CHAPTER ONE:

INTRODUCTION

1.1.                         Background

            Viral Hepatitis is an inflammation of the liver as a result of viral infections [1,2]. Infections caused by viral hepatitis B and C are a health problem worldwide, with about 296 million people worldwide in 2019 said to have chronic hepatitis B infection, and about 1,5 million people getting new infections every year, while for hepatitis C it was estimated at the start of 2020 that 56.8 million people have a chronic infection globally with 1.5 million new cases every year [1,3–6]. Of the viruses that cause hepatitis, hepatitis B and C viruses are is responsible for the highest morbidity and mortality globally, mostly from liver cirrhosis and hepatocellular carcinoma [5]. About 95% of people who are chronically infected with either hepatitis B or C or both not being conscious of their status [7]. Hepatitis B virus (HBV) remains endemic in sub-Saharan Africa even with the availability of hepatitis B vaccine and antiviral therapy against hepatitis B, with an estimated prevalence of 6.1%, while the prevalence of hepatitis C virus (HCV) in sub-Saharan Africa is estimated at 2.98% [7,8]. Both viruses are endemic in Cameroon and the prevalence varies from region to region, with an estimated prevalence of HBV at 11.2% and that of HCV at 6.5 % in the general population [9,10]. In the 1960s, there were reported out breaks of viral hepatitis in the haemodialysis units among patients (and staff) after which infections preventive and control measures were put in place and this led to a reduction in the number of new cases of hepatitis B and hepatitis C in the dialysis setting. Although the rate of new infections dropped down, the prevalence of HBV and HCV continue to be high in the dialysis populations especially in areas of high endemicity [11].

            Haemodialysis (HD) is the main renal replacement therapy in patients with end stage kidney failure (ESKF). It is a therapeutic procedure that replaces the normal blood filtering functions of the kidney, in conditions where the kidneys can no longer perform its functions efficiently [12]. The quality and life expectancy of  haemodialysis patients has improved, but maintenance haemodialysis also increases their risk of becoming infected with blood borne viruses such as hepatitis B virus and hepatitis C virus as they require prolonged vascular access, share the haemodialysis machines and other items with other patients who are positive for hepatitis B and C viruses, have frequent blood transfusions and longer duration on dialysis [13–16]. The seroconversion rate of these viruses in patients on maintenance dialysis is especially high in developing countries where it varies from zero to 4.8% for HBV and from zero to 53.37 % for HCV [17–21]. Blood transfusion, which is the main means of management of anaemia of chronic kidney disease (CKD) in the developing world, longer duration on dialysis and also the non-respect of infectious control measures have been identified as some of the risk factors associated with the transmission of these blood borne viruses in the dialysis unit in the less developed countries [14,13,19,18].

1.2.                         Problem statement

             HBV and HCV infections are a global public health problem which primarily affects the liver, but also have adverse extrahepatic manifestations in organs such the kidney, and can increase morbidity and mortality in patients with ESKF [5]. Previous studies in Cameroon have reported a seroconversion rate of 0-1.1% for HBV and 7.1-25% for HCV [14,17,18]. These studies identified factors such as frequent blood transfusion and longer duration on dialysis to be independently associated with increased seroconversion rate. Although these studies showed a high seroconversion rate for these viruses, they were carried out about 7 years ago and there has been increased access to hepatitis C treatment and increased availability of hepatitis B vaccine, however unlike in developed countries, hepatitis B positive patients are still not isolated in haemodialysis centres in Cameroon. This study therefore seeks to assess todays seroconversion rate of hepatitis B and hepatitis C in patients on maintenance haemodialysis.

1.3.                         Justification

       Despite the availability of vaccine for HBV and antiviral therapy for both HBV and HCV, we still continue to have new infections globally, few studies have been carried out in Cameroon to the evaluate the seroconversion rate of these viruses and factors associated with it in patients on maintenance haemodialysis. Three studies have been published in Cameroon to the best of our knowledge, two evaluated the seroconversion rate of HCV while the other evaluated the seroconversion rate of both HBV, HCV and human immunodeficiency virus in patients on maintenance haemodialysis [17,18,14]. These studies evaluated rate of seroconversion to HBV and HCV positivity and some of the factors associated with. However, it has been close to 7 years now since the last study was done. This study titled seroconversion to hepatitis B, C positivity and hepatitis C viraemia in patients on maintenance haemodialysis: The case of two centres in Cameroon will therefore seek to identify the present seroconversion rate and factors associated with it given the improvement in infection control and availability of antiviral therapy. The knowledge from this study will contribute to our understanding of seroconversion to hepatitis positivity in patients on maintenance haemodialysis, and will help to reduce morbidity and mortality as a result of affection by these viruses.

1.4.      Research goal

       The goal of this research is to find out the rate of seroconversion to hepatitis B, and C positivity and assess hepatitis C viraemia in hepatitis C positive cases in patients on maintenance haemodialysis, those factors which make them more susceptible to acquiring these infections and to assess infection control practices among nurses of the haemodialysis unit, the knowledge of which will help us implement better prevention strategies.

1.5.      Research questions

1. What is the seroconversion rate of hepatitis B and C in haemodialysis patients in the Regional Hospital Bamenda (BRH) compared to Yaounde General Hospital (YGH)?
2. What is the rate of hepatitis C viraemia in patients with hepatitis C antibodies?
3. What are the factors associated with seroconversion to hepatitis B and C positivity in these patients?
4. What is the knowledge on the infection control for the prevention of hepatitis B and C among nurses in the haemodialysis unit?

1.6.          Research objectives

     General Objective

To study the rate of hepatitis B and C seroconversion and to assess hepatitis C viraemia in hepatitis C antibody positive cases in patients on maintenance haemodialysis and to evaluate infection control practices among nurses in the Regional Hospital Bamenda (RHB) and Yaounde General Hospital (YGH).

Specific Objectives

1. To compare the seroconversion rate of hepatitis B and C positivity in patients in the Regional Hospital Bamenda and Yaounde General Hospital
2. To measure the rate of hepatitis C viraemia in patients with hepatitis C antibodies.
3. To identify factors associated with seroconversion of patients to hepatitis B surface antigen and hepatitis C antibody.
4. To assess infection control knowledge for the prevention of hepatitis B and C among nurses of the haemodialysis unit.