The cost-effectiveness of introducing nucleic acid testing to test for hepatitis B, hepatitis C, and human immunodeficiency virus among blood donors in Sweden

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.

Economic Evaluation of Nucleic Acid Testing for Screening of Blood Donations for Thalassemia Patients (ECONAT) in Western India

Background

Transfusion Transmitted infections(TTI) are of significant concern for blood safety. The thalassemia patients who receive multiple transfusions are at an increased risk of TTIs and the Nucleic Acid Test (NAT ) has been advocated for safe blood. Though NAT can reduce the window period compared to serology, cost is a constraint.

Methods

The thalassemia patient and NAT yield data from the centralized NAT lab in AIIMS Jodhpur was evaluated for cost-effectiveness using the Markov model. The incremental cost-effectiveness ratio (ICER) was calculated by dividing the difference between the cost for NAT and the cost of medical management of TTI-related complications by the product of the difference in utility value of a TTI health state with time and Gross National Income(GNI) per capita.

Results

Out of the 48,762 samples tested by NAT, 43 samples were discriminated NAT yield all of which were reactive for Hepatitis B (NAT yield of 1:1134). There was no HCV and HIV NAT yield despite HCV being the most prevalent TTI in this population. The cost of this intervention was INR 5,85,14,400. The number of lifetime QALY saved was 1.38 years. The cost of medical management is INR 82,19,114. Therefore the ICER for intervention is INR 3,64,45,860 per QALY saved which is 274 times the GNI per capita of India.

Conclusions

The provision of IDNAT-tested blood for thalassemia patients in Rajasthan state was not found to be cost-effective. Measures to bring down the cost or alternative options to increase blood safety should be explored.

Risk of hepatitis-E virus infections among blood donors in a regional blood transfusion centre in western India

BACKGROUND

Hepatitis-E virus (HEV) is an emerging infectious threat to blood safety. The enormity of the transmission of HEV and its clinical consequence are issues currently under debate. This study aimed to evaluate the prevalence of HEV-RNA in blood donors in western India.

MATERIALS AND METHODS

We screened 13 050 blood donors for HEV using HEV-RNA screening of 10 mini-pools using RealStar HEV RT-PCR Kit (95% limit of detection (LOD): 4.7 IU/ml). Furthermore, all HEV-RNA-positive donors were investigated for the presence of IgM/IgG antibody along with liver function tests.

RESULTS

Of the 13 050 blood donations, 7 (0.53%) were found to be HEV-RNA positive, and the prevalence of HEV nucleic acid testing yield cases among blood donors was 1 in 1864. All seven HEV-RNA-positive samples were tested with anti-HEV IgM and anti-HEV IgG antibodies; this resulted in two (28.5%) positive anti-HEV IgM and two (28.5%) positive anti-HEV IgG antibodies. Hepatic activity was measured, with two of seven HEV-RNA-positive donors demonstrating abnormal serum glutamic oxaloacetic transaminase (SGOT) andserum glutamic pyruvic transaminase (SGPT). Two HEV-RNA-positive blood donors who had abnormal SGOT and SGPT were found to have a high HEV viral load. Furthermore, we were able to follow up two HEV-RNA donors, and both were HEV-RNA positive and had anti-HEV IgM and anti-HEV IgG antibodies; moreover, their liver function tests were also abnormal. One of the HEV-RNA donors with high viral load did show hepatitis-E-like virus on electron microscopy.

CONCLUSION

Our studies indicate that there is a significant risk of blood-borne transmission of HEV. This finding may help to provide a direction towards the safety of blood transfusions in clinical settings in countries like India, which fall under the endemic category for HEV infection.

Transmission of viral hepatitis through blood transfusion in Sweden, 1968 to 2012

Introduction

Viral hepatitis remains a significant threat to transfusion safety, although largely mitigated by donor screening.

Aim

Our objective was to estimate the past and present burden of transfusion transmission of all types of viral hepatitis (A to E) and to find undiagnosed infections with hepatitis C virus (HCV).

