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

Advancing blood transfusion safety using molecular detection in the country of Georgia

BACKGROUND

In 2015, the country of Georgia initiated its hepatitis C virus (HCV) elimination program. Given a high background incidence of HCV infection, centralized nucleic acid testing (NAT) of blood donations was prioritized for implementation.

STUDY DESIGN AND METHODS

Multiplex NAT screening for HIV, HCV and hepatitis B virus (HBV) was launched in January 2020. An analysis was conducted of serological and NAT donor/donation data for the first year of screening (through December 2020).

RESULTS

A total of 54,116 donations representing 39,164 unique donors were evaluated. Overall, 671 donors (1.7%) tested positive for at least one infectious marker by serology or NAT, with the highest prevalence among donors aged 40-49 years (2.5%; n = 200), male (1.9%; n = 524), replacement (2.8%; n = 153) and first time (2.1%; n = 642) donors. Sixty donations were seronegative but NAT positive, and therefore would not have been found by traditional serology testing alone. These were more likely among female vs. male (adjusted odds ratio [aOR] 2.06; 95% confidence interval [95%CI]: 1.05-4.05), paid (aOR 10.15; 95%CI: 2.80-36.86) or voluntary (aOR 4.30; 95%CI: 1.27-14.56) vs replacement, and repeat vs. first time (aOR 13.98; 95%CI: 4.06-48.12) donors. On repeat serological testing (including HBV core antibody [HBcAb] testing), 6 HBV + donations, 5 HCV + donations and 1 HIV + donations were deemed NAT yield (detected through the implementation of NAT, and would have otherwise been missed by serology screening alone).

CONCLUSION

This analysis offers a regional model for NAT implementation, demonstrating the feasibility and clinical utility in a nationwide blood program.

Blood Donation Screening of Transfusion-Transmissible Viral Infection Using Two Different Nucleic Acid Testing (NAT) Platforms: A Single Tertiary Care Oncology Centre Experience

Nucleic acid testing (NAT) is used to screen transfusiontransmittable infections (TTIs) in donated blood samples and provide an additional layer of blood safety. In this study, we describe our experience in screening viral TTIs using two formats of NAT: cobas® MPX2 polymerase chain reaction- based minipool NAT (PCR MP-NAT) and Procleix Utrio Plus transcription-mediated amplificationbased individual donor-NAT (TMA ID-NAT). Data routinely collected as a part of blood bank operations were retrospectively analysed over a period of 70 months for TTIs. Blood samples were initially screened for HIV, HBV, HCV, syphillis by chemiluminescence and malaria by Rapid card test. In addition to serological testing, all samples were further screened by TMA-based ID-NAT (ProcleixUltrio Plus Assay) during Jan 2015-Dec 2016, and by PCR-based MP-NAT (Cobas® TaqScreen MPX2) during Jan 2017-Oct 2020. RESULTS: A total of 48,151 donations were processed over 70 months, of which 16,212 donations were screened by ProcleixUtrio Plus TMA ID-NAT and 31,939 donations by cobas® MPX2 PCR MP-NAT. Replacement donors and male donors outnumbered voluntary donors and female donors respectively. The overall NAT yield rate of MP-NAT was 1:2281 compared to 1:3242 with ID-NAT, during the respective time period. ID-NAT detected 5 HBV infections missed by serology, whereas MP-NAT detected 13 HBV infections and 1 HCV infection missed by serology. The proportion of donations that were both seroreactive and NAT reactive was higher with MP-NAT (59.8%) compared to ID-NAT (34.6%). Cobas® MPX2MP-NAT had higher overall NAT yield rate compared to ProcleixUtrio Plus ID-NAT and confirmed a higher proportion of seroreactive donations. Due to the ease of operation, simple algorithm, cobas® MPX2 PCR based MP-NAT can be an effective solution for blood screening in India.

Genetic diversity of the human immunodeficiency virus of type 1 in Gabonese transfusional settings

BACKGROUND

The high endemicity of transfusion-transmissible infections (TTIs) in sub-Saharan Africa is a real public health problem. To reduce the risk of HIV transmission through blood donation, the NBTC of Gabon has launched in recent years a reorganization of its blood transfusion system. This study aims to characterize the molecular strains of HIV-1 circulating in donors and to estimate the risk of viral transmission.

MATERIALS AND METHODS

A cross-sectional study was carried out during the period from August 2020 to August 2021 among 381 donors who had agreed to donate blood at the National Blood Transfusion Center (NBTC). Viral load was determined by Abbott Real-Time (Abbott m2000®, Abbott) and sequencing by the Sanger method (ABI 3500 Hitachi®). The phylogenetic tree was constructed by MEGA X software. Data were checked, entered, and analyzed using SPSS version 21.0 software, with p ≤ 0.05 considered statistically significant.

