Serological and vaccination profile of hemodialysis patients during an outbreak of hepatitis B virus infection

Practical Guide to Vaccination in All Stages of CKD, Including Patients Treated by Dialysis or Kidney Transplantation

Infection is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), including those receiving maintenance dialysis or with a kidney transplant. Although responses to vaccines are impaired in these populations, immunizations remain an important component of preventative care due to their favorable safety profiles and the high rate of infection in these patients. Most guidelines for patients with CKD focus on the importance of the hepatitis B, influenza, and pneumococcal vaccines in addition to age-appropriate immunizations. More data are needed to determine the clinical efficacy of these immunizations and others in this population and define optimal dosing and timing for administration. Studies have suggested that there may be a benefit to immunization before the onset of dialysis or transplantation because patients with early-stage CKD generally have higher rates of seroconversion. Because nephrologists often serve as primary care physicians for patients with CKD, it is important to understand the role of vaccinations in the preventive care of this patient population.

Vaccination in Chronic Kidney Disease

Infections after cardiovascular disease are the second most common cause of death in the chronic kidney disease population. Vaccination is an important component of maintaining health and wellness in patients with kidney disease. There is a changing epidemiologic landscape for several vaccine-preventable illnesses from childhood to adulthood and unfounded public perception of safety concerns. Several mechanisms have been proposed to cause inadequate vaccine protection in this high-risk group with chronic kidney disease. These have led to recent advances in new designs for vaccination strategies in kidney disease. In this article, we discuss the current evidence and recommendations for vaccination in those with kidney disease and needing renal replacement therapy (dialysis and transplant).

The Management of Viral Hepatitis in CKD Patients: An Unresolved Problem

Chronic kidney disease (CKD) patients in dialysis (HD) show peculiar, atypical features of clinical presentation and diseases (cardiovascular, metabolic, hematologic). This is also true for viral hepatitis infections, for which CKD patients represent an important risk group. In the past, hepatitis B virus (HBV) was the major cause of viral hepatitis in end-stage renal disease (ESRD). However, the introduction of a rigorous infection-control strategy, routine screening of patients and staff for hepatitis B serologic markers, vaccination of susceptible patients and staff, use of separate rooms and dedicated machines for HD of HbsAg-positive patients have all led to a decline in the spread of HBV infection in dialysis. Despite the prevalence of the antibody-hepatitis C virus (HCV), there has been a marked decrease in HD patients; after the introduction of routine screening for HCV and the use of erythropoietin, its occurrence ranges from 5% to 25% in the United States, with a prevalence of 6.8% in Europe. In CKD and in HD patients, the presence of HBV and HCV is an independent and significant risk factor for death and this risk may be at least partially attributed to chronic liver disease with its attendant complications. Liver disease can progress with modest hepatic inflammation and prominent fibrosis; the natural history of viral hepatitis in these patients is dependent on the immune dysfunction typical of kidney disease. Despite recent advances in antiviral therapy, there are still many uncertainties in regards to the efficacy and long-term outcomes of treatment with antiviral agents.

Primary seroresponses to double-dose compared with standard-dose hepatitis B vaccination in patients with chronic kidney disease: a systematic review and meta-analysis

Background

Clinical guidelines recommend double-dose hepatitis B vaccination for patients requiring dialysis, due to an increased risk of hepatitis B infection and reduced vaccine responsiveness. There are no recommendations for patients with chronic kidney disease (CKD) prior to dialysis.

Methods

We performed a systematic review and meta-analysis of randomized and quasi-randomized trials comparing efficacy (seroresponses) and harms of double-dose compared with standard-dose hepatitis B vaccination in patients with CKD, including those requiring dialysis. A systematic literature search (CENTRAL, MEDLINE and EMBASE) was performed using a predetermined search strategy. Relative risks were calculated from pooled data using a random-effects model with subgroup analysis by dialysis requirement and vaccine type.

Results

Seven studies (501 patients) fulfilled review criteria: four in patients receiving dialysis and three in patients not receiving dialysis. The incidence of seroconversion was not increased with double-dose vaccination overall [risk ratio (RR) 1.17, 95% confidence interval (CI) 0.98-1.39], by dialysis requirement or vaccine type. The incidence of seroprotection (reported by only four studies) was increased with double-dose vaccination overall (RR 1.53, 95% CI 1.17-2.00) but not by dialysis requirement. Adverse events were not reported by treatment arm, precluding comparison. The overall quality of included studies was moderate to low.

