Environmental transmission of hepatitis B and hepatitis C viruses within the hemodialysis unit

HEPATIC ALTERATIONS IN KIDNEY TRANSPLANT RECIPIENTS FROM THE LARGEST KIDNEY TRANSPLANT CENTER IN BRAZIL

ABSTRACT Background Kidney transplant is the treatment of choice for patients with end-stage renal disease and is associated with lower mortality when compared to dialysis methods. Brazil is the country with the second largest number of kidney transplants in the world and among these patients it has been observed that liver abnormalities are common. The frequency of liver abnormalities ranges from 20-50% post-transplantation, and have an important impact on the survival and quality of life of these patients. There are scarce data about the frequency, causes and characteristics of these alterations. Objective To determine the prevalence of the different causes of hepatic abnormalities in kidney transplant recipients, to associate the characteristics of these abnormalities with demographic, epidemiological and clinical variables, to compare the characteristics of hepatic alterations between different etiologies, and to evaluate possible changes in diagnosis over two different periods of time. Methods Descriptive, cross-sectional observational, epidemiological study was conducted at the outpatient “Hepato-Rim”clinic of Hospital São Paulo (EPM/UNIFESP), a center providing specialized care for patients with hepatic abnormalities and underlying kidney diseases. Results Five-hundred eighty-one transplant patients were evaluated. The most prevalent etiologies of liver abnormalities were hepatitis C and B, iron overload, nonalcoholic fatty liver disease (NAFLD), and drug-induced liver injury (DILI). The most common cause — hepatitis C — was analyzed in greater detail. Compared to the other causes, this infection was more frequent in older patients, female patients, and patients with a longer time since transplantation and hemodialysis. Analysis of the two periods showed that patients of period 1 (P1 — 1993 to 2005) were older and were more frequently referred because of positive serology; referral due to aminotransferases abnormalities predominated during period 2 (P2 — 2006 to 2018). The predominant diagnoses were hepatitis C and B during P1 and NAFLD and DILI during P2. Conclusion Assessment of the main hepatic alterations in kidney transplant recipients is important because it permits better management of these patients in terms of diagnostic investigation and treatment and contributes to the prevention of complications in this special population.

Prevention of Nosocomial Transmission of Hepatitis C Infection in a Hemodialysis Unit. A Prospective Study

Hepatitis C virus (HCV) infection in hemodialysis patients can be transmitted by transfusions and nosocomially. A high prevalence of HCV infection, over 50%, was demonstrated in our hemodialysis (HD) unit. In order to prevent the nosocomial spread of HCV infection in the HD unit a prospective study was begun separating anti-HCV positive patients from the negative ones. A total of 170 patients (83 anti-HCV positive) started this study in September 1994 and were followed for 4 years. A separate room and dedicated equipment were assigned to anti-HCV positive and anti-HCV negative patients. Of those 170 patients there were 15 hepatitis B virus (HBV) positive patients, 5 of whom were anti-HCV positive, who were treated in a separate room on dialysis equipment for anti-HCV positive or negative patients. Application of general precautions, as recommended by the Center for Disease Control and Prevention (CDC), was reinforced. During the first 12 weeks after implementing the precautions seven more anti-HCV positive patients were detected, and by December 1995 another two HCV infected patients were found. The follow-up included all changes in HD population treated until the end of 1998. The incidence of seroconversion to HCV was 12.9% in 1995, 7.1% in 1996, 5.0% in 1997, and 6.6% in 1998. The higher incidence of seroconversion in September to November 1994 was probably due to the nosocomial infection being in the incubation period at the time of isolation.

This prospective study in a large HD unit with a high prevalence of HCV infection demonstrates a relatively successful prevention of HCV spread. Procedure-related transmission of HCV in hemodialysis could be prevented by rigorous application of universal precautions as recommended by the CDC. As a second line of prevention, in highly burdened dialysis centers, segregation of HCV positive patients can help control nosocomial transmission.

