Correlates of hepatitis C virus (HCV) RNA negativity among HCV-seropositive blood donors

Prevalence and trends of hepatitis B and C virus biomarkers in Zimbabwe: comparative analyses of a nation's blood-donor surveillance data and meta-analyses of population studies

BACKGROUND

The disproportionate burden of viral hepatitis, particularly hepatitis B virus (HBV) is experienced by people living in low-resourced sub-Saharan Africa, where the estimated prevalence is 3-7 times the global average. Therefore to inform policy, we describe the seroprevalence and trends of hepatitis C (HCV) and HBV biomarkers: anti-HCV antibody and hepatitis B surface antigen (HBsAg), respectively, in Zimbabwe.

METHODS

We analysed data from 181,248 consecutive blood-donors, examined between January 2015 through December 2018. Additionally, we conducted a comprehensive literature review using PubMed and African Journals Online databases, meta-analysing selected papers from Zimbabwe, published between 1970 and 2020, that met specific criteria.

RESULTS

Overall age-standardized prevalence rate (ASPR) for anti-HCV was 8.67 (95%CI, 0.25-17.09) per 100,000, while that for HBsAg was 2.26 (95%, 1.89-2.63) per 1000 blood-donors, per year. Meta-analysis of 9 studies comprising 220,127 persons tested for anti-HCV revealed ASPR of 0.05% (95% 0%-0.19%) in blood-donors and 1.78% (95%CI, 0.01%-5.55%) in the general population, for an overall pooled ASPR of 0.44 (95%CI, 0.19%-0.76%). 21 studies comprising 291,784 persons tested for HBsAg revealed ASPR of 0.65% (95%CI, 0.31%-1.00%) in blood-donors and 4.31% (95%CI, 1.77%-6.50%) in the general population for an overall pooled ASPR of 4.02% (95%CI, 3.55%-4.48%), after HBV vaccine introduction. HBsAg prevalence was significantly higher before HBV vaccine introductions.

CONCLUSIONS

The prevalence of HBV is decreasing, consistent with the introduction of HBV vaccination, while HCV prevalence is increasing in Zimbabwe. This highlights the need for Improved blood-donor screening and more informative biomarker studies, particularly among repeat donors and children.

Background rate of low-level HCV RNA in anti-HCV confirmed-positive and minipool nucleic acid test-nonreactive blood donations

BACKGROUND

In 2019, the Food and Drug Administration revised the requirement for further testing of anti-HCV-reactive donations testing nucleic acid (NAT)-nonreactive via routine mini-pool (MP)-NAT. Individual donation (ID)-HCV NAT was required as a supplemental test prior to a second FDA-licensed anti-HCV assay; if ID-HCV-NAT is reactive, no further testing is required. This study investigated the rate of low-level RNA in anti-HCV-reactive donation samples prior to and following the implementation of supplemental ID-HCV NAT.

STUDY DESIGN/METHODS

A retrospective analysis was conducted on frozen plasma unit samples from 1161 anti-HCV confirmed-positive/HCV-NAT-nonreactive donations collected from December 2014 to January 2020. Samples were tested by multiple replicates on the Grifols Procleix Ultrio Elite (UE) assay and corresponding discriminatory HCV (dHCV) assay on the Procleix Panther System. Prospectively, the prevalence of low-level RNA in 2912 anti-HCV-reactive donations detected through routine screening from April 2020 through March 2021 was determined.

RESULTS

In retrospective analyses, 10 (0.86%) of 1161 plasma samples were UE reactive, of which four (0.34%) were dHCV reactive (in all replicates of UE and dHCV). Of 2912 anti-HCV-reactive donation samples testing NAT-nonreactive via routine MP-NAT, three (0.1%; 95% CI: 0.04-0.30) were dHCV reactive; 37% of the remaining samples were reactive by a second anti-HCV assay and thus serologically confirmed.

CONCLUSIONS

Retrospective and prospective analysis in comparison to earlier studies revealed that low-level HCV-RNA reactivity is decreasing over time. The very low HCV-RNA rates may be due to the widespread use of highly effective, direct-acting anti-viral treatments for those diagnosed with HCV infection.

Head-to-head comparison of Enzyme Linked Immunosorbent Assay (ELISA) and Enhanced Chemiluminescence Immunoassay (ECLIA) for the detection of Transfusion Transmitted Disease (TTD) Markers; HIV, HCV and HBV in blood donors, in India

Safe blood transfusion being the cornerstone of any Blood Transfusion Services requires meticulous testing for Transfusion Transmitted Disease (TTD) markers in donated blood. We performed head-to-head comparison of ELISA and ECLIA for detection of TTD markers for Human Immunodeficiency Virus (HIV), Hepatitis C Virus (HCV) and Hepatitis B Virus (HBV) in 10,164 Indian blood donors. All concordant reactive, discordant reactive and concordant non-reactive samples were re-confirmed using Individual Donor-Nucleic Acid Amplification Test (ID-NAT) as the 'gold standard' test. 223 samples were found reactive; out of which 93 (four HIV, 34 HCV and 55 HBV) samples were concordant reactive and tested positive by both methods while 130 discordant reactive samples were reactive either by ELISA or ECLIA. Out of 130 discordant reactive samples ELISA-reactive and ECLIA-non-reactive samples for HIV, HCV and HBV were 15, eight, and 29 respectively while ECLIA-reactive ELISA-non-reactive samples for HIV, HCV and HBV were 39, 36 and three respectively. Sensitivity of ECLIA and ELISA was 100 % for all three TTD markers, while specificity was 99.62 % and 99.85 % for HIV; 99.64 % and 99.84 % for HCV and 99.97 % and 99.70 % for HBV respectively. Strength of agreement and Kappa Statistics for ECLIA and ELISA compared to the gold standard test was poor and fair for HIV (k = 0.169 and 0.347), moderate and good for HCV (k = 0.539 and 0.763), and very good and good for HBV (k = 0.973 and 0.783). According to this study, it can be concluded both the testing techniques; ELISA and ECLIA have 100 % sensitivity for the detection for HBV, HCV and HIV in blood donors and therefore, either can be used for TTD screening in blood banks in India.

Sociodemographic and clinical characteristics of persons who experienced spontaneous hepatitis C viral clearance

Background

In the United States Hepatitis C virus (HCV) viral clearance is estimated to range between 20 and 30%. The objective of this study was to estimate the frequency of HCV clearance and identify correlates of viral clearance among patients newly identified as HCV antibody positive in a large urban health system in Los Angeles, California.

Methods

We identified patients between November 2015 and September 2017 as part of a newly implemented HCV screening and linkage-to-care program at University of California Los Angeles (UCLA) Health System. All patients were eligible for screening, though there were additional efforts to screen patients born between 1945 and 1965. We reviewed Medical records to categorize anti-HCV antibody positive patients as having spontaneously cleared HCV infection (HCV RNA not detected) or not (HCV RNA detected). We excluded those with a prior history of anti-HCV positivity or history of HCV treatment. We compared differences between those with and without detectable HCV RNA using chi-square test, Fisher’s exact test, and t-test as appropriate. We assessed factors associated with HCV clearance using logistic regression analysis.

Results

Among the 320 patients included in this study, 56% were male. Baby boomers (52–72 years of age) comprised the single largest age group (62%). We found spontaneous HCV clearance in 58% (n = 185). HCV viral clearance was slightly higher among women as compared to men (63% vs. 53%; p value = 0.07) and varied by race/ethnicity: clearance among Blacks/African Americans was 37% vs. 58% among whites (p value = 0.02). After adjusting for age, race/ethnicity, and sex we found that those diagnosed with chronic kidney disease had a tendency of decreased HCV viral clearance (adjusted OR = 0.34; 95% CI 0.14–1.03).

Conclusion

Of those patients newly identified as anti-HCV positive, 58% had cleared HCV virus, while the rest showed evidence of active infection. In addition, we found that clearance varied by race/ethnicity and clinical characteristics.