Conclusions

The current data do not support clinical guideline recommendations for administering double-dose vaccination for patients with CKD as seroconversion was not improved and seroprotection was inadequately assessed. Large high-quality studies are required to overcome the current evidence gap regarding vaccine dosing in CKD.

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

BACKGROUND

Changes in the delivery of healthcare in the developed world have resulted in frequent reporting of outbreaks of hepatitis B virus (HBV) infection in nonhospital healthcare settings, including hemodialysis units.

AIM

We performed a systematic review of HBV outbreaks in dialysis units of developed and less-developed countries published between 1992 and 2014 to elucidate the most frequent mechanisms of patient-to-patient transmission of HBV 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

12 papers reported on 16 outbreaks that involved 118 patients on maintenance dialysis; 10 fatal cases occurred. European outbreaks were smaller compared with the others (P = 0.0046). Information on specific transmission pathways was given in many outbreaks (n = 10; 62%); multiple deficiencies in standard or hemodialysis-specific procedures was the most common route of patient-to-patient transmission of HBV (80%, 8/10). De novo HBV from HBsAg negative/HBV DNA positive blood donors was found in 2 (20%) oubreaks. Sharing of contaminated HD machines was mentioned in 1 report.

CONCLUSIONS

Our systematic review of HBV outbreaks shows that incomplete adherence to standard and dialysis-specific infection control precautions was the most important cause of patient-to-patient transmission of HBV in dialysis units. This review should serve as a reminder to HD providers that the risk of HBV infection is still present among patients undergoing dialysis and that HBV may be easily transmitted in the dialysis setting whenever appropriate infection control practices are not strictly applied.

Hepatitis B vaccination in chronic kidney disease patients: a call for novel vaccines

The protective immunization rates in response to hepatitis B vaccination in chronic kidney disease (CKD) patients are lower than response rates in the general population because of genetic and CKD-related factors as well as logistic problems with a proper providing of the recommended vaccination schedules. This review focuses on third-generation vaccines and adjuvanted vaccines commercially introduced in some countries, investigated in clinical trials, especially involving CKD patients or used only in the experimental studies. In order to improve the immunization rate, the use of third-generation vaccines (yeast-derived pre-S2/S HBV vaccines, mammalian cell-derived pre-S2/S HBV vaccines, mammalian cell-derived pre-S1/pre-S2/S HBV vaccines), novel adjuvants (AS04, AS02, phosphorothioate oligodeoxyribonucleotide, hemokinin-1, a polysaccharide based on delta inulin, nano-complex Hep-c, cyclic diguanylate) or immunostimulants for enhancement of immunogenicity of existing recombinant hepatitis B vaccines is tried to improve results of hepatitis B vaccination prior to dialysis commencement or already on renal replacement therapy.

Vaccination issues in patients with chronic kidney disease

Infections are an important cause of morbidity and mortality among patients at all stages of chronic kidney disease. Prevention through vaccination remains the best strategy to minimize the adverse consequences associated with these infectious diseases in this, and all, populations. Unfortunately, patients with chronic kidney disease demonstrate inadequacies of specific immune-cell function that are required for generating a protective vaccine response. Nevertheless, early vaccination of this high-risk population has demonstrated good clinical outcomes during progression to late-stage disease. We review the available evidence linking immune impairment in adult patients with late-stage chronic kidney disease to diminished vaccine responses. We highlight the importance of early vaccination in disease with high risk for development of CKD and novel vaccine approaches in development that may help to address improvement in protective boosting of immunity during late-stage disease.

Improving hepatitis B vaccine efficacy in end-stage renal diseases patients and role of adjuvants

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.

Hepatitis B virus infection and the dialysis patient

Prevention of nosocomial transmission of hepatitis B virus (HBV) has been a signal achievement in the management of chronic kidney disease. The rate of serum hepatitis B surface antigen (HBsAg) seropositivity in patients on maintenance hemodialysis in the developed world is currently low (0-10%) but outbreaks of acute HBV infection continue to occur in this setting. The prevalence of HBV infection within dialysis units in developing countries appears higher (2-20%) based on relatively few reports. Although data are limited, HBV infection in dialysis population diminishes survival; HBV viral load in HBsAg-positive dialysis patients is reportedly low and stable over time. Updated recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No rigorously controlled treatment trials for treatment of hepatitis B with either interferon or lamivudine therapy in dialysis patients are currently available.