De novo HBV infection in a Mayo Clinic hemodialysis population: economic impact of reduced HBV testing and a call for changes in current US CDC guidelines on HBV testing protocols

Hemodialysis (HD) exposes end-stage renal disease patients to significantly higher risks for Hepatitis B Virus (HBV) infection, a major public health scourge. Therefore, current US CDC guidelines, last revised in 2001, call for monthly HbsAg tests. The charge to Medicare per HbsAg test is $100. In an economic analysis, we hypothesized that in the new environment of Medicare Fee Bundling, this is unwise and wasteful if de novo HBV infection rate among HD patients is <1%. We determined de novo HBV infection rate among a Mayo Clinic HD cohort, July 2000-July 2010. A retrospective analysis of all relevant medical records of the cohort was completed to identify de novo HBV infection. Nine hundred sixty-five HD patients were analyzed. One case of de novo HBV infection was identified in a 54-year old known IV drug user, a previous Hepatitis C carrier. This translates to a de novo HBV case incidence rate of 0.1%. De novo HBV infection among HD patients in the US, 2000-2010, is only 0.1%. In the early 1970s, rates were as high as 30%. We recommend 3-monthly HbsAg testing, but to continue current monthly testing for IV drug users and other high-risk groups. Huge cost savings would result, without any compromise of quality outcomes. With over 500,000 HD patients, this represents a mind-boggling $40 billion savings in Medicare charges over 10 years. The US CDC should revise these outdated guidelines, last revised in 2001, to fall in line with current clinical realities on the ground.

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.

Clinical significance of antibody to hepatitis B core antigen in multitransfused hemodialysis patients

BACKGROUND

In spite of the progress made in the prevention of transfusion transmitted infections over the last few years, transmission of HBV infection through transfusion of HBsAg negative blood has been documented.

OBJECTIVES

To assess the frequency and clinical significance of anti-HBc in multitransfused hemodialysis patients.

MATERIALS AND METHODS

One hundred and forty-three hemodialysis patients who had been receiving blood regularly with an average of 39.4 +/- 7.579 months on hemodialysis were enrolled in this study. HBV markers (HBsAg, anti-HBc, anti-HBs) were measured in these patients and in 100 healthy controls by the ELISA technique. The following data were obtained for all patients: socio demographic data, number of blood transfusions and some laboratory investigations.

RESULTS

In our patients, anti-HBc was positive in 9%, anti HBs in 7%, coexistant HbsAg/anti-HBc in 2.8% and anti HBc/anti HBs in 18.9%, meanwhile no patients were positive for HBsAg alone. In patients with only positive anti-HBc, the levels of anti-HBc were significantly related to abnormal results of liver function. In patients with positive anti-HBs/anti-HBc (n = 27), 18 patients had abnormal liver function, and 9 patients had normal liver function with no significant difference between them.

CONCLUSIONS

This study suggests that hepatitis B prevalence in our multitransfused hemodialysis patients is far in excess of that anticipated on the basis of HBsAg prevalence. Absence of HBsAg in the blood of hemodialyzed patients may not be sufficient to ensure lack of circulating HBV, and isolated positivity of anti-HBc may be a possible indicator of active hepatitis B infection.

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.

Hepatitis C among predialysis patients: prevalence and characteristics in a large cohort of patients

BACKGROUND

The factors associated with hepatitis C virus (HCV) infection in predialysis patients need to be better investigated. The aims of this study were to evaluate the prevalence, risk factors, clinical, biochemical and virological characteristics of chronic HCV infection in predialysis patients.

METHODS

Anti-HCV antibodies were determined in a large cohort of predialysis patients. Epidemiological and laboratorial characteristics of HCV infection were evaluated in predialysis patients and this group was matched to a control group consisting of predialysis patients without viral infection (1:3) and compared in terms of risk factors and alanine aminotransferase (ALT) levels. Logistic regression analysis was applied to identify variables independently associated with chronic HCV infection.

RESULTS

A total of 1,041 patients (61% males) with a mean age of 61 +/- 15 years and mean creatinine clearance of 36 +/- 18 ml/min were included. Forty-one (3.9%) patients were anti-HCV positive and, of these, 39 (95%) presented viremia. Predialysis patients with HCV more frequently showed a history of blood transfusion before 1992 (66.7 vs. 10.3%; p < 0.001) and major surgeries (53.8 vs. 17.1%; p < 0.001), a higher proportion of undetermined etiology of kidney disease (43.6 vs. 17.1%; p = 0.001), and higher ALT levels (1.3 vs. 0.4 xULN; p < 0.001). History of blood transfusion before 1992 (p < 0.001; OR: 19), intravenous drug abuse (p = 0.002; OR: 69) and ALT levels (p < 0.001; OR: 50) were the variables that were independently associated with chronic HCV infection. The accuracy of ALT in detecting HCV infection was 92%. The most prevalent HCV genotype was 1b (48.7%) and 56.5% of patients presented high HCV viral load.

