Transmission of anti-HCV within the household of haemodialysis patients

Hepatitis C Antibodies in Patients on Peritoneal Dialysis: Prevalence and Risk Factors

Our objective was to determine the prevalence of the antibody to hepatitis C (anti-HCV) in a population of endstage renal failure patients on continuous peritoneal dialysis (CPD) and study the possible risk factors associated with anti-HCV seropositivity and seroconversion. A cross-sectional study included 155 adult patients enrolled in the CPD program in a single renal unit of a teaching hospital who were screened for anti-HCV by second-generation enzyme immunoassay, which was confirmed by recombinant immunoblot assay. Serum was also assayed for hepatitis B surface antigen (HBsAg). History of renal transplantation, blood transfusions, and exposure to hemodialysis was obtained from medical records.

Ten of 155 patients (6.5%) in this study population were anti-HCV positive [anti-HCV(+)] and 11/155 (7.1%) were HBsAg positive; no patient was positive for both. All the anti-HCV(+) patients were on continuous ambulatory peritoneal dialysis (CAPD); no continuous cycling peritoneal dialysis (CCPD) patient was anti-HCV(+). Exposure to hemodialysis was a risk factor for anti-HCV seropositivity, with 7 out of 10 (70%) anti-HCV(+) patients having been on hemodialysis compared to 55/134 (41%) anti-HCV(-) (p < 0.05, Fisher's exact test). No difference was noted between anti-HCV(+) and anti-HCV(-) groups in relation to age, gender, duration on CPD, renal transplantation, or exposure to blood transfusions. Seroconversion occurred in only one patient after a mean observation period of 20±0.6 months.

The prevalence of anti-HCV seropositivity in this population of CPD patients is 6.5%, and HBsAg is 7.1%. Exposure to hemodialysis is a significant risk factor for development of anti-HCV seropositivity. Seroconversion rate appears to be low.

Clinical epidemiology of acute hepatitis C in South America

There is scarce data pertaining to acute hepatitis C (aHC) infection in South America. We aimed to describe clinical characteristics and evolution of aHC in a South American cohort. A retrospective survey was conducted at 13 hepatology units. All patients ≥16 years old with aHC diagnosis were included. Demographic, clinical and outcome information were registered in a standardized ad hoc questionnaire. Sixty-four patients were included. The majority were middle-aged (median age: 46 years) and female (65.6%); most of them were symptomatic at diagnosis (79.6%). HCV-1 was the most prevalent genotype (69.2%). Five patients had liver failure: three cases of severe acute hepatitis, one case of fulminant hepatitis and one case of acute-on-chronic liver failure. Nosocomial exposure was the most prevalent risk factor. Evolution was assessed in 46 patients. In the untreated cohort, spontaneous resolution occurred in 45.8% and was associated with higher values of AST/ALT and with the absence of intermittent HCV RNA viremia (P = 0.01, 0.05, and 0.01, respectively). In the treated cohort, sustained virological response was associated with nosocomial transmission and early treatment initiation (P = 0.04 each). The prevalence of nosocomial transmission in this South-American cohort of aHC stresses the importance of following universal precautions to prevent HCV infection. J. Med. Virol. 89:276-283, 2017. © 2016 Wiley Periodicals, Inc.

Hepatitis C infection in hemodialysis patients in Iran: a systematic review

Hemodialysis (HD) patients are recognized as one of the high-risk groups for hepatitis C virus (HCV) infection. The prevalence of HCV infection varies widely between 5.5% and 24% among different Iranian populations. Preventive programs for reducing HCV infection prevalence in these patients require accurate information. In the present study, we estimated HCV infection prevalence in Iranian HD patients. In this systematic review, we collected all published and unpublished documents related to HCV infection prevalence in Iranian HD patients from April 2001 to March 2008. We selected descriptive/analytic cross-sectional studies/surveys that have sufficiently declared objectives, a proper sampling method with identical and valid measurement instruments for all study subjects, and proper analysis methods regarding sampling design and demographic adjustments. We used a meta-analysis method to calculate nationwide prevalence estimation. Eighteen studies from 12 provinces (consisting 49.02% of the Iranian total population) reported the prevalence of HCV infection in Iranian HD patients. The HCV infection prevalence in Iranian HD patients is 7.61% (95% confidence interval: 6.06-9.16%) with the recombinant immunoblot assay method. Iran is among countries with low HCV infection prevalence in HD patients.

