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

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.

High prevalence of hepatitis C infection among patients receiving hemodialysis at an urban dialysis center

OBJECTIVE

To determine the seroprevalence and risk factors for hepatitis C virus (HCV) infection among patients at an urban outpatient hemodialysis center.

METHODS

This was a cross-sectional study of 227 patients undergoing hemodialysis at the Rogosin Kidney Center on December 15, 1998, with a response rate of 90% (227 of 253). Laboratory records were used to retrieve the total number of blood transfusions received and serologic study results. Univariate and multivariate analyses were used to examine the relationship among HCV serostatus, patient demographics, and HCV risk factors (eg, intravenous drug use [IVDU], intranasal cocaine use, multiple sexual partners, comorbidities, length of time receiving hemodialysis, and total number of blood transfusions received).

RESULTS

The seroprevalence of antibody to HCV (anti-HCV) was 23.3% (53 of 227) in the population. In univariate analysis, factors associated with HCV seropositivity included male gender, younger age, history of IVDU, history of intranasal cocaine use, history of multiple sexual partners, human immunodeficiency virus coinfection, increased time receiving dialysis, history of renal transplant, and positive antibody to hepatitis B core antigen. Multivariate logistic regression analysis showed that longer duration receiving dialysis and a history of IVDU were the only risk factors that remained independently associated with HCV seropositivity

CONCLUSIONS

HCV is markedly more common in our urban cohort of patients receiving hemodialysis compared with patients receiving dialysis nationally and is associated with a longer duration of receiving dialysis and a history of IVDU. Stricter and more frequent enforcement of universal precautions may be required in hemodialysis centers located in areas with a high prevalence of HCV infection or IVDU among the general population.

Severe evolution of chronic hepatitis C in renal transplantation: a case control study

BACKGROUND

To evaluate the impact of kidney transplantation on histopathological progression of hepatitis C virus (HCV)-related liver disease.

METHODS

In a retrospective study, 28 HCV-positive renal transplant patients, who underwent two sequential liver biopsies with a mean of 7.1+/-4.0 years, were compared with 28 matched immunocompetent controls.

RESULTS

According to the Metavir score, the initial and final activity scores (from 0 to 3) increased from 0.2+/-0.4 to 1.4+/-1.1 (P<0.001) and those of fibrosis (from 0 to 4) from 0.5+/-0.5 to 2.0+/-1.4 (P<0.001) in the transplanted group, respectively, whereas the respective differences were not significant in the control group. The yearly progression rate of activity and fibrosis was significantly higher in the renal transplant group as compared with the immunocompetent group: 0.26+/-0.41 vs 0.01+/-0.19 (P<0.01) and 0.26+/-0.35 vs 0.05+/-0.21 (P<0.03), respectively. Twenty (71.5%) and 14 (50.0%) of the renal allograft recipients had activity and fibrosis progression as compared with four (16%) (P<0.001) and four (16%) (P<0.01) in immunocompetent patients; six kidney recipients (21.4%) evolved to cirrhosis vs only one in the control group (3.6%) (P=0.07). Liver-related mortality was significantly higher during the follow-up period in renal transplant patients than in the control group (10 vs 0%) (P<0.05).

CONCLUSION

Using conventional immunosuppressive regimen, renal transplantation is associated with a more severe evolution of chronic hepatitis C as compared with HCV-infected immunocompetent subjects. Thus, the histopathological evaluation should be performed and anti-viral therapy discussed before renal transplantation.