CONCLUSION

Chronic HCV infection among predialysis patients is related to increased parenteral exposure. Elevated ALT levels suggest the need for HCV screening as part of the predialysis care since ALT seems to be a good marker of this infection.

Gamma glutamyltranspeptidase activity and viral hepatitis in dialysis population

BACKGROUND

Numerous investigations have reported that viral hepatitis is associated with significant hepatocellular damage, as expressed by raised aminotransferases in serum, in dialysis population. However, scarce information exists on the activity of gamma glutamyltranspeptidase (GGTP) in dialysis patients with infection by hepatotropic viruses.

OBJECTIVES

We measured serum GGTP values in a large cohort (n=757) of patients receiving long-term dialysis; healthy controls were also included. The relationship between GGTP values and a series of demographic, clinical, and biochemical parameters was analyzed.

METHODS

Serum GGTP levels were tested by spectrophotometry. A subset (n=333) of dialysis patients was tested by molecular technology (branched-chain DNA (bDNA) assay) to evaluate the relationship between serum GGTP and HCV viremia. A subgroup (n=78) of dialysis patients was analyzed by an ultrasound scan of gallbladder and biliary tract to assess the presence of gallstone disease. Multivariate analyses were made using regression models; serum GGTP values were included as a dependent variable. The usefulness of serum GGTP levels in detecting HBsAg and anti-HCV positivity was evaluated using receiver operating characteristics (ROC) curve analysis.

RESULTS

Univariate analysis showed that serum GGTP levels were significantly higher in HBsAg positive and/or anti-HCV positive patients than in HBsAg negative/anti-HCV negative patients on dialysis; 85.1+/-184.1 versus 25.86+/-23.9 IU/l (P=0.0001). The frequency of raised GGTP levels was 22.2% (41/184) among dialysis patients with chronic viral hepatitis. Multivariate analysis showed a significant and independent association between serum GGTP values and positive HBsAg (P=0.005) and anti-HCV antibody (P=0.0001) status. Mean GGTP values were significantly higher in study patients than controls, 32.32+/-60.02 versus 23.5+/-16.92 IU/L (P=0.01); however, no significant difference with regard to GGTP between study and healthy cohorts persisted after correction for age, gender, race, and viral markers. No relationship between gallstone disease and serum GGTP was found (NS). An independent and significant association (P=0.0291) between raised GGTP levels and detectable HCV RNA in serum was noted among patients tested by biology molecular techniques. ROC technology demonstrated that GGTP was equally useful for detecting HBV (P=0.0004) and HCV (P=0.0005) among dialysis patients.

CONCLUSIONS

We found an independent and significant association between serum GGTP values and HBsAg and/or anti-HCV antibody in dialysis population. Twenty-two percent of dialysis patients with chronic viral hepatitis had elevated GGTP. No difference in GGTP between HBsAg- negative/anti-HCV- negative dialysis patients and healthy individuals was found. Routine testing for serum GGTP levels to assess liver disease induced by hepatotropic viruses or other agents in dialysis population is suggested.

Hepatitis C in chronic kidney disease: predialysis patients present more severe histological liver injury than hemodialysis patients?

BACKGROUND

The characteristics of hepatitis C virus (HCV) infection in predialysis patients are poorly understood and they could be different from hemodialysis patients.

AIMS

To evaluate the demographics, laboratory and histological characteristics of chronic HCV infection in predialysis patients and to compare them with those observed in hemodialysis patients.

METHODS

Thirty-nine predialysis patients with chronic HCV infection were compared to HCV-infected hemodialysis patients (ratio of 1:3) in terms of demographics, laboratory and histological characteristics. The fibrosis progression rate (FPR) was calculated as the ratio between fibrosis stage and duration of infection.

RESULTS

Predialysis patients were older (57 +/- 10 vs. 45 +/- 12 years; p < 0.001), presented a higher proportion of elevated alanine aminotransferase (71.8 vs. 41.0%; p = 0.001) and aspartate aminotransferase (64.1 vs. 26.5%; p < 0.001), a higher proportion of interface hepatitis (66.7 vs. 47%; p = 0.033) and more advanced fibrosis (71.8 vs. 16.2%; p = 0.001). Among patients with estimated duration of infection, predialysis patients presented a longer duration of infection (22 vs. 6 years; p < 0.001) and no difference in FPR was observed between groups (p = 0.692).