Prevalence of hepatitis C virus (HCV) infection and HCV genotypes of hemodialysis patients in Salvador, Northeastern Brazil

Hepatitis C virus (HCV) infection has been identified as the major cause of chronic liver disease among patients on chronic hemodialysis (HD), despite the important reduction in risks obtained by testing candidate blood donors for anti-HCV antibodies and the use of recombinant erythropoietin to treat anemia. A cross-sectional study was performed to estimate the prevalence of HCV infection and genotypes among HD patients in Salvador, Northeastern Brazil. Anti-HCV seroprevalence was determined by ELISA in 1243 HD patients from all ten different dialysis centers of the city. HCV infection was confirmed by RT-PCR and genotyping was performed by restriction fragment length polymorphism. Anti-HCV seroprevalence among HD patients was 10.5% (95% CI: 8.8-12.3) (Murex anti-HCV, Abbott Murex, Chicago, IL, USA). Blood samples for qualitative HCV detection and genotyping were collected from 125/130 seropositive HD patients (96.2%). HCV-RNA was detected in 92/125 (73.6%) of the anti-HCV-positive patients. HCV genotype 1 (77.9%) was the most prevalent, followed by genotype 3 (10.5%) and genotype 2 (4.6%). Mixed infections of genotypes 1 and 3 were found in 7.0% of the total number of patients. The present results indicate a significant decrease in anti-HCV prevalence from 23.8% detected in a study carried out in 1994 to 10.5% in the present study. The HCV genotype distribution was closely similar to that observed in other hemodialysis populations in Brazil, in local candidate blood donors and in other groups at risk of transfusion-transmitted infection.

Chronic viral hepatitis in hemodialysis patients

Ever since the first outbreaks of hepatitis in hemodialysis units in the late 1960s, a number of hepatotropic viruses transmitted by blood and other body fluids have been identified. This review summarizes the current state of knowledge regarding these blood-borne agents from an epidemiologic and preventive perspective. Data source and study selection were obtained from research and review articles related to the epidemiology of viral hepatitis in hemodialysis and indexed on Medline and Embase from 1965 to 2004. Hepatitis B virus (HBV) was the first significant hepatotropic virus to be identified in hemodialysis centers. HBV infection has been effectively controlled by active vaccination, screening of blood donors, the use of erythropoietin, and segregation of HBV carriers. To date, HBV remains an important cause of morbidity in endemic areas. Hepatitis delta virus is a defective virus that can only infect HBV-positive individuals. Hepatitis C virus is the most significant cause of non-A, non-B hepatitis and is mainly transmitted by blood transfusion. The introduction in 1990 of routine screening of blood donors for HCV contributed significantly to the control of HCV transmission. An effective HCV vaccine remains an unsolved challenge, however. Pegylation of interferon-alpha has made it possible to treat HCV-positive dialysis patients. Unexplained sporadic outbreaks of hepatitis by the mid-1990s prompted the discovery of hepatitis G virus and hepatitis GB virus C in 1995 and the TT virus in 1997. Although epidemiologic analyses revealed high prevalence rates of both viruses in the hemodialysis population, their exact role in liver disease has yet to be determined. The vigilant observation of guidelines on universal precaution and regular virologic testing are the cornerstones of the effective control of chronic hepatitis in the setting of hemodialysis.

Surveillance and control of blood-borne virus infections in haemodialysis units

The risk of transmission of blood-borne viruses in renal dialysis units was reduced following the Rosenheim report recommendations issued in 1972. This document focused on the prevention and control of hepatitis B virus infections in renal dialysis and transplantation units. Good practice guidelines were produced, some of which may have been relaxed in conjunction with technological advances which included the use of disposable cartridges for haemodialysis. However, new viruses transmitted by blood and other body fluids have been identified over the years. A review of current practice for both patients and staff, together with updated good practice guidance, is necessary.

Prevalence of infected patients and understaffing have a role in hepatitis C virus transmission in dialysis

To assess hepatitis C virus (HCV) incidence rates and identify determinants of infection among hemodialysis patients, a multicenter study was conducted in 58 units in ITALY: An initial seroprevalence survey was conducted among 3,492 patients already on hemodialysis therapy as of January 1997 and among an additional 434 patients who began dialysis up to January 1998. HCV antibodies were assessed by third-generation enzyme immunoassays. Patients testing seronegative at baseline were enrolled into a 1-year incidence study with serological follow-up at 6 and 12 months. For patients who seroconverted, an HCV RNA assay was performed on stored baseline samples to confirm new infection. A nested case-control study was subsequently performed to investigate potential risk factors. For each incident case, three controls negative for both HCV antibodies and HCV RNA were randomly selected. At enrollment, HCV seroprevalence was 30.0%. During follow-up, 23 new HCV cases were documented, with a cumulative incidence of 9.5 cases/1,000 patient-years. By logistic regression analysis, an increased risk for HCV infection emerged for patients attending the dialysis units with a high prevalence of HCV-infected patients at baseline (odds ratio [OR], 4.6) and for those attending units with a low personnel-patient ratio (OR, 5.4). Among extradialysis factors, a history of surgical intervention in the previous 6 months (OR, 16.7) significantly increased HCV risk. These findings suggest that the combination of understaffing and a high level of infected patients in the dialysis setting increases the risk for HCV nosocomial transmission. This is likely related to an increased likelihood for breaks in infection control measures.

