Current testing strategies for hepatitis C virus infection in blood donors and the way forward

Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.

An autoregressive integrated moving average model for short-term prediction of hepatitis C virus seropositivity among male volunteer blood donors in Karachi,Pakistan

AIM： To identify the stochastic autoregressive integrated moving average （ARIMA） model for short term forecasting of hepatitis C virus （HCV） seropositivity among volunteer blood donors in Karachi, Pakistan.METHODS： Ninety-six months （1998-2005） data on HCV seropositive cases （1000-1 x month1） among male volunteer blood donors tested at four major blood banks in Karachi, Pakistan were subjected to ARIMA modeling. Subsequently, a fitted ARIMA model was used to forecast HCV seropositive donors for 91-96 mo to contrast with observed series of the same months. To assess the forecast accuracy, the mean absolute error rate （%） between the observed and predicted HCV seroprevalence was calculated. Finally, a fitted ARIMA model was used for short-term forecasts beyond the observed series.RESULTS： The goodness-of-fit test of the optimum ARIMA （2,1,7） model showed non-significant autocorrelations in the residuals of the model. The forecasts by ARIMA for 91-96 mo closely followed the pattern of observed series for the same months, with mean monthly absolute forecast errors （%） over 6 mo of 6.5%. The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed increasing tendency of HCV seropositivity with a mean ± SD HCV seroprevalence （1000^-1× month^-1） of 24.3 ±1.4 over the forecast interval.CONCLUSION： To curtail HCV spread, public health authorities need to educate communities and health care providers about HCV transmission routes based on known HCV epidemiology in Pakistan and its neighboring countries. Future research may focus on factors associated with hyperendemic levels of HCV infection.

TT virus and hepatitis G virus infections in Korean blood donors and patients with chronic liver disease

AIM:To determine the prevalences of TTV and HGV infections among blood donors and patients with chronic liver disease in Korea,to investigate the association of TTV and HGV infections with blood transfusion,and to assess the correlation between TTV and HGV viremia and hepatic damage. METHODS:A total of 391 serum samples were examined in this study.Samples were obtained from healthy blood donors(n=110),hepatitis B surface antigen(HBsAg)-positive donors(n=112),anti-hepatitis C virus(anti-HCV)-positive donors(n=69),patients with type B chronic liver disease (n=81),and patients with type C chronic liver disease(n=19). Trv DNA was detected using the hemi-nested PCR.HGV RNA was tested using RT-PCR.A history of blood transfusion and serum levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were also determined. RESULTS:TTV DNA was detected in 8.2%of healthy blood donors,16.1%of HBsAg-positive donors,20.3%of anti- HCV-positive donors,21.0%of patients with type B chronic liver disease,and 21.1%of patients with type C chronic liver disease.HGV RNA was detected in 1.8%of healthy blood donors,1.8%of HBsAg-positive donors,17.4%of anti-HCV-positive donors,13.6%of patients with type B chronic liver disease,and 10.5%of patients with type C chronic liver disease.The prevalence of TTV and HGV infections in HBV- or HCV-positive donors and patients was significantly higher than in healthy blood donors(P<0.05), except for the detection rate of HGV in HBsAg-positive donors which was the same as for healthy donors.There was a history of transfusion in 66.7%of TTV DNA-positive patients and 76.9%of HGV RNA-positive patients(P<0.05).No significant increase in serum ALT and AST was detected in the TTV or HGV-positive donors and patients. CONCLUSION:TTV and HGV infections are more frequently found in donors and patients infected with HBV or HCV than in healthy blood donors.However,there is no significant association between TTV or HGV infections and liver injury.

Flow cytometric detection of hepatitis C virus antigens in infected peripheral blood leukocytes: Binding and entry