Method

We performed a retrospective cohort study using a database of the entire computerised transfusion experience of Sweden from 1968 to 2012 and linking it to a nationwide database of notifiable infections. We then used two independent statistical approaches. Firstly, we tracked recipients of blood from donors with confirmed viral hepatitis. Secondly, we computed a donor-specific risk score, defined as the difference between the observed and the expected number of HCV infections among all previous recipients of all donors, where thresholds were determined using simulation.

Results

Among 1,146,307 transfused patients, more than 5,000 were infected with HCV. Transfusion transmission only occurred before 1992 when donor screening had been completely implemented. Overall, we found 44 donors and 1,180 recipients likely to be infected with HCV who were still alive but who remained undiagnosed.

Conclusion

There is still a substantial number of individuals in Sweden who have probably been infected with HCV through blood transfusion and who are still unaware of their infection. We recommend that a follow-up study should be conducted to validate the method we used by approaching these individuals and offer testing. This would also serve as an opportunity to offer treatment to those who remain infected.

When are infection risks of blood transfusion tolerable? Towards understanding the ethical views of stakeholders in the blood supply

Background and objectives

The perception of transfusion‐transmitted infections (TTIs) is sensitive to various concerns besides the probability and impact of infection, and some of these concerns may be ethically relevant. This paper aims to advance thinking about blood safety policies by exploring and explaining stakeholders’ reasons to consider TTI risks tolerable or intolerable.

Materials and methods

Inspired by critical empirical ethics and phenomenological hermeneutics, we held interviews and focus group discussions to explore the moral experience of policymakers, hematologists, blood donors and recipients. Respondents were invited to discuss general concerns about the blood supply, to address the tolerability of TTI risks compared with other hazards and to comment on the costs of blood safety. Arguments for tolerance or intolerance towards TTI risks were analysed qualitatively.

Results

Stakeholders’ views could be clustered into seven categories: (1) clinical impact; (2) probability of infection; (3) avoidability of infection; (4) cost and health benefits; (5) other consequences of safety measures; (6) non‐consequentialist ethical arguments; and (7) stakeholders’ interests. Various arguments were offered that resonate with current ethical thinking about blood safety. Assuming that resources spent on inefficient blood safety measures could be applied more beneficially elsewhere, for example, responders typically expressed tolerance towards TTI risks. Some other arguments seem novel, for instance arguments for risk intolerance based on the low probability of infection and arguments for risk tolerance if patients have a poor prognosis.

Conclusion

Understanding the moral experience of stakeholders enriches ethical debate about blood safety and prepares developing more widely acceptable policies.

Blood Donor Screening for Hepatitis E Virus in the European Union

This review article summarises hepatitis E virus (HEV) blood donation screening strategies in effect in the European Union (EU). Since 2012, eight EU countries have implemented HEV screening. Local rates of seroprevalence, RNA incidence, and molecular epidemiology are variable and not usually directly comparable. We report a range of HEV-RNA reactivity rates from 1 in 744 donations (France) to 1 in 8,636 donations (Wales) with an overall EU rate of 1 in 3,109 donations (3.2 million donations screened). HEV genotypes 3c, 3e, and 3f are the most frequently reported subtypes. In these 8 countries, both universal (n = 5) and selective (n = 3) screening policies have been introduced utilising either individual donation (ID; n = 1) or mini-pool (MP; n = 7; MP-6, -16, -24, and -96) testing. We also describe the Irish experience of HEV screening utilising an ID-NAT-based donor screening algorithm which intercepts donations even from those with low-level viraemia; 21 of 56 donors (37.5%) had a viral load (VL) < 100 IU/mL. We performed a MP-24 experiment which may prove useful to colleagues in relation to donor screening and associated blood component transmissibility. Irish results indicate that 59% of donors with a HEV-VL < 450 IU/mL may have screened negative in a MP-24.

Impact of Multiplex PCR in Reducing the Risk of Residual Transfusion-Transmitted Human Immunodeficiency and Hepatitis B and C Viruses in Burkina Faso

Background and Objective

The improved performance of serological tests has significantly reduced the risk of human immunodeficiency and hepatitis B and C viruses transmission by blood transfusion, but there is a persistence of residual risk. The objective of this study was to evaluate the impact of multiplex PCR in reducing the risk of residual transmission of these viruses in seronegative blood donors in Burkina Faso.