[Antibodies to hepatitis C virus in patients undergoing hemodialysis in Salvador, BA, Brazil]

BACKGROUND

Hepatitis C infection in hemodialysis units has been evaluated in different geographic regions.

AIMS

The prevalence of anti-HCV in patients undergoing hemodialysis program in the city of Salvador, State of Bahia, Brazil, was studied and its association with transfusions, duration of hemodialysis and ALT elevation.

METHOD

During a period of 17 months, all patients undergoing dialytic treatment, were evaluated. The total number of patients was 395, all of whom completed a questionnaire and provided serum samples for laboratory analysis. Serological levels were measured for ALT and the samples were tested for anti-HCV using ELISA II with a further confirmation using RIBA III.

RESULTS

Anti-HCV was positive in 23.8% (94/395). The presence of transfusions was associated with anti-HCV and as the number of transfusions used increased, so did the frequency of anti-HCV. Of the patients who never received transfusions, 12.5% (6/48) were anti-HCV positive. The duration of dialytic treatment lasted from 53.44 +/- 36.45 months in the anti-HCV positive group and 22.10 +/- 22.75 months for the group testing negative. ALT elevation was more frequent in the anti-HCV positive group. Positivity for the RIBA III fractions was 79.8%, 100%, 80.9% and 52.1%, for c100-3, c33, c22 and NS5, respectively. The anti-NS5 was even less frequent in the group with elevated ALT.

CONCLUSIONS

The prevalence of anti-HCV in patients undergoing chronic hemodialysis in Salvador, Bahia, is elevated and it is associated with transfusions, a longer duration of dialytic treatment and ALT elevation.

Molecular evidence for nosocomial transmission of hepatitis C virus in a French hemodialysis unit

A systematic virological follow-up of hemodialysis patients identified 11 cases of de novo hepatitis C virus (HCV) infection in the same unit that were not due to blood transfusion. There were three groups of infection, each occurring within a period of 3 months: four infections with genotype 1b, two infections with genotype 1b, and five infections, four with genotype 1a and one with genotype 5a. The possibility of patient-to-patient transmission was addressed by sequencing the first hypervariable region of the HCV genome in sera taken shortly after infection. Phylogenetic analysis indicated clustering of most of the cases of de novo infections. Sequence homologies identified potential contaminators among already infected patients. All patients who were infected with closely related HCV isolates were found to have been treated in the same area and during the same shift or on the previous one. These infections could have been due to occasional breaches of the usual hygiene measures. Strict adhesion to hygiene standards and routines, continuously supervised, remains the key rule in the management of dialysis patients. Nevertheless, the isolation of patients with HCV could reduce the risk of infection because occasional lapses of preventive hygiene measures or unpredictable accidents can always take place in a hemodialysis unit. This policy needs to be evaluated by large-scale prospective studies.

Blood-borne virus infections in dialysis units--a review

Hepatitis outbreaks in haemodialysis unit patients and staff were reported in the late 1960s. In 1972, the Rosenheim report in the UK established guidelines which included routine tests for hepatitis B surface antigen and isolation facilities for dialysing patients with hepatitis B virus which resulted in a dramatic fall in cases of hepatitis. However, since these guidelines were introduced, other blood-borne viruses, notably HCV and HIV have been discovered, and failures of infection control practices still lead to outbreaks of HBV in haemodialysis units. The prevalence of HCV in dialysis patients varies considerably throughout the world, with reported prevalence ranging from 3.9% to 71%. The number of blood transfusions and the length of time on dialysis have consistently been associated with HCV prevalence. Several reports provide evidence of patient-to-patient HCV transmission with environmental blood contamination the most significant factor in intra-unit transmission. There is no evidence that HCV has been transmitted by re-use of dialysis machines but being dialysed next to an HCV positive patient is associated with a significant risk of HCV acquisition. Several studies have shown that dialysing HCV positive patients in a separate unit or in a defined sector of a dialysis unit significantly reduces nosocomial HCV infection. HGV is prevalent in dialysis units where there is evidence of transmission to patients but no evidence of associated symptoms. HIV is infrequently transmitted in dialysis units and several units treating many HIV-positive patients have shown no evidence of transmission. Careful attention needs to be paid to infection control procedures and regular virological testing.