The evaluation of immune responses to hepatitis B vaccination in diabetic and non-diabetic haemodialysis patients and the use of tetanus toxoid

AIM

The aim of this study was to investigate whether haemodialysis (HD) patients suffering from diabetes mellitus could be considered at risk for the development of the protective antibodies to hepatitis B (HB) vaccination and, to evaluate the effectiveness of tetanus toxoid (TT) administrated 2 days before HB vaccination.

METHODS

Forty-nine HD patients were divided into two groups: group A (19 diabetic patients) and group B (30 non-diabetic patients). A dose of 40 microg recombinant HB vaccine was injected intramuscularly to the patients at 0, 1, 2 and 6 months.

RESULTS

After the completion of the course, the patients in group A were found to have a lower protective antibody rates than the patients in group B (57.8% vs 70%) (P > 0.05). After the administration of additional booster doses during 12 months, the protective antibody to hepatitis B surface antigen (HBsAb) levels were detected in 78.9% and 96.6% of the patients in group A and group B, respectively (P > 0.05). The patients not having protective HBsAb levels were administered TT and HB vaccines, and after course, all of them have produced protective HBsAb levels.

CONCLUSION

The present study showed that diabetic patients on HD may carry a greater risk of not seroconverting than non-diabetic ones for antibody response to HB vaccination. The use of TT 2 days before HB vaccination may be a useful and effective method of enhancing the immune response to HB vaccination, especially in the patients with diabetes mellitus on HD.

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 B virus infection profile in hemodialysis patients in Central Brazil: prevalence, risk factors, and genotypes

Hemodialysis patients are at high risk for hepatitis B virus (HBV) infection. A survey was conducted in the hemodialysis population of the state of Goiás, Central Brazil, aiming to assess the prevalence of HBV infection, to analyse associated risk factors, and also to investigate HBV genotypes distribution. A total of 1095 patients were interviewed in 15 dialysis units. Serum samples were screened for HBV serological markers by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) positive samples were tested for HBV DNA by polymerase chain reaction and genotyped by restriction fragment length polymorphism. Global HBV infection prevalence was 29.8% (95% CI: 27.1-32.5). Multivariate analysis of risk factors showed that male gender, length of time on hemodialysis, and blood transfusion before 1993 were associated with HBV positivity. HBV DNA was detected in 65.4% (17/26) of the HBsAg-positive samples. Thirteen of 17 HBV DNA positive samples were genotyped. Genotype D (61.5%) was predominant, followed by A (30.8%), while genotype F was detected in only one (7.7%) sample.

Chronic viral hepatitis in hemodialysis patients

Ever since the first outbreaks of hepatitis in hemodialysis units in the late 1960s, a number of hepatotropic viruses transmitted by blood and other body fluids have been identified. This review summarizes the current state of knowledge regarding these blood-borne agents from an epidemiologic and preventive perspective. Data source and study selection were obtained from research and review articles related to the epidemiology of viral hepatitis in hemodialysis and indexed on Medline and Embase from 1965 to 2004. Hepatitis B virus (HBV) was the first significant hepatotropic virus to be identified in hemodialysis centers. HBV infection has been effectively controlled by active vaccination, screening of blood donors, the use of erythropoietin, and segregation of HBV carriers. To date, HBV remains an important cause of morbidity in endemic areas. Hepatitis delta virus is a defective virus that can only infect HBV-positive individuals. Hepatitis C virus 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-alpha 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 and hepatitis GB virus C in 1995 and the TT virus in 1997. Although epidemiologic analyses revealed high prevalence rates of both viruses in the hemodialysis population, their exact role in liver disease has yet to be determined. 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 hemodialysis.

Meta-analysis: the effect of age on immunological response to hepatitis B vaccine in end-stage renal disease

BACKGROUND

Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non-uraemic population. A variety of inherited or acquired factors have been implicated in this diminished response. Age-associated changes in immune status may contribute to decreased vaccine efficacy in older individuals although contradictory results have been reported in individuals with normal kidney function.

AIMS

To evaluate the relationship between age and immune response to hepatitis B vaccine in patients with end-stage renal disease by performing a systematic review of the literature with a meta-analysis of clinical trials.

METHOD

We used the random effects model of DerSimonian and Laird; sources of heterogeneity in effect estimates were explored by performing sensitivity analyses.