CONCLUSION

Although predialysis patients with HCV infection present more severe histological injury than hemodialysis patients, this finding probably reflects a longer duration of infection with no evidence supporting that hepatitis C presents a more aggressive course in this group.

Hepatitis C virus antibodies and other markers of blood-transfusion-transmitted infection in multi-transfused Cuban patients

BACKGROUND

HCV was initially identified in 1989 when it was found to be the primary causative agent of non-A, non-B hepatitis,a condition associated with high rates of progressive and end-stage liver disease, cirrhosis, and hepatocellular carcinoma. Since then, appreciation of the significant worldwide health impact of HCV infection has grown. HCV infection was identified as a public health problem in Cuba in the 1990s. Despite universal blood donor screening, which was achieved in 1995 using the Cuban immunoassay system UMELISA HCV, the infection is still found in multi-transfused patients.

OBJECTIVES

To determine the magnitude of HCV, HBV and HIV-1&2 infections among Cuban blood recipients and to assess the role of potential risk factors.

STUDY DESIGN

Cross-sectional study of 318 patients from Havana City, Pinar del Río and Villa Clara, who had been previously treated with 10 or more units of allogenic blood or blood components in at least two different occasions. The patients were evaluated for HCV Ab, HBsAg, anti-HBc Ab, and HIV-1&2 Ab. Data management and statistical analysis were performed using EpiInfo and SSPS software.

RESULTS

Prevalence rates were 51.6% for HCV Ab; 5.3% for HBsAg; 45.0% for anti-HBc and 0% for HIV-1&2 Ab. Ten (3.1%) patients were co-infected with HCV and HBV Blood transfusion was not identified as the main risk factor for HCV transmission. The number of blood units received by the patients was not statistically associated with the HCV Ab prevalence.

CONCLUSIONS

Infection with HCV was identified more frequently than HBV and HIV among our study population. Patients undergoing hemodialysis were at the highest risk of becoming infected. Medical procedures including surgery, transplantation, invasive odontology, and sharing or reuse of needles and syringes, are associated with higher HCV Ab seroprevalences compared with blood transfusion alone.

Influence of hepatitis B virus virema upon serum aminotransferase activity in dialysis population

BACKGROUND

The control of the spread of hepatitis B virus (HBV) infection within dialysis units has been one of the major advances in the management of patients with end-stage renal disease (ESRD). However, clinical and biochemical expression of HBV in dialysis patients have not been adequately addressed. Elevated values of serum aminotransferase activity are a sensitive measure of hepatocellular injury, but the role of HBV infection in the development of liver disease among dialysis patients has not been adequately analysed. Also, the clinical impact related to the virological characteristics of HBV in dialysis has not been evaluated.

METHODS

Demographic, biochemical and virological data from 727 patients undergoing chronic dialysis in seven dialysis units in northern Italy were collected in order to assess the biochemical consequences related to the presence of HBV infection in this population. We have measured by RT-PCR technology the titers of HBV viremia in HBsAg positive patients receiving dialysis.

RESULTS

Univariate analysis showed that AST and ALT values were significantly higher in HBsAg positive/HBV DNA positive than HBsAg negative patients on dialysis; AST, 22.86+/-31.34 vs. 14.19+/-9.7 IU/L (P=0.00001); and ALT, 25.07+/-41.59 vs. 13.9+/-41.59 IU/L (P=0.00001). In the subgroup of HBsAg positive patients, the frequency of detectable HBeAg in serum was 14.9% (7/47). The median value of HBV DNA in patients with detectable HBV DNA in serum was 2.160 x 10(3) copies/mL (range, 2.5 x 10(2)-4 x 10(6) copies/mL). HBsAg positive/HCV positive patients had higher aminotransferase activity than other subgroups (P=0.0001). Multivariate analysis showed a significant and independent association between detectable HBsAg/HBV DNA in serum and AST (P=0.00001) and ALT (P=0.0001) activity AST and ALT levels were lower in dialysis than healthy individuals--this finding persisted in age- and gender-matched comparisons.

CONCLUSIONS

The HBV viral load in HBsAg positive patients receiving maintenance dialysis is not high. HBsAg positivity with detectable HBV DNA in serum is a strong and independent predictor of raised aminotransferase activity among dialysis patients. HBsAg positive patients had greater aminotransferase activity than HBsAg negative individuals even if both the groups had mean aminotransferase levels within the normal range considered for healthy population. Clinical trials aimed at identifying the best cut-off value to enhance the diagnostic yield of AST/ALT for detecting HBV in dialysis population are under way.

