Routine serologic testing for hepatitis C virus infection should be instituted among dialysis patients

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.

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.

High false-negative rate of anti-HCV among Egyptian patients on regular hemodialysis

Routine serological testing for hepatitis C virus (HCV) infection among hemodialysis (HD) patients is currently recommended. A dilemma existed on the value of serology because some investigators reported a high rate of false-negative serologic testing. In this study, we aimed to detect the false-negative rate of anti-HCV among Egyptian HD patients. Seventy-eight HD patients, negative for anti-HCV, anti-HIV, and hepatitis B surface antigen, were tested for HCV RNA by reverse transcriptase polymerase chain reaction (RT-PCR). In the next step, the viral load was quantified by real-time PCR in RT-PCR-positive patients. Risk factors for HCV infection, as well as clinical and biochemical indicators of liver disease, were compared between false-negative and true-negative anti-HCV HD patients. The frequency of false-negative anti-HCV was 17.9%. Frequency of blood transfusion, duration of HD, dialysis at multiple centers, and diabetes mellitus were not identified as risk factors for HCV infection. The frequency of false-negative results had a linear relation to the prevalence of HCV infection in the HD units. Timely identification of HCV within dialysis units is needed in order to lower the risk of HCV spread within the HD units. The high false-negative rate of anti-HCV among HD patients in our study justifies testing of a large scale of patients for precious assessment of effectiveness of nucleic acid amplification technology testing in screening HD patient.

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.

[Prevalence of anti-HCV antibodies and seroconversion incidence in five haemodialysis units in Morocco]

Dialysis patients are among groups at risk for development of hepatitis C infection (HCV). The aim of the study was to evaluate the prevalence and the incidence of seroconversion for HCV in five haemodialysis units in Morocco. The study was conducted during the period from September 2003 to September 2004. We studied 303 patients (148 females), mean age 49+/-16 years; dialysis duration was higher than five years in 64% of the cases. The prevalence of HCV infection was evaluated by using a fourth generation enzyme immunoassays. In the seronegative patients, we performed anti-HCV tests at three and six months intervals and monthly testing of alanine aminotransferase (ALT) activity and assessment of anti-HCV tests if the ALT activity was elevated. Moreover, risk factors, such as blood transfusion, surgery and other invasive procedures were recorded. Seroprevalence of HCV was 68.3%. Among 85 patients who were tested negative for anti-HCV at the entry of the study, four (4.60%) seroconverted in six month (estimated incidence: 9.41 new cases per year). HCV seropositivity was associated with longer duration of dialysis (p=0.000), and previous blood transfusions (p=0.047). The follow-up of the ALT in the seronegative patients did not show any significant variation. In conclusion, the prevalence and incidence of HCV infection in haemodialysis units in Morocco are dramatically elevated. High incidence seropositivity suggested nosocomial transmission of HCV; the dialysis processes itself, and blood transfusions are important risk factors for HCV transmission in these patients.

Hepatitis C inflection in dialysis patients: a link to poor clinical outcome?

Among the 350,000 maintenance dialysis patients in the USA, the mortality rate is high (20-23% per year) as is the prevalence of hepatitis C virus (HCV) infection (5-15%). An additional same number of dialysis patients in the USA may be infected with HCV but have undetectable HCV antibodies. Almost half of all deaths in dialysis patients, including HCV-infected patients, are due to cardiovascular disease. Since over two-thirds of dialysis patients die within 5 years of initiating dialysis and because markers of malnutrition-inflammation complex syndrome (MICS), rather than traditional cardiovascular risk factors, are among the strongest predictors of early death in these patients, the impact of HCV infection on nutritional status and inflammation may be a main cause of poor survival in this population. Based on data from our cross-sectional and limited longitudinal studies, we hypothesize that HCV infection confounds the association between MICS and clinical outcomes in dialysis patients and, by doing so, leads to higher short-term cardiovascular events and death. Understanding the natural history of HCV and its association with inflammation, nutrition and outcomes in dialysis patients may lead to testing more effective anti-HCV management strategies in this and other similar patient populations, providing benefits not only for HCV infection but the detrimental consequences associated with this infection. In this article, we review the link between the HCV infection and mortality in dialysis patients and compare HCV antibody to molecular methods to detect HCV infection in these individuals.

