CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Hepatitis B virus (HBV) infection remains one of the most serious and widespread infectious diseases affecting humanity today, posing a major global health burden, particularly in developing countries. HBV is a hepatotropic double-stranded DNA virus belonging to the Hepadnaviridae family, and it primarily targets hepatocytes—the functional cells of the liver—causing hepatic inflammation and progressive liver injury (Lavanchy, 2019). The infection manifests in a spectrum of clinical outcomes ranging from acute hepatitis to chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC), which is among the leading causes of liver-related deaths worldwide (Yuen et al., 2018; Terrault et al., 2018).

According to the World Health Organization (WHO, 2023), approximately 296 million people were living with chronic hepatitis B infection globally, with an estimated 1.5 million new infections occurring each year. HBV is responsible for nearly 820,000 deaths annually, mostly from cirrhosis and liver cancer. The global burden is disproportionately concentrated in sub-Saharan Africa and East and Southeast Asia, where perinatal (vertical) and horizontal (early childhood) transmissions are predominant modes of infection (WHO, 2023; Schweitzer et al., 2015). In these endemic regions, infection acquired early in life often progresses to chronic hepatitis, making prevention and early detection vital.

Pregnant women represent a critical population for HBV surveillance and prevention because of the significant risk of vertical transmission—the passage of HBV from mother to child during childbirth or through contact with infected maternal fluids. Without appropriate intervention, the risk of mother-to-child transmission (MTCT) ranges from 70% to 90% among mothers who are both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive (Pan et al., 2016). Infants infected through this route have a 90% likelihood of developing chronic HBV infection, compared to less than 5% in adults (Hou et al., 2019). Preventing HBV among pregnant women, therefore, plays a vital role in reducing both maternal complications and neonatal infections.

In Nigeria, hepatitis B virus infection remains a major public health concern. The country is classified as hyperendemic, with an estimated national prevalence ranging from 8% to 15%, depending on region and study population (Oladokun et al., 2021; Musa et al., 2015). The high prevalence is attributed to factors such as limited access to healthcare, low awareness, inadequate screening, unsafe medical practices, and poor vaccination coverage. Despite the introduction of the HBV vaccine into the National Programme on Immunization (NPI) in 2004, coverage and uptake remain suboptimal in many rural communities (Audu et al., 2020). As a result, many pregnant women remain unaware of their HBV status until complications arise, which increases the risk of both maternal and neonatal morbidity.

Dutse Local Government Area (LGA) in Jigawa State, located in northwestern Nigeria, is predominantly rural, with a large proportion of its population depending on Primary Health Centres (PHCs) for antenatal and delivery services. However, local data on the prevalence of hepatitis B infection among pregnant women in this area remain scarce. Limited epidemiological data hinder effective planning and implementation of HBV control strategies, including screening programs, maternal immunization, and post-exposure prophylaxis for newborns (Olayinka et al., 2016).

This research, therefore, aims to determine the prevalence of hepatitis B virus infection among pregnant women attending PHC Dutse, Jigawa State. By providing evidence-based information on the epidemiology of HBV among this vulnerable group, the findings will help guide public health interventions, policy formulation, and maternal healthcare strategies in the region. The study is expected to contribute to the broader goal of eliminating viral hepatitis as a public health threat by 2030, in line with the WHO Global Health Sector Strategy (GHSS) on viral hepatitis (WHO, 2022). Ultimately, the outcomes will assist policymakers, healthcare professionals, and researchers in developing effective approaches to prevent mother-to-child transmission and reduce the burden of HBV among women of reproductive age in Nigeria.

1.2 Statement of the Problem

Despite global efforts to reduce the burden of hepatitis B through vaccination and awareness campaigns, the infection continues to pose a threat to maternal and child health in Nigeria. The lack of routine screening for hepatitis B in antenatal clinics, coupled with inadequate public health education, has led to underreporting and late diagnosis of the disease.

In Dutse, many pregnant women attend antenatal care without undergoing HBV screening due to limited laboratory capacity and lack of awareness. Consequently, infected mothers may unknowingly transmit the virus to their newborns, perpetuating the cycle of infection.

Therefore, there is a pressing need to assess the prevalence of HBV among pregnant women attending PHC Dutse to provide baseline data for improved healthcare planning and targeted interventions.

1.3 Aim and Objectives of the Study

The Aim of the Research is to:

Determine the prevalence of hepatitis B virus among pregnant women attending KACHI PRIMARY HEALTH CENTRE (PHC) Dutse, Jigawa State.

The Objectives of this Research is to:

1. Determine the seroprevalence of hepatitis B surface antigen (HBsAg) among pregnant women attending PHC Dutse.
2. Assess the relationship between HBV infection and selected socio-demographic factors such as age, parity, and educational level.
3. Evaluate the level of awareness and knowledge about hepatitis B virus among the pregnant women.
4. Identify potential risk factors associated with HBV infection among the study population.

1.4 Research Questions

1. What is the prevalence of hepatitis B virus infection among pregnant women attending PHC Dutse?
2. What socio-demographic factors are associated with HBV infection among the pregnant women?
3. What is the level of knowledge and awareness about HBV infection among these women?
4. What risk factors contribute to the transmission of HBV among pregnant women in Dutse?

1.5 Significance of the Study

This study is significant in several ways:

• It will provide baseline data on the prevalence of HBV among pregnant women in Dutse, which can guide local health authorities in designing prevention and control programs.
• It will help promote the inclusion of routine HBV screening in antenatal care services.
• The findings will create awareness among pregnant women on the importance of hepatitis B vaccination and preventive practices.
• The study will contribute to existing literature on HBV epidemiology in northern Nigeria.

1.6 Scope of the Study

The study focuses on pregnant women attending antenatal care at PHC Dutse, Jigawa State. It will cover aspects such as socio-demographic characteristics, HBV seroprevalence, awareness levels, and potential risk factors. The study will not include other viral hepatitis infections (e.g., Hepatitis C or D).

1.7 Definition of Terms

• Hepatitis B Virus (HBV): A viral infection that attacks the liver and can cause both acute and chronic diseases.
• Prevalence: The proportion of individuals in a population found to have a condition at a specific time.
• Seroprevalence: The level of a pathogen in a population, as measured in blood serum.
• Pregnant Women: Women carrying a developing fetus within the uterus.
• KACHI PRIMARY HEALTH CENTRE (PHC): The first level of contact between individuals and the national health system.