Hepatitis B virus infection in Haemodialysis Centres from Santa Catarina State, Southern Brazil. Predictive risk factors for infection and molecular epidemiology

BACKGROUND

Patients under haemodialysis are considered at high risk to acquire hepatitis B virus (HBV) infection. Since few data are reported from Brazil, our aim was to assess the frequency and risk factors for HBV infection in haemodialysis patients from 22 Dialysis Centres from Santa Catarina State, south of Brazil.

METHODS

This study includes 813 patients, 149 haemodialysis workers and 772 healthy controls matched by sex and age. Serum samples were assayed for HBV markers and viraemia was detected by nested PCR. HBV was genotyped by partial S gene sequencing. Univariate and multivariate statistical analyses with stepwise logistic regression analysis were carried out to analyse the relationship between HBV infection and the characteristics of patients and their Dialysis Units.

RESULTS

Frequency of HBV infection was 10.0%, 2.7% and 2.7% among patients, haemodialysis workers and controls, respectively. Amidst patients, the most frequent HBV genotypes were A (30.6%), D (57.1%) and F (12.2%). Univariate analysis showed association between HBV infection and total time in haemodialysis, type of dialysis equipment, hygiene and sterilization of equipment, number of times reusing the dialysis lines and filters, number of patients per care-worker and current HCV infection. The logistic regression model showed that total time in haemodialysis, number of times of reusing the dialysis lines and filters, and number of patients per worker were significantly related to HBV infection.

CONCLUSIONS

Frequency of HBV infection among haemodialysis patients at Santa Catarina state is very high. The most frequent HBV genotypes were A, D and F. The risk for a patient to become HBV positive increase 1.47 times each month of haemodialysis; 1.96 times if the dialysis unit reuses the lines and filters > or = 10 times compared with haemodialysis units which reuse < 10 times; 3.42 times if the number of patients per worker is more than five. Sequence similarity among the HBV S gene from isolates of different patients pointed out to nosocomial transmission.

[Prevalence and associated factors to hepatitis C in hemodialysis patients in Brazil]

OBJECTIVE

The prevalence of hepatitis C virus (HCV) is higher in patients on hemodialysis than in the general population, probably due to greater exposure to risk situations. The purposes of the study were to determine anti-HCV antibodies prevalence among hemodialysis patients and dialysis clinics and patients factors associated with HCV transmission.

METHODS

A cross-sectional study was conducted in 752 hemodialysis patients in all 12 dialysis clinics of Fortaleza, Brazil, and were screened using third generation ELISA. Sociodemographic, clinical, and epidemiological data of 663 patients were collected through interviews. Nosocomial factors were assessed using a specific questionnaire tool. Statistical analysis was conducted using Student's t test, odds ratio and multivariate analysis.

RESULTS

The prevalence of anti-HCV was 52% (390/746; ranged from 6% to 72%). The anti-HCV positivity was higher in patients who had previous peritoneal dialysis (OR=1.76; 95% CI 1.12-2.76) and blood transfusion (OR=2.75; 95% CI 1.25-6.03). Dialysis age has been associated with anti-HCV positivity (OR=1.47; 95% CI 1.35-1.61). Clinics practices associated with anti-HCV positivity were: previous preparing of heparin (OR=2.92; 95% CI 1.23-6.92), failure in gloves use or change (OR=5.73; 95% CI 1.75-18.72), unsatisfactory dialysis machine disinfection (OR=2.79; 95% CI 1.57-4.96), and patient isolation in dialysis room (OR=0.18; 95% CI 0.05-0.61).

CONCLUSIONS

The results show high anti-HCV prevalence among hemodialysis patients and the association of nosocomial factors with new HCV infection cases.

Patterns of hepatitis B prevalence and seroconversion in hemodialysis units from three continents: the DOPPS

BACKGROUND

Hepatitis B (HBV) historically has been a public health issue within hemodialysis units. This study estimates HBV prevalence and seroconversion rates across seven countries and investigates associations with facility level practice patterns.

METHODS

The study sample was from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a cross-sectional, prospective, observational study of adult hemodialysis patients randomly selected from 308 dialysis facilities in France, Germany, Italy, Spain, the United Kingdom, Japan, and the United States. Logistic regression was used to model the odds ratio (OR) of HBV prevalence, and Cox regression was used to model time from entry into the study to HBV seroconversion.