RESULTS

We identified 17 clinical trials (1800 unique patients); six (35%) were controlled studies. Pooling of study results demonstrated a significantly decreased risk of response to hepatitis B vaccine among older dialysis patients (overall risk ratio: 0.74; 95% confidence intervals: 0.70-0.79). The P-value was 0.0139 for our test of study heterogeneity. A lowered risk of response to hepatitis B vaccine persisted after exclusion of trials based on plasma-derived vaccines; it was present even when 'older' individuals were defined as being as 50 years (RR: 0.85, 95% CI: 0.75-0.96) or more (cut-off 60 years RR: 0.75; 95% CI: 0.66-0.85). An effect of age on seroprotection rate was present in all clinical reports, irrespective of the geographic origin of the study group: Europe (RR: 0.76; 95% CI: 0.70-0.83) North America (RR: 0.67; 95% CI: 0.60-0.74) or other countries (RR: 0.83; 95% CI: 0.71-0.97). Additional doses of vaccine did not appear to have an impact on RR of response by age.

CONCLUSIONS

Our meta-analysis showed a clear association between older age and impaired response to hepatitis B virus vaccine in end-stage renal disease patients. Such a relationship is biologically plausible. Vaccination schedules with adapted vaccine doses and frequent serum testing for loss of immunity against hepatitis B virus are recommended in elderly patients on maintenance dialysis.

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.

Stage of chronic kidney disease predicts seroconversion after hepatitis B immunization: earlier is better

BACKGROUND

Hepatitis B virus (HBV) infection remains a concern in dialysis populations, and vaccination programs have been less successful than those in the general population. Reasons for poor response include malnutrition, uremia, and the generalized immunosuppressive state of patients with chronic kidney disease (CKD). This prospective cohort study evaluated factors impacting on the effectiveness of a vaccination program before dialysis therapy initiation, including level of kidney function.

METHODS

All patients receiving care in the Kidney Function Clinic (St Paul's Hospital, Vancouver, Canada) were screened for previous HBV infection or vaccination. Those who were marker negative were administered a standardized hepatitis B vaccination schedule recommended for patients with CKD. The primary outcome measure, seroconversion, is defined as hepatitis B surface antibody titer greater than 10 IU 3 months after completion of the vaccination schedule.

RESULTS

The study population of 165 patients included 64% men with a mean age of 60 years, mean serum creatinine level of 3.4 +/- 1.5 mg/dL (300 +/- 133 micromol/L), and median estimated glomerular filtration rate (GFR) of 20 mL/min (interquartile range, 14 to 20). Seroconversion rate was 82%. Multivariate analyses showed the independent predictive value of level of GFR. The model showed that patients with the lowest level of kidney function and who were older and had diabetes were less likely to seroconvert (P < 0.05).

CONCLUSION

This is the largest study to show in a well-characterized cohort that patients with higher GFR levels are more likely to respond to hepatitis B vaccination programs with seroconversion, independent of other factors. Future studies will explore specific mechanisms to explain this phenomenon.

Evolution of naturally acquired hepatitis B immunity in the long-term hemodialysis population

BACKGROUND

Although the natural history of vaccination-induced hepatitis B virus (HBV) antibodies (Abs) is becoming clearer, little is known about naturally acquired immunity. Some assume that these patients never lose their Abs.

METHODS

To document the natural history of HBV immunity, we prospectively followed up all naturally immune patients initiating hemodialysis (HD) therapy at St Michael's Hospital (Toronto, Canada). Patients presenting with Ab to hepatitis B surface antigen (HBsAb) who had no history of vaccination had a core Ab level measured to confirm natural immunity. When HBsAb titer decreased to less than 10 IU/L, patients were administered a single dose of 40 microg of Engerix B vaccine (Smith Kline Beecham Pharma Inc, Oakville, Ontario, Canada) intramuscularly as a booster dose.

RESULTS

We identified 29 patients beginning HD therapy with natural immunity. Nine patients (30%) subsequently lost immunity (defined as Ab titer decreasing to < 10 IU/L) during follow-up. They were older and had a lower Ab titer at initiation of HD therapy. Four of 5 patients with a low response to the booster dose were 75 years or older. Two patients with a low peak Ab titer after the booster dose again had their Ab titer decrease to less than 10 IU/L after 6 and 10 months. Both patients were switched to intradermal vaccination. All other patients were still immune after a median of 26 months.

CONCLUSION

Individuals who are naturally immune against HBV may experience a decrease in Ab titer. Their responses to booster vaccinations varied widely. It is possible that elderly patients with natural immunity require closer surveillance. We provide recommendations for surveillance in these patients.

Biological dynamics of hepatitis B virus load in dialysis population

BACKGROUND

Control of the spread of hepatitis B virus (HBV) infection in dialysis units has been one of major advances in the management of end-stage renal disease. However, the natural history of HBV in dialysis patients remains unclear. The aim of this study is to measure monthly HBV viral load (HBV DNA) in a large cohort (n = 29) of hepatitis B surface antigen (HBsAg)-positive chronic dialysis patients during 12 months.

