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RENAL DATA FROM THE ARAB WORLD |
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| Year : 2014 | Volume
: 25
| Issue : 3 | Page : 672-679 |
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| Viral hepatitis C and B among dialysis patients at the Rabat University Hospital: Prevalence and risk factors |
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Zineb Lioussfi, Zineb Errami, Aicha Radoui, Hakima Rhou, Fatima Ezzaitouni, Naima Ouzeddoun, Rabea Bayahia, Loubna Benamar
Department of Nephrology, Dialysis and Renal Transplantation, Ibn Sina Hospital, Rabat, Morocco
Click here for correspondence address and email
| Date of Web Publication | 9-May-2014 |
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 Abstract | | |
The aim of this study is to investigate the prevalence of hepatitis C virus (HCV) and hepatitis B virus (HBV) in maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis patients at the Rabat University Hospital and to identify the major risk factors for transmission. A retrospective study was performed in 67 chronic HD and 36 peritoneal dialysis patients. For the screening of viral infections, we tested for anti-HCV antibodies and HBs antigen (Hbs Ag). We compared infected and non-infected patients in order to determine the risk factors for contamination. In the HD unit, the prevalence of anti-HCV was 60% and the prevalence of HBs Ag was 6%. Duration of dialysis (P = 0.001) was the only risk factor in our HD patients. In peritoneal dialysis (PD), the prevalence of anti-HCV was 8%. Hbs Ag was detected in 2.6% of our PD patients. Viral hepatitis C is the main viral infection in our HD unit. The duration of dialysis is the main risk factor for infection in our study. The transmission is essentially nosocomial, requiring a strict adherence to infection control procedures.
How to cite this article:
Lioussfi Z, Errami Z, Radoui A, Rhou H, Ezzaitouni F, Ouzeddoun N, Bayahia R, Benamar L. Viral hepatitis C and B among dialysis patients at the Rabat University Hospital: Prevalence and risk factors. Saudi J Kidney Dis Transpl 2014;25:672-9 |
How to cite this URL:
Lioussfi Z, Errami Z, Radoui A, Rhou H, Ezzaitouni F, Ouzeddoun N, Bayahia R, Benamar L. Viral hepatitis C and B among dialysis patients at the Rabat University Hospital: Prevalence and risk factors. Saudi J Kidney Dis Transpl [serial online] 2014 [cited 2022 Jun 27];25:672-9. Available from: https://www.sjkdt.org/text.asp?2014/25/3/672/132236 |
| Introduction | |  |
Patients in end-stage renal disease (ESRD) undergoing chronic dialysis are at a high risk of exposure to hepatitis C virus (HCV) and hepatitis B virus (HBV). The main viral infection among patients on chronic hemodialysis (CHD) remains viral hepatitis C, which represents a major health issue, first with a high prevalence and then with a progressive risk to chronicity, developing either cirrhosis or hepatocellular carcinoma. In addition, there is the risk of cross-contaminations in dialysis units.
Several ways of transmission have been reported by studies, but the efficiency of hygienic measures in some dialysis units, [1] the low prevalence in peritoneal dialysis compared with hemodialysis (HD) [2] and the new cases of contamination in non-toxico-maniac nor transfused patients suggest a hand-borne nosocomial transmission. [3],[4] Prevention from viral infections in patients on chronic dialysis mainly rests on the strict adherence of hygienic and universal precautions.
The aim of this study is to determine the prevalence of anti-HCV antibody and HbsAg in ESRD patients undergoing either HD or peritoneal dialysis (PD) at the Rabat University Hospital and to specify the major risk factors of contamination in this population.
| Materials and Methods | | |
Patients
A transverse study was carried out during July 2009 in the dialysis unit, including all the ESRD patients, undergoing either HD or PD.
From our HD population in July 2009, 67 patients were enrolled in the study, with a sex ratio of 0.8 (31 male/36 female) and a mean age of 44.2 ± 12 years (25-88 years). The mean duration of HD was 10.6 ± 5.2 years (3-20 years). The native kidney disease could be determined in 61.2%, mostly chronic glomerulonephritis (19.4%) and diabetic nephropathy (10.4%). Our patients had between two and three dialysis sessions per week, lasting 4-5 h, with polysulfone membranes. Our unit is composed of 12 dialysis machines, there is a nurse for every six patients and every adjacent patient is separated by a meter.
From the PD population in July 2009, 38 patients were enrolled, all on continuous ambulatory peritoneal dialysis (CAPD). The mean age was 46 years ± 19 (10-80 years), with a male superiority (24 male/14 female). The mean duration of dialysis was 16.2 ± 9.27 months (3-36 months). The initial kidney disease was known in 60%, and was mostly chronic glomerulonephritis (13%) and diabetic nephropathy (21%). Ten patients (26%) resorted to HD before starting PD.
