Health care-associated transmission of hepatitis B and C viruses in hemodialysis units

An Updated View on the Antiviral Therapy of Hepatitis C in Chronic Kidney Disease

BACKGROUND

Hepatitis C virus infection remains common in patients with chronic kidney disease, including those on maintenance dialysis. The relationship between hepatitis C virus infection and chronic kidney disease is bi-directional; in fact, HCV is both a cause and consequence of chronic kidney disease. According to a systematic review with meta-analysis of observational studies (n = 23 studies) (n = 574,081 patients on long-term dialysis), anti-HCV positive serologic status was an independent and significant risk factor for death in patients with advanced chronic kidney disease on long-term dialysis. The overall estimate for adjusted mortality (all-cause death risk) with HCV was 1.26 (95% CI, 1.18; 1.34) (p < 0.0001). Interferon-based therapies are biased by low efficacy/safety in chronic kidney disease, but the advent of direct-acting antiviral drugs has made a paradigm shift in the treatment of HCV-infection. These medications give interruption of viral replication because they target specific non-structural viral proteins; four classes of DAAs exist-NS3/4A protease inhibitors, NS5A inhibitors, NS5B nucleoside and non-nucleoside polymerase inhibitors. All-oral, interferon-free, ribavirin-free combinations of DAAs are now available.

AIM

The goal of this narrative review is to report the available treatment options for HCV in advanced chronic kidney disease.

METHODS

We have made an extensive review of the medical literature and various research engines have been adopted.

RESULTS

Some combinations of DAAs are currently recommended for HCV in advanced CKD (including patients on maintenance dialysis): elbasvir/grazoprevir; glecaprevir/pibrentasvir; and sofosbuvir-based regimens. Solid evidence, based on registration and "real life" studies supports their efficacy (SVR rates > 90%) and safety even in patients with advanced CKD. No dosage adjustment is necessary and treatment duration is 8-12 weeks. However, recent data highlight that many patients with advanced CKD remain untreated, and numerous barriers to antiviral treatment of HCV still exist. Whether successful antiviral therapy with DAAs will translate into improved survival in the advanced CKD population is another point of future research.

Modeling suggests that microliter volumes of contaminated blood caused an outbreak of hepatitis C during computerized tomography

BACKGROUND & AIMS

Acute hepatitis C (AHC) is not frequently identified because patients are usually asymptomatic, although may be recognized after iatrogenic exposures such as needle stick injuries, medical injection, and acupuncture. We describe an outbreak of AHC among 12 patients who received IV saline flush from a single multi-dose vial after intravenous contrast administration for a computerized tomography (CT) scan. The last patient to receive IV contrast with saline flush from a multi-dose vial at the clinic on the previous day was known to have chronic HCV genotype 1b (termed potential source, PS). Here we sought to confirm (via genetic analysis) the source of infection and to predict the minimal contaminating level of IV saline flush needed to transmit infectious virus to all patients.

METHODS

In order to confirm the source of infection, we sequenced the HCV E1E2 region in 7 CT patients, in PS, and in 2 control samples from unrelated patients also infected with HCV genotype 1b. A transmission probabilistic model was developed to predict the contamination volume of blood that would have been sufficient to transmit infectious virus to all patients.

RESULTS

Viral sequencing showed close clustering of the cases with the PS. The transmission probabilistic model predicted that contamination of the multi-dose saline vial with 0.6-8.7 microliters of blood would have been sufficient to transmit infectious virus to all patients.

CONCLUSION

Analysis of this unique cohort provides a new understanding of HCV transmission with respect to contaminating volumes and viral titers.

Health care-associated hepatitis C virus infection

Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years.

Discrepancy between serological and virological analysis of viral hepatitis in hemodialysis patients

BACKGROUND AND AIM

Viral hepatitis is a health threat for hemodialysis (HD) patients and it may be transmitted during treatment. Some patients categorized to have viral hepatitis were found to be non-viremic. To clarify the discrepancy between the serological tests in HD patients, we conducted the study.