Hepatitis C virus infection in four haemodialysis units of southern Italy: epidemiological report

The haemodialysis patients are an high risk population for hepatitis viral infections. While the incidence of HBV has decreased worldwide, HCV is now the major cause of viral infection in these patients. The aim of our study was to define a complete map of patients undergoing routine replacement therapy by haemodialysis in the province of Foggia, Southern Italy, who were HCV Ab positive, the presence of viraemia and their genotypes; moreover, we investigated the probable factors involved in determining the infection as well as the means of prevention.

MATERIALS AND METHODS

We enrolled 330 patients treated in four haemodialysis centres (DC) and six secondary units; mean age was 57 years and mean duration of dialysis 76 months. Samples were drawn to determine cytolysis indexes and the HCV Ab status; in HCV positive patients, we also looked for viraemia and HCV genotypes. Data were analysed by a transversal cross-section study.

RESULTS AND CONCLUSIONS

Prevalence of HCV infection was 0.43 (males 0.45, females 0.42). The risk of contracting the infection was shown to be significantly different in the various DCs and did not seem to be related to the severity of the preventive measures. There was no significant difference between the various DCs in the comparison between the odds of HCV-RNA+ and HCV-RNA- patients. No significant prevalence of a given genotype emerged from a cross-sectional study related to the comparison between different genotypes. Moreover, transfusions of blood products seemed to have no significant relation to HCV infection. Finally, patients treated with haemodialysis for more than 36 months run a seven time greater risk of contracting HCV infection.

Hepatitis C virus infection in dialysis: a continuing problem

Patients on chronic dialysis are at increased risk of acquiring parenterally transmitted hepatitis viruses from blood product transfusions or nosocomial transmission in hemodialysis units, and biochemical abnormalities in liver function are seen in 10-44% of patients on chronic hemodialysis. In the past, hepatitis B virus (HBV) was the major cause of parenterally transmitted viral hepatitis in dialysis patients, and the remaining cases were attributed to non-A, non-B hepatitis (NANBH). The discovery of the hepatitis C virus (HCV) has shed light on the cause and clinical course of NANBH in patients on dialysis. The current debate is focused on strategies to reduce the transmission of HCV among dialysis patients and to lessen the consequences of liver disease among patients already infected.

Sexual transmission of hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) is the cause of almost all cases of parenterally transmitted non-A, non-B viral hepatitis (NANBH). HCV is an RNA virus, unrelated to the hepatitis viruses, A, B, D, or E; it was first identified in 1989. Although most infections become chronic, and it may lead to chronic liver disease, most patients with HCV infection are asymptomatic. The predominant modes of transmission are by blood, blood products, or other parenteral exposure, particularly injecting drug use. More contentious is the role of sexual transmission, although evidence for this was provided by studies of NANBH.

OBJECTIVE

This review considers the evidence for sexual transmission, and the types of studies used to estimate the rate of transmission and the factors that may influence it.

METHOD

A Medline search using the keywords hepatitis C, sex, transmission, and prevalence in MeSH and free text. References in papers were searched, and some unpublished data identified. References were further selected to illustrate different methodologies.

FINDINGS

Evidence for sexual transmission is provided by several types of study including prevalence studies in groups at risk of other STDs, investigation of cases identified from surveillance reports, and cross sectional and longitudinal partner studies. Many studies are limited by their small size, the sensitivity and specificity of early assays, lack of controls, or the difficulty of excluding other routes of transmission. One prospective cohort study reported an incidence of 12 per 1000 person years in the sexual partners of HCV infected patients. 1-3% of partners of HCV infected patients are found to be infected in cross sectional studies. Co-infection with HIV, duration of the relationship, or chronic liver disease may be independent cofactors increasing the risk of transmission. A meta-analysis of selected studies may be informative, and further larger prospective studies are required. There is a small but definite risk of sexual transmission of hepatitis C.

