1.1 Introduction
Yellow Fever is a viral hemorrhagic disease caused by the yellow fever virus, primarily transmitted by Aedes and Haemagogus mosquitoes. The symptom of the disease leads to fever and chills to a severe liver illness that includes bleeding and jaundice (WHO, 2021). Yellow fever, a viral hemorrhagic disease transmitted by infected mosquitoes, presents a significant public health challenge, particularly in tropical regions of Africa and South America. Despite ongoing efforts to control and prevent outbreaks, yellow fever continues to claim lives and strain healthcare systems.
Although an effective vaccine for yellow fever exists, logistical challenges, limited resources, and vaccine hesitancy often result in inadequate immunization coverage (CDC, 2022). Socioeconomic factors also play a role in the prevalence of yellow fever. Poor infrastructure, including inadequate sanitation and water management, contributes to the proliferation of mosquito breeding sites. Additionally, limited access to healthcare services impedes timely diagnosis and treatment, exacerbating the spread of the disease (Gershman & Staples, 2019).
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
Yellow fever has a long and storied history as a major public health concern, with its presence documented as far back as the 17th century. The disease likely originated in Africa and was transported to the Americas through the transatlantic slave trade, where it became endemic in tropical regions of both continents (Crosby, 2007). The history of yellow fever is marked by numerous severe outbreaks, particularly in the 18th and 19th centuries. One of the most notable early outbreaks occurred in Philadelphia in 1793, killing approximately 10% of the city's population and leading to significant advances in public health responses (Carrigan, 1994). Similar outbreaks occurred in various port cities in the United States and the Caribbean, highlighting the disease's devastating potential and its ability to spread rapidly in densely populated areas.
The yellow fever virus was first identified in the late 19th century, and the development of a vaccine in the mid-20th century provided a powerful tool for disease prevention (Monath & Vasconcelos, 2015). Despite these advancements, yellow fever remains a substantial health threat in many parts of the world. The World Health Organization (WHO) estimates that there are approximately 200,000 cases and 30,000 deaths annually due to yellow fever, with 90% of these occurring in Africa (WHO, 2021). Yellow fever, a viral disease caused by the yellow fever virus and transmitted primarily by Aedes and Haemagogus mosquitoes, has been a significant public health issue for centuries. The disease is endemic in tropical regions of Africa and South America, where environmental conditions and socioeconomic factors favor its persistence and spread. Historically, yellow fever has caused numerous devastating outbreaks, prompting the development of vaccines and vector control measures to mitigate its impact.
Several factors contribute to the continued high prevalence of yellow fever in endemic areas. Environmental conditions, such as high temperatures and humidity, create ideal breeding habitats for the mosquito vectors. These conditions are prevalent in tropical regions, making vector control challenging (Gershman & Staples, 2019).
The etiological agent of yellow fever, the yellow fever virus, was identified in 1927, and shortly thereafter, the role of Aedes mosquitoes as vectors was confirmed (Monath & Vasconcelos, 2015). This discovery was crucial for developing control measures aimed at reducing mosquito populations and limiting disease transmission. During the early 20th century, significant progress was made in controlling yellow fever through vector control programs, particularly in urban areas.
The development of the 17D yellow fever vaccine by Max Theiler in the 1930s marked a turning point in the fight against yellow fever. Theiler's work earned him the Nobel Prize in Physiology or Medicine in 1951, and the vaccine became a cornerstone of yellow fever prevention efforts (Frierson, 2010). Despite this breakthrough, the implementation of widespread vaccination campaigns faced numerous challenges, including logistical difficulties, vaccine supply shortages, and limited public health infrastructure in endemic regions.
Socioeconomic factors also play a critical role. In many endemic regions, limited access to healthcare services and poor infrastructure hinder effective disease management and prevention efforts. Poverty, inadequate sanitation, and lack of clean water contribute to the proliferation of mosquito breeding sites, increasing the risk of transmission (Mutebi & Barrett, 2002). Vaccination remains the most effective means of preventing yellow fever. However, logistical challenges in vaccine distribution, coupled with vaccine hesitancy and limited public health resources, often result in suboptimal vaccination coverage (CDC, 2022). Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the factors leading to high Prevalence of Yellow Fever Diseases Among People.
