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

Global epidemiology of hepatitis C virus in dialysis patients: A systematic review and meta-analysis

Dialysis is a replacement therapy for patients with End-Stage Renal Disease (ESRD). Patients on dialysis are at high risk of acquiring hepatitis C virus (HCV), which has become a leading cause of morbidity and mortality in this population. There is a wide range of prevalence of HCV in dialysis populations around the world. It is still unknown how prevalent HCV infection is among worldwide dialysis patients (including those undergoing hemodialysis and peritoneal dialysis). A review was conducted to estimate the global epidemiology of hepatitis C in dialysis patients. We searched PubMed, Excerpta Medica Database (Embase), Global Index Medicus and Web of Science until October 2022. A manual search of references from relevant articles was also conducted. Heterogeneity was evaluated by the χ2 test on Cochrane's Q statistic, and the sources of heterogeneity were investigated using subgroup analysis. In order to assess publication bias, funnel plots and Egger tests were conducted, and pooled HCV prevalence estimates were generated using a DerSimonian and Laird meta-analysis model. The study is registered with PROSPERO under CRD42022237789. We included 634 papers involving 392160 participants. The overall HCV case fatality rate was 38.7% (95% CI = 28.9-49). The global prevalence of HCV infection in dialysis population group were 24.3% [95% CI = 22.6-25.9]. As indicated by UNSD region, country, dialysis type, and HCV diagnostic targeted; Eastern Europe had the highest prevalence of 48.6% [95% CI = 35.2-62], Indonesia had 63.6% [95% CI = 42.9-82], hemodialysis patients had 25.5% [95% CI = 23.8-27.3], and anti-HCV were detected in 24.5% [95% CI = 22.8-26.2]. Dialysis patients, particularly those on hemodialysis, have a high prevalence and case fatality rate of HCV infection. Hemodialysis units need to implement strict infection control measures.

Circulation of an atypical hepatitis C virus (HCV) strain at a dialysis unit in northeast India

Patients undergoing hemodialysis are at an increased risk of hepatitis C virus (HCV) infection. The implementation of standard infection control measures can substantially decrease the risk of infections and other nosocomial infections. To study the HCV infection rates and genotypes in maintenance hemodialysis subjects in a dialysis unit. A total of 196 maintenance hemodialysis subjects were tested for HCV RNA for one year at a tertiary care teaching hospital in northeast India continuously. Genotyping was performed using direct sequencing (Sanger sequencing) of the 5′UTR‐core region. The HCV infection rate was 26.0%. On phylogenetic analysis, 29 sequences clustered around genotype 3 and subtype 3f were observed. High sequence similarities (75–100% homology) were observed among the isolated sequences. High molecular similarities in the isolates from the same dialysis unit with a high infection rate (26.0%) over a relatively short period of study (10 months) indicated an ongoing nosocomial transmission. Nosocomial transmission by subtype 3f is rare, and it has not been reported in dialysis cases previously. The strain is most likely evolving from common strains such as 3b or 3i and may spread due to migration or movement of people. Urgent implementation of adequate infection control measures is required.

The Role of Peritoneal Dialysis as the First-Line Renal Replacement Modality

Twenty years after its introduction, peritoneal dialysis (PD) is a well-established alternative to hemodialysis (HD) as a modality of renal replacement therapy. Much debate and research is apparent in the literature, comparing hemodialysis and PD as “opposite” modalities and trying to ascertain which modality should be more optimal.

In our opinion, HD and PD are two distinct modalities, each with its own advantages and disadvantages. In addition, it is clear that for both HD and PD, rates of technique failure are high, causing patients to transfer between modalities. The question is thus not which modality is best, but rather, which flow-chart of modalities makes best use of the advantages of each modality, while avoiding its disadvantages. In this respect, HD and PD appear to be complementary modalities.

The better preservation of residual renal function, lower risk of infection with hepatitis B and C, better outcome after transplantation, preservation of vascular access, and lower costs are arguments to promote PD as a good initial treatment. When PD-related problems arise (adequacy, ultrafiltration, peritonitis, patient burnout), a timely transfer to HD has to be planned.

This editorial tries to review arguments supporting the complementary nature of both modalities, and especially the role of PD as the first-line renal replacement therapy.

Hepatitis C virus infection and chronic renal disease: A review

Hepatitis C virus (HCV) is a parenterally-transmitted hepatotropic virus that often causes chronic infection, which can progress to cirrhosis and hepatocellular carcinoma. Development of highly effective direct-acting anti-viral agents (DAAs) has led to a paradigm change in the treatment of HCV infection over the last 4-5 years. Patients with chronic kidney disease (CKD) are at a higher risk of acquiring HCV infection. In these patients, diagnosis of HCV infection, assessment of the consequent liver disease and management of HCV infection pose some specific problems. This article reviews the available recent information on HCV infection and CKD, including the association between these conditions and their effect on each other, and prevention, evaluation, and management of HCV infection in persons with CKD. This review looks at this issue particularly from the perspective of readers in Asia, especially India, since the epidemiology of HCV-CKD association and the repertoire of anti-HCV drugs available in this region differ from those elsewhere.

Transmission of hepatitis C virus infection in hemodialysis: Current concepts

A variety of epidemiological data provides evidence for the occurrence of nosocomial transmission of hepatitis C virus (HCV) infection to hemodialysis (HD) patients. The most important factor implicated in HCV transmission between patients treated in the same dialysis unit is cross-contamination from supplies and surfaces as a result of failure of staff to follow infection control procedures. Parts of the HCV genome are highly variable and lend themselves to fingerprinting of each isolate using nucleic acid testing (NAT) and sequencing. This approach has permitted investigation of possible transmission routes within HD units. A systematic review of molecular virology papers revealed transmission of HCV via internal fluid pathways of the dialysis machines in a minority of reports only. Dialyzer reuse was not identified as a risk factor for HCV acquisition in multicenter databases. No randomized controlled trials exist on the impact of isolation on the risk of transmission of HCV to hemodialysis patients. A Belgian prospective multicenter study showed a reduction from 1.4% to 0% in the annual incidence of seroconversion for HCV without any isolation measures, by implementation of strict infection control procedures designed to prevent transmission of blood-borne pathogens, including HCV. However, an isolation policy for HCV-infected dialysis patients should be considered in dialysis units where nosocomial transmission of HCV persists despite reinforcement and audit of hygienic precautions for hemodialysis. Routine audit precautions (general and for dialysis machines) are recommended on a regular basis within HD units.