Assessing hepatitis C spontaneous clearance and understanding associated factors-A systematic review and meta-analysis

New advances in the treatment of hepatitis C provide high levels of sustained viral response but their expense limits availability in publicly funded health systems. The aim of this review was to estimate the proportion of patients who will spontaneously clear HCV, to identify factors that are associated with clearance and to support better targeting of directly acting antivirals. We searched Ovid EMBASE, Ovid MEDLINE and PubMed from 1 January 1994 to 30 June 2015 for studies reporting hepatitis C spontaneous clearance and/or demographic, clinical and behavioural factors associated with clearance. We undertook meta-analyses to estimate the odds of clearance for each predictor. Forty-three studies met the inclusion criteria, representing 20 110 individuals, and 6 of these studies included sufficient data to estimate spontaneous clearance. The proportion achieving clearance within 3, 6, 12 and 24 months following infection were, respectively, 19.8% (95% CI: 2.6%-47.5%), 27.9% (95% CI: 17.2%-41.8%), 36.1% (95% CI: 23.5%-50.9%) and 37.1% (95% CI: 23.7%-52.8%). Individuals who had not spontaneously cleared by 12 months were unlikely to do so. The likelihood of spontaneous clearance was lower in males and individuals with HIV co-infection, the absence of HBV co-infection, asymptomatic infection, black or nonindigenous race, nongenotype 1 infection, older age and alcohol or drug problems. This study suggests that patients continue to spontaneously clear HCV for at least 12 months following initial infection. However, injecting drug users are comparatively less likely to achieve clearance; thus, they should be considered a priority for early treatment given the continuing risks that these individuals pose for onwards transmission.

Prevalence of Occult Hepatitis C Virus Infection among Blood Donors in Jiangsu, China

OBJECTIVE

In 2010, only 1 donor blood sample was found to be anti-hepatitis C virus (HCV) negative and HCV RNA positive, as detected by nucleic acid testing. In occult HCV infection (OCI), HCV RNA is found in peripheral blood mononuclear cells (PBMCs). We investigated the prevalence of OCI among blood donors.

METHODS

We collected 513 samples from 334 eligible and 179 deferred donors, including 55 anti-HCV-positive, 113 alanine aminotransferase (ALT)-elevated, and 11 hepatitis B virus surface antigen (HBsAg)-positive blood donors. PBMCs were isolated, the 5'-untranslated region of HCV RNA was amplified by reverse transcription nested PCR, and the genotype of the core region was determined.

RESULTS

No HCV RNA was detected among the eligible samples. Among the deferred donors, 15 (27.2%) had detectable HCV RNA in 55 anti-HCV PBMC specimens. HCV RNA was detected in 1 (9.1%) HBsAg-positive and 9 (8%) ALT-elevated samples. The prevalence of OCI in the blood donors was 2.2% (10/458). HCV genotypes were determined in 10 subjects, indicating that 2 (20.0%) were subtype 2a, 7 (70.0%) were 1b, and 1 (10%) was 6a.

CONCLUSIONS

This study showed that OCI does exist among Chinese blood donors. However, to determine the epidemiology and outcome of this HCV infection, further follow-up with more participants and patients receiving blood components with OCI is needed.

Hospital-Based Hepatitis C Screening of Baby Boomers in a Majority Hispanic South Texas Cohort: Successes and Barriers to Implementation

OBJECTIVE

To comply with the 2012 CDC recommendations for hepatitis C virus (HCV) screening, we implemented a new HCV screening program for patients born between 1945 and 1965 at a South Texas safety-net hospital.

METHODS

Patients with no HCV diagnosis or prior HCV test received an automated order for HCV antibody (anti-HCV) tests combined with reflex HCV ribonucleic acid (RNA) polymerase chain reaction. An inpatient counselor educated anti-HCV-positive patients. A bilingual patient navigator assisted newly diagnosed chronic HCV patients with linkage to primary and specialty care. We examined results for Hispanic vs. non-Hispanic patients in the first 10 months of project implementation in 2013-2014.

RESULTS

Of 2,327 patients screened for HCV, the 192 (8%) patients who tested anti-HCV positive were younger than those who tested negative (56 vs. 58 years, respectively, p<0.001) and more likely to be male (p<0.001). Of the 167 anti-HCV-positive patients tested for HCV RNA, 108 (65%) were HCV RNA positive (5% of cohort). Barriers to care for HCV RNA-positive patients included a lack of health insurance, current substance abuse, incarceration, and homelessness. Hispanic HCV RNA-positive patients were more likely than non-Hispanic HCV RNA-positive patients to be substance abusers or incarcerated. Of all HCV RNA-positive patients, 103 patients (95%) received counseling, 94 patients (87%) were linked to primary care, 47 patients (44%) were linked to specialty care, and eight patients (7%) started treatment.

CONCLUSION

The prevalence of anti-HCV-positive and chronically HCV-infected patients was higher than many Hispanic or non-Hispanic white cohorts. Most Hispanic patients newly diagnosed with chronic HCV had barriers to care for HCV infection that must be overcome if HCV screening is to reduce morbidity and mortality in this population.

Hepatitis C Virus Subtype and Evolution Characteristic Among Drug Users, Men Who Have Sex With Men, and the General Population in Beijing, China

The aim of this study was to characterize the current molecular epidemiology of hepatitis C virus (HCV) infection and evaluate the evolutionary patterns of HCV subtypes in Beijing, China, among different subpopulations.The whole blood samples and behavioral data were collected from a total of 10,354 subjects, including drug users (DUs), men who have sex with men (MSM), and the general population, in Beijing from 2010 to 2011. Samples were tested for HCV infection using both enzyme-linked immunosorbent assay (ELISA) and real-time PCR. All viremic subjects were then sequenced by nested PCR over core/E1 and NS5B regions. Phylogenetic and phylogeographic analysis was performed by BEAST software.In total, 217 subjects (2.1%) were tested positive for HCV by antibody or vRNA-based testing. HCV prevalence rates for DUs, MSM, and the general population were 26.2%, 0.54%, and 0.37%, respectively. The 156 HCV RNA-positive samples were sequenced. Nine HCV genotypes, including 1a, 1b, 2a, 3a, 3b, 6a, 6n, 6u and 6v, were detected. The most prevalent subtypes were 3b (36.09%), 1b (32.54%), and 3a (16.57%). Bayesian evolutionary analysis estimated that the time of introduction of subtype 1b into Beijing was 2004 (95% CI: 1997.7, 2007.7), with subtypes 3a and 3b being introduced later in 2006. Evolutionary analyses further suggested that subtype 1b from Beijing and Shanghai were closely related, whereas subtype 3a sequences were more similar with sequences from Yunnan, Guangzhou, Hong Kong, and Jiangsu. Subtype 3b sequences were closely related to those from Yunnan, Guangdong, and Hong Kong.Thus, the current HCV epidemic in Beijing is complex, heavily affecting DUs, and involving multiple genotypes that likely spread from different regions in China with its large migrant population.

Host genetic variants influencing the clinical course of hepatitis C virus infection

The clinical course of hepatitis C virus (HCV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HCV infection. Recent genome-wide association studies identified several host genetic factors influencing treatment efficacy or clinical course in HCV infection. A landmark discovery was that IFNL3-IFNL4 variants are strongly associated with responses to interferon-based treatment. Genetic variants in IFNL3-IFNL4 as well as those in HLA class II loci influence the spontaneous clearance of acute HCV infection. Interestingly, these genetic variants also affect the activity of hepatitis, or disease progression in chronic hepatitis C. In addition, polymorphisms in apoptosis-related genes such as RNF7, TULP1, and MERTK are associated with fibrosis progression, and DEPDC5 and MICA variants are associated with HCV-related hepatocellular carcinoma. Understanding the genetic factors associated with the clinical course of HCV infection is essential for personalized treatment and surveillance of disease progression and hepatocellular carcinoma.

