1.1 Introduction
Hepatitis B virus (HBV) infection is a major global public health problem characterized by liver inflammation that may progress to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. According to World Health Organization reports, HBV infection remains highly endemic in many low- and middle-income countries, particularly in sub-Saharan Africa, where transmission often occurs early in life and leads to long-term complications (World Health Organization, 2023). The diagnosis and monitoring of HBV infection rely largely on serological markers that reflect different stages of viral replication and host immune response.
Hepatitis B surface antigen (HBsAg) is widely used as the primary marker for identifying active HBV infection. Its presence in serum indicates ongoing viral replication and infectivity, while its absence is often interpreted as lack of infection (Lok & McMahon, 2016). However, several studies have asserted that the absence of HBsAg does not always equate to complete viral clearance, as individuals may still show evidence of past exposure or immune response through other serological markers (Dienstag, 2018).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are significance of the study, scope of work, research hypothesis and questions, limitation of the study and definition of terms.
1.2 Background of Study
Hepatitis B virus (HBV) infection is a significant global health challenge, affecting millions of individuals worldwide and contributing substantially to morbidity and mortality associated with chronic liver disease, cirrhosis, and hepatocellular carcinoma. According to the World Health Organization (2023), approximately 296 million people are living with chronic Hepatitis B infection, with the majority residing in low- and middle-income countries where healthcare infrastructure and routine screening are limited. Hepatitis B surface antigen (HBsAg) screening is widely used to detect active infection, yet it does not always reflect the complete immunological status of the patient (World Health Organization, 2023).
It is reported that individuals who test negative for HBsAg may still exhibit serological markers such as Hepatitis B envelope antibody (anti-HBe), which indicate previous exposure, seroconversion, or low-level viral replication. Researchers have asserted that anti-HBe positivity is associated with reduced viral replication and a lower risk of liver disease progression; however, it does not entirely rule out ongoing infection or potential transmission risk. Several studies have contended that monitoring anti-HBe alongside HBsAg provides a more comprehensive understanding of the infection status and immune response of patients.
Dienstag (2018) stated that failure to consider anti-HBe in patient evaluation may result in underestimation of exposure rates and misclassification of infection status. Similarly, Lok and McMahon (2016) affirmed that the presence of anti-HBe is a critical marker for understanding the natural history of HBV infection and guiding patient management, including treatment decisions and counseling on transmission risks. On the other hand, gaps in local epidemiological data limit effective public health planning and preventive strategies, particularly in resource-limited settings. Furthermore, Mendy et al. (2015) reported that anti-HBe detection in patients previously screened for HBsAg is an essential indicator of seroconversion and immune control over viral replication, and its assessment contributes to safer blood transfusion practices and improved patient monitoring. This study is set against the backdrop of the need to evaluate the prevalence and clinical implications of Hepatitis B envelope antibody in patients who have been previously screened for HBsAg.
1.3 Statement of Problems
Investigation revealed that hepatitis B virus infection remains a major public health concern globally, particularly in low- and middle-income countries where screening, vaccination coverage, and long-term monitoring are often inconsistent. Routine screening for Hepatitis B surface antigen (HBsAg) is widely used to identify active infection; however, this approach alone does not always provide a complete picture of an individual's immunological and infectious status.
The presence of Hepatitis B envelope antibody (anti-HBe) among patients who have previously tested negative for HBsAg presents a clinical and epidemiological challenge, as it raises concerns about resolved infection, low-level viral replication, or the possibility of occult hepatitis B infection. According to World Health Organization reports, reliance solely on HBsAg screening is insufficient for comprehensive assessment of Hepatitis B infection dynamics, particularly in endemic regions.
Furthermore, limited local data exist on the prevalence and clinical relevance of Hepatitis B envelope antibody among patients who have undergone prior surface antigen screening. The problem is compounded by the risk of silent transmission and delayed detection of liver complications, which continues to place a burden on healthcare systems. It is against this backdrop that this study seeks to assess the presence and significance of Hepatitis B envelope antibody in patients who have been previously screened for the surface antigen in order to contribute evidence that is relevant for improved diagnosis, monitoring, and control of Hepatitis B infection.
1.4 Aim and Objectives of Study
The aim of the study is to evaluate the presence and relevance of Hepatitis B envelope antibody among patients previously screened for HBsAg and its implications for clinical and public health practices. In achieving this aim, the following specific objectives were laid out as follows:
- To assess the clinical significance of anti-HBe in predicting viral replication and disease progression.
- To determine the prevalence of anti-HBe among patients who tested negative for HBsAg.
- To identify gaps in the existing HBV screening system regarding anti-HBe inclusion.
- To recommend strategies for integrating anti-HBe testing into routine HBV diagnostics.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- What is the prevalence of anti-HBe among patients who previously tested negative for HBsAg?
- How does anti-HBe positivity relate to viral replication and disease progression in these patients?
- What gaps exist in the current HBV screening system regarding anti-HBe detection?
- How can anti-HBe testing be effectively integrated into routine HBV diagnostic practices?
1.6 Research Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
- H0: There is no significant relationship between anti-HBe positivity and disease progression among patients previously screened for HBsAg.
- H1: There is a significant relationship between anti-HBe positivity and disease progression among patients previously screened for HBsAg.
1.7 Significance of Study
The outcome of this research will inform policymakers on the inclusion of anti-HBe testing in routine HBV surveillance, contributing to better public health outcomes. Also, the research will help healthcare providers improve patient management by including anti-HBe assessment in routine evaluation.
Furthermore, the findings will assist public health authorities in designing more effective HBV prevention and control strategies. In addition, patients will be empowered with better knowledge about their infection status and risks.
Lastly, the study will increase awareness among healthcare providers regarding the limitations of current screening protocols and encourage adoption of more comprehensive diagnostic approaches.
1.8 Scope of Study
The scope of the research is focused on the presence of hepatitis b envelope antibody in patients who have been previously screened for the surface antigen. The study includes adult patients who have undergone HBsAg screening at Lagos State University Teaching Hospital and are willing to participate in additional anti-HBe testing.
1.9 Limitations of the Study
During the course of this study, there were some problems encountered which stood as limitations to the research work. Some of the limitations include:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
- Initial Cooperation Delay from Respondents: A particular limitation of this work came as a result of the respondent refusal to offer their cooperation at the initial time they were contacted. This contributed in making the success of this research study difficult.
1.10 Definition of Terms
Hepatitis B Virus (HBV): A DNA virus that infects the liver and can lead to acute or chronic liver disease (Dienstag, 2018).
Hepatitis B Surface Antigen (HBsAg): A protein present on the surface of HBV that indicates active infection and was used as the primary screening marker (Lok & McMahon, 2016).
Hepatitis B Envelope Antibody (Anti-HBe): A serological marker that develops in the blood after HBeAg seroconversion and indicates reduced viral replication and partial immune control (Mendy et al., 2015).
Occult Hepatitis B Infection: A condition where HBV DNA is present in the liver or blood despite negative HBsAg test results, which was often undetected in routine screening (Dienstag, 2018).
Seroconversion: The process by which an individual develops detectable antibodies in the blood in response to infection or vaccination, indicating an immune response (Lok & McMahon, 2016).
Screening: The systematic testing of individuals to detect disease or markers of disease in apparently healthy populations (World Health Organization, 2023).
…