A Large Nosocomial Outbreak of Hepatitis C Virus Infections at a Hemodialysis Center

Objective:

To identify modes of HCV transmission during an outbreak of HCV infection in a hemodialysis unit.

Design:

An epidemiologic study, virologie analysis, assessment of infection control practices and procedures, and technical examination of products and dialysis machines.

Setting:

A private hemodialysis unit treating approximately 70 patients.

Patients:

Detection of HCV RNA by PCR was performed among patients receiving dialysis in 2001. Case-patients were patients who had a first positive result for HCV RNA between January 2001 and January 2002 and either acute hepatitis, a seroconversion for HCV antibodies, or a previous negative result. Three control-patients were randomly selected per case-patient.

Results:

Of the 61 patients treated in the unit in 2001 and not infected with HCV, 22 (36.1%) became case-patients with onset from May 2001 to January 2002 for an incidence density rate of 70 per 100 patient-years. Phylogenic analysis identified four distinct HCV groups and an index case-patient for each with a similar virus among patients already known to be infected. No multidose medication vials or material was shared between patients. Connection to a dialysis machine by a nurse who had connected an HCV-infected patient “just before” or “one patient before” increased the risk of HCV infection, whereas using the same dialysis machine after a patient infected with HCV did not. Understating, lack of training, and breaches in infection control were documented. Direct observation of practices revealed frequent flooding of blood into the double filter on the arterial pressure tubing set.

Conclusions:

During this outbreak, HCV transmission was mainly patient to patient via healthcare workers' hands. However, transmission via dialysis machines because of possible contamination of internal components could not be excluded.

Transmission of hepatitis C virus in dialysis units: a systematic review of reports on outbreaks

BACKGROUND

Hepatitis C virus (HCV) outbreaks among patients on hemodialysis are still an important health concern all over the world.

AIMS

We performed a systematic review of reports on HCV outbreaks within dialysis units of developed and less-developed countries (between 1992 and 2015) to evaluate risk factors and practices associated with patient-to-patient transmission of HCV in this setting.

METHODS

The research was performed using the PubMed Database and the Outbreak Database; studies were selected according to the PRISMA algorithm. Inclusion criteria were established before the papers were retrieved in order to avoid selection biases.

RESULTS

36 papers reported on 45 outbreaks that involved 335 unique patients on maintenance hemodialysis; no fatal cases were detected. Nosocomial transmission of HCV was confirmed by phylogenetic analysis in most (n=31; 69%) reports. Sharing contaminated hemodialysis machines and multidose vials (heparin or saline solution) was suggested responsible for HCV transmission in 8 (18%) and 6 (13%) outbreaks, respectively. Breaches in environmental cleaning and disinfection practices, and failures in medication preparation and administration practices was considered in 29 (65%) outbreaks; however, the exact mechanism of transmission of HCV could not be ascertained in each facility where an outbreak occurred.

CONCLUSIONS

Our systematic review of reports on hepatitis C virus outbreaks shows that, although the full extent of HCV transmission in dialysis units is unknown, outbreaks continue to occur. Full compliance to standard/specific infection control procedures and routine serologic screening for HCV antibody play a pivotal role for preventing the transmission of HCV within hemodialysis units.

Viral hepatitis in hemodialysis: An update

Hepatitis outbreaks in hemodialysis (HD) patients and staff were reported in the late 1960s, and a number of hepatotropic viruses transmitted by blood and other body fluids have been identified. Hepatitis B virus (HBV) was the first significant hepatotropic virus to be identified in HD centers. HBV infection has been effectively controlled by active vaccination, screening of blood donors, the use of erythropoietin and segregation of HBV carriers. Hepatitis delta virus is a defective virus that can only infect HBV-positive individuals. Hepatitis C virus (HCV) 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-alfa 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, hepatitis GB virus C and the TT virus. 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 HD. Major recent advances in the viral diagnosis technology and the development of new oral, direct-acting antiviral agents allow early diagnosis and better therapeutic response. The current update will review the recent developments, controversies and new treatment of viral hepatitis in HD patients.

Study of the Associations Between TT Virus Single and Mixed Infections With Leukemia

BACKGROUND

The pathogenic association of Transfusion Transmitted Virus or Torque teno Virus (TT Virus) single and mixed infections with leukemia was under evaluation in these years but confront with controversies. This hypothesis is based on the higher prevalence of TT Virus infection in patients with leukemia compared with controls.

OBJECTIVES

The aim of this study was to determine the frequency of TT Virus, Cytomegalovirus (CMV), Hepatitis B Virus (HBV), and Hepatitis C Virus (HCV) infections in patients with leukemia and healthy controls.

PATIENTS AND METHODS

In this cross sectional study, 95 patients with leukemia and 100 healthy controls who were admitted to the Namazi Hospital affiliated to the Shiraz University of Medical Sciences, Shiraz, Iran, were enrolled between years 2012 and 2013. Blood samples treated with EDTA were collected from each patient with leukemia and controls. The existence of TT Virus infection was analyzed using the semi-nested PCR method. The immunological prevalence of HBV and HCV infections were evaluated using HBs-Ag and HCV-Ab ELISA based protocols, respectively. Active CMV infection was also evaluated using an immunofluorescence method. Also risk factors of leukemia and viral infections were statistically analyzed in patients with leukemia.

RESULTS

The TT Virus infection was significantly found in 40 of 95 (42.1%) and 12 of 100 (12%) patients with leukemia and controls, respectively. The HBs-Ag and HCV-Ab were detected in 27 of 95 (28.4%) and 18 of 69 (26.1%) patients with leukemia but were not found in the controls. Active CMV infection was also found in 11 of 69 (16%) patients and none of the controls. Significant co-infection of TT Virus was found with HBV (15 of 40; 37.5%), HCV (14 of 40; 35%) and CMV (7 of 40; 17.5%) in patients with leukemia.

