1.1 Introduction
Parasitic diseases are illnesses caused by organisms that live on or inside another living organism, known as the host, and obtain nourishment at the host's expense. These parasites include protozoa, helminths (worms), and ectoparasites such as lice and mites, all of which have significant effects on human health. According to the World Health Organization (2023), parasitic diseases continue to affect billions of people globally, with the highest burden occurring in tropical and subtropical regions where environmental conditions favor parasite survival and transmission. The impact of these diseases extends beyond health, contributing to poverty, reduced productivity, poor educational outcomes, and increased healthcare costs.
The spread of parasitic diseases is closely linked to environmental conditions. Factors such as poor sanitation, contaminated water supplies, improper waste disposal, stagnant water, high humidity, flooding, deforestation, and climate change create environments that promote the growth and transmission of parasites and their vectors. The Centers for Disease Control and Prevention (2024) reported that environmental contamination with parasite eggs, larvae, or cysts significantly increases the likelihood of infection through contaminated food, water, soil, or insect vectors.
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
Parasitic diseases are among the most common infectious diseases affecting humans and animals worldwide. According to the World Health Organization (2023), parasitic diseases are caused by organisms that live in or on a host and obtain nutrients at the host's expense, often leading to illness, disability, and, in severe cases, death. These diseases include malaria, schistosomiasis, ascariasis, hookworm infection, giardiasis, amoebiasis, and other neglected tropical diseases that continue to place a heavy burden on public health, particularly in developing countries.
Cheesbrough (2018) reported that contaminated soil, polluted water, poor drainage systems, and inadequate sanitation provide suitable conditions for parasite eggs, larvae, cysts, and vectors to survive and infect humans. In many rural and urban communities, poor environmental hygiene exposes individuals to repeated contact with disease-causing parasites through contaminated food, water, and soil. These conditions remain common in areas where access to basic sanitation and clean water is limited. Similarly, according to Garcia (2020), environmental sanitation is one of the most effective approaches to preventing parasitic infections. Garcia stated that proper waste disposal, access to safe drinking water, improved sewage systems, and good personal hygiene significantly reduce exposure to parasites. Where these environmental services are lacking, infections continue to spread rapidly, particularly among children, pregnant women, and economically disadvantaged populations.
In the same vein, according to Centers for Disease Control and Prevention (2024), contaminated water, poor sanitation, and unsafe food handling remain major sources of transmission for many intestinal parasites. The organization affirmed that individuals living in environments with poor hygiene infrastructure are more likely to experience repeated infections because parasites easily contaminate water sources, agricultural products, and household surroundings. Furthermore, according to Hotez et al. (2020), neglected tropical diseases continue to affect more than one billion people globally, with parasitic infections accounting for a significant proportion of these illnesses. The researchers contended that poverty and poor environmental conditions reinforce each other, creating a cycle where inadequate sanitation increases disease transmission, while illness limits educational attainment, economic productivity, and community development. Environmental improvement therefore remains an essential component of sustainable disease prevention.
Moreover, according to United Nations Environment Programme (2022), rapid urbanization, indiscriminate waste disposal, deforestation, flooding, and environmental degradation have increased human exposure to vectors and parasites. The organization reported that changes in land use and poor environmental planning alter natural ecosystems, creating breeding grounds for mosquitoes, snails, flies, and other organisms involved in transmitting parasitic diseases. Communities with weak environmental management systems often experience higher infection rates than those with effective sanitation and waste management practices.
Correspondingly, according to the Intergovernmental Panel on Climate Change (2023), climate change has become an important environmental factor influencing the spread of vector-borne and parasitic diseases. The panel stated that increasing temperatures, changing rainfall patterns, prolonged flooding, and rising humidity create favorable ecological conditions for parasite development and vector multiplication. This study is set against the backdrop of the continued spread of parasitic diseases resulting from poor environmental sanitation, unsafe water sources, inadequate waste management, climate-related environmental changes, and weak environmental health practices.
