hep C NAT positive donors eventually developed seropositivity and out of 44 Hep B NAT positive donors, 31 developed seropositivity within six months of follow up, following counseling of the donors. This data translate into NAT yield of 1:1559 donors for all virus taken together. NAT yield for Hep B 1:1807 donors were much higher than HIV 1 in 1:15906 and HCV yield of 1:39761. Semiautomated minipool NAT testing system was found to be cost effective way for improving blood safety. INTERPRETATION AND CONCLUSION: Seronegative NAT yield in voluntary blood donors are quiet high in western part of India and in line with rest of the country is mainly due to Hepatitis B infection. Implementation of strict donor screening, Hep B vaccination of the population and sample mutation of NAT testing should be under taken on war footing.

Three-Year Experience in NAT Screening of Blood Donors for Transfusion Transmitted Viruses in Croatia.

BACKGROUND: Croatia implemented individual donation (ID)-NAT testing of blood donors in 2013 for three viruses HBV, HCV, and HIV-1 as a mandatory test for all blood donors. This study assessed the impact of NAT screening 3 years after its implementation. METHODS: A total of 545,463 donations were collected and screened for HBV, HCV, and HIV-1 using the Procleix Ultrio Plus Assay. All initially reactive (IR) NAT samples were retested in triplicate and, if repeatedly reactive (RR), NAT discriminatory assay (dNAT) was performed. ID-NAT positive donations were confirmed by RT-PCR on the COBAS AmpliPrep/TaqMan platform. RESULTS: Out of 545,463 samples tested, 108 (0.02%) were RR in NAT. There were 82 (75,9%) HBV reactive, 16 (14.8%) HCV reactive, and 10 (9.3%) HIV-1 reactive samples. 51 (47.2%) samples were ID-NAT positive only. Out of these 51 NAT yield cases, 1 window period HIV-1 and 50 occult HBV infections (OBI) were determined. There were only two potential HBV DNA transmissions from OBI donors. CONCLUSION: The implementation of NAT screening for three viruses has improved blood safety in Croatia. During the 3-year period, 1 window period HIV-1 and a number of occult HBV donations were identified.

Hepatitis E virus in donor plasma collected in Japan.

BACKGROUND AND OBJECTIVES: Human hepatitis E virus (HEV) is prevalent worldwide. Iatrogenic HEV has recently been identified based on the reports of transfusion-transmitted cases. The detection rate of HEV-RNA and seroprevalence of HEV-IgG/IgM have been regionally evaluated in Japan, and donor plasma collected in Hokkaido is currently screened by nucleic acid amplification testing. However, the detection rate of HEV-RNA in blood donors in Japan outside of Hokkaido has not been reported. MATERIALS AND METHODS: A total of 620 140 qualified donor plasma samples from Japanese regions excluding Hokkaido were tested for HEV-RNA (pools of 50 or 500) between 2004 and 2014. HEV-RNA-positive plasma bags were identified, and the HEV viral load, genotype and anti-HEV immunoglobulin (Ig)G/IgM were evaluated. RESULTS: The detection rate of HEV-RNA (pools of 50) was 1/15 075 and higher in eastern than in western Japan. All 36 HEV-RNA-positive samples were genotype 3 with viral load ranging from <1·69 to 7·22 log10 copies/ml. CONCLUSIONS: Our detection rate of HEV-RNA in donor populations in Japan outside Hokkaido (1/15 075 donations) is generally lower than reported in Europe and lower than previously reported for Hokkaido (1/8173 donations). As methods varied, we cannot exclude that these differences are reflective of differing RNA detection limits. In contrast to Hokkaido where genotype 4 has been reported among blood donations, all our positive donations were genotype 3, which is less pathogenic.

A significantly lower potency observed for the 3rd WHO International Standard for Parvovirus B19V DNA with the cobas TaqScreen DPX test.

BACKGROUND: In the context of the Official Medicines Control Laboratories plasma pool testing for Parvovirus B19 DNA, we use the cobas TaqScreen DPX test. When we re-evaluated this method using the 3rd B19 DNA WHO IS at the final concentration of 4 log IU/mL, we observed a titre lower than expected, i.e. 3.79 log IU/mL. Therefore, we further investigated the accuracy of the DPX test. MATERIALS & METHODS: The following B19V DNA materials were tested by using both the DPX test and an in-house real-time PCR: The 1st, 2nd and 3rd WHO ISs for B19V DNA The Non WHO B19V DNA Reference Material for NAT The Biological Reference Preparation B19 virus DNA for NAT testing, batch 1 . RESULTS: The DPX test showed a good accuracy for all B19V DNA materials with the exception of the 3rd WHO IS for B19V DNA. In fact, an underestimation of about 38% was observed for all dilutions of this standard with respect to the nominal titre. With the B19V in-house real-time PCR, all four materials proved to be well calibrated against the 1(st) WHO IS for B19V DNA, used as external standard curve. CONCLUSION: In this study, we demonstrated that the DPX test underestimates the B19V DNA content of the 3rd WHO IS for B19V DNA and that this is not due to an incorrect potency assigned to the standard but, most probably, to a mismatch between the primers/probe and the sequence of the target region in the 3rd WHO IS for B19V DNA.