RESULTS

In this sample, mean HBV facility prevalence was 3.0% with a median of 1.9%. The percentage of facilities with an HBV prevalence 0% to 5% was 78.5%. Adjusted HBV prevalence was higher in France, Germany, and Italy and lower in Japan and the United Kingdom. The majority of facilities (78.1%) had a seroconversion rate of 0 conversions per 100 patient-years. Presence of a protocol for HBV-infected patients was significantly associated with HBV seroconversion in the separate practice pattern model [risk ratio (RR) = 0.52, P = 0.03] and in the combined practice pattern model (RR = 0.44, P = 0.01).

CONCLUSION

There are differences in HBV prevalence and rate of seroconversion both at the country and the hemodialysis facility level. Presence of a protocol for HBV-infected patients was strongly and significantly associated with decreased risk for seroconversion. The observed variation suggests opportunities for improved HBV outcomes with further definition of optimal practice patterns at the facility level.

Hepatitis B virus transmission in Brazilian hemodialysis units: serological and molecular follow-up

A serological and molecular study of hepatitis B virus (HBV) infection was carried out in dialysis units in Central Brazil. Between 1995 and 1999, serum samples from all HBsAg-positive hemodialysis patients (n = 43) were tested for HBeAg/anti-HBe and subtyping by monoclonal ELISA. HBV DNA was detected by PCR and positive samples were genotyped by restriction fragment polymorphism pattern (RFLP) methodology. TheHBsAg prevalence declined in this population during the survey period (12-5.8%). HBeAg and anti-HBe were detected in 23 (53.5%) and 18 (41.9%) sera, respectively. Thirty-six samples could be HBsAg subtyped: 21 were subtype ayw(3), 14 belonged to adw(2) and one was identified as adw(4). HBV DNA was present in 30 serum samples. Of these, 20 (66.7%) were genotype D, 9 (30%) genotype A, and 1 (3.3%) genotype F. In addition, the RFLP pattern could be determined in samples from 18/20 genotype D patients: D3 (10 strains), D7 (7 strains) and D4 (1 strain); from 8/9 genotype A patients: A1 (6 strains) and A3 (2 strains); and from the patient infected with genotype F: F1. Patterns D3 and D7 were associated closely with HBV infection in the two largest hemodialysis units studied. These findings confirm the value of the RFLP method as an effective molecular epidemiological tool for elucidating HBV transmission in hemodialysis units.

Implications for the role of endogenous nitric oxide inhibitors in hemodialysis hypotension

Hypotensive episodes during hemodialysis in patients with end-stage renal disease in the absence of inadequate maintenance of the plasma volume, pre-existence of cardiovascular disease, or autonomic nervous system dysfunction is accompanied by increase in the plasma concentrations of the end-products of nitric oxide metabolism, above the levels expected based on the reduction of urea. Factors that can influence the synthesis of nitric oxide or the regulation of the effects of this free radical in patients with chronic renal failure are reviewed. Convergence of these factors and their interactions during the hemodialysis procedure are discussed as the basis for the generation of excessive amounts of nitric oxide that serves as an important contributing factor in the development of symptomatic hypotension.

Prognosis of anti-hepatitis C virus antibody-positive patients on regular hemodialysis therapy

The prevalence of hepatitis C virus (HCV) infection is high in patients who are on chronic hemodialysis, but the role of HCV infection and HCV-related liver disease in the mortality of these patients has not been shown. Therefore, we conducted a prospective cohort study of 1470 patients who were on chronic hemodialysis (17 to 89 yr old) from 16 dialysis centers in Japan. Among them, 276 patients (18.8%) were positive for anti-HCV antibodies and 1194 patients were negative. The patients were followed for 6 yr from 1993 to 1999. Only one case, a patient from the anti-HCV-antibody-positive group, was lost to the follow-up during this period. The mortality was higher in the anti-HCV-antibody-positive group (91 of 276 patients died) than in the anti-HCV-antibody-negative group (277 of 1193 died) (33.0% versus 23.2%, P< 0.01). A Cox proportional hazard examination showed that positivity for anti-HCV antibodies was one of the risk factors for death with an adjusted relative risk of 1.57 (95% confidence interval, 1.23 to 2.00). As a cause of death, hepatocellular carcinoma and liver cirrhosis were significantly more frequent in the anti-HCV-antibody-positive patients than in the anti-HCV-antibody-negative patients (5.5% versus 0.0%, P< 0.001; 8.8% versus 0.4%, P< 0.001, respectively). These findings show that the mortality is increased in anti-HCV-antibody-positive patients who are on chronic hemodialysis. Hepatocellular carcinoma and liver cirrhosis are factors that may influence the mortality.