METHODS

A total of 1681 HD patients was included. Blood samples were analyzed for hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody (anti-HCV). Detection of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA were performed in either HBsAg (+) or anti-HCV (+) samples. HBV DNA/HCV RNA was also measured in a subset of HBsAg (-) and anti-HCV (-) patients. Liver function tests were analyzed and compared with the serological and virological tests.

RESULTS

The serological tests showed that 230 patients (13.7%) were HBsAg (+) and 290 (17.3%) were anti-HCV (+). We were unable to detect HBV DNA in 97 of 230 (42.2%) HBsAg (+) patients, and HCV RNA could not be found in 76 of 290 (26.2%) anti-HCV (+) patients. In 167 HBsAg (-) patients, only one showed a trace amount of HBV DNA. None of 151 anti-HCV (-) patients showed detectable HCV RNA. The prevalence rate of viral hepatitis remains high in Taiwanese HD patients: 13.7% for HBV and 17.3% for HCV. However, virological analysis showed 42.2% non-viremic rate for HBsAg and 26.2% non-viremic rate for anti-HCV.

CONCLUSIONS

The findings might challenge the presently suggested principles of bed and machine dedication and the diagnosis of viral hepatitis in HD patients.

Effect of dialysis modality on survival of hepatitis C-infected ESRF patients

BACKGROUND AND OBJECTIVES

Hepatitis C virus (HCV) infection is associated with increased mortality and morbidity in end-stage renal failure (ESRF) patients. Despite a lower incidence and risk of transmission of HCV infection with peritoneal dialysis (PD), the optimal dialysis modality for HCV-infected ESRF patients is not known. The aim of this study was to evaluate the impact of dialysis modality on the survival of HCV-infected ESRF patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study included all adult incident ESRF patients in Australia and New Zealand who commenced dialysis between January 1, 1994, and December 31, 2008, and were HCV antibody-positive at the time of dialysis commencement. Time to all-cause mortality was compared between hemodialysis (HD) and PD according to modality assignment at day 90, using Cox proportional hazards model analysis.

RESULTS

A total of 424 HCV-infected ESRF patients commenced dialysis during the study period and survived for at least 90 days (PD n = 134; HD n = 290). Mortality rates were comparable between PD and HD in the first year (10.7 versus 13.8 deaths per 100 patient-years, respectively; adjusted hazard ratio [HR] 0.65, 95% CI 0.34 to 1.26) and thereafter (20 versus 15.9 deaths per 100 patient-years, respectively; HR 1.27, 95% CI 0.86 to 1.88).

CONCLUSIONS

The survival of HCV-infected ESRF patients is comparable between PD and HD.

Improving hand hygiene compliance rates in the haemodialysis setting: more than just more hand rubs

BACKGROUND

Haemodialysis patients are at high risk for developing healthcare-associated infections as well as acquiring multidrug-resistant microorganisms. Hand hygiene is considered to be the single most effective tool to prevent healthcare-associated infections. The number of indications and the extent of indication-specific compliance with hand rubs in the haemodialysis setting are currently unknown.

METHODS

We conducted a prospective, three-phase, observational intervention study on hand hygiene during haemodialysis treatments. Optimized hand hygiene standard operating procedures (SOPs) for dialysis connections (Intervention I) and disconnections (Intervention II) were compiled and implemented during two predefined intervention periods.

RESULTS

A total of 8897 indications for hand rubs were observed throughout this study. In the course of the study, we identified an increase in the number of hand rubs performed (6-9, mean number per dialysis procedure), parallelled by a decrease in the indications for hand rubs (21-15), resulting in a significant increase of overall hand rub compliance (30-62%). The greatest improvement was seen before aseptic tasks (21-52%), the indication with the greatest impact on preventing healthcare-associated infections. There was no difference between haemodialysis via central venous catheter access or arterio-venous (AV) fistulas.

CONCLUSIONS

This study provides the first detailed data on the number of and indications for hand rubs during dialysis. An >100% increase in overall hand hygiene compliance could be achieved by a comparably moderate increase in hand rubs performed in combination with optimized hand hygiene SOPs.