Universal precautions prevent hepatitis C virus transmission: a 54 month follow-up of the Belgian Multicenter Study. The Universitaires Cliniques St-Luc (UCL) Collaborative Group

The isolation of anti-hepatitis C virus (HCV) in hemodialyzed (HD) patients has been repeatedly advocated to prevent nosocomial HCV transmission. We evaluated the incidence of seroconversion for HCV in Belgian HD patients, and demonstrate the complete prevention of HCV transmission by adherence to the universal precautions advocated by the Centers for Disease Control (Atlanta, GA, USA). All (N = 963) HD patients from 15 units, none of which isolates anti-HCV positive patients, were tested by a second or third generation enzyme-linked immunosorbent assay (with confirmation by a second- or third-generation recombinant immunoblot assay or the polymerase chain reaction) every 18 months from May 1991 to November 1995. Follow-up was available in 488 patients (drop-outs resulting from death or transplantation mainly). The yearly incidence of seroconversion for HCV over the initial 18 months was 1.41%, with evidence suggestive of nosocomial HCV transmission. Universal precautions were therefore reinforced. The incidence of seroconversion subsequently fell to 0.56% and 0%, respectively (P = 0.014), despite the facts that the average transfusion load and the proportion of patients with dialyzer reuse or with monitors disinfected after each session did not change significantly. We conclude that the strict enforcement of universal precautions fully prevents HCV transmission to HD patients. The isolation of anti-HCV positive patients is not warranted.

Hepatitis C virus heteroduplex tracking assay for genotype determination reveals diverging genotype 2 isolates in Italian hemodialysis patients

A heteroduplex tracking assay (HTA) was developed for genetic analyses of the hepatitis C virus (HCV) using single-stranded probes from the core (C)/E1 region. Nucleotide sequencing of reverse transcriptase (RT)-PCR products from 15 Italian dialysis patients confirmed the specificity and accuracy of the HTA genotyping method, which identified 5 of 15 (33.3%) 1b, 7 of 15 (46.7%) 3a, and 3 of 15 (20%) type 2 infections. The genotypes of an additional 12 HCV antibody-positive blood donors from different geographical locations were also in agreement with the genotypes determined by the Inno-LiPA HCV II kit (Innogenetics) and/or restriction fragment length polymorphism (RFLP). Isolates which had between 35 to 40% nucleotide divergence from control subtype 1a, 1b, 2a, 2b, or 3a standards could be typed. Surprisingly, HTA detected one 1b-2 coinfection which was missed by DNA sequencing. Three samples that were designated non-2a or 2b type 2 by HTA were found to be type 2a by both RFLP and direct nucleotide sequencing of the 5' untranslated region. The genetic distance between patient type 2 and control 2a, 2b, and 2c isolates indicated that a new subtype was present in the population being studied. Serotyping (RIBA serotyping strip immunoblot assay kit) of 23 dialysis patients showed that the genotype could be determined in 6 of 8 (75%) C/E1 RT-PCR-negative and 15 of 23 (65.2%) RT-PCR-positive samples, indicating that the two tests complement each other.

Detection of anti-hepatitis C-virus antibodies and hepatitis C-virus RNA in Lebanese hemodialysis patients

Hemodialysis patients are at high risk of developing HCV infection. Reports from various countries have shown a prevalence of 12-29% among this group. The present study aimed at assessing the utility of HCV antibodies and HCV-RNA detection in the diagnosis of HCV in Lebanese hemodialysis patients. One hundred and eight hemodialysis patients from various hospitals in Lebanon were assayed for the presence of anti-HCV antibodies by ELISA and LIA, and for the presence of HCV-RNA by RT-PCR of the 5' Non-coding region (5' NCR). Specificity of the amplicons was confirmed by Southern hybridization. Seventeen out of 108 patients were reactive in ELISA and positive in the Line Immunoassay (LIA). Eleven out of the 17 were positive by RT-PCR. Three out of 29 patients nonreactive in ELISA were positive by RT-PCR. Our results indicate that hemodialysis patients in this study may be grouped into 4 categories. These include (1) patients with viremia and no immune response, (2) patients with no viremia and with an immune response, (3) patients with both viremia and immune response and (4) patients with no viremia and no immune response. The first 3 categories may reflect the different phases of HCV infection and imply that detection of both anti-HCV antibodies and HCV-RNA are needed for the establishment of adequate diagnosis. In addition, data collected from patients implicated in this study show that infection by HCV may be dialysis machine-related, rather than transfusion-related. However, cross-contamination unrelated to machines may also occurs.

Epidemiology of hepatitis C virus infection in an area of Southern Italy

BACKGROUND/AIMS

Hepatitis C virus (HCV) has been recognized as a major cause of liver disease, but little is known about its diffusion at population level. To estimate the prevalence and incidence of HCV infection and to explore potential risk factors at population level, an epidemiologic study was carried out.

METHODS

A cohort was built up in 1985, on a random sample of the population of Castellana, a small town in southern Italy (Bari province), and followed up until 1993. HCV ELISA II and RIBA HCV 2.0 were used as screening and confirmatory tests, respectively.