Diagnostic discordance for hepatitis C virus infection in hemodialysis patients

BACKGROUND

Hepatitis C virus (HCV) infection is associated with an increase in proinflammatory cytokine levels. Similar changes are seen in maintenance hemodialysis patients with malnutrition-inflammation-cachexia syndrome (MICS), which is associated with poor clinical outcomes in this population. We hypothesized that HCV transcription-mediated amplification (TMA), a sensitive qualitative molecular test for HCV RNA, may identify maintenance hemodialysis patients with HCV infection not detected by means of antibody enzyme immunoassay (EIA), particularly in those with MICS.

METHODS

We evaluated HCV status in 314 maintenance hemodialysis patients by using HCV antibody EIA (version 2.0; Abbott Laboratories, Abbott Park, IL) and HCV TMA (Bayer Diagnostics Laboratories, Berkeley, CA).

RESULTS

Twenty-five patients (8%) were EIA positive (EIA+)/TMA+; 4 patients (1%), EIA+/TMA negative (TMA-), and 22 patients (7%), EIA-/TMA+. In the 47 TMA+ patients, the sensitivity of EIA for HCV infection was only 53%. TMA+ patients had lower albumin levels and higher tumor necrosis factor alpha and serum glutamic oxaloacetic transaminase levels than TMA- patients. EIA+/TMA+ patients were more likely than EIA-/TMA+ or EIA-/TMA- patients to have hypoalbuminemia and higher iron and transaminase levels. Of all TMA+ patients, EIA- patients were more likely to have diabetes, be on dialysis therapy longer, and have lower liver enzyme levels and higher proinflammatory cytokine levels, including tumor necrosis factor alpha and interleukin 6.

CONCLUSION

Maintenance hemodialysis patients infected with HCV according to TMA have clinical features suggestive of MICS. In this population, HCV EIA appears to have a low sensitivity for the identification of HCV infection, which may be caused by the confounding effect of MICS or other demographic or clinical factors. These apparently false-negative HCV antibody test results are seen in persons with a longer time on hemodialysis therapy, mirroring observations in other populations with serious progressive conditions, such as human immunodeficiency virus infection.

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.

The impact of transplantation with deceased donor hepatitis c-positive kidneys on survival in wait-listed long-term dialysis patients

Whether transplantation of deceased donor kidney allografts from donors with antibodies against hepatitis C virus (HCV) confers a survival advantage compared with remaining on the kidney transplant waiting list is not yet known. We studied 38,270 USRDS Medicare beneficiaries awaiting kidney transplantation who presented with end-stage renal disease from April 1, 1995 to July 31, 2000. Cox regression was used to compare the adjusted hazard ratios for death among recipients of kidneys from deceased donors, and donors with antibodies against hepatitis C (DHCV+), controlling for demographics and comorbidities. In comparison to staying on the waiting list, transplantation from DHCV+ was associated with improved survival among all patients (adjusted hazard ratio for death 0.76, 95% CI 0.60, 0.96). Of patients receiving DHCV+ kidneys, 52% were themselves hepatitis C antibody positive (HCV+), so outcomes associated with use of these grafts may have particular implications for HCV+ transplant candidates. Recommendations for use of DHCV+ kidneys may require analysis of data not currently collected from either dialysis or transplant patients. However, transplantation of DHCV+ kidneys is associated with improved patient survival compared to remaining wait-listed and dialysis dependent.

Antigenicity of a recombinant NS3 protein representative of ATPase/helicase domain from hepatitis C virus

It has been shown that the Hepatitis C virus nonstructural NS3 protein possesses at least two enzymatic domains: a serine-protease domain and an adenosine triphosphatase (ATPase)/helicase domain. In this report, a truncated fragment of NS3 (26 kDa), representing main epitopes from the (ATPase)/helicase domain, has been expressed in Escherichia coli. The recombinant protein was purified by Ion Metal Affinity Chromatography (IMAC) with more than 90% purity. The recognition of B-cell linear epitopes in the NS3 protein was evaluated by immunoblot. The recombinant NS3 protein was reduced and carboxymethylated, and the recognition of either conformational and/or linear B-cell determinants was evaluated by ELISA. The inclusion of the recombinant NS3 protein in a third-generation diagnostic system UltraMicroELISA (UMELISA) allowed an increase in the sensitivity, due to the detection of a new variety of false-negative sera in blood donor test samples.