AIM： We designed two synthetic-core-specific peptides core 1 （C1） and core 2 （C2）, and an E1-specific peptide （El）. We produced specific polyclonal antibodies against these peptides and used the antibodies for detection of HCV antigens on surface and within infected peripheral blood leukocytes. METHODS： Peripheral blood from a healthy individual who tested negative for HCV RNA was incubated with HCV type 4 infected serum for i h and 24 h at 37 ℃. Cells were stained by direct and indirect immunofluorescence and measured by flow cytometry. RESULTS： After 1 h of incubation, antibodies against C1, C2, and El detected HCV antigens on the surface of 27%, 26% and 73% of monocytes respectively, while 10%, 5% and 9% of lymphocytes were positive with anti-C1, anti-C2 and anti-E1 respectively. Only 1-3% of granulocytes showed positive staining with anti-C1, anti-C2 and anti E1 antibodies. After 24 h of incubation, we found no surface staining with anti-C1, anti-C2 or anti-E1. Direct immunostaining using anti-C2 could not detect intracellular HCV antigens, after 1 h of incubation with the virus, while after 24 h of incubation, 28% of infected cells showed positive staining. Only plus strand RNA was detectable intracellularly as early as 1 h after incubation, and remained detectable throughout 48 h post-infection. Interestingly, minus RNA strand could not be detected after 1 h, but became strongly detectable intracellularly after 24 h post-infection. CONCLUSION： Monocytes and lymphocytes are the preferred target cells for HCV infection in peripheral blood leukocytes. Our specific anti-core and anti-E1 antibodies are valuable reagents for demonstration of HCV cell cycle. Also, HCV is capable of infecting and replicating in peripheral blood mononuclear cells as confirmed by detection of minus strand HCV RNA as well as intracellular staining of core HCV antigen.

Dried blood spots,valid screening for viral hepatitis and human immunodeficiency virus in real-life

AIM To detect chronic hepatitis B(CHB),chronic hepatitis C(CHC) and human immunodeficiency virus(HIV) infections in dried blood spot(DBS) and compare these samples to venous blood sampling in real-life.METHODS We included prospective patients with known viral infections from drug treatment centers,a prison and outpatient clinics and included blood donors as negative controls. Five drops of finger capillary blood were spotted on filter paper,and a venous blood sample was obtained. The samples were analyzed for HBs Ag,antiHBc,anti-HBs,anti-HCV,and anti-HIV levels as well as subjected to a combined nucleic acid test(NAT) for HBV DNA,HCV RNA and HIV RNA.RESULTS Samples from 404 subjects were screened(85 CHB,116 CHC,114 HIV and 99 blood donors). DBS had a sensitivity of > 96% and a specificity of > 98% for the detection of all three infections. NAT testing did not improve sensitivity,but correctly classified 95% of the anti-HCV-positive patients with chronic and past infections. Anti-HBc and anti-HBS showed low sensitivity in DBS(68% and 42%).CONCLUSION DBS sampling,combined with an automated analysis system,is a feasible screening method to diagnose chronic viral hepatitis and HIV infections outside of the health care system.

Modelling the prevalence of hepatitis C virus amongst blood donors in Libya:An investigation of providing a preventive strategy

AIM: To determine hepatitis C virus(HCV) seroprevalence among the Libyan population using blood donors and applying the autoregressive integrated moving average(ARIMA) model to predict future trends and formulate plans to minimize the burden of HCV infection.METHODS: HCV positive cases were collected from 1008214 healthy blood donors over a 6-year period from 2008 to 2013. Data were used to construct the ARIMA model to forecast HCV seroprevalence among blood donors. The validity of the model was assessed using the mean absolute percentage error between the observed and fitted seroprevalence. The fitted ARIMA model was used to forecast the incidence of HCV beyond the observed period for the year 2014 and further to 2055.RESULTS: The overall prevalence of HCV among blood donors was 1.8%, varying over the study period from 1.7% to 2.5%, though no significant variation was found within each calendar year. The ARIMA model showed a non-significant auto-correlation of the residuals, and the prevalence was steady within the last 3 years as expressed by the goodness-of-fit test. The forecast incidence showed an increase in HCV seropositivity in 2014, ranging from 500 to 700 per 10000 population, with an overall prevalence of 2.3%-2.7%. This may be extended to 2055 with minimal periodical variation within each 6-year period.CONCLUSION: The applied model was found to be valuable in evaluating the seroprevalence of HCV among blood donors, and highlighted the growing burden of such infection on the Libyan health care system. The model may help in formulating national policies to prevent increases in HCV infection and plan future strategies that target the consequences of the infection.