RESULTS

The overall anti-HCV prevalence was 26.0% (511/1969) at enrollment. The HCV infection incidence rate was 34.2x100,000 person-years (3 cases/8766 persons-years). A secular trend (referent born before 1930; born 1930-39 Odds Ratio (OR) 0.72, 95% Confidence Interval (95% CI) 0.56-0.94; born 1940-49, OR 0.33, 95% CI 0.25-0.44; born 1950 or after, OR 0.15, 95% CI 0.09-0.23) and geographical pattern (referent born outside Bari province; born in Bari province, OR 1.71, 95% CI 0.93-3.16; born in Castellana G, OR 2.29, 95% CI 1.29-4.05) were found by logistic regression analysis after controlling for several confounding factors.

CONCLUSIONS

The high prevalence, moderate incidence, and marked decrease in HCV infection in the cohort of birth in a population without known risk factors suggest that an epidemiological transition has been operating at population level since the 1950's.

Hepatitis C in dialysis patients

Patients on hemodialysis have a higher prevalence of hepatitis C (HCV) infection compared with the general population. Several factors have been associated with an increased risk of HCV infection in hemodialysis patients, including number of blood transfusions, duration of hemodialysis, previous transplantation, intravenous drug abuse, male gender, and in-center hemodialysis. In addition, there is mounting evidence to suggest nosocomial transmission within hemodialysis units. Although the precise modes of transmission have not been identified, breakdown in standard infection control practices, physical proximity to an infected patient, and sharing of dialysis machines are possible causes. Nonetheless, at the present time, the Centers for disease Control and Prevention (CDC) does not recommend dedicated machines, patient isolation, or a ban on re-use in hemodialysis patients with HCV infection. Consequently, strict adherence to universal precautions and careful attention to hygiene are recommended to reduce the transmission of HCV in dialysis units.

New insights into hepatitis C virus infection of hemodialysis patients: the implications

The authors compared the diagnostic performance of a second-generation recombinant immunoblot assay (RIBA) (RIBA HCV 2.0 SIA) and the recently introduced third-generation RIBA (RIBA HCV 3.0 SIA) with that of hepatitis C virus (HCV) RNA by the polymerase chain reaction (PCR) in 55 patients on chronic hemodialysis. Compared with HCV RNA by PCR, RIBA 3.0 increased the sensitivity of HCV detection to 72% as compared with 56% of RIBA 2.0. Both assays underestimated the prevalence of HCV infection as determined by PCR. However, RIBA HCV 3.0 outperformed RIBA HCV 2.0, detecting all of the RIBA 2.0-positive patients plus an additional eight (8 of 22 RIBA 2.0 negative; confidence interval [CI] = [17.2%, 59.3%]). Forty-three of 51 patients with positive RIBA 3.0 or positive HCV RNA by PCR underwent a liver biopsy. Thirty (70%) had chronic hepatitis (three with cirrhosis), 10 (23%) had nonspecific changes, and three (7%) had normal liver histology. Thirty of 37 patients (81%) with hepatitis C viremia and positive anti-HCV had chronic hepatitis, whereas none of the viremic patients with negative anti-HCV had chronic hepatitis. Among the reactive antigens on RIBA 3.0, c33c was found to be most predictive of chronic hepatitis (P = 0.0002). Detection of HCV RNA continues to be the method of choice in the early phase of HCV infection. In places where a validated HCV RNA assay is not available, RIBA HCV 3.0 (soon to be commercially available) is a better alternative. Early detection of HCV infection and the implementation of an isolation strategy might be important in preventing the spread of HCV infection among hemodialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrafamilial transmission of hepatitis C virus in hemodialysis patients

The prevalence of hepatitis C virus (HCV) infection in chronic hemodialysis patients ranges from 20 to 50% and these patients may serve as a reservoir of infection for their household contacts. The aim of this study was to investigate the prevalence of anti-HCV in hemodialysis patients and their families, and to evaluate possible routes of infection. One hundred eighty-six family members of 84 hemodialysis patients and 529 healthy adults were enrolled. The family members consisted of 50 spouses, 96 children, 11 parents, 29 siblings, and other relatives living together with the patients. Serum samples were collected for testing anti-HCV. Exposure to risk factors was obtained by a questionnaire and an interview. The results showed that prevalence of anti-HCV in hemodialysis patients was 44%, whereas in family members it was 5.4%, not significantly different from that of age-matched healthy adults (standardized morbidity rate = 1.51, P = 0.390). The anti-HCV rate in family members tended to increase with age, and a spouse of an infected hemodialysis patient had a higher risk of HCV infection than other family members (15% vs. 2.6%, odds ratio 6.6, P = 0.058). Except for the age factor, no difference was found between seropositive and seronegative family members with respect to risk factors such as blood transfusion, surgery, frequent injections, dental procedures, or acupuncture. It was concluded that, although the anti-HCV positivity of hemodialysis patients is high, the risk of HCV infection for their family members is not higher than that of the general population. Among family members, spouses of seropositive hemodialysis patients have the highest risk of HCV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