Hepatitis B and C and renal failure

Hepatitis C is the most common cause of liver disease in the dialysis patient. The prevalence of chronic hepatitis C determined by anti-HCV testing in this population ranges from 6% to 38%. Using second generation EIA assays, the prevalence of anti-HCV among patients participating in the 1997 National Surveillance of Dialysis Associated Diseases in the United States was 9.3%. Polymerase chain reaction testing for HCV RNA has shown that the prevalence of HCV infection can be as high as 20% to 30% of dialysis patients. The causes and source of infection in patients with chronic renal failure on hemodialysis are multiple. Before the introduction of routine screening of blood donors for anti-HCV, blood transfusions were an important risk factor for acquisition of hepatitis C. Other potential sources of infection include exposure to contaminated equipment and nosocomial routes such as patient-to-patient exposure. The risk of infection appears to correlate with the duration of hemodialysis and the number of transfusions. Interestingly, dialysate and buffers have been shown to be virus free even when used in hepatitis C infected patients. The natural history of chronic hepatitis C infection in patients with renal failure is not well characterized. Although persistent elevations in ALT levels occur in 12% to 50% of dialysis patients, the frequency of persistently normal ALT levels in HCV-infected dialysis patients appears to be higher than in HCV-infected patients without renal failure. Overt liver disease and liver failure rarely occur. The degree of inflammation in liver biopsies of renal failure patients is usually mild. Thus, progressive liver disease may be less common in patients with advanced renal disease but further studies are required to assess the true impact of hepatitis C infection in this high risk population. The impact of hepatitis C infection on morbidity and mortality of patients with end-stage renal disease remains poorly defined. Initial studies have failed to show a significant increase in mortality among HCV-infected hemodialysis or renal transplant patients within the first 5 years following transplantation. In contrast, recent studies with extended follow-up of renal transplant recipients suggest that hepatitis C infection may affect patient and graft survival during the second decade. Further studies are required to identify the mechanisms of infection of patients with end-stage renal disease and to define better treatment strategies for these patients before and after kidney transplantation.

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.

Phylogenetic investigation for the risk of hepatitis C virus transmission to surgical and dental patients

Blood loss during treatment carries a potential risk for the transmission of blood-borne pathogens in hospital patients. To determine whether nosocomial transmission of hepatitis C virus (HCV) occurs in surgical wards and dental hospitals, we tested anti-HCV antibodies and HCV RNA in sera from these patients and analysed the hypervariable region 1 (HVR1) sequence of HCV phylogenetically in the HCV RNA-positive patients. Five of 83 patients from a surgical ward were positive for HCV RNA, and six patients from one dental hospital and nine patients from a second were found to be positive for HCV RNA during the examination period. The HVR1 sequences were amplified from these patients' serum, and after subcloning, multiple clones of the HVR1 sequence from each patient were determined. The phylogenetic analysis of these sequences showed that HVR1 species from each patient could be classified into one to three genetic clusters of HVR1 quasi-species and that these clusters were independent of each other among patients. Thus, there was no evidence of HCV transmission in our study, and unrecognized transmission of HCV may be a rare event in surgical and dental patients at university hospitals.

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

Since the cloning of hepatitis C virus (HCV), a number of serologic and virologic tests for detecting infections with this virus have been made available for clinical practice. This led to the recognition of HCV as a major health hazard in hemodialysis (HD) centers. Yet the nephrology community has not been offered explicit recommendations about routine serologic testing for HCV of dialysis patients and consequently has remained unclear and divided about the utility of this testing. This review presents evidence in support of instituting routine serologic testing for HCV among dialysis patients. It concludes that because of the peculiar features of HCV infection in HD patients, serologic testing for HCV is the only means for unequivocal diagnosis of hepatitis C and an irreplaceable instrument for monitoring the incidence and the prevalence of the infection in this population. Serologic surveillance for HCV infection is crucial for identifying the association of new cases of HCV infection with potential risk factors for HCV transmission, particularly nosocomial, that can be modified in a way to prevent further dissemination of the virus. Data collected from routine serologic testing for HCV will undoubtedly improve our understanding of the epidemiology of HCV in the dialysis population and will provide a strong foundation for developing preventive measures and infection control strategies that are highly effective in controlling HCV infection. Routine serologic testing for HCV is also of direct benefit to the individual patient since establishing the HCV serologic status of each patient is important for optimizing patient care.