Hepatitis C virus among blood donors and general population in Middle East and North Africa:Meta-analyses and meta-regressions

BACKGROUND Despite the Middle East and North Africa(MENA)Region reported to have the highest prevalence of hepatitis C virus(HCV)globally,HCV infection levels in the majority of MENA countries remain inadequately characterized.Blood donor data have been previously used as a proxy to assess levels and trends of HCV in the general population,however,it is unclear how comparable these populations are in MENA and whether blood donors provide an appropriate proxy.AIM To delineate HCV epidemiology among blood donors and the general population in the MENA.METHODS The data source was the systematically gathered MENA HCV Epidemiology Synthesis Project Database.Random-effects meta-analyses and meta-regressions were conducted.For comparison,analyses were conducted for Europe,utilizing the Hepatitis C Prevalence Database of the European Centre for Disease Prevention and Control.RESULTS One thousand two hundred and thirteen HCV antibody prevalence measures and 84 viremic rate measures were analyzed for MENA.Three hundred and seventyseven antibody prevalence measures were analyzed for Europe.In MENA,pooled mean prevalence was 1.58%[95%confidence interval(CI):1.48%–1.69%]among blood donors and 4.49%(95%CI:4.10%–4.90%)in the general population.In Europe,pooled prevalence was 0.11%(95%CI:0.10%–0.13%)among blood donors and 1.59%(95%CI:1.25%–1.97%)in the general population.Prevalence in the general population was 1.72-fold(95%CI:1.50–1.97)higher than that in blood donors in MENA,but it was 15.10-fold(95%CI:11.48–19.86)higher in Europe.Prevalence was declining at a rate of 4%per year in both MENA and Europe[adjusted risk ratio:0.96(95%CI:0.95–0.97)in MENA and 0.96(95%CI:0.92–0.99)in Europe].Pooled mean viremic rate in MENA was 76.29%(95%CI:67.64%–84.02%)among blood donors and 65.73%(95%CI:61.03%–70.29%)in the general population.CONCLUSION Blood donor data provide a useful proxy for HCV infection in the wider population in MENA,but not Europe,and could improve HCV burden estimations and assess progress toward HCV elimination by 2030.

Follow-up study of hepatitis C virus infection in uremic patients on maintenance hemodialysis for 30 months

INTRODUCTIONA high prevalence of antibodies to hepatitis C virus(HCV)(range from 3.3%-80%)has beenreported in hemodialysis(HD)patients,andworrisome as it often becomes chronic and induceschronic liver disease,therefore thenephrologists face a major challenge of how toprevent it.The main route of HCV transmission

Prevalence of occult hepatitis B virus infection

Occult hepatitis B virus(HBV) infection(OBI) is characterized by the persistence of HBV DNA in the liver tissue in individuals negative for the HBV surface antigen.The prevalence of OBI is quite variable depending on the level of endemic disease in different parts of the world,the different assays utilized in the studies,and the different populations studied.Many studies have been carried out on OBI prevalence in different areas of the world and categories of individuals.The studies show that OBI prevalence seems to be higher among subjects at high risk for HBV infection and with liver disease than among individuals at low risk of infection and without liver disease.

Hepatitis C virus in Pakistan:A systematic review of prevalence,genotypes and risk factors

In Pakistan more than 10 million people are living with Hepatitis C virus (HCV), with high morbidity and mortality. This article reviews the prevalence, genotypes and factors associated with HCV infection in the Pakistani population. A literature search was performed by using the keywords; HCV prevalence, genotypes and risk factors in a Pakistani population, in Pubmed, PakMediNet and Google scholar. Ninetyone different studies dating from 1994 to May 2009 were included in this study, and weighted mean and standard error of each population group was calculated. Percentage prevalence of HCV was 4.95% ± 0.53% in the general adult population, 1.72% ± 0.24% in the pediatric population and 3.64% ± 0.31% in a young population applying for recruitment, whereas a very high 57% ± 17.7% prevalence was observed in injecting drug users and 48.67% ± 1.75% in a multi-transfused population. Most prevalent genotype of HCV was 3a. HCV prevalence was moderate in the general population but very high in injecting drug users and multi-transfused populations. This data suggests that the major contributing factors towards increased HCV prevalence include unchecked blood transfusions and reuse of injection syringes. Awareness programs are required to decrease the future burden of HCV in the Pakistani population.