RESULTS

A total of 381 donors were enrolled in the study. Among the 359 seronegative donors, five (5) seronegative donors were detected positive for HIV-1 using Real-Time PCR. The residual risk was 648 per 1,000,000 donations. The prevalence of residual infection was 1.4% [0,01; 0,03]. Sixteen (16) samples were sequenced. The strains obtained were CRF02_AG (50%), subtype A1 (18.8%), subtype G (12.5%), CRF45_cpx (12.5%) and subtype F2 (6.2%). Six sequences clustered with A1, G, CRF02_AG, and CRF45_cpx subtypes.

CONCLUSION

The residual risk of HIV-1 transmission by blood transfusion remains a concern in the Gabonese transfusional settings. A policy based on improving the current screening strategy would involve the implementation of the nucleic acid test (NAT) in order to optimize the safety of the donation by detecting the HIV-1 subtypes in circulation in the donors.

Effectiveness of Using Nucleic Acid Amplification Test to Screen Blood Donors for Hepatitis B, Hepatitis C, and HIV: A Tertiary Care Hospital Experience From Pakistan

Background Ensuring blood safety is the primary goal of transfusion medicine. Despite extensive serological tests and strict safety measures, the risk of transfusion-transmitted infections (TTIs) still exists. As applied to blood screening, Nucleic Acid Amplification Test (NAT) offers much higher sensitivity for detecting viral infections. It is, however, currently available to a handful of centers due to the high cost. This study aims to establish the Effectiveness of NAT by assessing the NAT yield and residual risk of transmission of Hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV with and without NAT testing. Material and method This prospective cross-sectional study recruited blood donors from January 2020 to November 2022. All donors underwent routine serologic screening. Only serologically negative donors were tested for HBV, HCV, and HIV by NAT. The NAT yield and residual risk (RR) per million donors were computed for viral infections in seronegative blood donors and calculated using the incidence/window period model. Result A total of 59708 donors were included during the study period. The overall prevalence of TTI's were: For HCV 1.7% (n = 1018), HBV 1.5% (n = 918), HIV 0.07% (n = 47), Syphilis 1.2% (n = 758) and malaria 0.3% (n = 218). Out of 57759 seronegative donors, thirty-four NAT-reactive samples were identified, with 3 cases of HCV, 31 cases of HBV, and Nil HIV cases. NAT yield of HBV was 1 in 1863 with an RR of 8.6 per million, followed by HCV with a NAT yield of 1 in 19253 and RR of 0.8 per million donations. NAT testing reduced RR for HBV by 48.9% and HCV by 94.5%. Conclusion Our study showed that NAT detected 34 out of 57759 cases initially missed by serological tests. The study suggests that the parallel use of serology and NAT screening of donated blood would be beneficial.

The impact of nucleic acid testing to detect human immunodeficiency virus, hepatitis C virus, and hepatitis B virus yields from a single blood center in China with 10-years review

BACKGROUND

Since 2010, the Blood Center of Zhejiang province, China, has conducted a pilot nucleic acid amplification testing (NAT) screening of blood donors for Hepatitis B virus (HBV), Hepatitis C virus (HCV), and Human immunodeficiency virus (HIV). This study aims to assess the results of NAT testing over 10 years to establish the effects and factors influencing NAT yields of HBV, HCV, and HIV.

METHODS

Blood donations from seven different blood services were screened for HBV DNA, HCV RNA, and HIV RNA using 6 mini pools (6MP) or individual donation (ID)-NAT method between August 1, 2010, and December 31, 2019, at the NAT centralized screening center. We compared 3 transcription-mediated amplification (TMA) assays and 2 polymerase chain reaction (PCR) assays. Further, HBV, HCV, and HIV NAT yields were calculated and donor characteristics and prevalence of HBV NAT yields analyzed. Donors with HCV and HIV NAT yield were also followed up.

RESULTS

1916.31 per million donations were NAT screening positive overall. The NAT yields for HBV, HCV, HIV and non-discriminating reactive were 1062.90 per million, 0.97 per million, 1.45 per million, and 850.99 per million, respectively, which varied in the seven blood services and different years. HBV NAT yields were higher than those of HCV and HIV and varied across demographic groups. Risk factors included being male, old age, low education level, and first-time donors. We found no differences in NAT yields of HBV, HCV, and HIV between the 3 TMA and 2 PCR assays; nonetheless, statistically, significant differences were noted between the five assays.