Methods

This cross-sectional study was conducted from March to September 2017. The serological tests were performed on sera using ARCHITECT_SRi1000 (Abbot diagnosis, USA). Detection of viral nucleic acids was performed by multiplex PCR on mini-pools of seronegative plasma for HBV, HCV and HIV using SaCycler-96 Real Time PCR v.7.3 (Sacace Biotechnologies). Multiplex PCR-positive samples from these mini-pools were then individually tested by the same method.

Results

A total of 989 donors aged 17 to 65 were included in the present study. “Repeat donors” accounted for 44.79% (443/989). Seroprevalences for HIV, HBV, and HCV were 2.53% (25/989), 7.28% (72/989) and 2.73% (27/989), respectively. Of the 14 co-infections detected, HBV/HCV was the most common with 0.71% (7/989) of cases. Of 808 donations tested by multiplex PCR, 4.70% (38/808) were positive for HBV while no donation was positive for HIV or HCV.

Conclusion

Our study showed a high residual risk of HBV transmission through blood transfusion. Due to the high prevalence of blood-borne infections in Burkina Faso, we recommend the addition of multiplex PCR to serologic tests for optimal blood donation screening.

Nationwide Implementation of Pathogen Inactivation for All Platelet Concentrates in Switzerland

Introduction

Bacterial contamination of platelet concentrates (PCs) has been identified as the most prevalent transfusion-associated infectious risk. To prevent PC-related septic transfusion reactions, the Intercept® pathogen inactivation procedure was introduced for all PCs in Switzerland in 2011.

Methods

Based on numbers of transfused units and mandatorily reported adverse events with high imputability, we compare the risks associated with transfusion of conventional PCs (cPCs) and pathogen-inactivated PCs (PI-PCs).

Results

From 2005 to 2011, a total of 158,502 cPCs have been issued in Switzerland, and 16 transfusion-transmitted bacterial infections (including 3 fatalities) were reported. This corresponds to a morbidity and mortality rate of ca. 1:9,900 and 1:52,800, respectively. From 2011 to 2016, a total of 205,574 PI-PCs have been issued, and no transfusion-transmitted bacterial infection was reported. Despite continuously increasing transfusion reaction rates per 1,000 RBC and plasma issued between 2008 and 2016, we observed reductions of 66% for life-threatening and fatal reactions and of 26% for all high-imputability transfusion reactions related to PI-PCs as compared to cPCs. No increased rates of bleeding or clinical observations of ineffectiveness of PI-PCs have been reported. After implementation of PI-PCs, the annual increase in platelet usage per 1,000 inhabitants decelerated.

Discussion

Swiss hemovigilance data confirm a favorable safety profile of the nationwide introduced Intercept pathogen inactivation procedure and its reliable prevention of septic transfusion reactions and fatalities due to bacterially contaminated PCs.

Pathogen reduction and blood transfusion safety in Africa: strengths, limitations and challenges of implementation in low-resource settings

Transfusion-transmitted infection risk remains an enduring challenge to blood safety in Africa. A high background incidence and prevalence of the major transfusion-transmitted infections (TTIs), dependence on high-risk donors to meet demand, suboptimal testing and quality assurance collectively contribute to the increased risk. With few exceptions, donor testing is confined to serological evaluation of human immunodeficiency virus (HIV), hepatitis B and C (HBV and HCV) and syphilis. Barriers to implementation of broader molecular methods include cost, limited infrastructure and lack of technical expertise. Pathogen reduction (PR), a term used to describe a variety of methods (e.g. solvent detergent treatment or photochemical activation) that may be applied to blood following collection, offers the means to diminish the infectious potential of multiple pathogens simultaneously. This is effective against different classes of pathogen, including the major TTIs where laboratory screening is already implemented (e.g. HIV, HBV and HCV) as well pathogens that are widely endemic yet remain unaddressed (e.g. malaria, bacterial contamination). We sought to review the available and emerging PR techniques and their potential application to resource-constrained parts of Africa, focusing on the advantages and disadvantages of such technologies. PR has been slow to be adopted even in high-income countries, primarily given the high costs of use. Logistical considerations, particularly in low-resourced parts of Africa, also raise concerns about practicality. Nonetheless, PR offers a rational, innovative strategy to contend with TTIs; technologies in development may well present a viable complement or even alternative to targeted screening in the future.

