A total of 100 consecutive patients of chronic renal failure from March 2012-June 2013 undergoing haemodialysis for the first time in the haemodialysis unit of our hospital were included in the study after taking their written consent and permission from Instititutional Research and Ethical Committee. Patients on maintenance dialysis in our hospital were excluded. All patients were interviewed regarding the risk factors of HCV infection (history of transfusion of blood /blood products, number of dialysis at other centers, frequency of therapeutic injections/intravenous fluids, surgical interventions (major/minor), dental treatment, shaving by communal barber, intravenous drug abuse (IVDA), ear/nose piercing, tattooing, accupuncture, sexual history and household exposure to HCV).

Single predialysis blood sample was collected from each patient after taking all aseptic and universal precautions. All the samples were screened for anti-HCV antibodies by 3^rd generation HCV Microlisa (J. Mitra & Co. Pvt. Ltd.) according to the manufacturer’s instructions. The plasma samples were stored at -70^oC and tested for HCV-RNA by Real time PCR using HCV REALTM (Sacace Biotechnologies). Genotyping was done by Linear array HCV –genotyping kit(Roche Diagnostic, Mannheim, Germany) from an accredited laboratory. All the patients undergoing haemodialysis in our tertiary care hospital were screened for HCV infection by detecting anti-HCV antibodies by 3^rd generation HCV Microlisa (J.Mitra & Co. Pvt. Ltd.) and one dedicated machine is used for HCV reactive patients and used material is discarded separately.

All the collected data were entered and analysed by SPSS (16.0) version. There is substantial agreement between the two tests. Kappa statistic was 0.61 (substantial agreement).

Screening of 100 HD patients for HCV infection showed that 30 (30%) were positive for anti-HCV antibodies by third generation ELISA test. PCR detected HCV-RNA in 20 (20%). The combined figure of the two tests revealed that in all, 32(32%) was having HCV infection. Of these 32, 18(56.25%) were positive by both the tests (ELISA+PCR) and 12 (37.5%) by ELISA for anti-HCV antibodies alone. HCV-RNA (PCR) alone detected HCV infection in 2(6.25%) patients [Table/Fig-1]. The overall agreement between the two methods of detection was substantial by Kappa agreement value.(Kappa value 0.61).

Major risk factors observed in 32 patients having HCV infection were number of dialysis at other centers (62.5%), history of transfusion of blood/blood products (56.2%), therapeutic injections/intravenous fluids (46.8%), Shaving at community barbers 31.5% and major/minor surgical procedures was (21.8%) [Table/Fig-2]. The most common genotype in 20 patients who had shown HCV viraemia was genotype 3 in 14(70%) followed by genotype 1 in 5(25%)and genotype 4 in 1 (5%).

There is variability in HCV testing practices in dialysis centres. In Northern India, most of the recent published data on HCV prevalence in haemodialysis patients is based on detection of anti-HCV antibodies by third generation ELISA test [7–9]. Only a limited number of studies have used PCR for detecting infection among which most have used PCR only for confirmation of infection in cases of positive samples for anti-HCV antibodies and not as a screening test in all the studied patients [10]. We observed the prevalence of 32% by detecting both anti-HCV antibodies and HCV-RNA, which corroborates the findings of Jaiswal et al., (30%) from central India [9]. Anti-HCV antibodies alone were detected in 30% in our study which is higher than that of Jasuja et al., (21.8%) from New Delhi, but falls within the range of 3-45% reported from different regions of India [8–11]. There were 70 seronegative (negative for anti-HCV antibodies) patients in our study and HCV-RNA by PCR was detected in 2 (2.8%) of them. The rate of HCV antibody negative viraemia by PCR in HD patients has been reported to be between 0-12% globally [12]. Various studies from neighbouring countries and our country have also reported HCV-RNA detection in range of 5-7% in HCV seronegative patients [8,13–15] [Table/Fig-3]. From all these studies, we have reported the lowest (2.8%) detection of HCV-RNA in HCV seronegative patients. It could be because most of our patients had already visited number of private clinics in smaller towns and by the time they reached our tertiary care hospital, were in chronic stage of disease, so easily diagnosed by detecting anti-HCV antibodies.

The most common risk factor observed in our patient population was the history of dialysis at other centres (62.5%). This is similar to other studies from India [9,16]. History of transfusion of blood/blood products (56.29%), therapeutic injections/intravenous fluids (46.8%) and shaving at community barbers (31.5%) were other important risk factors observed in the present study and are consistent with the findings of Mujtaba et al., [17]. Many patients believe that injectables/intravenous fluids act faster and relieve the symptoms more quickly than oral drugs. A high frequency of injection use, most of which are administered under unsterile conditions, put the patients on risk of acquiring HCV infection. The commonest HCV genotype observed in 20 patients of the present study having HCV Viraemia was 3 (70%) followed by 1 (25%) which is similar to other studies from Northern India [18,19]. However, an important finding of our study was the presence of genotype 4 which has been reported from Pakistan but not from Northern India [17]. This could be because of proximity of the area of the present study to that of Pakistan, a neighbouring country. As the response to therapy differs in different genotypes and upto 80% of the genotypes 2 and 3 can be cured with standard treatment, most of our patients could be cured of HCV infection as they carry genotype 3 [20].

Thus, we can conclude that HCV infection is a major problem in our haemodialysis patients. Although serological assays are reliable, easily available and have relatively low cost in detecting exposure to HCV in HD patients, they definitely fail to detect active infection especially so in this immunocompromised patient population. However, we observed that by the time patients reach our remotely located tertiary care centre, a significant proportion of them already have ongoing HCV infection which could be detected by testing for anti-HCV antibodies. This is also evident from the prevalence of 2.8% (HCV-RNA detected by RT-PCR) observed in anti-HCV antibody negative patients of our study. The value (2.8%) is much less than that reported by other studies from Northern India [8,21]. Kappa value (0.61) also shows that the overall agreement between the two HCV infection detection methods (anti-HCVantibodies and HCV-RNA) is substantial in our study. Although, HCV-RNA detection by PCR is the only sensitive, reliable and a gold standard test for HCV infection, it may not be possible to adopt it as a screening test due to its high cost, high technical skill requirement. However, the best way to control the transmission of HCV infection in HD units is strict adherence to universal precautions, sterilization and proper maintenance of dialysis machines and proper disposal of used material. There is no substitute for these measures and their implementation in the dialysis unit remains the cornerstone of decreasing the prevalence of HCV infection in HD patients.

HCV core antigen testing by ELISA was not performed which is another method for detection of current HCV infection.

Although serological assays are reliable, easily available and have relatively low cost in detecting exposure to HCV in HD patients, they definitely fail to detect active infection especially so in this immunocompromised patient population. However, we observed that by the time patients reach our remotely located tertiary care centre, a significant proportion of them already have ongoing HCV infection which could be detected by testing for antiHCV antibodies. Although, HCV-RNA detection by PCR is the only sensitive, reliable and a gold standard test for HCV infection, it may not be possible to adopt it as a screening test due to its high cost, high technical skill requirement.