Implementing hospital-based baby boomer hepatitis C virus screening and linkage to care: Strategies, results, and costs

BACKGROUND/OBJECTIVE

The US Preventive Services Task Force recommends 1-time hepatitis C virus (HCV) screening of all baby boomers (born 1945-1965). However, little is known about optimal ways to implement HCV screening, counseling, and linkage to care. We developed strategies following approaches used for HIV to implement baby boomer HCV screening in a hospital setting and report results as well as costs.

DESIGN/PATIENTS

Prospective cohort of 6140 baby boomers admitted to a safety-net hospital in South Texas from December 1, 2012 to January 31, 2014 and followed to December 10, 2014.

PROCEDURES/MEASUREMENTS

The HCV screening program included clinician/staff education, electronic medical record algorithm for eligibility and order entry, opt-out consent, anti-HCV antibody test with reflex HCV RNA, personalized inpatient counseling, and outpatient case management. Outcomes were anti-HCV antibody-positive and HCV RNA-positive results.

RESULTS

Of 3168 eligible patients, 240 (7.6%) were anti-HCV positive, which was more likely (P < 0.05) for younger age, men, and uninsured. Of 214 (89.2%) patients tested for HCV RNA, 134 (4.2% of all screened) were positive (chronic HCV). Among patients with chronic HCV, 129 (96.3%) were counseled, 108 (80.6%) received follow-up primary care, and 52 (38.8%) received hepatology care. Five patients initiated anti-HCV therapy. Total costs for start-up and implementation for 14 months were $286,482.

CONCLUSIONS

This inpatient HCV screening program diagnosed chronic HCV infection in 4.2% of tested patients and linked >80% to follow-up care. Yet access to therapy is challenging for largely uninsured populations, and most programmatic costs of the program are not currently covered.

Improving the safety of blood transfusion by using a combination of two screening assays for hepatitis C virus

BACKGROUND AND OBJECTIVES

To illustrate that the combination of a single nucleic acid amplification test (NAT) with a single immunoassay for hepatitis C virus (HCV) detection, as proposed internationally, may lead to the omission of anti-HCV reactive sera with non-reactive NAT results.

MATERIALS AND METHODS

In total, 822 of 519, 299 serum samples from 11 blood centres in China were retested for anti-HCV by using 10 screening assays to detect HCV antibodies. A recombinant immunoblot assay (RIBA HCV 3·0; Ortho-Clinical Diagnostics) was performed to define confirmed HCV infection status. Samples with positive or indeterminate RIBA-HCV results were tested by quantitative tests for HCV RNA (Roche Diagnostics).

RESULTS

We found that 47 of the 822 (5·72%) serum samples were RIBA-positive without detectable HCV RNA. For these samples, the 10 anti-HCV immunoassays gave discordant and unsatisfactory results (detection rate ranging from 10·64 to 34·04%; ratio per 100 000 donations ranging from 5·97 to 8·09). Compared with a single anti-HCV screening assay, the two-assay combination increased the detection of these samples. The five best combinations [Sorin and Lizhu enzyme immunoassays (EIAs), Ortho and Lizhu EIAs, Sorin and Wantai EIAs, Sorin EIA and Roche CIA and Ortho and Wantai EIAs] increased the detection rate from 46·81 to 55·57%, thus reducing the ratio per 100 000 donations of HCV-seropositive samples.

CONCLUSION

The combination of two anti-HCV screening immunoassays in parallel with an HCV NAT is a better strategy for HCV detection in blood centres to improve the safety of blood transfusion.

Factors associated with spontaneous clearance of hepatitis C virus in Chinese population

Hepatitis C virus (HCV) infections spontaneously clear in approximately 15-45% of infected individuals. Factors which influence spontaneous HCV clearance remain to be identified. The purpose of the present study was to identify variables associated with spontaneous HCV clearance in a referred population of Chinese patients. The prevalence of host, viral, and environmental factors known to influence the outcome of HCV infections was compared in 92 HCV spontaneous clearance subjects and 318 HCV persistent infection subjects. Univariate and multivariate analyses were performed to identify those factors associated with spontaneous HCV clearance. In univariate analysis, female gender, a history of icteric hepatitis, serologic evidence of concurrent HBV infection, and rs12979860 CC genotype were positively associated with spontaneous HCV clearance, while alcohol consumption was negatively associated with clearance. In multivariate analysis, female gender, a history of icteric hepatitis, concurrent HBV infection, and rs12979860 CC genotype remained independent variables associated with spontaneous HCV clearance. Spontaneous HCV clearance is more likely to occur in females, subjects with a history of icteric hepatitis, HBV coinfections, and those with the rs12979860 CC genotype.

Role of IL28B for chronic hepatitis C treatment toward personalized medicine

Genome-wide association studies recently revealed that certain interleukin-28B (IL28B) polymorphisms are strongly associated with responses to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy in patients chronically infected with hepatitis C virus (HCV) genotype 1, as well as with spontaneous clearance of HCV. Subsequent reports revealed that IL28B genotypes also affect treatment efficacy in chronic infection with other HCV genotypes. Furthermore, there have been several reports that implicate IL28B genotypes in inflammatory status, progression of fibrosis and adverse clinical outcomes in chronic hepatitis C (CHC). Therapy of CHC recently entered a new era with the deployment of direct-acting antivirals. These include nonstructural 3/4A protease inhibitors which have shown promise in combination with PEG-IFN/RBV in several clinical trials. IFN-free therapy is expected to be useful especially in IFN-resistant patients and may become the standard of care in the future. Several clinical trials have revealed an association between IL28B genotype and treatment efficacy in triple therapy or IFN-free regimens. On the other hand the mechanism of the effect of IL28B on HCV infection has not yet been elucidated. Recently, it was shown that the polymorphism of IFN-lambda 4 (IFNL4) is in high linkage disequilibrium with that of near IL28B, and more strongly associated with spontaneous or treatment-induced HCV clearance than IL28B genotypes, especially in individuals of African ancestry. This finding provides new insights into the genetic regulation of HCV clearance and its clinical management. IL28B genotyping will be also useful for personalized CHC treatment in the forthcoming era of direct-acting antivirals.

Donor Risk Index for African American liver transplant recipients with hepatitis C virus

African American (AA) liver transplant (LT) recipients with hepatitis C virus (HCV) have higher rates of graft loss than other racial/ethnic groups. The Donor Risk Index (DRI) predicts graft loss but is neither race- nor disease-specific and may not be optimal for assessing donor risk for AA HCV-positive LT recipients. We developed a DRI for AA with HCV with the goal of enhancing graft loss predictions. All U.S. HCV-positive adult AA first deceased donor LTs surviving ≥30 days from March 2002 to December 2009 were included. A total of 1,766 AA LT recipients were followed for median 2.8 (interquartile range [IQR] 1.3-4.9) years. Independent predictors of graft loss were donor age (40-49 years: hazard ratio [HR] 1.54; 50-59 years: HR 1.80; 60+ years: HR 2.34, P < 0.001), non-AA donor (HR 1.66, P < 0.001), and cold ischemia time (CIT) (HR 1.03 per hour >8 hours, P = 0.03). Importantly, the negative effect of increasing donor age on graft and patient survival among AAs was attenuated by receipt of an AA donor. A new donor risk model for AA (AADRI-C) consisting of donor age, race, and CIT yielded 1-year, 3-year, and 5-year predicted graft survival rates of 91%, 77%, and 68% for AADRI <1.60; 86%, 67%, and 55% for AADRI 1.60-2.44; and 78%, 53%, and 39% for AADRI >2.44. In the validation dataset, AADRI-C correctly reclassified 27% of patients (net reclassification improvement P = 0.04) compared to the original DRI.

CONCLUSION

AADRI-C identifies grafts at higher risk of failure and this information is useful for risk-benefit discussions with recipients. Use of AA donors allows consideration of older donors.

