Introduction
Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major causes of global morbidity and mortality, particularly in low- and middle-income countries where access to preventive and therapeutic services remains limited [
1,
2]. In India, an estimated 29 million individuals are living with HBV infection and 5.5 million with HCV infection [
2]. Among patients with chronic kidney disease (CKD) receiving dialysis, the risk of infection is increased because of frequent vascular access procedures, blood transfusions, and underlying immune dysregulation [
3,
4].
Hemodialysis (HD) centers face additional challenges, including lapses in infection control, equipment contamination, and patient transfers between facilities, all of which may increase the risk of hospital-acquired transmission [
5,
6]. Reported HCV prevalence in Indian dialysis units ranges from 15% to 80%, whereas HBV prevalence ranges from 3.4% to 43%, with variation by region and infection control standards [
5]. The lower prevalence of HBV likely reflects vaccination efforts and higher rates of spontaneous viral clearance [
6].
Despite advances in infection control strategies and antiviral therapies, new HBV and HCV infections continue to occur among patients receiving HD, underscoring the need for ongoing surveillance and preventive measures. This study aimed to determine the seroconversion rates of HBV and HCV among patients with CKD receiving maintenance HD and to identify demographic, dialysis-related, and biochemical factors associated with seroconversion.
Materials and Methods
This prospective cohort study was conducted between January 2023 and July 2024 at a government-funded tertiary care hospital in New Delhi, India. Adult patients aged ≥18 years with CKD stage 5 on dialysis (CKD-5D) who were receiving maintenance HD and were seronegative for both hepatitis B surface antigen (HBsAg) and anti-HCV antibodies at baseline were eligible for inclusion. Patients with previous HBV or HCV infection or those receiving antiviral or immunosuppressive therapy were excluded. To minimize potential confounding from non–dialysis-related transmission routes, patients with the following risk factors were also excluded: (1) history of injection drug use; (2) high-risk sexual behavior; (3) household contact with individuals known to have HBV or HCV infection; (4) history of tattooing, body piercing, or acupuncture within 6 months before enrollment; and (5) history of blood transfusion, surgical procedures, or invasive interventions within 6 months before enrollment.
The required sample size was calculated assuming an expected seroconversion rate of 15%, a 95% confidence level, and 20% relative precision, yielding an initial estimate of 544 participants. After applying a finite population correction based on an estimated total eligible dialysis population of approximately 300 patients and accounting for a 10% anticipated loss to follow-up, the final target sample size was set at 220 participants.
Baseline demographic, clinical, and dialysis-related data were collected for all enrolled patients. Blood samples were obtained at baseline and again at the 6-month follow-up. Anti-HCV antibody testing was performed using a fourth-generation enzyme-linked immunosorbent assay (ELISA) kit (Merilisa Gen 4; Meril Diagnostics). HBsAg detection was performed using a third-generation ELISA kit (Trustwell HBsAg ELISA; Trustwell Diagnostics).
All patients who demonstrated seroconversion to HBsAg positivity or anti-HCV antibody positivity during the 6-month follow-up period underwent qualitative nucleic acid amplification testing (NAAT) for HBV DNA or HCV RNA to confirm active infection. All seroconverted patients tested positive for the corresponding viral nucleic acid.
The primary outcome was seroconversion to HBsAg positivity or anti-HCV antibody positivity during the 6-month follow-up period. Potential risk factors were assessed using a structured questionnaire. Measures implemented to minimize bias included standardized laboratory protocols, blinding of laboratory personnel to patient risk profiles, and uniform follow-up intervals for all participants.
Statistical analyses were performed using IBM SPSS ver. 22.0 (IBM Corp.). Categorical variables were compared using the chi-square test or Fisher exact test, as appropriate. Continuous variables were compared using the Student t-test. Logistic regression analysis was performed to calculate odds ratios (ORs) with 95% confidence intervals (CIs). A p-value of <0.05 was considered to indicate statistical significance.
Ethical approval was obtained from the Institutional Ethics Committee of Vardhman Mahavir Medical College and Safdarjung Hospital (S. No: IEC/VMMC/SJH/Thesis/2023/CC-154). Informed consent was obtained from all participants.
Results
A total of 220 patients met the inclusion criteria, completed baseline testing, and were included in the analysis. All patients completed 6 months of follow-up. The mean age of the cohort was 42.8±15.2 years (range, 18–84 years), and men comprised 61.4% (135/220) of the study population. Most patients (97.7%, 215/220) received HD 2 to 3 times per week. Demographic, clinical, and dialysis-related characteristics—including dialysis duration, number of dialysis centers visited, dialyzer reuse, and blood transfusion history—are presented in
Table 1.
HBV seroconversion occurred in 7.3% (16/220) of patients during follow-up. HBV seroconversion was significantly associated with multiple dialysis center visits (
p=0.008). Elevated serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) levels were also significantly associated with HBV seroconversion (
p<0.001). No significant associations were observed with dialysis duration, dialysis frequency, or dialyzer reuse (
Tables 1,
2).
Over 6 months, 10.5% (23/220) of patients developed anti-HCV antibody positivity. HCV seroconversion was significantly associated with multiple dialysis center visits (≥5 centers: 23.3% vs. 0% for 1 center;
p=0.002), dialysis duration ≥2 years (20% vs. 4.8% for ≤1 year;
p=0.01), and dialyzer reuse (13.8% vs. 0%,
p=0.01). Elevated SGOT and SGPT levels were strongly associated with HCV seroconversion (both
p<0.001) (
Tables 1,
2).