Methods
Screening of viral infections
HCV antibody test was performed according to the KDOQI guidelines [5] and European best practice guidelines (EBGP) [6] before starting dialysis at the unit and every six months following that using a fourth-generation enzyme-linked immunosorbent assay (ELISA) test. In HCV antibody carriers, the confirmation was performed by quantitative polymerase chain reaction (PCR) (Test AmpliPrep/Cobas TaqMan HCV-Roche Diagnostics Basel, Switzerland) with, a detection threshold of 15 IU/mL. Genotype testing was performed only in a few cases.
We systematically tested for HbsAg, anti-Hbc and anti-Hbs antibodies by the ELISA technique in all our patients. For some patients, the confirmation was done by the real-time PCR method
Risk factors for contamination
We studied risk factors for contamination among all the patients: Duration of dialysis, number of blood transfusions, quantity of red blood cells transfused, dental care needs and history of surgery including renal transplant. In order to evaluate risk factors, we compared two groups of patients according to their serological status, in each dialysis group: group I consisting of the infected patients and group II the non-infected ones.
| Results | | |
In hemodialysis patients
HCV prevalence
In July 2009, among 67 patients on CHD, anti-HCV antibody was positive in 40 patients, a prevalence rate of 60%. PCR was positive for 28 patients, with a prevalence of 42%, and the mean viral charge of HCV RNA was 724 693 ± 1441717 IU/mL. The genotype was performed in 12 among 28 infected patients, and we noticed genotype 1b in all these patients.
One patient was positive for anti-HCV antibody before starting the dialysis sessions in our unit. The mean period for seroconversion of HCV markers after the beginning of HD is 4.4 ± 3.4 years (1-13 years). After a mean period of 7.8 ± 5.7 years (1-19 years) from seroconversion, no infected patient showed symptoms for cirrhosis or hepatocarcinoma.
HCV infection risk factors
In univariate analysis, the HCV exposure risk is related to duration of dialysis and to surgical history [Table 1]. Main surgical procedures are parathyroidectomies, traumatology surgeries and renal transplantations.
In a multivariate study, duration of dialysis remains the only risk factor related to the high prevalence [Table 2]. Indeed, the prevalence of HCV infection increases from 36% during the five first dialysis years to 82% in the latest ten years and 98% in the latest 15 years [Figure 1].
HBV
Among our 67 CHD patients, four was tested positive for Hbs Ag, resulting in a prevalence of 6%. Two patients were already infected before their admission in the unit. The two remaining patients got infected in the first year after starting dialysis. We noticed a co-infection with HCV in two cases. Thirty-five patients (52%) had exposure to HBV previously and were immunized, carrying anti-Hbc and anti-Hbs antibodies. The rest of the patients having negative anti-Hbc and anti-Hbs received a hepatitis B vaccination. Recombinant HBV vaccine 40 IU was administered by the subcutaneous route according to a 0-, 1- and 2-month schedule, with an anti-Hbs anti-body titration three months after the last injection. Only 28 patients (16%) were protected, with an anti-Hbs antibody rate over 100 IU/ mL and a mean of 347 ± 401 IU/mL.
In PD patients
HCV prevalence
From a total of 38 patients, anti-HCV antibody screening was positive in three cases, corresponding to a seroprevalence of 8%. We did not notice any HCV seroconversion in the uninfected population after a mean dialysis duration of 16.2 ± 9.27 months. Among the three patients, only one was in HD before changing for PD. PCR was negative in one patient and the mean viral charge in the two remaining patients was 7 095 512 ± 855698 IU/mL. A hepatic biopsy was performed in the two cases anti-HCV antibody (+) PCR (+) and showed a chronic hepatitis with a minimal activity and a moderate portal fibrosis (A1F2).
HBV prevalence
The Hbs Ag detection was positive in one patient, meaning a HBV prevalence of 2.6%, with a positive PCR. The hepatic biopsy showed signs of chronic hepatitis with no activity or fibrosis (A0F0). After a mean duration of 16.2 ± 9.27 months (3-36 months), no new HBV case appeared in our unit. None of the other patients had positive anti-Hbc.
| Discussion | | |
Hepatitis C is the main viral infection among HD patients. Its prevalence in this population at risk has been studied since the 1990s, and is different from country to country and between HD units. The prevalence is estimated to be around 13%, with values fluctuating between 3% and 23% according to a prospective study: Dialysis Outcomes and Practice Patterns Study (DOPPS). [7] [Table 3] summarizes the results of some publications about the prevalence of HCV in HD patients across the five continents.