Distribution of different hepatitis C virus genotypes in patients with hepatitis C virus infection

AIM:To investigate the presence of mixed infection and discrepancy between hepatitis C virus(HCV) genotypes in plasma,peripheral blood mononuclear cells(PBMCs),and liver biopsy specimens.METHODS:From September 2008 up to April 2009,133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study.Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications.HCV genotyping was done using INNO-LiPATM HCV in serum,PBMCs,and liver biopsy specimens and then conf irmed by sequencing of 5'-UTR fragments.RESULTS:The mean age of patients was 30.3 ± 17.1 years.Multiple transfusion was seen in 124(93.2%) of patients.Multiple HCV genotypes were found in 3(2.3%) of 133 plasma samples,9(6.8%) of 133 PBMC samples,and 8(18.2%) of 44 liver biopsy specimens.It is notable that the different genotypes found in PBMCs were not the same as those found in plasma and liver biopsy specimens.CONCLUSION:Our study shows that a signif icant proportion of patients with chronic hepatitis C are affected by multiple HCV genotypes which may not be detectable only in serum of patients.

Occult hepatitis B virus infection in Egypt

The emerging evidence of the potentially clinical importance of occult hepatitis B virus(HBV) infection(OBI) increases the interest in this topic. OBI may impact in several clinical contexts, which include the possible transmission of the infection, the contribution to liver disease progression, the development of hepatocellular carcinoma, and the risk of reactivation. There are several articles that have published on OBI in Egyptian populations. A review of MEDLINE database was undertaken for relevant articles to clarify the epidemiology of OBI in Egypt. HBV genotype D is the only detectable genotype among Egyptian OBI patients. Higher rates of OBI reported among Egyptian chronic HCV, hemodialysis, children with malignant disorders, and cryptogenic liver disease patients. There is an evidence of OBI reactivation after treatment with chemotherapy. The available data suggested that screening for OBI must be a routine practice in these groups of patients. Further studies needed for better understand of the epidemiology of OBI among Egyptian young generations after the era of hepatitis B vaccination.

Epidemiology of hepatitis C virus in Iran

In Iran,the prevalence of hepatitis C virus(HCV) infection is relatively low according to the populationbased epidemiological studies. However,the epidemiology of HCV is changing and the rate of HCV infection is increasing due to the growth in the number of injecting drug users in the society. In addition,a shift has occurred in the distribution pattern of HCV genotypes among HCV-infected patients in Iran. Genotype 1a is the most prevalent genotype in Iran,but in recent years,an increase in the frequency of 3a and a decrease in 1a and 1b have been reported. These variations in the epidemiology of HCV reflect differences in the routes of transmission,status of public health,lifestyles,and risk factors in different groups and geographic regions of Iran. Health policy makers should consider these differences to establish better strategies for control and prevention of HCV infection. Therefore,this review was conducted to present a clear view regarding the current epidemiology of HCV infection in Iran.

New perspectives in occult hepatitis C virus infection

Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases.

Hepatitis C virus and neurological damage

Chronic hepatitis C virus(HCV) infection exhibits a wide range of extrahepatic complications, affecting various organs in the human body. Numerous HCV patients suffer neurological manifestations, ranging from cognitive impairment to peripheral neuropathy. Overexpression of the host immune response leads to the production of immune complexes, cryoglobulins, as well as autoantibodies, which is a major pathogenic mechanism responsible for nervous system dysfunction. Alternatively circulating inflammatory cytokines and chemokines and HCV replication in neurons is another factor that severely affects the nervous system. Furthermore, HCV infection causes both sensory and motor peripheral neuropathy in the mixed cryoglobulinemia as well as known as an important risk aspect for stroke. These extrahepatic manifestations are the reason behind underlying hepatic encephalopathy and chronic liver disease. The brain is an apt location for HCV replication, where the HCV virus may directly wield neurotoxicity. Other mechanisms that takes place by chronic HCV infection due the pathogenesis of neuropsychiatric disorders includes derangement of metabolic pathways of infected cells, autoimmune disorders, systemic or cerebral inflammation and alterations in neurotransmitter circuits. HCV and its pathogenic role is suggested by enhancement of psychiatric and neurological symptoms in patients attaining a sustained virologic response followed by treatment with interferon; however, further studies are required to fully assess the impact of HCV infection and its specific antiviral targets associated with neuropsychiatric disorders.