Interleukin-28B genetic variations and spontaneous clearance of hepatitis C antibody-positive blood donors in China

BACKGROUND

Single-nucleotide polymorphisms (SNPs) near the interleukin (IL)28B gene have been shown to be associated with spontaneous clearance of hepatitis C virus (HCV) infection in western populations. Anti-HCV-reactive and HCV RNA-negative samples were often found in Chinese blood donors. This study was to determine whether the IL28B gene variant is also associated with the natural outcome of HCV infection in Chinese blood donors.

STUDY DESIGN AND METHODS

A total of 111 anti-HCV-negative blood donors and 100 anti-HCV-reactive subjects were enrolled in this study. HCV-infected blood donors were classified into spontaneous clearance group and chronic infection group through HCV RNA detection. IL28B genetic variations (rs8099917 and rs12979860) were genotyped by polymerase chain reaction and direct sequencing.

RESULTS

A total of 24 (24.0%) donors spontaneously cleared HCV. The rs12979860 C allele frequency was 90.3% and the rs8099917 T allele frequency was 96.7% in our study. The rs12979860 CC genotype was strongly associated with spontaneous HCV clearance. Female blood donors had a higher rate of spontaneous HCV clearance than male donors (15/42 [35.7%] vs. 9/58 [15.5%], p = 0.02).

CONCLUSIONS

The rs12979860 CC variant upstream of IL28B gene is associated with spontaneous clearance of HCV in Chinese blood donors and female donors are more likely to clear HCV infection than male donors.

Transfusion transmission of HCV, a long but successful road map to safety

Improved blood banking practices and the development and implementation of increasingly sensitive serological and nucleic acid amplification technology assays for screening donors for HCV over the past few decades have helped minimize the residual risk from transfusion transmitted HCV in the developed world. Furthermore, studies of transfusion transmitted infections and of donors identified as infected by routine screening have provided significant insights into HCV transmission, epidemiology and pathogenesis. However, transfusion transmission of HCV is still a significant route of infection in the developing world. Key preventive mechanisms to ensure safe blood include elimination of paid donors and development of national donor pools comprising volunteer repeat blood donors, combined with implementation of standardized and maximally sensitive screening assays for HCV. There is also a need to develop up-to-date data on HCV disease burden on a global scale, in part, derived from systematic screening of donors for HCV infection. We suggest the creation of blood donor databases and specimen repositories, both at national and international levels, to facilitate epidemiological surveillance and pathogenesis and treatment studies in the future.

Different HCV genotype distributions of HIV-infected individuals in Henan and Guangxi, China

Background

Due to shared transmission routes, hepatitis C virus (HCV) infection is highly prevalent among people infected with human immunodeficiency virus (HIV). Highly active antiretroviral therapy (HAART) is associated with hepatotoxicity, leading to the negative effects on patients with HIV/HCV co-infection. In order to provide valuable information for HCV management in this particular population, we investigated the HCV genotypes in HIV-infected individuals from Henan and Guangxi, the two provinces with the most HIV-infected cases in China.

Methods

Individuals, who acquired HIV infection through various risk routes, were recruited from Henan and Guangxi. Test of antibodies against HCV (anti-HCV) was conducted, and detection of HCV RNA was performed by PCR amplification. HCV subtypes were determined by direct sequencing of amplicons, followed by phylogenetic analysis.

Results

We recruited a total of 1,112 HIV-infected people in this present study. Anti-HCV was detected from 218 (50.1%) patients from Henan and 81 (12.0%) patients from Guangxi, respectively. The highest prevalence of HIV/HCV co-infection was observed from FBDs (former blood donors) (87.2%) in Henan and IDUs (intravenous drug users) (81.8%) in Guangxi, respectively. The seroprevalence rate of HCV among people with sexual contact was significantly higher in Henan than in Guangxi (18.7% vs. 3.5%, P<0.05). The positive rate of HCV RNA in Henan and Guangxi was 30.6% (133/435) and 11.2% (76/677), respectively. Moreover, we found that 20 anti-HCV negative samples were HCV positive by PCR amplification. HCV subtype 1b (52.7%) was predominant in Henan, followed by subtype 2a (41.9%). The most frequently detected subtypes in Guangxi were 6a (35.6%) and 3b (32.9%).

Conclusion

The HCV genotype distributions were different in HIV-infected people from Henan and Guangxi. HIV/HCV co-infection was not only linked to the transmission routes, but also associated with the geographic position.

The National Heart, Lung, and Blood Institute retrovirus epidemiology donor studies (Retrovirus Epidemiology Donor Study and Retrovirus Epidemiology Donor Study-II): twenty years of research to advance blood product safety and availability

The Retrovirus Epidemiology Donor Study (REDS), conducted from 1989 to 2001, and the REDS-II, conducted from 2004 to 2012, were National Heart, Lung, and Blood Institute-funded, multicenter programs focused on improving blood safety and availability in the United States. The REDS-II also included international study sites in Brazil and China. The 3 major research domains of REDS/REDS-II have been infectious disease risk evaluation, blood donation availability, and blood donor characterization. Both programs have made significant contributions to transfusion medicine research methodology by the use of mathematical modeling, large-scale donor surveys, innovative methods of repository sample storage, and establishing an infrastructure that responded to potential emerging blood safety threats such as xenotropic murine leukemia virus-related virus. Blood safety studies have included protocols evaluating epidemiologic and/or laboratory aspects of human immunodeficiency virus, human T-lymphotropic virus 1/2, hepatitis C virus, hepatitis B virus, West Nile virus, cytomegalovirus, human herpesvirus 8, parvovirus B19, malaria, Creutzfeldt-Jakob disease, influenza, and Trypanosoma cruzi infections. Other analyses have characterized blood donor demographics, motivations to donate, factors influencing donor return, behavioral risk factors, donors' perception of the blood donation screening process, and aspects of donor deferral. In REDS-II, 2 large-scale blood donor protocols examined iron deficiency in donors and the prevalence of leukocyte antibodies. This review describes the major study results from over 150 peer-reviewed articles published by these 2 REDS programs. In 2011, a new 7-year program, the Recipient Epidemiology and Donor Evaluation Study-III, was launched. The Recipient Epidemiology and Donor Evaluation Study-III expands beyond donor-based research to include studies of blood transfusion recipients in the hospital setting and adds a third country, South Africa, to the international program.

Discovery of critical host factor, IL-28B, associated with response to hepatitis C virus treatment

Chronic hepatitis C affects 2.2-3.0% of the world population (130 million-170 million). Pegylated interferon-α (PEG-IFN-α) in combination with ribavirin (RBV), the approved and standard therapy, leads to viral eradication in about 50% of treated patients. In 2009, genome-wide association studies (GWAS) identified host genetic variation to be critical for predicting treatment response and spontaneous clearance in patients infected with hepatitis C virus (HCV). A correlated set of polymorphisms in the region of the interleukin-28B (IL-28B) gene on chromosome 19, coding for interferon (IFN)-λ3 were associated with clearance of genotype 1 hepatitis C virus (HCV) in patients treated with PEG-IFN-α and RBV. The same polymorphisms were subsequently associated with spontaneous clearance of HCV in untreated patients. In addition, prediction of viral response to PEG-IFN-α and RBV therapy of patients with recurrent HCV infection after orthotopic liver transplantation depends on the IL-28B genotype of both recipient and donor tissues. Diagnosis of a patient's IL-28B genotype is likely to aid in clinical decision making with standard-of-care regimens. Future studies will investigate the possibility of individualizing treatment duration and novel regimens according to IL-28B genotype. As GWAS yield unexpected data, this approach could lead to the development of novel drug therapy, such as already appears promising with IFN-λ. In this Okuda lecture, I present the current understanding in regard to the relationship between host variations and clinical outcome of hepatitis C.