Unusual serological response to hepatitis E virus in plasma donors consistent with re-infection.

Hepatitis E virus (HEV)-positive plasma donations, identified by a plasma mini-pool screening approach, were analysed using serological methods for the presence of anti-HEV IgM and IgG. Avidity testing was performed on the IgG-reactive donations. Anti-HEV IgG with high avidity was observed in two donors together with high viral loads, but with the absence of anti-HEV IgM. These data are suggestive of re-infection in a small proportion of plasma donors, which has not previously been reported.

Infectivity of blood components from donors with occult hepatitis B infection - results from an Australian lookback programme.

BACKGROUND AND OBJECTIVES: Previous studies have demonstrated that transfused blood components from donors with occult hepatitis B virus infection (OBI) are potentially infectious. This study reports the results of an Australian lookback programme for the period subsequent to the commencement of individual donation HBV NAT in July 2010 and estimates the HBV transmission rate for components from two categories of donors, confirmed OBI and HBV inconclusive (anti-HBc reactive with non-discriminated NAT result). MATERIALS AND METHODS: Using the results of lookback investigations, we estimated HBV transmission rates by donor category and type of component transfused based on the prevalence of antibodies to HBV core antigen (anti-HBc) in recipients adjusted for the estimated prevalence in the general population. RESULTS: After subtracting the background anti-HBc rate, we derived an adjusted transmission rate (all components) with lower and upper bounds as follows: 0·85% (0·00-2·35%) for OBI donors, 2·83% (1·23-4·33%) for inconclusive donors and 1·81% (0·21-3·31%) for total (OBI and inconclusive) donors. The median adjusted transmission rate for total donors was higher (but not statistically) for plasma (3·01%) than RCCs (2·86%), but there was no evidence of transmission for cryoprecipitate or platelets (0% for both components). CONCLUSION: Our lookback study suggests a low (0·2-3·3%) but measurable rate of HBV transmission in Australia associated with donors with OBI and supports published evidence that at least some blood component types from OBI donors, including a proportion undetectable by ID-NAT can transmit HBV by transfusion.

Current epidemiology and clinical practice in arboviral infections - implications on blood supply in South-East Asia.

Arthropod-borne viruses (arboviruses) are a growing threat to global health. Complex vector-virus-host interactions lead to unpredictable epidemiological patterns. Difficulties in accurate surveillance including imperfect diagnostic tools impair effective response to outbreaks. With arboviral infections causing a wide spectrum of disease severity, from asymptomatic infection to fatal neuroinvasive and haemorrhagic fevers, the potential impact on blood safety is significant. Asymptomatic or presymptomatic individuals may introduce virus into the blood supply by donation, while recipients can potentially suffer severe consequences. Dengue, West Nile and chikungunya outbreaks have led to responses by blood transfusion services which can inform future planning. Reports of transfusion-associated transmission demonstrate the potentially fatal consequences of lack of haemovigilance. South-East Asia remains vulnerable to arboviruses with permissive climate and high levels of endemic transmission as well as the potential for emerging and re-emerging arboviral diseases. Resource limitations constrain the use of expensive technologies for donor screening. Continued surveillance and research will be required to manage the arboviral threat to the blood supply.

Mini review: current molecular methods for the detection and quantification of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus type 1.

The detection of acute human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection is vital for controlling the spread of HIV, HBV, and HCV to uninfected individuals. Considering that these viruses have high replication rates and are undetectable by serological markers, early detection upon transmission is crucial. Various nucleic acid assays have been developed for diagnostics and therapeutic monitoring of infections. In the past decade, rapid and sensitive molecular techniques such as PCR have revolutionized the detection of a variety of infectious viruses, including HIV, HCV, and HBV. Here, we describe two of the most commonly used licensed methods for the detection and quantification of HIV, HCV, and HBV: the cobas TaqScreen MPX (PCR) test and the Tigris System. We used transcription-mediated amplification to review and compare the development and efficiency of these technologies.

Hepatitis E virus in Scottish blood donors.

BACKGROUND AND OBJECTIVES: Published prevalence figures for hepatitis E virus (HEV) reveal significant regional differences. Several studies have reported virus transmission via blood transfusion. The aim of this study was to establish HEV seroprevalence and investigate a potential HEV RNA presence in Scottish blood donors. MATERIALS AND METHODS: IgG and IgM were determined in individual serum samples. HEV RNA was investigated in plasma mini-pools corresponding to 43 560 individual donations using nested PCR. Samples amenable to reamplification with primers from a different region were considered confirmed positives, sequenced and analysed. RESULTS: A total of 73 of 1559 tested individual sera (4·7%) were IgG positive, none tested positive for IgM. Plasma mini-pool testing revealed an HEV RNA frequency of 1 in 14 520 donations. Three confirmed positives belonged, as expected to genotype 3. CONCLUSIONS: HEV IgG and RNA figures in Scottish blood donors are lower than those published for the rest of the UK, but sufficiently high to prompt further studies on potential transmission rates and effects of HEV infection, especially for immunosuppressed individuals.