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.

Cost effectiveness of adding nucleic acid testing to hepatitis B, hepatitis C, and human immunodeficiency virus screening of blood donations in Zimbabwe

BACKGROUND

The aim of this study was to assess the cost effectiveness of introducing individual-donation nucleic acid testing (ID-NAT), in addition to serologic tests, compared with the exclusive use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) I and II among blood donors in Zimbabwe.

STUDY DESIGN AND METHODS

The costs, health consequences, and cost effectiveness of adding ID-NAT to serologic tests, compared with serologic testing alone, were estimated from a health care perspective using a decision-analytic model.

RESULTS

The introduction of ID-NAT in addition to serologic tests would lower the risk of HBV, HCV, and HIV transmission to 46.9, 0.3, and 2.7 per 100,000 donations, respectively. ID-NAT would prevent an estimated 25, 6, and 9 HBV, HCV, and HIV transfusion-transmitted infections per 100,000 donations, respectively. The introduction of this intervention would result in an estimated 212 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio is estimated at US$17,774/QALY, a value far more than three times the gross national income per capita for Zimbabwe.

CONCLUSION

Although the introduction of NAT could further improve the safety of the blood supply, current evidence suggests that it cannot be considered cost effective. Reducing the test costs for NAT through efficient donor recruitment, negotiating the price of reagents, and the efficient use of technology will improve cost effectiveness.

Deceased tissue donor serology and molecular testing for HIV, hepatitis B and hepatitis C viruses: a lack of cadaveric validated tests

Vital to patient safety is the accurate assessment and minimization of risk for human immunodeficiency virus (HIV), Hepatitis C (HCV), and Hepatitis B (HBV) virus transmission by deceased donor organ and tissue transplantation. The pathogens are tested by serological kits based on enzyme-linked immunosorbent assay (ELISA), chemiluminescence (CLIA) and eletrochemiluminescence (ECLIA) immunoassays. Organ transplantation is a highly successful life-saving treatment in Brazil, but the Brazilian Health Surveillance Agency currently mandates that all deceased organ donors are screened for HIV, HCV and HBV following living donor policies. In this review, six ELISA (Wama^®, Bio-Rad^®, Biomerieux^®, DiaSorin^®, Acon Biotech^® and Biokit^®), three CLIA (Abbott^®, Siemens^®, Diasorin^®) and one ECLIA (Roche^®) were utilized for evaluating the effectiveness of those serological tests for deceased donors in Brazil according to manufacturer's guidelines. NAT for HIV, HCV and HBV can assist with detection of pre-seroconversion for those infections, and only Cobas^® TaqScreen MPX^® test, the Tigris System^® Procleix Ultrio Assay^® and the Bio-Manguinhos^® HIV/HCV/HBV NAT are commercially available. Between all the tests, only the manufacturer Abbott^® and Cobas^® TaqScreen MPX^® test are currently validated for cadaver samples.

Introducing Pathogen Reduction Technology in Poland: A Cost-Utility Analysis

BACKGROUND

Mirasol® pathogen reduction technology (PRT) uses UV light and riboflavin to chemically inactivate pathogens and white blood cells in blood components. In the EU, Mirasol PRT is CE-marked for both plasma and platelet treatment. In Poland, the decision to introduce PRT treatment of the national supply of fresh frozen plasma has spurred interest in evaluating the cost-effectiveness of this strategy.

METHODS

A decision-analytic model evaluated the incremental costs and benefits of introducing PRT to the existing blood safety protocols in Poland.

RESULTS

Addition of PRT treatment of plasma to current screening in Poland is estimated to cost 2.595 million PLN per quality-adjusted life year (QALY) (610,000 EUR/QALY); treating both plasma and platelet components in addition to current safety interventions had a lower cost of 1.480 million PLN/QALY (348,000 EUR/QALY).