CONCLUSIONS

Confirmation of the significantly higher frequency of TT Virus, HBV, HCV and CMV single infection and their co-infection in patients with leukemia compared with healthy controls, emphasizes the determinative role of TT Virus pathogenesis in clinical outcomes observed in patients with leukemia, which requires extensive evaluation by further studies.

Outbreak of Hepatitis C Virus Infection in a Hemodialysis Unit: Potential Transmission by the Hemodialysis Machine?

Objective:

To identify the routes of transmission during an outbreak of infection with hepatitis C virus (HCV) genotype 2a/2c in a hemodialysis unit.

Design:

A matched case-control study was conducted to identify risk factors for HCV seroconversion. Direct observation and staff interviews were conducted to assess infection control practices. Molecular methods were used in a comparison of HCV infecting isolates from the case-patients and from patients infected with the 2a/2c genotype before admission to the unit.

Setting:

A hemodialysis unit treating an average of 90 patients.

Patients:

A case-patient was defined as a patient receiving hemodialysis with a seroconversion for HCV genotype 2a/2c between January 1994 and July 1997 who had received dialysis in the unit during the 3 months before the onset of disease. For each case-patient, 3 control-patients were randomly selected among all susceptible patients treated in the unit during the presumed contamination period of the case-patient.

Results:

HCV seroconversion was associated with the number of hemodialysis sessions undergone on a machine shared with (odds ratio [OR] per additional session, 1.3; 95% confidence interval [CI95], 0.9 to 1.8) or in the same room as (OR per additional session, 1.1; CI95, 1.0 to 1.2) a patient who was anti-HCV (genotype 2a/2c) positive. We observed several breaches in infection control procedures. Wetting of transducer protectors in the external pressure tubing sets with patient blood reflux was observed, leading to a potential contamination by blood of the pressure-sensing port of the machine, which is not accessible to routine disinfection. The molecular analysis of HCV infecting isolates identified among the case-patients revealed two groups of identical isolates similar to those of two patients infected before admission to the unit.

Conclusions:

The results suggest patient-to-patient transmission of HCV by breaches in infection control practices and possible contamination of the machine. No additional cases have occurred since the reinforcement of infection control procedures and the use of a second transducer protector.

Hepatitis C virus infection: the new global epidemic

Hepatitis C virus infects an estimated 170 million people worldwide. It is a major cause of liver cirrhosis, end-stage liver disease and hepatocellular carcinoma. It is also a leading cause of liver transplant in the USA. The virus is primarily transmitted parenterally, but there is significant mother-to-child transmission. Partly due to the virus's genetic diversity, it evades the host immune response and it has been difficult to identify candidate vaccines. However, significant advances have been made in the treatment of chronic hepatitis C virus infection. Currently, the combination of pegylated interferon-alpha and ribavirin is the standard treatment for chronic hepatitis C virus infection, and leads to long-term eradication of the virus in approximately 54% of people. Treatment response is dependent on the infecting genotype, with 76 to 80% of those with genotypes 2 and 3, but only approximately 40% with genotype 1 or 4 achieving a sustained virologic response. Since treatment is expensive and associated with significant adverse effects, more effective strategies for the prevention of transmission are needed, especially in resource-limited countries, where the burden of disease is the highest.

Prevalence of bacterial contamination of glucose test strips in individual single-use packets versus multiple-use vials

BACKGROUND

Glucose measurement is the cornerstone of diabetes control. In the hospital setting, the same device and package of test strips (50 or 100 strips) can be used to monitor glucose in several patients, which can increase cross contamination. The objective of our study is to measure bacterial contamination in glucose test strips, comparing results in individual single-use packets (one hospital) versus multi-use vials (two hospitals) in Spain.

METHODS

Test strips were collected from five different wards. Each hospital also collected two unopened vials from a single ward as controls. They were sent to a reference laboratory for microbiologic study. A number equal or higher than two colony forming units per strip was considered as a positive result.

RESULTS

Out of 423 glucose test strips collected and cultured, 146 were contaminated (34%); only 7% of individually packed strips were contaminated versus 45% of strips packed in multi-use vials, with a high statistical significance (p < .001).

CONCLUSIONS

In the strips from multi-use vials, a high contamination rate was found and highly pathogenic organisms were identified, such as methicillin-resistant Staphylococcus epidermidis or Staphylococcus hemolyticus. In contrast, in strips packed individually, there was a much lower contamination rate and no such pathogen organisms were found. Therefore, in the hospital setting, the use of blood glucose test strips in individual packages would be more advantageous (mainly from a clinical point of view, but also from a financial one) than those packed in multi-use vials.

Intrafamilial transmission of hepatitis C virus in patients with severe haemophilia A

The history behind the production of clotting factor concentrates produced differences in the prevalence of Hepatitis C Virus (HCV) and other blood-borne infections in haemophilic patients. Prevalence rates of HCV infection up to 100% were reported in patients treated with concentrates before 1985. Conversely, nowadays, viral inactivation and recombinant technologies have effectively prevented transfusion-transmitted viral pathogens. Recently, new HCV infections in three young brothers were observed. In the absence of any other risk of transmission, their HIV/HCV coinfected uncle, who was living in the same house, was subject to study. Plasma samples of the four relatives were investigated in order to test whether the infections have a common source. A phylogenetic approach using the most variable (E2) viral sequences was carried out using samples from the four family members. The HCV sequences from the study resulted highly related, being those obtained from the uncle the most ancestral ones. Because of the chronological order in which the infections occurred and the relatedness of the sequences, an infection from the uncle to his nephews is the most likely explanation. Special cares must be applied in the case of household contact among members of a family with inherited bleeding disorders.