Discussion
This study found 6-month seroconversion rates of 7.3% for HBV and 10.5% for HCV among patients receiving HD, which are higher than national prevalence estimates for the general population. According to the National Viral Hepatitis Control Program (NVHCP) operational guidelines, the estimated HBV prevalence is 1% to 2% in the general population of India and 3% to 4% among patients receiving dialysis. Similarly, estimated HCV prevalence is approximately 1% in the general population but increases to 4% to 5% in dialysis units [
7,
8]. Multiple center attendance emerged as the strongest predictor for both infections, consistent with prior studies [
9,
10]. This likely reflects inconsistent infection control and variable adherence to guidelines between facilities.
Patients treated at multiple dialysis centers had nearly twice the risk of acquiring HBV or HCV compared with those treated at a single center (
Table 1), as also reported by Jasuja et al. [
9]. This finding aligns with the NVHCP emphasis on continuity of care and standardized infection control practices [
8]. Longer dialysis duration was associated with increased HCV seroconversion, whereas no such association was observed for HBV, consistent with the findings of Mittal et al. [
6]. This difference may reflect greater awareness, higher vaccination coverage, and higher rates of spontaneous clearance for HBV.
In this cohort, a longer duration of dialysis was significantly associated with HCV seroconversion, with a higher incidence among patients undergoing dialysis for 3 years or longer compared with those with shorter dialysis duration. This pattern may reflect cumulative exposure from repeated vascular access, invasive procedures, and ongoing contact with the dialysis environment. In contrast, no clear association was observed between dialysis duration and HBV seroconversion. These observations are consistent with findings reported by Masoodi et al. [
10].
Notably, dialyzer reuse appeared to be associated with a lower HCV seroconversion rate; however, this observation is difficult to interpret due to the small sample size and potential confounding, including the possibility of stringent reprocessing practices (
Table 1). No significant association between dialyzer reuse and HBV seroconversion was observed (
Table 1). NVHCP guidelines indicate that dialyzer reuse must follow strict reprocessing protocols and should not be considered safer without validated evidence [
8].
Patients who seroconverted had elevated liver enzyme levels, consistent with active infection, whereas age, sex, dialysis frequency, and blood transfusion history were not significantly associated with new infections. Consistent with other studies [
11,
12], these findings suggest that institutional infection control practices, rather than patient demographic characteristics, represent key determinants of seroconversion risk in dialysis units.
Biochemical findings were consistent with the seroconversion patterns observed. Patients who seroconverted for HBV or HCV had significantly higher SGOT and SGPT levels, suggesting active hepatic inflammation (
Table 2). In contrast, hemoglobin, creatinine, urea, sodium, and potassium levels did not differ significantly between seroconverted and non-seroconverted groups, consistent with findings reported by Patel et al. [
13]. Although these parameters are important for monitoring kidney disease, they are not reliable indicators of viral seroconversion because their variability may be masked by underlying renal dysfunction and the effects of dialysis.
Strengths of this study include its prospective design, standardized testing, and complete follow-up. Limitations include the single-center design, relatively short follow-up, and the inability to assess all potential confounders, including comorbidities, adherence to infection control practices, socioeconomic factors, staff-to-patient ratios, and dialysis equipment characteristics. Although qualitative molecular confirmation was performed for all seroconverted patients, quantitative viral load testing and viral genotyping were not performed. Future studies incorporating quantitative polymerase chain reaction testing and viral characterization could provide additional insight into HBV and HCV transmission and disease course among patients receiving HD. A potential further limitation is that baseline screening relied on serologic testing without NAAT. Patients in the window period of acute HBV or HCV infection may test negative for HBsAg and anti-HCV antibodies despite detectable viral nucleic acid. If such patients were inadvertently enrolled, subsequent positive testing during follow-up could be misclassified as incident seroconversion, which could overestimate the true nosocomial transmission rate. Nevertheless, serologic screening remains the standard and most cost-effective approach for large-scale surveillance in resource-limited settings. Future studies incorporating baseline NAAT in addition to serology could more accurately differentiate pre-existing window-period infections from true incident seroconversions occurring during follow-up.
The clinical course and outcomes of acute HBV and HCV infections differ substantially, particularly with respect to spontaneous clearance, chronicity, and response to antiviral therapy [
8]. In the present study, treatment outcomes following seroconversion could not be systematically assessed because therapeutic decisions and follow-up were determined by treating clinicians and were outside the predefined study objectives. Future prospective studies with longer follow-up are needed to assess antiviral treatment initiation, viral clearance, and long-term outcomes among seroconverted patients on HD.
The implications of this study include the need to standardize protocols across dialysis centers, strengthen HBV vaccination coverage, and consider eliminating dialyzer reuse to reduce infection risk. Routine biannual screening remains essential.
Article information
Ethics Approval
This study was approved by the Institutional Ethics Committee of Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi–110029 (S. No. IEC/VMMC/SJH/Thesis/2023/CC-154), and was performed in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from participants for publication of this study and accompanying images.
Conflicts of Interest
The authors have no conflicts of interest to declare.
Availability of Data
All data generated or analyzed during this study are included in this published article. Additional data may be requested from the corresponding author.
Authors’ Contributions
Conceptualization: SK, RK, DN; Data curation: PY, AP; Formal analysis: PY, AP; Methodology: SK, RK, DN; Supervision: SK, RK, DN; Validation: SK, RK; Visualization: SK, DN; Writing–original draft: PY, AP; Writing–review & editing: all authors. All authors read and approved the final manuscript.