CONCLUSION

In summary, NAT screening in blood donations reduces the risk of transfusion-transmitted infections and shortens the window period for serological marker screening. Therefore, a sensitive NAT screening method, ID-NAT workflow, and recruitment of regular low-risk donors are critical for blood safety.

Viral safety of recovered plasma for contract fractionation; an Iranian experience, 2006-2015

OBJECTIVE

The current study analysed the viral safety among Iranian blood donors.

BACKGROUND

Plasma products demand is increasing in the world. With contract plasma fractionation, the plasma wastage decreases and the access of patients to plasma-derived medicines (PDM) improves.

STUDY AND DESIGN METHOD

Screening results including hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV), and human immunodeficiency virus (HIV) Ag/Ab of 19 054 036 donations from 2006 to 2015 were analysed. The plasma for fractionation was tested for HBV DNA, HCV RNA, HIV RNA, HAV RNA, and Parvovirus B19 DNA by fractionators. New samples were collected from the positive donors and retested. The prevalence of serological and nucleic acid testing (NAT) markers per 10⁵ donations, 95% confidential interval (CI), and p-values were calculated.

RESULTS

The prevalence of markers was as follows: 250/10⁵ donations for HBsAg from 516 in 2006 to 116/10⁵ donations in 2015; 74/10⁵ donations for HCV, decreasing from 127 to 41/10⁵ and 3.6/10⁵ for HIV during current study. During 10 years, 5 713 641 units of recovered plasma were shipped for contract fractionation to produce PDM; 0.26/10⁵ donations for HBV DNA and 0.14/10⁵ for HCV RNA were reported positive. The results of five retested samples for HBV and one sample for HCV were negative.

CONCLUSION

The prevalence of HBV, HCV, and HIV in blood donations was extremely low. Thanks to the availability, high quality and safety of recovered plasma as a result of the improvements in the quality system at IBTO, this plasma could be used for the production of PDMPs.

Assessing the global burden of hemorrhage: The global blood supply, deficits, and potential solutions

There is a critical shortage of blood available for transfusion in many low- and middle-income countries. The consequences of this scarcity are dire, resulting in uncounted morbidity and mortality from trauma, obstetric hemorrhage, and pediatric anemias, among numerous other conditions. The process of collecting blood from a donor to administering it to a patient involves many facets from donor availability to blood processing to blood delivery. Each step faces particular challenges in low- and middle-income countries. Optimizing existing strategies and introducing new approaches will be imperative to ensure a safe and sufficient blood supply worldwide.

Characteristic of HBV nucleic acid amplification testing yields from blood donors in China

BACKGROUND

Nucleic acid amplification testing (NAT) for blood screening has been previously performed in some countries to determine NAT yields. The current study sought to explore the non-discriminating reactive NAT yields using individual-NAT (ID-NAT) and characteristics of HBV NAT yields through a 10-year retrospective analysis in Zhejiang, China.

METHODS

Blood donations were analyzed using individual-NAT mode by the transcription-mediated amplification (TMA) method. Supplementary HBV serological tests were performed using chemiluminescent immunoassay, and HBV viral load assay was performed by real-time polymerase chain reaction. Follow-up studies were performed in partial donors with low HBV viral loads.

RESULTS

Non-discriminating reactive NAT yields and HBV NAT yields varied in different years. The yields ranged from 853.73 per million to 2018.68 per million and 624.60 per million to 1669.50 per million, respectively. In the 476 NAT yields, 19 were probable window periods (WP), 33 probable occult hepatitis B virus infections (OBIs), 409 were confirmed OBIs and 15 were chronic HBV infections. ID-NAT results were categorized in four groups, and the findings showed that the levels of HBV DNA viral loads were different in the four different groups (χ² = 275.02, p < 0.01). HBV viral load distribution was significantly different between anti-HBs positive and anti-HBc positive samples (χ² = 49.429, p < 0.01). Notably, only 42.03% donors were NAT repeated positive in the 138 repeat donors' follow up tests.

CONCLUSION

NAT screening of blood donations can reduce the risk of transfusion-transmitted HBV infections. Positive proportions of anti-HBs and anti-HBc are correlated with the HBV viral load level. However, low level of viral load donors pose risks in HBV NAT assays, and show fluctuating state for HBV viral load and leads to non-repeated NAT results during follow up studies.