Phylogenetic investigation of nosocomial transmission of hepatitis C virus in an oncology ward

Nosocomial hepatitis C virus (HCV) infections have been reported from different health-care settings worldwide. Twenty patients, treated at the same oncology department, with no previous record of hepatitis C infection, tested positive for anti-HCV antibodies between November 2007 and June 2008. Twelve of the newly infected patients were found to be HCV RNA positive. The common origin of the infections was assumed. To investigate the relatedness of the detected viral strains phylogenetic analyses were performed using sequences from the NS5B and E1/E2 genome regions. A patient carrying HCV for years was also involved in the study. She was treated at the same oncology department and was considered a possible infectious source. The previous HCV carrier harbored subtype 1b, while all other patients were infected with subtype 1a. Sequences from the 12 newly infected patients formed two groups. The viral sequences within the groups were very closely related. A greater evolutionary distance was observed between the two groups; however, their relatedness could be demonstrated by sequences from both regions with high statistical support. The results indicated that nosocomial transmission occurred. The phylogenetic analyses suggested that the viruses originated from a common source, possibly a patient carrying highly divergent variants. This presumed infectious source could not be identified in the course of this study. The genotype distribution of Hungarian control sequences included in the analysis confirmed this conclusion, since HCV genotype 1a was found to be relatively uncommon.

The prevalence of molecular and immunologic infective markers of hepatitis viruses in patients with hematological malignancies

Acute and chronic viral hepatitis infections are corresponding to increase the risk of different types of hematological malignancies especially with leukemia. In this study the serological and molecular markers of hepatitis viruses were evaluated in patients with different types of leukemia in comparing with control group. In this cross sectional study, 100 EDTA-treated blood samples were collected from leukemia patients and also from healthy control group, respectively. Serological and molecular markers of HBV, HCV and HDV viruses were analyzed for determination of the role of these hepatitis viruses in clinical outcomes of leukemia disorders. Increasing risk factors of leukemia were evaluated statistically in two studied groups by SPSS software. One of molecular and immunological markers of HBV, HDV and HCV was found in 24 of 100 (24%), 22 of 100 (22%), and 1 of 100 (1%) patients with leukemia and in 12 of 100 (12%), 6 of 100 (6%), and 2 of 100 (2%) control patients. Significant differences were detected in detection of HBsAg (P = 0.02), HBeAb (P = 0.009), and HCV-RNA (P = 0.05) between leukemia patients and control group, respectively. The high prevalence of HBV and HCV infective markers were detected in ALL and AML patients. Identification of high prevalence of HBV and HCV infective markers in leukemia patients proposed strong association between hepatitis viral infections and leukemia. Therefore, evaluation of the prevalence of viral hepatitis infections in larger groups of patients with long lasting follow up is suggesting.

Decreased prevalence and incidence of HCV markers in haemodialysis units: a multicentric French survey

BACKGROUND

A variety of epidemiological data provide evidence for the nosocomial transmission of hepatitis C virus (HCV) infections to haemodialysis patients. We conducted a multicentric study to determine the prevalence and incidence of HCV infection in French haemodialysis units.

METHODS

Patients undergoing chronic haemodialysis in 56 French units (4718 patients) were systematically screened for anti-HCV antibodies using third-generation tests. The incidence was estimated by detecting HCV RNA in seronegative patients using a standardized real-time PCR assay on pooled samples.

RESULTS

Testing for HCV antibodies identified 361 patients with anti-HCV antibodies, giving a prevalence of 7.7%. Multivariate analysis demonstrated that anti-HCV status was linked to the time on haemodialysis, previous kidney transplantation and the presence of anti-HBc antibodies, whereas erythropoietin therapy and carrying out dialysis in dedicated spaces seem to protect against HCV infection. Only two of the 4357 patients without anti-HCV antibodies tested positive for HCV RNA, giving an estimated incidence of 0.05% new HCV infections/year. Molecular analyses indicated that the two patients probably acquired HCV outside the haemodialysis unit.

CONCLUSION

This decreased prevalence and incidence emphasizes the importance of adhering to the recommended universal infection-control precautions. Virological follow-up based on detecting anti-HCV antibodies with sensitive, specific new-generation serological tests could be adequate for dialysis units with few HCV infections. However, new infections in haemodialysis units should be identified by determining the HCV RNA status of seronegative patients. Standardized real-time PCR assays, plus pooling serum samples, make this a promising method for large-scale epidemiological studies.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

Analytical evaluation of HCV core antigen and interest for HCV screening in haemodialysis patients

BACKGROUND

It is important to diagnose a hepatitis C virus infection in the acute phase in order to reduce the incidence of this infection in high-risk populations like haemodialysis patients. But detection systems for serum HCV antibodies are insensitive in the acute phase because of the long serological window. Previous studies showed that the HCV core antigen (HCV Ag) may be an alternative to HCV RNA in this context.

OBJECTIVES

To evaluate the performances of the new Abbott ARCHITECT((R)) HCV Ag test and its usefulness in screening for HCV infections in haemodialysis patients.

STUDY DESIGN

The serum HCV Ag titre was compared to the HCV RNA viral load in 98 samples from HCV-infected patients to determine the correlation between the two markers and the influence of genotype. We screened 2752 patients from 37 French haemodialysis units who tested negative for HCV antibodies using the HCV Ag and RNA assays.

RESULTS

The HCV Ag titre was correlated with the HCV RNA (Spearman test coefficient 0.9041, p<0.0001) and all genotypes and subtypes were detected. The HCV Ag and HCV RNA results agreed well for haemodialysis patients. Diagnostic specificity of HCV Ag was high (99.2%) considering HCV RNA as the reference. The two seronegative patients (of 2752) who were HCV RNA positive were also HCV Ag positive.

CONCLUSIONS

The ARCHITECT HCV Ag test is a reliable, highly specific assay for screening acute HCV infections in haemodialysis units. It is a robust alternative to HCV RNA testing.