CONCLUSIONS

The results suggest that in Poland the cost per QALY of PRT is high albeit lower than found in previous economic analyses of PRT and nucleic acid testing in North America. Treating both platelets and plasma components is more cost-effective than treating plasma alone. Wide confidence intervals indicate high uncertainty; to improve the precision of the health economic evaluation of PRT, additional hemovigilance data are needed.

Predicting the presence of hepatitis B virus surface antigen in Chinese patients by pathology data mining

Hepatitis B virus (HBV) is a pathogen of worldwide health significance, associated with liver disease. A vaccine is available, yet HBV prevalence remains a concern, particularly in developing countries. Pathology laboratories have a primary role in the diagnosis and monitoring of HBV infection, through hepatitis B surface antigen (HBsAg) immunoassay and associated tests. Analysis of HBsAg immunoassay and associated pathology data from 821 Chinese patients applied 10-fold cross-validation to establish classification decision trees (CDTs), with CDT results used subsequently to develop a logistic regression model. The robustness of logistic regression model was confirmed by the Hosmer-Lemeshow test, Pseudo-R(2) and an area under receiver operating characteristic curve (AUROC) result that showed the logistic regression model was capable of accurately discriminating the HBsAg positive from HBsAg negative patients at 95% accuracy. Overall CDT sensitivity and specificity was 94.7% (± 5.0%) and 89.5% (± 5.7%), respectively, close to the sensitivity and specificity of the immunoassay, providing an alternative to predict HBsAg status. Both the CDT and logistic regression modeling demonstrated the importance of the routine pathology variables alanine aminotransferase (ALT), serum albumin (ALB), and alkaline phosphatase (ALP) to accurately predict HBsAg status in a Chinese patient cohort. The study demonstrates that CDTs and a linked logistic regression model applied to routine pathology data were an effective supplement to HBsAg immunoassay, and a possible replacement method where immunoassays are not requested or not easily available for the laboratory diagnosis of HBV infection.

Reducing infection transmission in solid organ transplantation through donor nucleic acid testing: a cost-effectiveness analysis

For solid organ transplant (SOT) donors, nucleic acid-amplification testing (NAT) may reduce human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission over antibody (Ab) testing given its shorter detection window period. We compared SOT donor NAT + Ab versus Ab alone using decision models to estimate incremental cost-effectiveness ratios (ICERs; cost per quality-adjusted life year [QALY] gained) from the societal perspective across a range of HIV/HCV prevalence values and NAT costs. The cost per QALY gained was calculated for two scenarios: (1) favorable: low cost ($150/donor)/high prevalence (HIV: 1.5%; HCV: 18.2%) and (2) unfavorable: high cost ($500/donor)/low prevalence (HIV: 0.1%; HCV: 1.5%). In the favorable scenario, adding NAT screening cost $161 013 per QALY gained for HIV was less costly) for HCV, and cost $86 653 per QALY gained for HIV/HCV combined. For the unfavorable scenario, the costs were $15 568 484, $221 006 and $10 077 599 per QALY gained, respectively. Universal HCV NAT + Ab for donors appears cost-effective to reduce infection transmission from SOT donors, while HIV NAT + Ab is not, except where HIV NAT is ≤$150/donor and prevalence is ≥1.5%. Our analyses provide important data to facilitate the decision to implement HIV and HCV NAT for deceased SOT donors and shape national policy regarding how to reduce infection transmission in SOT.

Neonatal transfusion-transmitted hepatitis C virus infection following a pre-seroconversion window-phase donation in Sweden

A 9-day-old child developed a transfusion-transmitted hepatitis C virus (HCV) infection following a pre-seroconversion window-phase donation. Retrospective analysis of donor plasma revealed detectable HCV core antigen (154 fmol/l), as well as HCV RNA (87,000 IU/ml). Of 5.24 million Swedish plasma samples from December 1998 to September 2012, 5 additional window-phase donations were identified.