Progress in evaluating the status of hepatitis C infection based on the functional changes of hepatic stellate cells (Review)

Hepatitis C virus (HCV) infection is a global public health problem. Cirrhosis and hepatocellular carcinoma are the main causes of death in patients with chronic hepatitis C (CHC) infection. Liver fibrosis is an important cause of cirrhosis and end‑stage liver disease after CHC infection. Along with the course of infection, liver fibrosis exhibits a progressive exacerbation. Hepatic stellate cells (HSCs) are involved in both physiological and pathological processes of the liver. During the chronic liver injury process, the activated HSCs transform into myofibroblasts, which are important cells in the development of liver fibrosis. At present, HCV infection still lacks specific markers for the accurate detection of the disease condition and progression. Therefore, the present review focused on HSCs, which are closely related to HCV‑infected liver fibrosis, and analyzed the changes in the HSCs, including their surface‑specific markers, cytokine production, activation, cell function and morphological structure. The present review aimed to propose novel diagnostic markers, at both the cellular and molecular level, which would be of great significance for the timely diagnosis of the disease. According to this aim, the characteristic changes of HSCs during HCV infection were reviewed in the present article.

THE IMPACT OF POSITIVE ANTI-HBC MARKER ON PERMANENT DEFERRAL OF VOLUNTARY BLOOD DONORS IN EASTERN CROATIA AND ESTIMATION OF OCCULT HEPATITIS B VIRUS INFECTION RATE

Recently an increase has been reported in the number of HBV transmissions from anti-HBc positive blood donors that were repeatedly negative in HBsAg and nucleic acid testing using the most sensitive tests available. The aim of the study was to show the effect of anti-HBc antibody testing performed in 2006 on permanent deferral of voluntary blood donors (VBDs), and to estimate occult hepatitis B infection (OBI) rate in this population after the introduction of mandatory molecular testing in the 2013-2016 period. More than 30,000 blood donations collected during the 2005-2007 period and more than 14,000 VBDs having donated blood during the 2013-2016 period after the introduction of molecular testing from eastern Croatia were included in the study. Serologic testing was performed with HBsAg assay throughout the study period, and anti-HBc assay was only performed in 2006. As part of the confirmatory algorithm testing, all HBsAg positive and unclear results were tested with molecular tests. Anti-HBc prevalence among VBDs in 2006 was 1.5%, with a rate of 1:197, whereas HBsAg prevalence was stable from 2005 to 2007 (0.04%, 0.1% and 0.1%, respectively). The calculated OBI rate from 2013 to 2016 was 1:30,250. Ten of 161 (12.4%) VBDs had serologic anti-HBc-only pattern. Anti-HBc testing in 2006 resulted in statistically more deferrals of VBDs compared to 2005 and 2007, and to the rest of Republic of Croatia. The strategy of universal anti-HBc testing of VBDs in addition to the existing HBsAg and molecular screening could be an additional measure to prevent HBV transmission by blood and blood components.

Investigation of transfusion associated hepatitis C virus infection in Taiwan, 2015-2018

Continuous strengthening of the safety of blood products to reduce the risk of transfusion-transmitted HCV in recipients is an important issue of Taiwanese government concern. Since 2013, highly sensitivity serology and NAT assays were simultaneously used for blood donation screening to shorten the window period of HIV, HBV and HCV infections. 15 cases of suspected transfusion-transmitted HCV infection were analyzed in 2015-2018. No HCV nucleic acid was detected among a total 91 bags of donated blood. Eleven cases among the 15 suspected recipients were positive for HCV nucleic acid, and 9 recipients had genotype results. Of these 9 recipients, five for genotype 1b (5/9, 55.6%), three for genotype 2a (3/9, 33.3%) and one for genotype 2b (1/9, 11.1%). We will continuously monitor the blood safety of recipients. There have been no confirmed cases of acute hepatitis C (AHC) infection due to transfusions of HCV contaminated blood product in 2015-2018 in Taiwan.

Anti-HBc prevalence among Croatian blood donors in a 14-year period (2004-2017): Assessment of trends, risks and need for implementing routine testing

OBJECTIVES

The anti-HBc prevalence over a 14-years period (2004-2017), trends, infectivity, residual risk, and need for testing in blood donors (BD) of the Croatian Institute of Transfusion Medicine were assessed.

MATERIAL AND METHODS

Anti-HBc was tested in 19,969 BD serum samples collected in 2004 (N=7561), 2013 (N=7318) and 2017 (N=5090). All serums were initially screened for HBsAg, anti-HCV, HIV Ag/Ab, and anti-TP. 2013 and 2017 samples were also tested by ID-NAT.