Infecção pelo vírus da hepatite c em pacientes em hemodiálise: prevalência e fatores de risco

CONTEXTO: Doentes com doença renal crônica em tratamento hemodialítico apresentam risco aumentado de aquisição do vírus da hepatite C (VHC). Elevadas taxas de prevalência têm sido detectadas em unidades de diálise do mundo inteiro. Estudos recentes têm demonstrado que a infecção pelo VHC interfere de forma negativa na sobrevida dos pacientes em hemodiálise e naqueles submetidos ao transplante renal. OBJETIVOS: Determinar a prevalência e os fatores de risco da infecção pelo VHC em pacientes submetidos a hemodiálise. MÉTODOS: Realizou-se estudo transversal entre janeiro e dezembro de 2007. Neste período, 236 pacientes em hemodiálise foram testados pelo ELISA de terceira geração. Os casos positivos foram submetidos a pesquisa qualitativa do HCV-RNA pelo método de PCR. Consideraram-se como portadores de infecção pelo VHC aqueles pacientes com anti-VHC e HCV-RNA positivos. Dosagens mensais de ALT e a média do valor de 12 meses foram obtidas em 195 pacientes. Do total de pacientes, 208 (88,1%) responderam ao questionário padronizado visando a identificação de fatores de risco associados à infecção pelo VHC. RESULTADOS: A prevalência de pacientes anti-VHC positivos encontrada entre os 236 testados foi de 14,8% (35/236); destes, a pesquisa do HCV-RNA foi positiva em 71,6% (25/35). Portanto, a prevalência da infecção crônica pelo VHC foi de 10,6% (25/236) dos pacientes. Pela análise bivariada, os principais fatores de risco associados à infecção pelo VHC foram o tempo de hemodiálise, o número de transfusões de sangue, a realização prévia de diálise peritonial e história de doença sexualmente transmissível. Contudo, após análise multivariada, somente o tempo de hemodiálise e história de doença sexualmente transmissível foram significativamente associados à infecção pelo VHC. Pacientes com mais de 10 anos de hemodiálise apresentaram risco de aquisição do VHC 73,9 (IC de 17,5 a 311,8) vezes maior quando comparados a pacientes com até 5 anos de tratamento. Indivíduos com doença sexualmente transmissível prévia apresentaram risco 4,8 (IC de 1,1 a 19,9) vezes superior de contaminação pelo VHC quando comparados àqueles sem doença sexualmente transmissível. O valor médio da ALT foi significantemente maior nos pacientes infectados pelo VHC (44,0 ± 13,5 U/L versus 33,5 ± 8,0 U/L, P<0,001). CONCLUSÃO: A infecção pelo VHC apresentou elevada prevalência na unidade de diálise analisada. O tempo de tratamento dialítico e história prévia de doença sexualmente transmissível foram os principais fatores de risco associados à infecção pelo VHC. Indivíduos em hemodiálise com infecção crônica pelo VHC apresentaram maior atividade de ALT que pacientes sem hepatite C crônica.

Infection control guidelines for prevention of health care-associated transmission of hepatitis B and C viruses

Viral hepatitis was first identified as an occupational hazard for health care workers more than 60 years ago. For the past few decades, hepatitis B has been one of the most significant occupational infectious risks for health care providers. With the increasing prevalence of hepatitis C infections around the world, occupational transmission of this flavivirus from infected patients to their providers has also become a significant concern. Several factors influence the risk for occupational blood-borne hepatitis infection among health care providers, among them: the prevalence of infection among the population served, the infection status of the patients to whom workers are exposed (ie, the source patient's circulating viral burden), the types and frequencies of parenteral and mucosal exposures to blood and blood-containing body fluids, and whether the patient or provider has been immunized with the hepatitis B vaccine. This article reviews patient-to-provider, patient-to-patient, and provider-to-patient transmission of hepatitis B and C in the health care setting. Current prevention strategies, precautions, and guidelines are discussed.

Mathematical modeling of hepatitis C virus transmission in hemodialysis

BACKGROUND

A deterministic mathematical model is developed to explain nontransfusion nosocomial transmission of hepatitis C virus (HCV) from patient to patient during hemodialysis sessions.

METHODS

The model requires 4 sequential steps for cross-transmission: (1) The dialysis session contains at least 1 patient infected with HCV; (2) a hemodialysis staff member connects an uninfected patient to dialysis after having connected an infected patient; (3) the hemodialysis staff member does not change gloves between an infected patient and an uninfected patient; and (4) the uninfected patient is contaminated after exposure to the blood of an infected patient.

RESULTS

We tested the model by comparing observed incidences of HCV infection from epidemiologic studies with calculated incidences. Calculated incidences are closed to observed incidences. We assessed the impact of prevalence of HCV infection, no glove change between patients, and nurse:patient ratio on the incidence of HCV infection. We found linear relationships between incidence and prevalence and between incidence and no glove change, and an increasing logarithmic relationship between incidence and nurse:patient ratio.

CONCLUSION

Our model should be able to estimate the likely incidence of infection in hemodialysis centers. Compliance with recommended hand hygiene and glove use practices, especially glove changes between patients, is essential to prevent HCV infection in hemodialysis centers, particularly those with high HCV prevalence. Mathematical modeling can used as a tool for control.

Hepatitis C in hemodialysis patients: current global magnitude, natural history, diagnostic difficulties, and preventive measures

Hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality in hemodialysis (HD) patients. The reported prevalence of HCV among the HD population has varied greatly from 1.9 to 84.6% in different countries in recent years. The length of time on HD is generally believed to be associated with HCV acquisition in HD subjects. Nevertheless, several recent reports failed to recognize any significant role of blood transfusion. Although there are some considerations about the accuracy of serologic testing in detecting HCV in HD patients, the accumulated data in this review suggest the false-negativity rate to be not more than 1.66% (153/9,220). Therefore, substituting virologic for serologic testing in the routine diagnosis of HCV infection in HD patients seems unreasonable. Several phylogenetic analyzes of viral isolates suggested nosocomial patient-to-patient transmission of HCV among HD patients for which the main potential source is believed to be contaminated hands and articles. However, isolation of HCV-infected HD patients and use of dedicated machines are currently unjustified while strict adherence to universal precautions seems to be enough to control disease spread in HD units. The present article is an update on epidemiological and clinical features of HCV in HD population.

Clinical and laboratory characteristics of acute hepatitis C in patients with end-stage renal disease on hemodialysis

BACKGROUND

Patients with end-stage renal disease (ESRD) undergoing hemodialysis are a risk group for hepatitis C virus (HCV) infection. The characteristics of acute hepatitis C infection in this population are not well known.

GOALS

To evaluate the clinical and laboratory characteristics of acute hepatitis C in ESRD patients treated with hemodialysis.