Hepatitis B virus: genotypes and subtypes in Brazilian hemodialysis patients

There are no data concerning the genotypic analysis of hepatitis B virus (HBV) infection in Brazilian dialysis centers. Serum samples from all hemodialysis patients (n = 282) in Goiânia City, Central Brazil, were tested for hepatitis B surface antigen (HBsAg). An overall prevalence of 12.0% was found, ranging from 0 to 33.3% depending on dialysis centers. Positive samples (n = 34) were submitted to serological subtyping by monoclonal ELISA and HBV DNA detection by polymerase chain reaction (PCR). Among 30 PCR-positive samples, 26 were genotyped by use of the line probe assay technology (INNO-LiPA HBV, Innogenetics, Gent, Belgium). HBV genotypes A (50. 0%) and D (46.2%) were the most frequently found whereas genotype F (3.8%) was rare in this population. Serological subtypes adw2 (44. 1%) and ayw3 (41.2%) were dominant. By contrast, adw4 and ayw2 were found at a low frequency (2.9%). A correlation was observed in the distribution of genotypes and subtypes by dialysis center. Genotype D and subtype ayw3 were predominant in 2 hemodialysis centers whereas genotype A and subtype adw2 were predominant in the others. The findings of high HBsAg prevalence rates restricted to certain dialysis centers and the data obtained through genotyping and serological subtyping suggest HBV nosocomial transmission in these hemodialysis centers.

[Detection of hepatitis C virus antibodies in a pool of 5 sera: their use in seroepidemiologic studies]

In order to evaluate the reduction in the cost of testing for antibodies against hepatitis C (EIA) by the pool method, we tested serum samples from a rural population and from patients in a hemodialysis program. Two thirds of the high risk groups were positive. Pooling reduced the reagent use by 80% in the rural population and by 13% in the hemodialysis patients. We conclude that pool testing reduces the cost of anti-HCV detection in low-risk groups.

Validation of self-reported transfusion histories in renal dialysis patients

The purpose of this analysis was to assess the validity of self-reported transfusion histories in dialysis patients. Using data from a cross-sectional study of a dialysis population being investigated for hepatitis C virus (HCV) infection, the correspondence between self-reported transfusion history and transfusion records was explored. Demographic data and dialysis histories were examined in relation to the accuracy of self-reports. Overall, the questionnaire data and the blood bank records agreed for 89% of participants. The Kappa statistic was 0.72 (95% CI: 0.61, 0.83) indicating an acceptable level of agreement. The effect of non-differential exposure misclassification on the risk estimates for transfusion history as a determinant of HCV infection is demonstrated. Exploring the discrepancies between self-reports and documented transfusion histories underlines the need to communicate clearly medical interventions in chronically ill patients. Additionally, it suggests that studies into transfusion-acquired blood-borne pathogens should use all available information sources to establish exposure.

Hepatitis C virus infection in dialysis: a continuing problem

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

Hepatitis C virus seroconversion and genotype prevalence in patients and staff on chronic hemodialysis

The prevalence of hepatitis C virus (HCV)-RNA positivity among hemodialysis patients varies between 10 and 70%. Few previous surveys revealed high frequency of seroconversion of HCV-RNA-negative patients over the years of hemodialysis. Only few studies reported HCV genotype variability. We evaluated all 65 patients on chronic hemodialysis in our dialysis unit. All sera positive to anti-HCV on ELISA were retested by reverse transcriptase polymerase chain reaction to HCV-RNA. Sixteen patients were found anti-HCV positive on ELISA, and 8 of them were also PCR positive. Three of these eight patients seroconverted during the year 1995. Four patients had both 1a and 1b genotypes of HCV, coexistence of genotypes 1b and 4a in one patient and genotypes 1a, 1b and 2a in the remaining three patients. Mean serum aminotransferase, duration of dialysis, and number of blood units transfused were significantly higher in the HCV-PCR-positive patients compared with the HCV-PCR-negative patients. Because strict isolation methods were initiated at the end of 1995, not one new case of HCV among dialysis patients was found in 1998, although new hemodialysis patients were diagnosed as having HCV. In conclusion, genotypes 1a and 1b, as is true for the general population in Israel, were also the predominant genotypes among hemodialysis patients; the coexistence of more than one genotype is common among hemodialysis patients; seroconversion is common among these patients and strict isolation methods are efficient and should be recommended.