1.3 Statement of Problems
Investigation revealed that parasitic diseases remain a major public health challenge because environmental conditions such as poor sanitation, unsafe water, improper waste disposal, stagnant water, and flooding continue to promote the survival and spread of parasites. These conditions increase the risk of infections such as malaria, schistosomiasis, and intestinal worm diseases, particularly in communities with inadequate environmental health facilities. On the other hand, poor awareness of environmental hygiene and weak sanitation practices further increase people's exposure to parasitic infections (World Health Organization [WHO], 2023).
Additionally, many disease control efforts focus mainly on treatment rather than eliminating the environmental conditions that support parasite transmission. Inadequate waste management, poor drainage systems, and limited access to clean water continue to expose many people to repeated infections, especially children and vulnerable populations (Centers for Disease Control and Prevention [CDC], 2024).
Furthermore, there is a need to better understand how environmental factors contribute to the spread of parasitic diseases in order to develop more effective prevention and control strategies. Identifying these factors will provide useful information for improving environmental sanitation, public health interventions, and disease prevention. It is against this backdrop that this study seeks to examine the environmental factors influencing the spread of parasitic diseases.
1.4 Aim and Objectives of Study
The aim of this study is to examine the environmental factors influencing the spread of parasitic diseases. In achieving this aim, the following specific objectives were laid out as follows:
- To identify the environmental factors responsible for the spread of parasitic diseases.
- To examine the influence of poor sanitation on the spread of parasitic diseases.
- To determine the effect of unsafe water sources on the spread of parasitic diseases.
- To assess the role of waste disposal practices in the spread of parasitic diseases.
- To identify measures for reducing the spread of parasitic diseases through environmental management.
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 environmental factors are responsible for the spread of parasitic diseases?
- How does poor sanitation influence the spread of parasitic diseases?
- What effect do unsafe water sources have on the spread of parasitic diseases?
- What role do waste disposal practices play in the spread of parasitic diseases?
- What measures can reduce the spread of parasitic diseases through environmental management?
1.6 Research Hypotheses
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.
Hypothesis One
- H0: There is no significant relationship between environmental factors and the spread of parasitic diseases.
- H1: There is a significant relationship between environmental factors and the spread of parasitic diseases.
Hypothesis Two
- H0: Poor sanitation has no significant influence on the spread of parasitic diseases.
- H1: Poor sanitation has a significant influence on the spread of parasitic diseases.
Hypothesis Three
- H0: Unsafe water sources have no significant effect on the spread of parasitic diseases.
- H1: Unsafe water sources have a significant effect on the spread of parasitic diseases.
Hypothesis Four
- H0: Waste disposal practices have no significant role in the spread of parasitic diseases.
- H1: Waste disposal practices have a significant role in the spread of parasitic diseases.
Hypothesis Five
- H0: Environmental management measures have no significant effect on reducing the spread of parasitic diseases.
- H1: Environmental management measures have a significant effect on reducing the spread of parasitic diseases.
1.7 Significance of Study
The outcome of this research will benefit government agencies by providing information for planning effective environmental health policies. Also, the research will provide useful information for improving environmental sanitation as a means of reducing the spread of parasitic diseases.
Furthermore, the study will assist healthcare workers in strengthening disease prevention and community health education. It will also help environmental health officers improve sanitation monitoring and environmental control activities.
Lastly, the study will provide researchers with relevant information for future studies on parasitic diseases and environmental health.
1.8 Scope of Study
This study focuses on the environmental factors influencing the spread of parasitic diseases in Lagos State, Nigeria. The study covers environmental sanitation, waste disposal, drainage systems, water supply, and hygiene practices that contribute to the transmission of parasitic diseases among residents of the state.
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
Environmental Factors:
These are physical, biological, and social conditions such as sanitation, water quality, drainage, climate, and waste disposal that influence human health and the transmission of diseases (World Health Organization, 2023).
Parasitic Diseases:
These are diseases caused by parasites that live in or on a host and obtain nourishment from the host, resulting in illness (Centers for Disease Control and Prevention, 2024).
Environmental Sanitation:
This refers to activities aimed at maintaining a clean environment through proper waste disposal, drainage maintenance, and safe water supply to prevent disease transmission (World Health Organization, 2023).
Waste Disposal:
This is the process of collecting, treating, and disposing of solid or liquid waste in a safe manner to protect public health and the environment.
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