STUDY

ESRD patients on hemodialysis with acute hepatitis C, characterized by elevated alanine aminotransferase (ALT) followed by anti-HCV seroconversion were studied.

RESULTS

Thirty-six patients (58% females, 44+/-12 y), with a mean time on hemodialysis of 2 years, were included. Only 2 (6%) patients had jaundice. ALT elevation was observed in all patients. Median peak ALT was 4.7 x upper limit of normal. The median interval between ALT elevation and anti-HCV seroconversion was 1 month (0 to 8). None of the patients with detectable HCV-RNA showed spontaneous clearance of viremia within 12 weeks of follow-up. Three (8%) patients presented ALT elevation followed by anti-HCV seroconversion with undetectable HCV-RNA.

CONCLUSIONS

Acute hepatitis C is frequently asymptomatic in ESRD patients on hemodialysis and should be suspected in all patients presenting elevated ALT. Determination of HCV-RNA is important for the confirmation of infection. Anti-HCV seroconversion seems to occur early and spontaneous clearance of HCV-RNA is uncommon.

Impact of hepatitis C virus infection and other comorbidities on survival in patients on dialysis

The impact of hepatitis C virus (HCV) and other comorbid conditions upon survival is not well quantified in patients on dialysis. We identified HCV-infected and uninfected persons in the USRDS using claims data in 1997-1998 and followed until September 22, 2002 or death. We used Gray's time-varying coefficients model to examine factors associated with survival. Subjects with a renal transplant were excluded. A total of 5737 HCV-infected and 11 228 HCV-uninfected persons were identified. HCV-infected subjects were younger (mean age 57.8 vs 65.3 years), more likely to be male (57.6%vs 49.6%) and black (54.0%vs 36.4%). They were more likely to have a diagnosis of drug (16.5%vs 4.6%) and alcohol use (14.0%vs 3.1%), and to be human immunodeficiency virus (HIV) co-infected (7.4%vs 1.8%) (all comparisons, P < 0.0005). In an adjusted Gray's time-varying coefficient model, HCV was associated with an increased risk of mortality (P < 0.0005). The hazards were highest at the time of HCV diagnosis and decreased to a stable level 2 years after diagnosis. Other factors associated with increased risk of mortality were (P < 0.0005 unless stated) HIV coinfection; diagnosis of drug use (P = 0.001); coronary artery disease (P = 0.006); stroke; diabetes as the primary cause for renal failure; peripheral vascular disease; depression and presence of anaemia. HCV was associated with higher risk of death in patients on dialysis, even after adjusting for concurrent comorbidities. The risk was highest at the time of HCV diagnosis and stabilized over time. Clinical trials of HCV screening and treatment to reduce mortality in this population are warranted.

Improvement of hepatitis C virus (HCV) genotype determination with the new version of the INNO-LiPA HCV assay

Hepatitis C virus (HCV) isolates have been classified into six main genotypes. Genotyping methods, and especially the widely used line probe assay (LiPA), are frequently based on the 5'-untranslated region (5'UTR). However, this region is not appropriate for discriminating HCV strains at the subtype level and for distinguishing many genotype 6 samples from genotype 1. We investigated the capacity of a novel LiPA (Versant HCV Genotype 2.0 assay) based on the simultaneous detection of 5'UTR and Core regions for genotypes 1 and 6 to provide correct HCV genotypes (characterized with a phylogenetic analysis) in a set of HCV strains mainly encountered in Western countries. The improvement was assessed by comparing the results to those obtained with the previous version of the assay. Of the 135 tested samples, 64.7% were concordant for genotype group and subtype with sequencing reference results using the Versant HCV Genotype 2.0 assay versus 37.5% with the previous version. The yield was mainly related to a better characterization of genotype 1, since the accuracy, tested in 62 genotype 1 samples, increased from 45.2% with the first version to 96.8% with the new one. However, this new version necessitates a specific PCR and could no longer be used after 5'UTR PCR used for current HCV infection diagnosis. Moreover, the information provided by 5'UTR hybridization is not reliable for correctly identifying the diversity within genotypes 2 and 4. Thus, the Versant HCV Genotype 2.0 assay remains a useful tool for clinical practice when only the discrimination between major HCV genotypes is necessary.

Determining the source of nosocomial transmission in hemodialysis units in Tunisia by sequencing NS5B and E2 sequences of HCV

Hepatitis C virus infection is a significant problem in hemodialysis units. HCV is very variable genetically with six genotypes. Clinical and epidemiological investigation of a new infection requires the determination of both the genotype and the strain of the HCV involved. A prospective, epidemiologic study of 395 dialysis patients in Tunisia was conducted from November 2001 to November 2003 to identify the source of nosocomial transmission using phylogenetic analysis of NS5b and E2 sequences. Hepatitis C infection was diagnosed by screening for anti-HCV antibodies and HCV RNA in sera using third generation ELISA and a qualitative RT-PCR assay. HCV strains were genotyped by sequencing the NS5b region. The genetic relatedness of the HCV strains was studied by sequencing the NS5b and the HVR-1 regions of the HCV genome. Two de novo cases of HCV infection were detected during the follow-up. One of them has been described previously. The case described in this study occurred in a center in which 12 patients were already infected with HCV strains belonging to genotypes 1b (n = 8) and 1a (n = 4). Phylogenetic analysis of the NS5b region from the HCV strains circulating in this center disclosed four clusters, confirmed by analysis of the HVR-1 region, providing strong evidence for nosocomial infection. Epidemiological data showed that these patients were dialyzed during the same shift and in the same area. Phylogenetic analysis of NS5b sequences is useful for determining the HCV genotype and providing evidence of nosocomial transmission.