[Incidence hepatitis C virus seroconversion after the implementation of a prevention and control program at a hemodialysis unit]

This study aimed at reporting the incidence of the hepatitis C virus as well as the prevention and control measures adopted in an hemodialysis unit. It is a prospective study developed with patients attended from September 1996 to December 1998 in an hemodialysis unit. The consultations from September 1996 to December 1996 were considered the control group and the ones from January 1997 to December 1998 the intervention group. Regarding the period of the control group, the routine of the unit was organized based on the regulation 2042 that systematizes the services of renal therapy. In the subsequent period, complementary measures were implemented. From 1997 to 1998, authors observed the reduction in the number of cases of hepatitis C.

Occasional infection of hepatitis C virus occurring in haemodialysis units identified by serial monitoring of the virus infection

To examine whether hepatitis C virus (HCV) infection still occurs in haemodialysis units even after a decrease in the number of blood transfusions and in those contaminated with HCV, we tested anti-HCV antibodies and HCV RNA in 142 patients from Japanese haemodialysis units, and examined the serial prevalence of anti-HCV antibodies in 86 patients from 1992 to 1997. A high prevalence of HCV infection was observed: 34 (23.9%) and 38 (26.8%) of the 142 patients were positive for serum anti-HCV antibodies and HCV RNA, respectively. These positive rates were related to the duration of haemodialysis. We found that five patients treated in the same unit seroconverted from 1993 to 1995. Four of the five patients had been treated at the same shift and were affected at the same time. Phylogenetic analysis of the hypervariable region 1 (HVR1) sequence of HCV from serum of these patients showed that three of the four patients' sequences were phylogenetically clustered and that two of the three were closely related. Thus, an occasional transmission of HCV occurred in the haemodialysis unit. The universal precautions by staff such as carefully changing gloves may be important in inhibiting spread of HCV because no instances of infection have been seen since the instigation of educational measures for unit staff.

Nosocomial transmission of hepatitis C virus

Nosocomial transmission of hepatitis C virus (HCV) may occur in a variety of circumstances. This problem is best characterised in haemodialysis units. In this setting, molecular analysis of viral isolates indicates that patient to patient is the most frequent mode of HCV transmission. Spreading of HCV is mainly related to non-strict observance of universal precautionary measures, which are an efficient and, possibly, sufficient means for prevention. Epidemics or single instances of patient-to-patient transmission have only occasionally been reported in hospital settings other than haemodialysis units, and, again, non-observance of universal precautionary measures, or inadequate cleaning or disinfecting of medical instruments was involved. Transmission from an infected surgeon to patients has been reported, but infection from doctors to patients seems to be exceptional. Thus, although prospective studies have not been performed, nosocomial transmission of HCV unrelated to haemodialysis appears to be an infrequent and preventable event.

Counselling patients with hepatitis C

Hepatitis C virus (HCV) is usually but not exclusively transmitted by the parenteral route. Some precautions are recommended for infected patients as well as his/her close contacts and family members. The risk of sexual transmission and from household contacts is very low. Use of condoms is only recommended in cases of multiple partners and for those at high risk of transmission. Some personal objects should not be shared, i.e. razors, toothbrushes and nail clippers, but it is not necessary to avoid sharing eating utensils. Sexual partners may be tested for anti-HCV HCV-positive individuals should refrain from donating blood, organs and tissue. Clear and evidenced-based information should be provided to patients as to the means of prevention with special attention to individual risk groups such as IV drug abusers. The risk of HCV transmission after needlestick injury, although low, justifies universal precaution measurements for health-care workers. Nosocomial transmission has been described after medical procedures, especially haemodialysis and endoscopy. Thus, disinfection procedures as well as universal precautions are essential for all health-care workers. It is also important for HCV patients to inform health-care workers beforehand about their HCV status. Perinatal transmission is rare and is usually related to the degree of maternal viral load. Pregnancy is not contra-indicated in HCV. infected individuals and breast-feeding is allowed. Finally, HCV patients with active disease should be advised to refrain from alcohol intake, especially during antiviral therapy. After HCV infection it is necessary to consider not only diagnostic and therapeutic steps but also the risk of transmission in the patient's circle and consequences for the patient.