Hepatitis B virus infection profile in central Brazilian hemodialysis population

Hepatitis B has proved to be a major health hazard in hemodialysis patients. In order to investigate the hepatitis B virus (HBV) infection profile in the hemodialysis population of Goiânia city--Central Brazil, all dialysis patients (N = 282) were studied. The prevalence of any HBV marker (HBsAg, anti-HBs, and anti-HBc) was 56.7% (95% CI: 51.1-62.7), ranging from 33.3% to 77.7% depending on dialysis unit. HBV-DNA was detected in 67.6% and 88.2% of the HBsAg-positive serum samples, in 91.3% and 100% of the HBsAg/HBeAg-positive samples, and in 18.2% and 63.6% of the HBsAg/anti-HBe-reactive sera by hybridization and PCR, respectively. The length of time on hemodialysis was significantly associated with HBV seropositivity. Only 10% of the patients reported received hepatitis B vaccination. The findings of a high HBV infection prevalence in this population and the increased risk for HBV infection on long-term hemodialysis suggest the environmental transmission, emphasizing the urgent need to evaluate strategies of control and prevention followed in these units.

Long-term follow-up of hepatitis C virus infection among organ transplant recipients: implications for policies on organ procurement

BACKGROUND

Hepatitis C virus (HCV) infection causes slowly progressive liver disease. Therefore, the full impact of HCV infection after transplantation may require 5-10 years of follow-up.

METHODS

We have previously reported the effect of HCV infection, acquired from the donor (study 1) or acquired before transplantation (study 2), on the incidence of liver disease, and on patient and graft survival with a median follow-up of 3-5 years. In study 1, we compared 24 recipients of organs from donors who were positive to antibody to HCV (anti-HCV) to 74 recipients of organs from anti-HCV-negative donors. In study 2, we compared 23 anti-HCV-positive recipients to 80 anti-HCV-negative recipients of kidneys from anti-HCV-negative donors. In this report, we extend the median follow-up period for patient and graft survival to 6-7 years, and discuss the implications of our finding on policies for organ procurement.

RESULTS

In study 2, after extended follow-up, there continued to be no significant difference between groups with respect to graft loss, but mortality remained significantly higher among recipients with anti-HCV before transplantation. Compared with recipients without anti-HCV before transplantation, the relative risk of graft loss among recipients with anti-HCV before transplantation was 1.30 (0.66-2.58), the relative risk of death was 2.60 (1.15-5.90), and the relative risk of death due to sepsis was 6.30 (1.99-20). In study 1, after extended follow-up, there continued to be no significant differences between groups, with respect to graft loss or death. Compared with recipients of organs from anti-HCV-negative donors, the relative risk of graft loss among recipients of organs from anti-HCV-positive donors was 0.95 (0.54-1.67), and the relative risk of death was 1.00 (0.49-2.02).

CONCLUSIONS

The two studies presented in this report provide an apparent paradox, with respect to the impact of HCV infection acquired at the time of transplantation versus before transplantation on posttransplantation clinical outcomes. However, the increased mortality among recipients who acquired HCV infection before transplantation, but not among recipients who acquired HCV at the time of transplantation, could be explained by the longer duration of HCV infection in the former group. These findings are consistent with the known slowly progressive nature of HCV infection. However, in the absence of definitive evidence for an adverse effect on patient or graft survival, we believe that the decision to accept a kidney from an anti-HCV-positive donor should be made by the patient, after discussion with the treating physician.

Hepatitis C in dialysis patients

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

Special consideration for bloodborne pathogens in the PACU

Routine care of postoperative patients implies considerable exposure to blood products as well as to coughs and secretions. In the PACU, coughed secretions are often frankly contaminated with blood, and coughing is unpredictable after airway irritation. For these reasons, PACU nurses are exposed to many small inocula of potentially infected blood products. This review summarizes the current knowledge regarding transmission of viral pathogens to health care workers, particularly hepatitis and human immunodeficiency viruses. Although the risk of acquiring these bloodborne pathogens from patients via coughs or splashes is small, the precise risks have not been quantified, and the stakes are high. Protection of PACU personnel by the use of universal precautions should be a routine part of patient care in the PACU.