| Abstract|| |
Chronic kidney disease is an emerging public health issue in Africa. At end-stage renal disease (ESRD), patients need hemodialysis (HD), which may expose them to blood transmitted infections, such as the hepatitis C virus (HCV). Sub-Saharan Africa has the highest HCV prevalence in the world, but data on HD patients is scarce and shows an exceptionally high rate in Senegal. To assess the efficacy of preventive measures in reducing HCV infection among dialysis patients, we retrospectively conducted a cross-sectional study in three Senegalese HD centers, including all HD patients who performed HCV serology between 1 st and 31 st August 2011. The demographical, clinical, and biological data were collected for each patient. We included 106 patients with a mean age of 43.4 ± 15.8 years (range from 18 to 80 years), with 52.8% males. HD vintage was 60.5 ± 15 months (range from six to 206 months). The main causes of kidney disease included nephrosclerosis (36%) and diabetes (24%). The prevalence of HCV was 5.6%, with one patient co-infected with the hepatitis B virus. After adjusting for age and sex, HD vintage was the only risk factor for HCV infection, while nutritional status and the number of blood transfusions did not significantly correlate with HCV infection. We conclude that during the past decade, the prevalence of HCV infection in HD patients living in Senegal has declined considerably, mainly because of improved transfusion measures and better clinical practice in the HD centers. Such efforts should be maintained and reinforced to reduce the seroprevalence of HCV infection.
|How to cite this article:|
Seck SM, Dahaba M, Gueye S, Ka EF. Trends in hepatitis C infection among hemodialysis patients in Senegal: Results of a decade of prevention. Saudi J Kidney Dis Transpl 2014;25:1341-5
|How to cite this URL:|
Seck SM, Dahaba M, Gueye S, Ka EF. Trends in hepatitis C infection among hemodialysis patients in Senegal: Results of a decade of prevention. Saudi J Kidney Dis Transpl [serial online] 2014 [cited 2019 Sep 21];25:1341-5. Available from: http://www.sjkdt.org/text.asp?2014/25/6/1341/144319
| Introduction|| |
Chronic kidney disease (CKD) is an emerging public health issue in Africa.  Progress in renal replacement therapies has dramatically improved the quality of life and survival of patients with end-stage renal disease (ESRD). However, hemodialysis (HD) patients are more exposed to blood-transmitted infections, such as hepatitis C virus (HCV), which can result in cirrhosis and hepatocarcinoma. , Sub-Saharan Africa has the highest HCV prevalence rate (5.3%) in the world,  but data on HD patients are scarce, particularly in the West African countries. A previous report in 1998, demonstrated a markedly high prevalence of HCV infection (80%) in Senegalese patients undergoing HD.  Since then, the number of the dialysis population has grown significantly and preventive strategies have been developed to reduce the burden of HCV in HD units.
In this study we aim to determine the efficacy of preventive measures in reducing HCV infection among our HD patients.
| Patients and Methods|| |
We conducted a cross-sectional retrospective study in the three biggest hemodialysis centers in Senegal from 1 and 31 August, 2011. We included all ESRD patients, who were dialyzed for at least three months, and who had serological tests for HCV performed within a year. The patients with acute kidney injury and patients whose serological tests were not available were excluded from the study.
For each patient, we collected the following clinical and biological data: Age, gender, cause of ESRD, HD vintage, history of invasive procedures and blood transfusions, before or after initiation of HD, and physical examination, serum aminotransferases, alkaline phosphatase, and dosage of anti-HCV antibodies (anti-HCV Ab). In each center, serological tests were performed at dialysis onset and then every six months during routine follow-up for dialysis.
Determination of HCV serology used a third generation enzyme-linked immunosorbent assay (ELISA) method, and reverse transcriptase polymerase chain reaction (RT-PCR) was performed in case of a positive screening. The genotype of the HCV isolates was determined by sequencing the NS5B region.
| Statistical analyses|| |
We performed the analysis of the data using the SPSS software version 16.0. Data were presented as the mean ± standard deviation or percentage according to the type of the variables. The statistical tests used to compare averages and variables were adapted to the type and distribution of variables (t-test, Man- Whitney, Chi-square). The risk factors associated with HCV were identified using uni-variate and multivariate logistic regression analyses. All statistical tests were considered statistically significant when the P value was ≤0.05.