METHODS

HBV DNA was measured using the Amplicor HBV Monitor Test (Roche Diagnostics, Branchburg, NJ), an in vitro assay using polymerase chain reaction nucleic acid amplification and DNA hybridization for the quantitative measurement of HBV DNA in serum.

RESULTS

We observed three HBV DNA patterns: (1) patients persistently positive by Amplicor HBV Monitor Test (persistent HBV DNA; 7 of 29 patients; 24.1%), (2) individuals with alternatively positive and negative results (intermittent HBV DNA; 18 of 29 patients; 62.1%), and (3) patients persistently negative by Amplicor HBV Monitor Test (4 of 29 patients; 13.8%). HBV viral load was greater in patients with persistent compared with intermittent HBV DNA (persistently HBV DNA positive; 2.686 x 10(4) copies/mL; 95% confidence interval [CI], 5.2499 x 10(4) to 1.8158 x 10(4)copies/mL) versus intermittently HBV DNA positive (1.071 x 10(3) copies/mL; 95% CI, 8.524 x 10(3) to 4.09 x 10(2) copies/mL; P = 0.0001). In the entire group, HBV load at study entry was low and did not change versus the end of follow-up.

CONCLUSION

Three patterns of HBV viremia in dialysis patients over time were assessed; HBV load was not high and was relatively stable. HBsAg-positive patients who were intermittently HBV DNA positive had less HBV viral load than persistently HBV DNA-positive patients. Periodic testing for HBV DNA to assess the virological status of HBsAg-positive dialysis patients is recommended.

Risk factors for hepatitis B virus infection in Rio de Janeiro, Brazil

BACKGROUND

Despite international efforts to prevent hepatitis B virus (HBV) infection through global vaccination programs, new cases are still being reported throughout the world.

METHODS

To supply data that might assist in improving preventive measures and national surveillance for HBV infection, a cross-sectional study was conducted among individuals referred to the Brazilian National Reference Center for Viral Hepatitis (Rio de Janeiro) during a two-year period. Reported risk factors among infected subjects ("HBV-positive") were compared to those of subjects never exposed ("HBV-negative") to HBV. Two subgroups were further identified within the HBV-positive group, "acute" infection and "non-acute" infection.

RESULTS

A total of 1,539 subjects were tested for HBV, of which 616 were HBV-positive (79 acute infection and 537 non-acute infection). HBV-positive subjects were more likely to be of male gender (63% versus 47%); and to report multiple sexual partners (12% versus 6%) and illicit drug use (IDU and/or intranasal cocaine use) (6% versus 3%). Among the HBV-positive subgroups, age differed significantly, with 48% being under 30 years of age in subjects acutely infected compared to 17% in those with non-acute infection.

CONCLUSIONS

The association of multiple sexual partners with past HBV infection and the age distribution of currently infected subjects suggest that sexual transmission played a major role in the transmission of HBV in this study population. Thus, vaccination during adolescence should be considered.

Hepatitis C and hepatitis B virus infection in different hemodialysis units in Belo Horizonte, Minas Gerais, Brazil

The prevalence, virological and epidemiological aspects of the hepatitis C virus (HCV) and the hepatitis B virus (HBV) infections vary among hemodialysis patients in different countries. Aiming at analyzing these aspects of HCV and HBV infections in hemodialysis patients in Belo Horizonte, MG, Brazil, we studied three hemodialysis units including 434 patients. Serology was used to detect anti-HCV and HBsAg. Reverse trancriptase nested polymerase chain reaction (RT-nested-PCR) of the 5'-noncoding region was used to detect circulating HCV RNA and restriction fragment length polymorphism analysis for genotyping. Seroprevalence varied from 26.5% to 11.1% for hepatitis C and from 5.9% to 0% for hepatitis B. Risk factors observed for HBV and/or HCV infections were the number of patients per dialysis unit, duration of treatment, number of clinics attended, number of blood units transfused, and lower level scholarity. Alanine aminotransferase levels were altered with a higher frequency in HBV or HCV seropositive patients. Half of ten patients, negative for anti-HCV, had detectable viremia by RT-nested-PCR, indicating that this technique should be used to confirm infections in this group of patients. The HCV genotype 1 was the most frequently observed, followed by the genotype 2, but no correlation was detected between genotype and clinical or epidemiological data.

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.