IL28B polymorphism associated with spontaneous clearance of hepatitis C infection in a Southern Brazilian HIV type 1 population

About one-third of people infected with human immunodeficiency virus-1 (HIV-1) are coinfected with hepatitis C virus (HCV) because of shared transmission routes. Studies report that HIV-1 complicates hepatitis C infection by increasing HCV viral load and reducing spontaneous clearance. Single nucleotide polymorphisms (SNPs) upstream of the IL28B gene have been associated with spontaneous and treatment-induced clearance of HCV infection. The aim of this study was to evaluate the association between the SNP rs12979860 of the IL28B gene and spontaneous clearance of HCV infection in a Brazilian HIV-1 population. The SNP was analyzed by polymerase chain reaction (PCR) followed by restriction digestion in 138 anti-HCV-positive patients. Spontaneous clearance was observed in 34 subjects (24.6%). Genotype distribution was significantly different between spontaneous clearance and HCV chronic patients. The CT/TT genotypes conferred a nearly 3-fold increased odds to chronic HCV infection relative to the CC genotype (odds ratio, 2.78; 95% confidence interval, 1.16-6.64; p=0.011). In conclusion, the rs12979860 polymorphism is associated with spontaneous clearance of HCV in HIV-1 Brazilian infected patients.

Clinical evaluation of the signal-to-cutoff ratios of hepatitis C virus antibody screening tests used in China

The clinical diagnosis of hepatitis C virus (HCV) infection is important to direct an accurate course of therapy. Previous studies have reported a correlation between the signal-to-cutoff (S/CO) ratios of the anti-HCV screening test and confirm HCV infections for American anti-HCV screening kits as well as for those in China. It is currently unknown whether clinical laboratories use the same threshold S/CO ratios under routine conditions and if these values are acceptable for the analysis of Chinese samples. A total of 336 anti-HCV screening-test-positive serum samples were tested in duplicate using different lots of three most commonly used enzyme immunoassay (EIA) kits available in China. Samples were also tested using the Architect Anti-HCV chemiluminescent microparticle immunoassay (CMIA) kit and measured for HCV RNA. Recombinant immunoblot assays (RIBA) were additionally performed on samples with HCV RNA-negative results with RIBA HCV 3.0. The relationship between S/CO ratios and confirmed HCV infection rates were analyzed. The threshold S/CO ratio for each screening kit correlated with the ≥ 95% positive predictive value was InTec 12.0, KHB 4.0, Wantai 5.0, and Abbott Architect 5.0. Therefore, the same threshold S/CO ratios for manufactured domestically EIA kits was difficult to attain. A multi-center study with a large sample size is required to identify a uniform threshold S/CO ratio for use in different diagnostic laboratories. Alternatively, individual laboratories may be required to establish threshold S/CO ratios in their own laboratories to obtain consistent diagnostic results.

Impact of host responses on control of hepatitis C virus infection in Chinese blood donors

A study was undertaken to explore the molecular mechanisms underlying control of HCV infection in blood donors in China. Factors including clinical information, anti-HCV reactivity (S/CO), IFN-α and IFN-γ, viral loads and genotypes were correlated with 160 index plasma samples at three statuses of 45 recovered, 76 chronic or 39 false positive anti-HCV reactive blood donors. The spontaneous recovery rate was 37.2%. Viral loads of 76 HCV plasmas ranged between 59.8 IU/ml and 2.43 × 10(6)IU/ml (median 3.67 × 10(4)IU/ml). Genotypes 1, 2, 3 and 6 of 63 HCV strains were identified phylogenetically. Recovered donors were significantly younger (p=0.002) and had lower level IFN-γ (p=0.001) than chronically HCV infected donors. Circulating levels of IFN-α and IFN-γ were higher in those with low viral load and were low in middle or high viral load samples. The ratio of IFN-α to IFN-γ (IFN-α/γ) was significantly positively correlated with viral load (p=0.037), and viral load was inversely correlated with IFN-γ in chronic HCV infection regardless of genotype. The study revealed clearly different relationships between IFN-α and IFN-γ in relation to viral load in HCV. A novel measure of IFN-α/γ ratio could be a new approach to evaluate long term outcome of HCV infection.

A higher correlation of HCV core antigen with CD4+ T cell counts compared with HCV RNA in HCV/HIV-1 coinfected patients

Development of HCV infection is typically followed by chronic hepatitis C (CHC) in most patients, while spontaneous HCV viral clearance (SVC) occurs in only a minority of subjects. Compared with the widespread application of HCV RNA testing by quantitative RT-PCR technique, HCV core antigen detection may be an alternative indicator in the diagnosis of hepatitis C virus infections and in monitoring the status of infectious individuals. However, the correlation and differences between these two indicators in HCV infection need more investigation, especially in patients coinfected by HIV-1. In this study, a total of 354 anti-HCV and/or anti-HIV serum positive residents from a village of central China were enrolled. Besides HCV-related hepatopathic variables including clinical status, ALT, AST, anti-HCV Abs, as well as the altered CD4+/CD8+ T cell counts, HCV core antigen and HCV viral load were also measured. The concentration of serum HCV core antigen was highly correlated with level of HCV RNA in CHC patients with or without HIV-1 coinfection. Of note, HCV core antigen concentration was negatively correlated with CD4+ T cell count, while no correlation was found between HCV RNA level and CD4+ T cell count. Our findings suggested that quantitative detection of plasma HCV core antigen may be an alternative indicator of HCV RNA qPCR assay when evaluating the association between HCV replication and host immune status in HCV/HIV-1 coinfected patients.

Correlates of spontaneous clearance of hepatitis C virus in a Danish human immunodeficiency virus type 1 cohort

BACKGROUND

Around a quarter of individuals infected with hepatitis C virus (HCV) are spontaneously able to clear the virus. Correlates of spontaneous HCV clearance are not well established and the aim of this study was to characterize factors associated with spontaneous HCV clearance in a human immunodeficiency virus (HIV)-co-infected cohort.

METHODS

We analyzed 327 anti-HCV-positive HIV-1-infected patients using multivariate logistic regression. HCV clearance was defined as the presence of anti-HCV with undetectable HCV RNA from at least 2 measurements more than 6 months apart.

RESULTS

We included 327 HIV-1-infected individuals, predominantly of Caucasian race; 112 (34%) were females, 258 (79%) were injecting drug users (IDU), 25 (8%) were men who have sex with men (MSM), and 20 (6%) were hepatitis B surface antigen (HBsAg)-positive. Seventy-six (23%; 95% confidence interval (CI) 18-28) had cleared their HCV infection and 251 (77%; 95% CI 72-82) had a chronic infection. The clearance rate in HBsAg-positive individuals was 65%. Being female, HBsAg-positive, or belonging to HIV exposure groups IDU and MSM predicted higher HCV clearance rates (adjusted odds ratio (aOR) 1.8, 95% CI 1-3.2; aOR 7.6, 95% CI 2.7-21; aOR 5.2, 1.2-23.5; and aOR 10.2, 95% CI 1.8-58, respectively). Race, acquired immunodeficiency syndrome (AIDS), and antiretroviral therapy were not associated with HCV clearance.

CONCLUSIONS

The HCV clearance rate in this HIV-1 cohort was 23%. MSM and IDUs may have higher clearance rates due to their repeated exposure to low-dose HCV, leading to immune memory. Our data suggest an interaction of hepatitis B virus and HCV that influences the outcome of acute HCV infection.

Prevalence and risk factors of Hepatitis C among individuals presenting to HIV testing centers, Hawassa city, Southern Ethiopia

Background

Hepatitis C virus (HCV), either alone or in combination with Human Immunodeficiency virus (HIV), constitutes a major public health concern. This study was conducted to describe the prevalence and risk factors for HCV infection in people with and without HIV infection.

Methods

Blood samples and data on socio-demographic and risk factors for HCV infection were collected from consecutive 400 HIV- positive and 400 HIV- negative individuals attending HIV testing centers in Hawassa city, from October to December, 2008. All sera were tested for antibody to HCV infection (anti-HCV) using enzyme linked immunosorbent assay (ELISA). Sera positive for anti-HCV were further tested for viral ribonucleic acid (RNA) levels using real-time polymerase chain reaction.