The prevalence in our HD patients was 60%, which is a higher rate compared with the literature. It is even higher than the prevalence seen in the general population of Morocco (1.93%) [16] and the blood donors (1.08%). [17]
The prevalence of HCV in our PD center is low (8%). In other studies, this prevalence fluctuates between 5% [18] and 30%, [19] depending on PD centers, geographic areas and HD history. It is estimated at 312% in France, [20] 5.7% in Germany, [18] 5.3% in Korea, [21] 2.2% in Hong Kong, [22] and 30% in China. [19]
The history of HD is a major risk factor of HCV contamination in the CHD population. The mean period of dialysis among HCV (+) patients on CHD varies between 2.75 [23] and 8.6 years. [15] In a multi-center study performed in south France, Dussol concluded that an over eight-year period constitutes the main risk factor for HCV infection. [24] In our series, we found a period of 10.6 ± 5.17 years as the unique risk factor in multivariate analysis [Table 4].
Blood transfusion and quantity of red blood cells transfused were considered as contamination risk factors for HCV in CHD. [30] However, erythropoietin use for treating ESRD anemia and a systematic screening for certain infections including viral hepatitis on blood donors since 1994 led to a significant reduction in the risk of post-transfusion infection. [31] The genomic screening innovation [32] in some countries such as France since 2001 has reduced this risk. Moreover, 20% of the HCV (+) patients of our study population have never been transfused, and 90% were contaminated after 1994, the starting year for systematic control of blood donations and the screening for viral hepatitis in Morocco.
In PD, the risk of contamination by HCV is reduced and, unlike HD, the duration of dialysis does not constitute a risk factor for this population. [2] Studies comparing prevalence in PD and HD showed low rates of anti-HCV (+) in PD [Figure 2]. The main risk factor in PD is the medical history of HD before starting peritoneal exchanges. Huang found a prevalence of 15.4% of HCV in PD, but after disqualifying patients with an HD history, the prevalence was 5.9%. [37] Several factors might explain this low prevalence in PD, mainly the lack of vascular access or an extra-corporal circulation and the homemade technique that reduces the nosocomial transmission.
Published data from the DOPPS study [38] showed that the mean prevalence of HBV fluctuates between 0% in the United Kingdom and 6.6% in Italy [Table 5]. The low prevalence observed in UK is explained by the large spread of PD to treat ESRD. [38] In our unit, 6% are Hbs Ag positive, despite the systematic vaccination in chronic dialysis patients. The prevalence is higher compared with the general population in Morocco: 1-3%, [39] and to blood donors: 2.01%. [17]
The management of viral infections in chronic dialysis essentially remains on preventive measures. Indeed, the incidence and prevalence of infections have decreased thanks to screening and prevention progress, but also to adequate hygienic and disinfection practice. [40] However, we still have de novo contaminations in HD units due to difficulties in applying universal hygienic precautions. Moreover, PD and home dialysis do help to prevent from infections. An early renal transplantation reduces the contamination risk.
Systematic and repeated screening of anti-HCV antibodies by the ELISA technique is necessary in each HD patient newly registered in a HD unit or when one gets transferred from another HD unit. [5] In case of positive serology, a second sample is indicated to eliminate an error. Then, a PCR investigation is needed to confirm the presence of viral RNA. The National Kidney Foundation states the situations for serological screening and PCR confirmation. [5]
There is still a debate concerning the separation between infected and uninfected patients, based on the argument of contracting virus by parenteral and nosocomial means of transmission. On the other hand, identifying and isolating contaminators are still difficult, and a negative serological test does not exclude infection due to the six-month possible serological interval. In our HD unit, infected and uninfected patients are not separated.
Nowadays, there is no efficient vaccine against HCV. RNA viruses quickly evolve, and to get a vaccine against many genotypes is a hard task. [41]
Concerning HBV infection, recommendations are for systematic vaccination in ESRD patients at an early stage in order to maximize the vaccine response. Available data show that this vaccination protects a large majority of HD patients, but vaccine-induced antibody levels decline with time. However, immune memory remains intact for more than 20 years following immunization, and both adults and children with declining antibody levels are still protected against significant HBV infection. [42]
HCV is the most common viral infection in patients on chronic dialysis in the Rabat University Hospital, especially in the HD unit. This phenomenon might be related to the long survival on HD and to the difficulties to follow hygienic universal procedures. Preventing infections starts by being rigorous in hygienic measures and also by promoting PD and kidney transplantation.
Conflict of interest: None
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Correspondence Address:
Dr. Zineb Lioussfi
Department of Nephrology, Dialysis and Renal Transplantation, Ibn Sina Hospital, Rabat
Morocco
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/1319-2442.132236
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5] |
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