| Results|| |
Among a targeted population of 138 HD patients, 106 (76.81%) were included in the study. The mean age of the patients was 43.4 ± 15.8 years (range of 18 - 80 years) with a male predominance (52.8%). The mean HD vintage was 60.5 ± 15 months (6 - 206 months). The etiology of ESRD was hypertension and diabetes in more than half of the study patients [Figure 1]. In all the participating centers, the medical staff received continuous training for improvement of clinical practice in HD. The serological tests for detection of HCV were positive in six patients (prevalence of 5.6%) and one of them presented a co-infection with hepatitis B virus. Since the initiation of HD, a majority of patients (96.2%) received blood transfusion at least once and 30.1% underwent invasive procedures, such as, surgery, gastroscopy, and dental extractions. [Table 1] presents the main clinical and biological findings in the study patients with and without HCV. On account of financial inaccessibility, genotype determination was performed in only three patients and revealed genotype 1b. Two patients were treated with interferon. Isolation patients were treated with interferon. Isolation of patients with positive HCV tests was not applied in any of the three centers. Univariate analysis showed a significant correlation between HCV infection and dialysis vintage (OR = 2.5; P = 0.02), and age (OR = 1.2; P = 0.04), and number of blood transfusions (OR = 1.35; P = 0.05). In multiple logistic regression analysis, only dialysis vintage remained significantly associated with the presence of anti-HCV antibodies [Table 2].
|Table 1: Biological parameters (data are expressed as the means and ranges)|
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| Discussion|| |
The real burden of HCV in West African hemodialysis patients is unknown. Our present study is the first one that has assessed the seroprevalence of HCV in a large multicenter cohort from this area. As expected, hepatitis C is more frequent in HD patients than in the general population living in West Africa (2.4%)  and Senegal (1.4%).  However, it is far below the reported prevalence in HD patients from other African regions, which ranges from 5-68%. ,,,, North African countries seem to have a higher prevalence  than the sub-Saharan ,, and East African countries. ,
Interestingly, the low HCV infection prevalence in our HD population is in contrast with the generally higher prevalence reported in the developing world, and compared to the developed countries. ,,, Moreover, our results show a marked decline in HCV infection prevalence among Senegalese HD patients between 1998 and 2010 (from 80% to 5.6%).  The same decreasing trend has been noted in many other countries. ,, This remarkable decline can be explained by more adherence of the medical staff in the Dialysis Units to the aseptic measures and a better transfusion policy, with the introduction of systematic screening for HCV among blood donors in Senegal, in 2007. Furthermore, the availability of erythropoietin has reduced the indication for blood transfusion and the associated risk of infection.
There are a such as Morocco  and Tunisia. 
Consistent with the previous studies, ,,, we found a strong correlation between the dialysis vintage and the presence of anti-HCV antibodies. This association is suggestive of a nosocomial pattern of HCV transmission in our patients, but it is difficult to confirm in the absence of systematic HCV serology at dialysis onset and genotype determination. 
In sub-Saharan Africa, the most common route of HCV transmission may be iatrogenic, through blood transfusions and invasive procedures.  The estimated risk of being infected with HCV from a blood transfusion is 2.5 infections per 1000 units.  This risk could be even higher in HD patients, who receive blood transfusions more frequently because of erythropoietin inaccessibility.
Isolation of patients with HCV is not mandatory in Senegalese HD centers, but it could be an additional strategy to reduce seroconversion in HD patients.  Other factors such as age and blood transfusions are frequently reported in the literature. ,,,, In our study they were not significantly correlated with HCV infection, probably because of the small number of cases. Similar to a previous report from Morocco, invasive procedures such as abdominal surgery and dental extraction were not significantly associated with the occurrence of HCV infection. 
We had some limitations in our study. First, we included only the patients who had recent HCV tests. Second, PCR was not systematically done in all the patients. Furthermore, the study design did not permit inferences either about the causal nature of the associations or a distinction between the patients infected before and after initiation of dialysis.
Despite the observed decline in HCV very few data about distribution of HCV genotypes in African hemodialysis patients, but the subtype 1b found in our patients is similar to the predominant strains in north African countries prevalence, prevention strategies should be maintained and reinforced, with a particular focus on inter-individual transmission within the dialysis centers, as the duration of hemodialysis was the strongest determinant of hepatitis infection in our patients. Implementation of regular audits in accordance with the best practice clinical guidelines, as we did in our HD centers, must be encouraged in all HD centers, in order to decrease the risk of nosocomial transmissions. ,,
We conclude that our study suggests that the prevalence of HCV infection in Senegalese HD patients has declined considerably during the last decade, approaching levels reported in the developed countries. This epidemiological transition is mainly due to improved blood safety control at the national level and better practice in the HD centers. However, dialysis vintage remains a risk factor for HCV infection, and preventive measures must be reinforced to minimize new cases of nosocomial transmissions.
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Dr. Sidy Mohamed Seck
Faculty of Health Sciences, Gaston Berger University, Route de Ngallèle BP 234, Saint-Louis
[Table 1], [Table 2]