Blood safety and availability: continuing challenges in China's blood banking system

Social and economic development, along with increased health care coverage, has caused a sharp increase in the clinical demand for blood in China. Whole blood collection has increased rapidly in the past decade but has failed to keep pace with the ever-increasing demand. Overall, the country's blood safety has been improved with 99% of whole blood donations collected from voluntary unpaid donors. However, the unmet clinical demand for blood and the increasing incidence of human immunodeficiency virus and syphilis in the general population pose new challenges to China's blood banking system. To ensure a safe and adequate blood supply, continued efforts are required to recruit and retain a sufficient number of low-risk voluntary blood donors, improve donor prescreening and blood testing process, ease donor restrictions, and strengthen patient blood management.

Hepatitis B surface antigen variants in voluntary blood donors in Nanjing, China

Background

Hepatitis B virus (HBV) is still one of the serious infectious risks for the blood transfusion safety in China. One plausible reason is the emergence of the variants in the major antigenic alpha determinant within the major hydrophilic region (MHR) of hepatitis B surface antigen (HBsAg), which have been assumed to evade the immune surveillance and pose a challenge to the disease diagnosis. It is well documented that some commercial ELISA kits could detect the wild-type but not the mutant viruses. The high prevalence of HBV in China also impaired the application of nucleic acid testing (NAT) in the improvement of blood security. Molecular epidemiological study of HBsAg variations in China is still limited. This study was designed to identify the prevalence of mutations in the HBsAg in voluntary blood donors in Nanjing, China.

Methods

A total of 20,326 blood units were enrolled in this study, 39 donors were positive for HBV S gene in the nested-PCR. Mutations in the major hydrophilic region (MHR; aa 99-169) were identified by direct sequencing of S region.

Results

Among of 20,326 blood units in the Red Cross Transfusion Center of Nanjing from October 2008 to April 2009, 296 samples (1.46%, 296/20,326) were HBsAg positive in the 2 successive rounds of the ELISA test. In these HBsAg positive units, HBV S gene could be successfully amplified from 39 donors (13.18%, 39/296) in the nested-PCR. Sequence analysis revealed that 32 strains (82.1%, 32/39) belong to genotype B, 7 strains (17.9%, 7/39) to genotype C. Besides well known G145R, widely dispersed variations in the MHR of S region, were observed in 20 samples of all the strains sequenced.

Conclusions

HBV/B and HBV/C are dominant in Nanjing, China. The mutations in the MHR of HBsAg associated with disease diagnosis are common.

Cost savings associated with testing of antibodies, antigens, and nucleic acids for diagnosis of acute HIV infection

Efforts to identify all persons infected with HIV in the United States are driven by the hope that early diagnosis will lower risk behaviors and decrease HIV transmission. Identification of HIV-infected people earlier in the course of their infection with HIV antigen/antibody (Ag/Ab) combination assays (4th-generation HIV assays) should help achieve this goal. We compared HIV RNA nucleic acid test (NAT) results to the results of a 4th-generation Ag/Ab assay (Architect HIV Ag/Ab Combo [HIV Combo] assay; Abbott Diagnostics) in 2,744 HIV antibody-negative samples. Fourteen people with acute HIV infection (HIV antibody negative/NAT positive) were identified; the HIV Combo assay detected nine of these individuals and was falsely negative in the remaining five. All five persons missed by the HIV Combo assay were in the stage of exponential increase in plasma virus associated with acute HIV infection (3, 7, 20, 35, 48). In contrast, most acutely infected persons detected by the HIV Combo assay demonstrated either a plateauing or decreasing plasma viral load. The HIV Combo assay also classified as positive five other samples which were negative by NAT. Taken together, the HIV Combo assay had a sensitivity of 73.7% and a specificity of 99.8%. Using published data, we estimated secondary transmission events had HIV infection in these five individuals remained undiagnosed. Screening of our population with NAT cost more than screening with the HIV Combo assay but achieved new diagnoses that we predict resulted in health care savings that far exceed screening costs. These findings support the use of more sensitive assays, like NAT, in HIV screening of populations with a high prevalence of acute HIV infection.