Results

The rate of anti-HCV positivity was 10.5% in the HIV- infected individuals compared with 6% in the HIV negative group (p = 0.002). HCV-RNA was detected in 9.1% of anti-HCV positive samples and rates were comparable between HIV- infected and HIV- non-infected individuals. There was no significant difference in odds of HCV infection in participants with and without HCV risk factors in either HIV sero-group.

Conclusion

HIV infected individuals had significantly higher rate of anti-HCV although most of them showed no evidence of viraemia. Hence, while priority should be given for HIV infected patients, testing those with anti-HCV for HCV-RNA remains important.

Novel findings for the development of drug therapy for various liver diseases: Genetic variation in IL-28B is associated with response to the therapy for chronic hepatitis C

Hepatitis C infection is a global health problem. Spontaneous viral clearance was observed in approximately 30% of individuals with acute infection. In the therapy using a combination of pegylated interferon-α and ribavirin, approximately 50% of chronic hepatitis C patients infected with high viremia of hepatitis C virus infection (HCV) genotype 1 reached a sustained viral response. These findings were strongly expected to reflect variations of the host genome. To reveal genetic effects against viral clearance or treatment response, four independent groups applied a genome-wide association study (GWAS) to HCV infection. These groups almost simultaneously reported a strong association of interleukin (IL)-28B polymorphisms with viral clearance or final decision of HCV therapy. The discovered single nucleotide polymorphisms (SNPs) also revealed the enigma that the viral clearance rate was dependent on ethnic type. The significant SNPs are useful for prediction prior to treatment because of the strong association with clinical outcome. In addition, the unexpected results revealed by GWAS could promote the development of a novel drug related to IL-28B. Herein, we present current understanding in regard to the relationship between host variations and clinical outcome of hepatitis C.

A polymorphism near IL28B is associated with spontaneous clearance of acute hepatitis C virus and jaundice

BACKGROUND & AIMS

A single nucleotide polymorphism (SNP) upstream of the IL28B gene has been associated with response of patients with chronic hepatitis C to therapy with pegylated interferon and ribavirin and also with spontaneous clearance of acute hepatitis C in a heterogeneous population. We analyzed the association between IL28B and the clinical presentation of acute hepatitis C virus (HCV) infection in a homogeneous population.

METHODS

We analyzed the SNP rs12979860 in 190 women from the German anti-D cohort (infected with HCV genotype 1b via contaminated rhesus prophylaxis) and its association with spontaneous clearance. Clinical data were available in 136 women with acute infection who were also evaluated for IL28B genotype. Based on results of a TaqMan polymerase chain reaction assay, the rs12979860 SNP genotypes studied were C/C, C/T, or T/T.

RESULTS

Spontaneous clearance was more common in patients with the C/C genotype (43/67; 64%) compared with C/T (22/90; 24%) or T/T (2/33; 6%) (P < .001). Jaundice during acute infection was more common among patients with C/C genotype (32.7%) than non-C/C patients (with C/T or T/T) (16.1%; P = .032). In C/C patients, jaundice during acute infection was not associated with an increased chance of spontaneous clearance (56.3%) compared with those without jaundice (60.6%). In contrast, in non-C/C patients, jaundice was associated with a higher likelihood of spontaneous clearance (42.9%) compared with those without jaundice (13.7%).

CONCLUSIONS

The SNP rs12979860 upstream of IL28B is associated with spontaneous clearance of HCV. Women with the C/T or T/T genotype who did not develop jaundice had a lower chance of spontaneous clearance of HCV infection.

Hepatitis C virus prevalence and clearance among US blood donors, 2006-2007: associations with birth cohort, multiple pregnancies, and body mass index

BACKGROUND

During the period 1992-1993, the prevalence of hepatitis C virus (HCV) antibodies (anti-HCV) among US blood donors was 0.36%, but contemporary data on the prevalence of antibody to HCV and the prevalence of HCV RNA are lacking.

METHODS

We performed a large, cross-sectional study of blood donors at 6 US blood centers during 2006-2007. Anti-HCV was measured with enzyme-linked immunosorbent assay followed by immunoblot, and HCV RNA was measured with nucleic acid testing. Adjusted odds ratios (aORs) were derived using multivariable logistic regression.

RESULTS

Of 959,281 donors, 695 had anti-HCV detected (prevalence, 0.072%). Of those with anti-HCV, 516 (74%) had test results positive for HCV RNA, and 179 (26%) had test results that were negative for HCV RNA. Compared with the prevalence during the period 1992-1993, prevalence during 2006-2007 was lower and peaked in older age groups. Anti-HCV was associated with a body mass index (BMI) >30 (aOR, 0.6; 95% confidence interval [CI], 0.5-0.8), and among women, it was associated with higher gravidity (aOR for 5 vs 0 pregnancies, 3.2; 95% CI, 1.9-5.4). HCV RNA negative status was associated with black race (aOR, 0.4; 95% CI, 0.2-0.7), having more than a high school education (aOR, 1.6; 95% CI, 1.1-2.4), and BMI >30 (aOR, 2.4; 95% CI, 1.4-3.9).

CONCLUSIONS

Decreasing HCV prevalence is most likely attributable to culling of seropositive donors and a birth cohort effect. We found new associations between anti-HCV prevalence and gravidity and obesity. Recently discovered genetic factors may underlie differences in HCV RNA clearance in black donors.

Co-infection by hepatitis C virus in HIV-infected patients in southern Brazil: genotype distribution and clinical correlates

Background

Prevalence rates of Hepatitis C Virus (HCV) co-infection, the distribution of HCV genotypes, and the frequency of spontaneous resolution of hepatitis C in patients infected with the Human Immunodeficiency Virus (HIV) have a worldwide disparity. The purpose of this study is to investigate the prevalence of HCV antibodies (anti-HCV) in patients with HIV, the proportion and correlates of infection by different HCV genotypes, and rates of spontaneous resolution of HCV infection.

Methods

A cross-sectional study was conducted among 1143 HIV patients under follow-up in a HIV/AIDS outpatient reference center of the Brazilian public health system. From 357 anti-HCV positive patients, a consecutive sample of 227 individuals HCV treatment-naïve was interviewed and 207 was tested for HCV-RNA and genotypes.

Results

Anti-HCV was detected in 357 patients (31.2%). HCV-RNA was undetectable in 16.4% of 207 anti-HCV positive individuals. Genotype 1 was diagnosed in 81.5% of the sample, genotype 2 in 1.7% and genotype 3 in 16.2%. Male gender was the unique characteristic associated with higher prevalence of genotype 1 HCV.

Conclusions

Co-infection by HCV is frequent among patients with HIV in our State, and it is particularly high the infection by HCV genotype 1. Further investigation is necessary to explain the important regional variation in the proportion of infection by the different HCV genotypes and to better understand rates of spontaneous HCV clearance.

A case-control study of factors associated with resolution of hepatitis C viremia in former blood donors (CME)

BACKGROUND

Nucleic acid testing (NAT) is performed on blood collected in the United States allowing for the classification of hepatitis C virus (HCV) antibody-positive donors into resolved and chronic hepatitis C infections. We report a case-control study of factors associated with HCV resolution.

STUDY DESIGN AND METHODS

Blood donors with resolved (HCV antibody positive, RNA negative defined as "cases") or chronic (HCV antibody positive, RNA positive defined as "controls") based on their index donation HCV test results were enrolled. Participants completed a risk factor, symptoms, and treatment questionnaire followed by HCV antibody, HCV RNA, and liver biochemical testing.