High prevalence of a rare hepatitis C virus in patients treated in the same hemodialysis unit: evidence for nosocomial transmission of HCV

Hepatitis C virus (HCV) is a major cause of hepatitis among patients treated with maintenance hemodialysis. Blood transfusion appears to be the primary risk factor, but nosocomial transmission of HCV in the dialytic environment has been hypothesized. We addressed this issue by analyzing the individual variation of genomic sequences of HCV in 28 patients on chronic hemodialysis (HD) from the same department and 25 environmentally unrelated patients with HCV-related liver disease. Genome variations of HCV were studied by single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products obtained from the 5'-untranslated region of the viral genome and by sequence analysis. Six different SSCP patterns were identified in HD patients versus 16 in control patients. Among HD patients the three more frequent SSCP patterns accounted for 85% of observations, while in the control group each pattern was found in 4 to 12% of patients. The ability of SSCP to discriminate sequence variation was proven by sequence analysis which confirmed identity/diversity of sequences selected by SSCP. Moreover, sequence analysis permitted a recognition of the most frequent genome observed in HD patients as a type 4 HCV, which is considered to be rare in the Italian population. The relative homogeneity of HCV variants in HD patients treated in the same HD and the high prevalence in this unit of a rare viral variant support the possibility of a nosocomial transmission of HCV in the dialytic environment.

Hepatitis C transmission in a hemodialysis unit: molecular evidence for spread of virus among patients not sharing equipment

Three cases of simultaneous seroconversion to hepatitis C virus (HCV) in a hemodialysis unit initiated the investigation of the viral strains of 14 seropositive patients in the unit by nucleotide sequencing. The results showed that five patients had been infected with the same viral strain, and indicated that two other patients were sharing a second strain. Transmission was not related to blood transfusions and not associated with the dialysis machines, but occurred between patients treated on the same shift. The number of cases was higher than expected from the serological data. Thus, spread of virus may occur at high frequencies in environments where parenteral routes are made accessible, in spite of rigorous preventive measures. This may raise concern that non-transfusion associated spread of HCV may be present and unnoticed in several hospital settings.

Hepatitis C virus infection in haemodialysis patients: a clinical and virological study

A cohort of 66 patients on maintenance haemodialysis was examined for serological (anti-HCV) and virological (HCV-RNA) evidence of infection with hepatitis C virus (HCV). Nine (13.6%) were anti-HCV positive, all of whom had detectable HCV-RNA in their serum. Statistical analysis of various risk factors (including length of time on haemodialysis, history of blood transfusion, history of renal transplantation and of previous hepatitis B infection) showed that only the length of time on haemodialysis was significantly associated with the acquisition of HCV infection. Genotypic analysis showed that five patients were infected with genotype 1 and a further two were infected with genotype 4. The latter finding is of significance because strains of genotype 4 are extremely uncommon in Western Europe. These results demonstrate that intra-unit transmission of HCV-infection took place in a group of patients on maintenance haemodialysis.

Incidence and risk factors for hepatitis C seroconversion in hemodialysis: a prospective study. The UCL Collaborative Group

To delineate the incidence and risk factors for seroconversion (SC) for HCV, from May 1991 to November 1992 we followed all 401 patients (no i.v. drug abusers) dialyzed in 15 Belgian hemodialysis (HD) units, none of which isolates anti-HCV (+) patients. The sensitive ELISA II test was performed in the same laboratory for all patients. ELISA II (+) sera were considered truly positive if specific antibodies were detected by RIBA II against at least one HCV antigen. Blood transfusions given from 12 months prior to inclusion in the study, dialyzer reuse and frequency of dialysis monitor sterilization were recorded. In May 1991, prevalence of truly positive ELISA II tests averaged 13.5% (54/399). During the three consecutive six-month periods, ELISA II became truly positive in 3 of 305 (1%), 4 of 314 (1.3%) and 1 of 313 (0.3%) patients, respectively, which was an average yearly incidence of 1.7%. SC was preceded (1 to 6 months) in all cases by an unexplained, unprecedented increase in the alanine aminotransferase level. The mean monthly rate of transfusions was significantly higher (P < 0.001) in eight patients with SC (0.7 +/- 0.6 U) than in 393 patients without SC (0.1 +/- 0.01 U). However, three of eight patients with SC had not been transfused at all. SC was observed in only 3 of 13 units (1, 3 and 4 cases, respectively) dialyzing ELISA (+) patients. In the unit with three SC, patients were always assigned a fixed station: SC was observed only in patients dialyzed next to an ELISA II (+) patient (3 of 8 vs. 0 of 30, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus infection in hemodialysis patients in southern Sweden: epidemiological, clinical, and diagnostic aspects

