1.1 Introduction
Drinking water quality refers to the physical, chemical, and microbiological condition of water intended for human consumption. Safe drinking water should be free from harmful microorganisms and dangerous levels of substances that pose risks to human health. According to the World Health Organization, contaminated drinking water is associated with the transmission of diseases caused by bacteria, viruses, and parasites. Assessing water quality is therefore important for protecting public health and identifying possible sources of infection (WHO, 2022).
Gastrointestinal parasitic infections on the other hand are illnesses caused by parasites that enter the digestive system, often through contaminated water or food. In Nigeria, drinking water is obtained from different sources, including boreholes, hand-dug wells, rivers, public water supplies, and packaged water. The safety of these sources depends on factors such as the protection of the water source, treatment methods, environmental sanitation, and storage practices.
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
The assessment of drinking water quality developed from the need to protect people against diseases associated with unsafe water. In earlier times, communities relied mainly on the appearance, smell, and taste of water to judge its suitability for consumption. However, these characteristics were not reliable indicators of safety because water containing harmful microorganisms often appeared clean. Over time, water quality assessment expanded to include physical, chemical, and microbiological testing. The introduction of filtration, disinfection, and improved water supply systems helped reduce exposure to several waterborne pathogens. However, different organisms require different control measures, and some parasites are more resistant to commonly used disinfectants than ordinary indicator bacteria.
Safe drinking water is essential for human survival, good health, and daily activities. Water is used for drinking, cooking, washing food, and maintaining personal hygiene. When water becomes contaminated with human or animal waste, it can serve as a pathway for harmful organisms to enter the body. The quality of drinking water is therefore an important factor in preventing diseases, particularly in communities where sanitation and water treatment facilities are inadequate. As cited by the World Health Organization (2022), drinking water safety depends on controlling hazards from the water source to the point where water is consumed.
Gastrointestinal parasitic infections occur when parasites enter the digestive system and survive or multiply within the body. Some intestinal parasites are transmitted through the ingestion of infective cysts, oocysts, or eggs in contaminated water or food. For example, Giardia duodenalis causes giardiasis, while Entamoeba histolytica causes amoebiasis. The symptoms of these infections range from mild digestive discomfort to prolonged diarrhoea and other serious complications. The Centers for Disease Control and Prevention (2024) reported that giardiasis is commonly transmitted when a person swallows water or food contaminated with the parasite. Similarly, the World Health Organization (2023) reported that unsafe drinking water, inadequate sanitation, and poor hygiene remain important environmental risks to human health.
Water quality assessment involves examining different characteristics of water. Physical indicators include colour, odour, turbidity, and temperature, while chemical indicators include pH and selected dissolved substances. Microbiological testing examines organisms that indicate contamination or cause disease. Where gastrointestinal parasites are the focus, appropriate laboratory procedures are required to detect relevant parasitic stages. Routine bacterial indicator tests alone do not establish whether all intestinal parasites are absent, so the choice of testing methods must reflect the purpose of the study.
In the Nigerian context, households obtain water from sources that differ in availability, treatment, and protection from environmental pollution. Boreholes and wells are widely used in areas where reliable public water supplies are limited, while rivers and streams serve some communities for domestic purposes. Packaged water is also consumed, although its safety depends on production standards, handling, and storage. Each source requires appropriate assessment because its appearance or popularity does not automatically establish that it is safe.
This study is set against the backdrop of the need for reliable local evidence on drinking water safety and gastrointestinal parasitic infections in Delta State, Nigeria.
1.3 Statement of Problems
Investigation revealed that gastrointestinal parasitic infections, including amoebiasis and giardiasis, are associated with the ingestion of contaminated water or food. These infections are capable of causing diarrhoea, abdominal discomfort, and other digestive problems, with children and people living in communities with poor sanitation facing particular risks. On the other hand, differences in water sources, handling practices, and household treatment methods make it necessary to assess drinking water quality and examine its relationship with reported gastrointestinal parasitic infections rather than assume that all water sources are equally safe.
Furthermore, inadequate routine testing of some local water sources and limited access to reliable information about contamination levels has the potential to make it difficult for residents to identify unsafe water. Additionally, without local evidence linking water quality indicators with gastrointestinal parasitic infections, public health authorities and communities may struggle to identify priority areas for intervention. It is against this backdrop that this study seeks to assess drinking water quality and its relationship with gastrointestinal parasitic infections in Delta State, Nigeria.
1.4 Aim and Objectives of Study
The aim of this study is to assess drinking water quality and its relationship with gastrointestinal parasitic infections in Delta State, Nigeria.
The specific objectives of this research are to:
- Determine the physical and chemical characteristics of selected drinking water sources in Delta State.
- Examine selected drinking water samples for relevant microbiological indicators and intestinal parasites using appropriate laboratory methods.
- Determine the occurrence of gastrointestinal parasitic infections among the study participants using an appropriate diagnostic approach.
- Examine the relationship between drinking water quality and gastrointestinal parasitic infections among the study participants.
- Identify water source characteristics and household water handling practices associated with potential contamination and infection risk.
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 are the physical and chemical characteristics of selected drinking water sources in Delta State?
- What relevant microbiological indicators and intestinal parasites are detected in the selected drinking water samples?
- What is the occurrence of gastrointestinal parasitic infections among the study participants?
- What relationship exists between drinking water quality and gastrointestinal parasitic infections among the study participants?
- Which water source characteristics and household water handling practices are associated with potential contamination and infection risk?
1.6 Significance of Study
The outcome of this research will provide information about the safety of selected drinking water sources and encourage informed decisions about water treatment and storage. The findings will also provide evidence to support water safety monitoring, sanitation programmes, and public health planning in Delta State.
Furthermore, the results will identify sampled water sources with quality concerns, supporting decisions about additional testing and appropriate corrective measures. It will also offer local evidence for health education and the identification of communities requiring further investigation into water-related infections.
Lastly, the findings will serve as a source of local information for future studies on drinking water contamination and gastrointestinal parasitic infections.
1.7 Scope of Study
This study focuses on the assessment of drinking water quality and its relationship with gastrointestinal parasitic infections in Delta State, Nigeria. The research is potentially limited by the number of water sources examined, the period of sample collection, laboratory resources, and the availability of reliable health information.
1.8 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).
1.9 Definition of Terms
Drinking Water:
Water intended for human consumption, including water used for drinking and food preparation. Its safety is assessed against relevant health-based and water quality requirements (World Health Organization, 2022).
Water Quality:
Water quality is the physical, chemical, and microbiological characteristics of water that determine its suitability for a particular use.
Water Quality Assessment:
Water quality assessment is the process of collecting and examining water samples to determine their characteristics and identify possible contamination.
Gastrointestinal Tract:
Gastrointestinal Tract is the digestive system, which includes the stomach and intestines and is responsible for processing food and absorbing nutrients.
Gastrointestinal Parasitic Infections:
Gastrointestinal parasitic infections are illnesses caused by parasites that enter or inhabit the digestive system.
Intestinal Parasites:
Intestinal parasites are organisms that live in or affect the human intestines and obtain nutrients or shelter from their host. Examples include Giardia duodenalis and Entamoeba histolytica (Centers for Disease Control and Prevention, 2024).
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