RESULTS

Over a 14-years period, the anti-HBc prevalence significantly decreased among Croatian BD (5.24% in 2004, 2.56% in 2013, and 1.32% in 2017). Similarly, the prevalence of anti-HBc-only profiles decreased from 0.62% in 2004, 0.25% in 2013, and 0.21% in 2017. The 4-time decreasing trend was observed in all age groups of BD from 2017 but mostly among repeat donors (5.90% to 1.38%). First-time donors showed no significant difference in anti-HBc prevalence probably due to their younger age (<29 years) and HBV vaccine status. However, similar anti-HBs carriage rates (80.56%, 87.57%, and 82.09%) were reported in anti-HBc positive donors over the study period. HBsAg and HBV DNA were not detected. No OBI infection was found in the study despite an OBI frequency of 1:10,900 donations previously reported in Croatia. A HBV decreasing residual risks of 68, 88, and 12 per million donations were estimated for years 2004, 2013, and 2017, respectively.

CONCLUSION

Anti-HBc testing is an additional measure of preventing HBV infection by transfusion. Implementation of anti-HBc testing will result in the deferral of 1.3% BD and should be supported by cost-benefit analyses.

Transfusion-transmissible infections among Serbian blood donors: declining trends over the period 2005-2017

BACKGROUND

The mass migrations experienced by the Western Balkans in the past decades have significantly changed the demographic structures and have probably altered the prevalence of transfusion-transmitted infections (TTIs) among blood donors. However, data on the prevalence of TTIs in the Western Balkans countries remain incomplete. This study reports the prevalence of TTIs among blood donors in Serbia in the period 2005-2017.

MATERIALS AND METHODS

Between January 2005 and December 2017, in the four largest Serbian transfusion centres, mandatory serology tests for screening HBV, HCV, HIV and syphilis infection were used for all blood donations.

RESULTS

Of the total of 1,660,019 blood donations made, 3,377 (0.203%) were positive for one of the TTIs: 1,440 (0.087%), 1,055 (0.064%), 215 (0.013%), and 667 (0.040%) were positive for HBV, HCV, HIV and syphilis, respectively. Serbia showed a declining trend of prevalence of HBV and HCV infection, while prevalence of HIV and syphilis remained unchanged. Prevalence of TTIs varied between different transfusion centres and showed a north-to-south upward trend.

DISCUSSION

The reported prevalence of TTIs among blood donors in Serbia was low and continued to follow a declining trend over the period of study.

Transfusion Transmissible Infections: Maximizing Donor Surveillance

Introduction

The World Health Organization (WHO) recommends that all blood transfusion services must screen donated blood for human immunodeficiency virus (HIV) one and two, hepatitis B, hepatitis C and syphilis. A mandatory screening for malaria is also warranted in malaria endemic areas. Our study aimed at analyzing the prevalence and different diagnostic methods of screening transfusion transmitted infections (TTIs) in replacement and voluntary, non-remunerated donors in the blood bank of a tertiary care hospital in Islamabad, Pakistan.

Methods

The cross-sectional, descriptive study was conducted on 30,470 blood donors from July 2015 to October 2017, in the blood bank of a 500-bed teaching hospital in Islamabad. Initially all blood donors were screened for HIV one, HIV two, hepatitis B and hepatitis C by serological testing. The seronegative samples were further tested by nucleic acid amplification test (NAT). Malaria was screened using immuno-chromatographic antigen-detection tests, while treponema pallidum was screened by electrochemiluminescence immunoassay to detect treponema pallidum (TP) antibodies. All infected blood and blood products were discarded and donors were contacted. The donors were deferred from blood donation according to WHO guidelines. They were also counselled and referred to the infectious diseases clinic. The collected data was analyzed on IBM's statistical package for the social sciences (SPSS) version 21.

Results

The results revealed that amongst the 30,470 donors, 997 (3.27%) donors were found infected with one or more TTI while 29,473 (96.73%) donors were found safe. Individuals who tested positive on serology for hepatitis B were 322 (1.06%), hepatitis C were 392 (1.29%) and HIV were 49 (0.16%). The seronegative donors were tested by NAT. NAT on seronegative samples showed that 10 (0.03%) donors tested positive for hepatitis B virus deoxyribonucleic acid, while only three (0.01%) were positive for hepatitis C ribonucleic acid. No donor was found positive for HIV by NAT testing. Syphilis testing revealed a frequency of 228 (0.75%) positive results while only five (0.02%) donors were found infected with malaria.

Conclusion

The results testify that standardized blood component screening can save transmission of infections through blood transfusion. They also establish the superiority of NAT screening over serological tests in decreasing the residual risk of transfusion transmitted infections.