[The evolution of the hypervariable region-1 of hepatitis C virus may predict liver fibrosis outcome after renal transplantation]

The aim of our study was to assess hepatitis C virus (HCV) evolution and long term liver histology outcome in anti-HCV(+)/RNA(+) renal-transplant (RT) patients. Fifty-five anti-HCV(+)/RNA(+) RT patients underwent every 3-4 years after transplantation liver biopsies (LB) (2 LBs, N = 55; 3 LBs, N = 44; 4 LBs, N = 10). The hypervariable region (HVR)-1 of the HCV genome from all patients was characterized over time. Overall, the rate of liver fibrosis progression was 0.07 +/- 0.03 Metavir units/year. We identified three groups of patients: those in whom liver fibrosis remained stable (group I, N = 21), those with progressing liver fibrosis (group II, N = 21), and those with a regression in liver fibrosis (group III, N = 13). Initial fibrosis stage and high diversification of the HVR-1 of HCV genome between the transplantation and the first liver biopsy were independent factors associated with liver fibrosis regression. In conclusion, in this study, after renal transplantation, HCV infection is not harmful upon liver histology in more than fifty percent of the patients. The diversification of the HVR-1 of the HCV genome might be used to predict liver fibrosis outcome.

Retrospective investigation of patients exposed to possible transmission of hepatitis C virus by a capillary blood glucose meter

A 75-year-old female with no known risk factors for hepatitis C virus (HCV) infection was hospitalized and a diagnosis of HCV seroconversion was established (HCV immunoblot and a positive quantitative viral load). An epidemiological investigation revealed that, during a previous hospitalization resulting in a diagnosis of diabetes, she had shared a Glucotrend capillary blood glucose meter (CBGM; Roche Diagnostics, France) with a known HCV-positive diabetic patient. Poor hygiene practices were observed when using this device. Since the Glucotrend CBGM had been purchased, the suspected source patient had been hospitalized eight times and another 19 diabetic patients with known anti-HCV antibodies also regularly attended the same hospital. Consequently, 35 diabetic patients who had been hospitalized at the same time as the suspected source patient and 1305 patients who had used the Glucotrend CBGM were invited to undergo serum anti-hepatitis B virus, anti-HCV and anti-human immunodeficiency virus testing. Among the 35 diabetic patients, none of the 24 subjects tested were positive. Among the 1305 other patients, 995 were tested and 19 (2%) were anti-HCV positive. Although this prevalence is higher than that reported in the general French population, this excess risk cannot be attributed to use of the CBGM. Furthermore, molecular analysis showed that the two HCV strains isolated did not belong to the same phylogenetic cluster. However, as a result of this incident, measures were taken to minimize the transmission of bloodborne viruses in the hospital concerned. Other French hospitals were informed by a national alert message from the French Agency for the Safety of Health Products.

Hepatitis C virus infection among dialysis patients in Tunisia: incidence and molecular evidence for nosocomial transmission

In order to study the incidence of hepatitis C virus (HCV) infection in Tunisian haemodialysis patients and detect its nosocomial transmission, 395 patients were enrolled in a prospective study (November 2001-2003). HCV serological and virological status was determined initially using, respectively a third generation ELISA and an RT-PCR qualitative assay. The genotype of the HCV isolates was determined by sequencing NS5B region. The issue of nosocomial transmission was addressed by sequencing the HVR-1 region of the E2 gene. About 20% of the patients had anti-HCV antibodies and HCV-RNA was detected in 73% of the anti-HCV positive patients. Two cases of de novo HCV infection were identified in two dialysis centers, during virological follow-up of patients susceptible to HCV infection. The incidence of de novo HCV infection was 0.5%. Determining the genotypes in the first center disclosed that all HCV-positive patients were infected with genotype 1b; sequencing of the HVR-1 region of the E2 gene provided strong evidence that the isolate from the newly infected patient and another infected dialysis patient were closely related, confirming nosocomial contamination. The investigation of the second center is pending. Besides, one patient with negative HCV serology had detectable HCV-RNA at the beginning of the study. This case had HCV genotype 1b, two other infected dialysis patients in the same unit had HCV genotypes 4k and 3a; thus precluding nosocomial transmission. Thanks to molecular and phylogenetic methods, one case of nosocomial HCV transmission in haemodialysis was confirmed. Epidemiological investigation suggested nosocomial transmission via the medical and/or nursing staff.

A cluster of hepatitis C virus infections associated with ozone-enriched transfusion of autologous blood in Rome, Italy

OBJECTIVE

To describe an outbreak of hepatitis C virus (HCV).

DESIGN

Retrospective cohort study.

SETTING

Outpatient department of a hospital in Rome, Italy.

PATIENTS

All 42 patients exposed to ozone therapy by autohemotherapy or intramuscular injection from January to June 2001.

METHODS

Epidemiologic investigation, serologic analysis, and virus genotyping.

RESULTS

Thirty-one (74%) of the patients agreed to participate in the study. Three (9.7%) had symptoms of HCV infection. This incidence rate was higher than the rate of 1.4 per 100,000 per year in the regional population. Six patients were positive for HCV antibodies and HCV RNA for a prevalence rate of 19.4%, which was much higher than the estimate of 0.9% in the population. Virus genotype 1b was found in two case-patients (one symptomatic) and 2c in four case-patients (two symptomatic), one of whom was known to have an HCV infection since 1986 and could have been the source of infection. The infected patients were all being exposed to ozone-enriched transfusions of autologous blood. Although the specific mode of transmission between patients was not detected, transmission probably occurred during one of the three busiest therapeutic sessions in the 6-month period.

CONCLUSIONS

Transmission of HCV infection may occur during medical procedures with limited bleeding. Standard precautions must be applied in any healthcare setting; restricting the number of individuals treated during each therapeutic session could be an effective way of avoiding accidental transmission of infection.

Characterization of HCV strains in an oncohematological pediatric department reveals little horizontal transmission but multiple introductions by un-screened blood products in the past

Because several children were found infected with hepatitis C virus (HCV) at a pediatric oncohematological department in Vilnius, 474 children were tested for anti-HCV. Fifty-eight percent of 96 children treated with blood and plasma products manufactured before the introduction of anti-HCV screening of blood in Lithuania in 1994 were positive for anti-HCV versus 3.4% of those treated after 1994. The possible route of transmission for 45 of these was investigated by phylogenetic analyses within the NS5B region. Children treated before 1995 were infected with a multiplicity of strains of different subtypes, predominantly 1b found in 21 cases, 3a in 5 cases, 2 in 3 cases, 1a in 1 case, and not subtypeable genotype 1 strains in 2 cases. Children who had received blood products after 1994 were infected with only two subtypes, 1b in six and 3a in seven. Genetic analysis showed multiple introductions of HCV before 1995 and that horizontal spread between patients had occurred only to a minor extent at the department. However, two transmission chains involved children treated before 1995. Another chain involved five children treated after 1994. Since the most important risk factor for acquiring hepatitis C was blood products manufactured before the introduction of donor screening for anti-HCV, the spread between children would not have been revealed without molecular tools. These and the background strains provide the first reported sequence data on Lithuanian HCV strains. In general, these were shown to form autochthonous clades, except the 3a strains that were related to strains from the former USSR.