RESULTS

We enrolled 100 cases and 202 controls. In a multivariate logistic regression model, significant independent effects for spontaneous viral clearance were observed for African American (inverse; odds ratio [OR], 0.11; 95% confidence interval [CI], 0.01-0.87), autologous blood donation (OR, 4.70; 95% CI, 2.02-10.94), alcohol intake (OR, 2.39; 95% CI, 1.13-5.03), and transfusion before May 1990 (inverse; OR, 0.36; 95% CI, 0.14-0.91). Cases admitting injection drug use had shorter time since first injection than did controls. Forty-nine index RNA positive controls received antiviral therapy and 25 (51%) were RNA negative at enrollment; surprisingly several RNA-negative cases received liver biopsies and/or antiviral treatment.

CONCLUSIONS

We document the role donor screening plays in the identification, subsequent medical evaluation, and treatment among individuals who presumably did not know that they were at risk for HCV infection. Additionally, we confirmed race/ethnicity as a determinant of clearance and suggest infectious dose and route of infection may play a role in clearance.

Sero-epidemiology of transfusion-transmissible infectious diseases among blood donors in Osogbo, south-west Nigeria

BACKGROUND

Transfusion-transmissible infectious agents such as hepatitis B virus (HBV), human immunodeficiency virus (HIV), hepatitis C virus (HCV) and syphilis are among the greatest threats to blood safety for transfusion recipients and pose a serious public health problem. This cross-sectional study was undertaken with the aim of determining the seroprevalence of HIV, HCV, hepatitis B surface antigen (HBsAg) and syphilis and correlates the findings with sex and age to ascertain the associations, if any, in the occurrence of the pathogens.

MATERIALS AND METHODS

HBsAg, antibodies to Treponema pallidum and HCV were determined using Clinotech test strips. Antibodies to HIV types 1 and 2 were screened with Determine and Immunocomb. All the reactive samples were confirmed using enzyme-linked immunosorbent assays. Antibodies to Treponema pallidum were confirmed with a Treponema pallidum haemagglutination test.

RESULTS

A total of 1,410 apparently healthy prospective blood donors aged between 18 and 64 years (mean+/-SD, 32.58 +/- 10.24 years) who presented for blood donation at the Ladoke Akintola University of Technology Teaching Hospital Blood Bank, Osogbo were studied. The male:female ratio was 6:1. Of the prospective blood donors, 406 (28.8%) had serological evidence of infection with at least one infectious marker and 36 (2.6%) had dual infections. The overall seroprevalence of HBsAg, HIV, HCV and syphilis was found to be 18.6%, 3.1%, 6.0% and 1.1%, respectively. The highest prevalences of HBsAg, HIV, HCV and syphilis infections occurred among commercial blood donors and those aged 18 to 47 years old, the most sexually active age group. There were no significant associations between pathogens except for syphilis and HIV (p > 0.001).

CONCLUSION

The high seroprevalence of blood-borne pathogens among prospective blood donors in Osogbo, Nigeria calls for mandatory routine screening of blood donors for HBV, HIV, HCV and syphilis.

Prevalence of antibodies to hepatitis C virus in apparently healthy Port Harcourt blood donors and association with blood groups and other risk indicators

BACKGROUND

Testing for hepatitis C virus (HCV) is not yet mandatory in blood transfusion laboratories in Port Harcourt, Nigeria, so the current prevalence rate of this infection in our locality is unknown. The aim of this study was to determine the prevalence of HCV among apparently healthy blood donors in our area and also to assess some of the risk factors associated with the infection.

MATERIALS AND METHODS

The presence of anti-HCV antibodies was determined in the serum of 300 blood donors in Port Harcourt, Nigeria. A second-generation rapid screening test, the HEP C SPOT HCV assay was used. Initial reactive results were confirmed by repeat testing with UBI HCV EIA 4.0 enzyme immunoassay. The ABO and Rh blood groups of donors were also determined using standard serological procedures.

RESULTS

The majority of our blood donor population was constituted of males (88%) and commercial donors (63%). The blood group distribution of the donors was as follows: O RhD-positive (73%), AB RhD-positive. (4.0%), A RhD-positive (10.0%), B RhD-positive (3.0%), O RhD-negative (4.0%), A RhD-negative (3.0%), AB RhD-negative (1.0%) and B RhD-negative (2.0%). Fifteen of the 300 donors were positive for HCV, giving a prevalence rate of 5.0% in this study population. The age group 21-30 years was identified as the highest risk group with 60% of the subjects with HCV infection being in this group, compared to 20% each in the age groups 31-40 years and 41-50 years old. Twelve of the 15 (80%) HCV-positive subjects were commercial donors. The prevalence of HCV was statistically significantly higher among female donors than among male donors (chi2 = 81.000, p < 0.01). With regards to the distribution of HCV-positivity according to blood group, 4.1% of the O RhD-positive subjects, 10% of the A RhD-positive subjects and 25% of the AB RhD-positive were HCV-positive. No cases of HCV-positivity were found among the donors with other blood groups. No statistically significant relationship was found to exist between blood groups and HCV prevalence (p > 0.05).

CONCLUSION

There was a moderate prevalence of HCV infection (5%) in apparently healthy blood donors in Port Hartcourt, Nigeria. The prevalence was higher among commercial donors and in donors in the age bracket of 21-30 years of age.

The inverse relationship between chronic HBV and HCV infections among injection drug users is associated with decades of age and drug use

Infection with hepatitis C virus (HCV) may suppress co-infection with hepatitis B virus (HBV) during acute or chronic HBV infection. We examined relationships between HBV infection, HCV infection and other factors among injection drug users (IDUs) with antibodies to both viruses. Participants enrolled in a cross-sectional study during 1998-2000 were considered to have been infected with HBV if they had core antibody, to be chronically infected if they had hepatitis B surface antigen (HBsAg), to have been infected with HCV if they had HCV antibody and to be chronically infected if they had HCV RNA. Among 1694 participants with antibody to both viruses, HBsAg prevalence decreased with increasing age among those positive for HCV RNA [from 4.55% in those 18-29 years to 1.03% in those >or=50 years old (P(trend) = 0.02)], but not among those who were negative for HCV RNA. Chronic HBV infection was less common overall among those with chronic HCV infection (odds ratio [OR], 0.25; P < 0.0001), but this inverse relationship was much stronger in the oldest (>50 years; OR = 0.15) than the youngest (18-29 years; OR = 0.81) participants (P(trend) = 0.03). Similar results were obtained when duration of injection drug use was substituted for age (P(trend) = 0.05). Among IDUs who have acquired both HBV and HCV, chronic HBV infection is much less common among those with chronic HCV infection, but this inverse relationship increases markedly with increasing years of age and injection drug use. Co-infection with HCV may enhance the resolution of HBsAg during the chronic phases of these infections.

Clearance of hepatitis C virus RNA from the peripheral blood mononuclear cells of blood donors who spontaneously or therapeutically control their plasma viremia

We determined whether hepatitis C virus (HCV) RNA could be detected associated with peripheral blood mononuclear cells (PBMC) of seropositive blood donors who had spontaneously or therapeutically cleared their plasma viremia. Blood donor plasma viremia status was first determined with a highly sensitive transcription-mediated amplification (TMA) test performed in duplicate assays. PBMC from 69 aviremic and 56 viremic blood donors were then analyzed for the presence of HCV RNA with TMA adapted to detect viral RNA in PBMC and with a reverse transcription-nested polymerase chain reaction assay. PBMC-associated HCV RNA was detected in none of the 69 aviremic donors, including all 6 subjects with a sustained viral response following antiviral therapy. PBMC-associated HCV RNA was detected in 43 of the 56 viremic donors. The 13 viremic donors with no detectable PBMC-associated HCV RNA all had very low viral loads (6 positive only in 1 of 2 duplicate plasma TMA assays, 6 with viral loads below 100 HCV RNA copies/mL, and 1 with a viremia of 2700 HCV RNA copies/mL). The absence of detectable PBMC HCV RNA detection in all 69 aviremic donors reported here contrasts with prior studies, possibly as a result of the higher sensitivity of the TMA assay used to test for plasma viremia.