A prevalence of hepatitis C virus (HCV) antibodies of 12% was found in 276 patients from 11 dialysis units. Between zero and 22% of the patients in the different units were anti-HCV positive. The epidemiology of HCV was studied in two units during a 2 year period by antibody assays and the polymerase chain reaction and correlated with clinical manifestations. Two types of epidemiologic patterns were found that may explain the wide difference of HCV prevalence described in different dialysis units. In one unit there was no evidence of spread within the unit, and the prevalence of HCV was dependent on the status of the patients entering for treatment. In the other unit, a clustering of infected patients could be seen in which 13 of 36 were infected during a 3 year period. Some patients who had not received blood transfusions were among the infected. Hepatitis C infection was the most common explanation for repeated abnormal transferase levels. Most of the HCV-infected patients reacted both for anti-HCV and HCV RNA. HCV RNA was in general detected earlier than anti-HCV seroconversion. Among 20 HCV RNA-positive serum samples that were anti-HCV ELISA-positive 18 had indeterminate and two negative reactions by immunoblot (RIBA 2). Thus the RIBA 2 test should be used with caution as a confirmatory antibody test in this group of patients.

Hepatitis C markers in hemodialysis patients

The prevalence of hepatitis C virus (HCV) infection among the patients of a hemodialysis unit in Taiwan was determined by an immunoblot and reverse transcriptase-polymerase chain reaction algorithm to be 58.8% (67 of 114 patients) after serological surveys with two advanced-generation enzyme-linked immunosorbent assays (ELISAs) for anti-HCV and a C 100-3 single-antigen test. The results of the second-generation ELISAs, the supplementary immunoblot test, and the test for HCV RNA were in good agreement with each other, from 86.0 to 98.2%. The first-generation C 100-3 test lacked the sensitivity of the four other systems. The two advanced-generation screening ELISAs for anti-HCV, a multiple-recombinant-antigen test, the Abbott second-generation ELISA, and a synthetic peptide multiple-antigen test, the UBI HCV EIA, provided reliable and virtually equivalent detection of potentially infected blood. Antibodies to capsid 1 and capsid 2 determinants of the Liatek immunoblot system were the most frequently detected reactivities to HCV in the HCV-infected hemodialysis patients. The percentage of HCV-infected patients with abnormal liver function (alanine aminotransferase level, greater than 100 IU/liter) was higher than that of the uninfected patients. The prevalence of HCV infection was correlated to the duration of hemodialysis treatment and the amount of blood transfused, and the most common transmission mode was thought to be patient-to-patient transmission through the dialysis equipment. Several means of reducing the frequency of transmission between hemodialysis patients are suggested.

Hepatitis C in dialysis patients: relationship to blood transfusions, dialysis and liver disease

Antibodies to hepatitis C virus (anti-HCV) were determined in an unselected group of 340 patients with chronic renal failure treated with maintenance dialysis. A second generation hepatitis C virus (HCV) enzyme-linked immunosorbent assay (ELISA) was used and confirmation made by a second generation recombinant immunoblot assay (RIBA). Sixteen patients (4.7%) were anti-HCV positive and 8 (2.4%) were anti-HCV indeterminate. All anti-HCV positive and anti-HCV indeterminate patients had received blood transfusions. No statistically significant differences were found between anti-HCV positive and indeterminate patients considering blood transfusions, dialysis and liver disease. The combined group of anti-HCV positive and indeterminate patients had had more blood transfusions (P < 0.005) and had been on dialysis for a longer period (P < 0.01) compared with anti-HCV negative patients. Further, significant correlation with elevation of transaminases and anti-HCV was observed (P < 0.001). Thirty patients (8.8%) had elevated transaminase levels and 13 (43%) of these were anti-HCV positive or indeterminate. In conclusion, HCV infection accounts for a substantial proportion of liver disease in dialysis patients, probably most often transmitted by blood transfusions but other routes of transmission could not be excluded.