1.3 Statement of Problems
Investigation revealed that although an effective vaccine for yellow fever has been available for decades, vaccination coverage remains inadequate in many endemic regions. Challenges such as logistical difficulties in vaccine distribution, vaccine hesitancy, and limited public health infrastructure impede the achievement of widespread immunization. Consequently, large segments of the population remain vulnerable to yellow fever outbreaks (WHO, 2021; CDC, 2022).
Additionally, poverty, inadequate sanitation, and limited access to healthcare services are prevalent in many yellow fever-endemic regions. These socioeconomic conditions contribute to the persistence of mosquito breeding sites and hinder effective disease management and control efforts. Poor infrastructure and resource constraints make it difficult to implement comprehensive vector control programs and ensure timely medical intervention (Gershman & Staples, 2019).
Furthermore, the effective control of yellow fever relies on robust surveillance systems to detect and respond to outbreaks promptly. However, many endemic regions lack the necessary public health infrastructure and resources to maintain such systems. This deficiency leads to delays in outbreak detection and response, allowing the disease to spread unchecked (Monath & Vasconcelos, 2015). Hence, it is against this backdrop that this study aims to identify the factors leading to high Prevalence of Yellow Fever Diseases Among People.
1.4 Aim and Objectives of Study
The aim of the study is to assess the factors leading to high Prevalence of Yellow Fever Diseases Among People. In achieving this aim, the following specific objectives were laid out as follows:
- To assess the capacity and effectiveness of public health infrastructure and surveillance systems in detecting and responding to yellow fever outbreaks;
- To evaluate how increased human mobility and migration patterns contribute to the spread of yellow fever;
- To analyze the relationship between socioeconomic conditions, such as poverty, sanitation, and access to healthcare, and the prevalence of yellow fever;
- To identify specific socioeconomic barriers that hinder effective disease management and control; and
- To suggest improvements to strengthen public health infrastructure and enhance outbreak response mechanisms.
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:
- Does an increased human mobility and migration pattern contribute to the spread of yellow fever?
- What is the capacity and effectiveness of public health infrastructure and surveillance systems in detecting and responding to yellow fever outbreaks?
- What are the specific socioeconomic barriers that hinder effective disease management and control?
- What is the relationship between socioeconomic conditions, such as poverty, sanitation, and access to healthcare, and the prevalence of yellow fever?
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.
- H01: Poor socioeconomic conditions, including poverty, inadequate sanitation, and limited access to healthcare services, are positively correlated with the high prevalence of yellow fever in affected regions.
- H02: Weak public health infrastructure and inadequate surveillance systems lead to delays in outbreak detection and response, contributing to the sustained high prevalence of yellow fever.
1.7 Significance of Study
The findings of this research will inform improvements in yellow fever vaccination programs by addressing logistical challenges, vaccine hesitancy, and infrastructure limitations. Enhanced vaccination coverage can significantly reduce the incidence of yellow fever and prevent outbreaks (CDC, 2022). Also, this study will provide a foundation for future research on yellow fever and other vector-borne diseases. By identifying key factors and gaps in current knowledge, it can guide further studies aimed at understanding and mitigating the spread of these diseases (Frierson, 2010).
Furthermore, this study is of great significance as it provides a comprehensive understanding of the factors contributing to the high prevalence of yellow fever. The insights gained can lead to more effective public health interventions, improved vaccination and vector control programs, better socioeconomic conditions, and strengthened public health infrastructure, ultimately reducing the burden of yellow fever and improving health outcomes in affected regions.
Finally, the findings of this research will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.8 Scope of Study
The scope of the research is focused on assessment of factors leading to high Prevalence of Yellow Fever Diseases Among People using Isa Local Government Area of Sokoto State as a case study.
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
Yellow Fever:
A viral hemorrhagic disease caused by the yellow fever virus, primarily transmitted by Aedes and Haemagogus mosquitoes (WHO, 2021).
Prevalence:
The proportion of a population found to have a condition (typically a disease) at a specific time. In this context, it refers to the extent of yellow fever cases in a given population (CDC, 2022).