CONCLUSION

Our results indicate that PBMC are unlikely to serve as a long-lived reservoir of HCV in aviremic subjects.

Factors associated with hepatitis C viremia in a large cohort of HIV-infected and -uninfected women

BACKGROUND

Co-infection with hepatitis C virus (HCV) is common among HIV-infected women.

OBJECTIVE

To further our understanding of the risk factors for HCV viremia and the predictors of HCV viral load among women.

STUDY DESIGN

We investigated sociodemographic, immunologic, and virologic factors associated with presence and level of HCV viremia among 1049 HCV-seropositive women, 882 of whom were HIV-infected and 167 HIV-uninfected at their entry into the Women's Interagency HIV Study.

RESULTS

Plasma HCV RNA was detected in 852 (81%) of these 1049 women (range: 1.2-7.8 log(10)copies/ml). HCV-viremic women were more likely to have an HIV RNA level >100,000 copies/ml (P=0.0004), to have reported smoking (P=0.01), or to be Black (P=0.005). They were less likely to have current or resolved hepatitis B infection. HCV RNA levels were higher in women who were >35 years old, or HIV-infected. Current smoking and history of drug use (crack/freebase cocaine, marijuana, amphetamines, or heroin) were each associated with both presence and level of viremia.

CONCLUSIONS

Substance abuse counseling aimed at eliminating ongoing use of illicit drugs and tobacco may reduce clinical progression, improve response to treatment, and decrease HCV transmission by lowering levels of HCV viremia in women.

Estimating past hepatitis C infection risk from reported risk factor histories: implications for imputing age of infection and modeling fibrosis progression

Background

Chronic hepatitis C virus infection is prevalent and often causes hepatic fibrosis, which can progress to cirrhosis and cause liver cancer or liver failure. Study of fibrosis progression often relies on imputing the time of infection, often as the reported age of first injection drug use. We sought to examine the accuracy of such imputation and implications for modeling factors that influence progression rates.

Methods

We analyzed cross-sectional data on hepatitis C antibody status and reported risk factor histories from two large studies, the Women's Interagency HIV Study and the Urban Health Study, using modern survival analysis methods for current status data to model past infection risk year by year. We compared fitted distributions of past infection risk to reported age of first injection drug use.

Results

Although injection drug use appeared to be a very strong risk factor, models for both studies showed that many subjects had considerable probability of having been infected substantially before or after their reported age of first injection drug use. Persons reporting younger age of first injection drug use were more likely to have been infected after, and persons reporting older age of first injection drug use were more likely to have been infected before.

Conclusion

In cross-sectional studies of fibrosis progression where date of HCV infection is estimated from risk factor histories, modern methods such as multiple imputation should be used to account for the substantial uncertainty about when infection occurred. The models presented here can provide the inputs needed by such methods. Using reported age of first injection drug use as the time of infection in studies of fibrosis progression is likely to produce a spuriously strong association of younger age of infection with slower rate of progression.

Evaluation of a multiplex human immunodeficiency virus-1, hepatitis C virus, and hepatitis B virus nucleic acid testing assay to detect viremic blood donors in northern Thailand

BACKGROUND

Screening of blood donors with nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) has been implemented recently in the United States. There are limited data, however, on the additional NAT yield of donors in developing countries in Asia where the prevalence of infection is higher. In addition, data on hepatitis B virus (HBV) NAT in high prevalence areas are minimal.

STUDY DESIGN AND METHODS

A total of 5083 whole-blood donors at the Chiang Mai University Hospital, Thailand, blood bank were evaluated with a commercially available NAT assay (Procleix Ultrio, Gen-Probe, Inc.) to screen individual donations.

RESULTS

No NAT yield cases were found for HIV-1 or HCV. There were 17 samples with discrepant HBV DNA NAT and hepatitis B surface antigen (HBsAg) tests, however. Seven of these were HBV DNA NAT-positive, HBsAg-negative; of these 7, 1 was NAT-positive at baseline, but negative on follow-up, and considered a false-positive, 1 had an acute infection, and 5 had chronic prevalent HBV infections, for a NAT yield of 6 in 4798 HBsAg negative donors (1:800). In addition there were 10 NAT-negative, HBsAg-positive serum samples. All were anti-hepatitis B core antigen immunoglobulin G-positive; on testing with a more sensitive NAT target capture assay, 5 were positive (1.8-20.6 IU/mL) and 5 were negative.

CONCLUSION

Multiplex NAT screening of individual-donor serum samples in Northern Thailand detected approximately 1 per 800 HBV NAT-positive, HBsAg-negative donors. The especially high prevalence of HBV infection in Thailand and other Asian countries suggests that HBV NAT screening of donors will be more cost-effective than in other areas.

Current incidence and estimated residual risk of transfusion-transmitted infections in donations made to Canadian Blood Services

BACKGROUND

New testing methods such as nucleic acid amplification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion-transmitted infections (TTIs) has been developed. Thus, available RR estimates for Canada need to be updated.

STUDY DESIGN AND METHODS

Incidence rates for known TTI markers were determined for all allogeneic whole-blood donations made to Canadian Blood Services between 2001 and 2005; they were derived from NAT conversions or seroconversions of repeat donors with at least two donations in a 3-year period. RR estimates for human immunodeficiency virus (HIV)-1 and hepatitis C virus (HCV) derived from the classical incidence/window-period model were compared to those obtained by the new method that estimates incidence from NAT-positive, antibody-negative donations (NAT-yield cases) from all donors divided by person-years.

RESULTS

With the classical method, the RR of HIV (1 per 7.8 million donations) and HCV (1 per 2.3 million) were low; HBV RR was higher (1 per 153,000). HCV RR was significantly lower when estimated with the new method (1 per 13 million). Eleven HCV NAT-yield cases were predicted by applying the classical method to our seroconversion data but only 2 were observed (p = 0.011). Observed HIV-1 NAT-yield cases (n = 1) matched those predicted (n = 0.7).

CONCLUSION

New tests have reduced an already low risk of TTI in Canada. HCV RR estimates by two different methods differed but both were low.

The changing epidemiology and natural history of hepatitis C virus infection

Injection drug use remains the predominant mode of transmission of hepatitis C virus (HCV) infection. Growing numbers of persons who have been chronically infected with HCV for 20 or more years are coming to medical attention and are at risk for serious complications of chronic infection, including cirrhosis and hepatocellular carcinoma. Factors linked with the development of advanced fibrosis and cirrhosis include age at infection, duration of infection, heavy alcohol use, coinfections with HIV or hepatitis B virus, and male sex. Emerging risk factors for disease progression include steatosis, insulin resistance (and factors associated with the metabolic syndrome), and host genetics.

Correlates of spontaneous clearance of hepatitis C virus among people with hemophilia

People with hemophilia were formerly at very high risk of infection with hepatitis C virus (HCV). Approximately 20% of HCV-infected patients spontaneously clear the virus. To identify correlates of spontaneous clearance of HCV, we studied a cohort of HCV-infected hemophilic subjects without human immunodeficiency virus infection who had never been treated with interferon. Plasma HCV RNA was persistently undetectable in 192 (27.0%) of 712 HCV-seropositive subjects. In multivariate analyses, HCV clearance was more likely in subjects infected with HCV at younger age, especially with infection before age 2 years (40.1%) compared with after age 15 years (14.9%, P(trend) < .0001), and with relatively recent infection, especially after 1983 (42.8%) compared with before 1969 (18.2%, P(trend) < .0001). HCV clearance was marginally reduced with African ancestry (19%) and greatly increased with chronic hepatitis B virus (HBV) infection (59.1%, P = .001). Resolved HBV infection, coagulopathy types and severity, types of clotting factor treatment, and sex were not associated with HCV clearance. In conclusion, hemophilic subjects coinfected with chronic HBV and those infected with HCV before age 2 years or after 1983 were significantly more likely to spontaneously clear HCV viremia. These data highlight and clarify the importance of nongenetic determinants in spontaneous recovery from HCV infection.