Hepatitis C infection is acquired pre-ESRD

BACKGROUND

Hepatitis C is more prevalent in patients with end-stage renal disease (ESRD) than in the general population. Previously, infection from nosocomial sources was an important cause for this increase. In the past decade, the risk from these sources has lessened, but the estimated percentage of patients with ESRD with hepatitis C virus (HCV) antibody (anti-HCV) has not changed.

METHODS

This is a prospective observational study of hemodialysis patients in 4 urban units in Birmingham, AL. Testing for anti-HCV was performed at the initiation of dialysis therapy and then yearly from August 1998 through August 2004. Race, sex, age, ESRD date, comorbid conditions, and outcomes were recorded.

RESULTS

The prevalence of anti-HCV was 16.8% in 860 patients (89% black). Patients new to ESRD had a prevalence of 14.4%. Seroconversion in previously anti-HCV-negative patients was 2.5%. Anti-HCV occurred in black men 3 times more than in black women (odds ratio, 3.3; 95% confidence interval, 2.2 to 5.0). Mean age at ESRD was significantly younger in anti-HCV-positive than HCV-negative patients (47.3 versus 54.1 years; P < 0.0001). Age, race, sex, and history of drug abuse were predictors of anti-HCV positivity.

CONCLUSION

The prevalence of anti-HCV among patients with ESRD varies from community to community. New patients are major contributors to the prevalence of anti-HCV in patients with ESRD, particularly those who are younger, male, black, or have a history of drug use. Measuring anti-HCV levels in patients with chronic kidney disease may help identify those at risk for additional disorders.

Incidence of HCV infection in French hemodialysis units: a prospective study

A large prospective study was carried out from 1997 to 2000 in 25 French hemodialysis units including 1,323 patients to determine the incidence of hepatitis C virus (HCV) infection. Monthly testing of alanine aminotransferase (ALT) activity, and assessment of HCV RNA and anti-HCV antibodies if the ALT activity was elevated, identified 14 new infections in 7 different units, giving an incidence of 0.4% new HCV infections per year. Molecular analyses and epidemiological data indicated that five patients became infected with HCV outside the unit where they were dialyzed, while the nine remaining patients acquired HCV from infected patients on dialysis during the same shift at the same unit. HCV was cleared in six of the seven (85.7%) patients with acute hepatitis C who were given standard doses of alpha-interferon (alpha-IFN). The persistence of nosocomial transmission of HCV in hemodialysis units emphasizes the need to implement infection control practices. Identifying new infections is crucial because alpha-IFN treatment results in long term clearance of HCV RNA in a large proportion of patients.

Incidence and patterns of hepatitis C virus seroconversion in a cohort of hemodialysis patients

BACKGROUND

The aim of this multicenter hemodialysis (HD) cohort study is to prospectively investigate the incidence of hepatitis C virus (HCV) infection in Greece from 1993 to 1995 and delineate early virological and serological events associated with HCV seroconversion in the HD setting.

METHODS

Sequential serum samples collected weekly from 562 patients were tested biochemically and serologically by means of a second- (EIA-2) and third-generation enzyme immunoassay (EIA-3). All patients with positive antibody to HCV test results (anti-HCV + ) and sequential samples from seroconverting patients were tested for HCV RNA.

RESULTS

Anti-HCV prevalence at study entry was 29% (163 of 562 patients), and viremia was detectable in 110 of 163 anti-HCV + patients (67.5%). HCV incidence was 6.2 cases/100 person-years. Seroconversions could not be attributed to transfusions after study entry (only 1 patient had been administered transfusion), and HD unit was associated with increased hazard for seroconversion ( P = 0.002), even after adjusting for potential differences among their patients. According to Kaplan-Meier estimation, the median interval by which the HCV RNA assay detected HCV infection earlier than anti-HCV testing was 246 and 154 days for EIA-2 and EIA-3, respectively. Detectable HCV RNA and at least 2 consecutive abnormal alanine aminotransferase levels in the preseroconversion period were observed in 29 of 30 (97%) and 14 of 32 patients (44%), respectively. Reductions in HCV RNA levels immediately after seroconversion were transient or did not occur.

CONCLUSION

On the grounds of apparent nosocomial transmission, the wide window period of HCV infection in HD patients emphasizes the need for strict adherence to specific infection-control measures in this setting.

Serotyping of hepatitis C virus in hemodialysis patients: comparison with a standardized genotyping assay

The aims of this study were to investigate the prevalence of hepatitis C virus (HCV) genotypes and serotypes in anti-HCV-positive hemodialysis patients and determine the concordance between genotyping and serotyping methods. Sixty-two hemodialysis patients were included in this study. HCV RNA was determined using polymerase chain reaction assay and genotypes using a line probe assay. HCV serotyping was performed with competitive enzyme-linked immunosorbent assay. Genotype 4 (52 patients) was the most predominant genotype, followed by type 1 (10 patients). The most prevalent HCV serotype was type 4 (41 patients), followed by serotype 1 (6 patients). We detected multiple serotypes in 4 patients and untypeable strains in 11. The overall sensitivity of serotyping assay was 82% for the study patients. According to the genotyping results, the sensitivity of serotyping was 60% and 86.5% for HCV types 1 and 4, respectively. There was a 100% concordance between results of serotyping and genotyping in the identification of HCV type 1 and 91% concordance in HCV type 4. Serological typing method may be of great value in microbiology laboratories that require a simple assay for identification of HCV genotypes, although the sensitivity of this assay may be limited by the immunocompetence of infected hemodialysis patients.