Occult hepatitis B virus co-infection in human immunodeficiency virus-positive patients: A review of prevalence, diagnosis and clinical significance

The prevalence of human immunodeficiency virus(HIV) and hepatitis B virus(HBV) co-infection is high as they share similar mechanisms of transmission. The development and widespread use of highly sensitive tests for HBV diagnosis has demonstrated that a significant proportion of apparently healthy individuals with evidence of exposure to HBV continue to carry fully functional HBV DNA in their hepatocytes, a situation that predisposes them to the development of progressive liver disease and hepatocellular carcinoma. The presence of co-infections frequently influences the natural evolution of each of the participating infections present by either facilitating their virulence or competing for resources. Furthermore, the drugs used to treat these infections may also contribute to changes in the natural course of these infections, making the analysis of the impact of co-infection more difficult. The majority of studies has examined the impact of HIV on overt chronic hepatitis B, finding that co-infection carries an increased risk of progressive liver disease and the development of hepatocellular carcinoma. Although the effect of HIV on the natural history of occult hepatitis B infection(OBI) has not been fully assessed, all available data suggest a persisting risk of repeated flares of hepatitis and progressive liver disease. We describe studies regarding the diagnosis, prevalence and clinical significance of OBI in HIVpositive patients in this short review. Discrepancies in worldwide prevalence show the urgent need for the standardization of diagnostic criteria, as established by the Taormina statements. Ideally, standardized protocols for testing should be employed to enable the comparison of data from different groups. Additional studies are needed to define the differences in risk for OBI without HIV and in HIV-HBV co-infected patients with or without overt disease.

Hepatitis C virus antibodies among transfused children with sickle cell anaemia at University of Ilorin Teaching Hospital

Background: Hepatitis C is an infectious disease of the liver caused by the Hepatitis C virus (HCV) resulting to a chronic Hepatitis. Chronic HCV infection constitutes a serious health challenge in places where prevalence is substantial. In Nigeria, there is a high risk because donor blood is not routinely screened for HCV. Patients with sickle cell anaemia (SCA) are considered a subset of the population at higher risk of acquiring the virus, due to their frequent needs for transfusion of blood and its products. However, the magnitude of HCV infection has not been adequately measured in our general population and specific data on HCV in SCA patients are scanty, hence a prospective case controlled study to determine the prevalence of HCV antibodies in transfused SCA patients attending the sickle cell anaemia clinic in the University of Ilorin Teaching Hospital (UITH), Ilorin was taken. Objective: To determine the prevalence of Hepatitis C virus antibodies among transfused children with SCA in Ilorin. Subjects and Method: Eighty two transfused SCA children aged 6 months to 14 years were recruited consecutively from February 2008 to January 2009 while eighty four non transfused SCA children of the same age range recruited over the same period served as controls. Hepatitis C virus antibody screening was done using a second generation ELISA method. Results: The overall prevalence of HCV antibody was 3.0%, while it was 3.7% and 2.4% in the transfused and non transfused SCA patients respectively (χ2 = 0.23, p = 0.68). The patients were also comparable across the social class when subcategorized into high and low social class (χ2 = 0.37, p = 1.00 (subjects), χ2 = 0.42, p = 1.00 (controls). Conclusion: The prevalence of Hepatitis C virus anti- bodies in transfused SCA patients is low. The difference in prevalence between transfused and nontransfused SCA patient was not statistically significant. This was cautiously interpreted due to the hospital based premise of the work. Therefore, Hepatitis C virus antibody acquisition might be from sources other than transfusion of unscreened blood.

Prevalence of Hepatitis B and C Virus in Health Care Personnel in Ibn Sina Hospital, Rabat, Morocco

Risk of infection by hepatitis B (HBV) and C (HCV) viruses remains a permanent problem, not only for health care workers but also for patients. It is often a major public health concern in low incomes countries. The aims of this study were to determine seroprevalence of viral hepatitis B (HBV) and C (HCV), frequency occurrence of blood exposure accidents (BEA) and identify key risk factors for infection among 601 health care workers of Ibn Sina Hospital in Rabat. In this study nineteen health personnel (3.16%) were HBsAg positive and fifteen (2.50%) were anti-HCV antibodies positive. The seropositivity to hepatitis B and C in the surgical department respectively was 4.22% and 3.45%. Nurses were the most affected by hepatitis virus infections. We noticed that HCV came first with a prevalence of 4.44%. The seropositivity reached its acme within the health staff having practiced for more than 20 years, hepatitis C coming first with a prevalence of 4.27%. Globally, 34 health care personnel are positive for HBV or HCV, 32 among them were victims at least once of blood exposure accident (BEA) while practicing. The needlestick represented 81.25% of the BEA type. Prevalence of hepatitis B and C serologic markers in health care workers in our Hospital outnumbered that of the general population. Nurses, surgery department personnel and the professional having worked for a long time were the main factors behind the high risks of infections.