1.1 Introduction
Fruits and vegetables are important for a healthy diet and help in preventing certain diseases and cancers (Said, 2012). There are reports that the consumption of fruits and vegetables provides some protection against cardiovascular diseases, diabetes, obesity, stroke, Alzheimer disease, and cataracts among others (Van et al., 2000 and Willett et al., 1995). Fruit and vegetable consumption also promotes health in diverse ways as they are rich in vitamins, minerals, phytochemicals especially antioxidants as well as a reliable source of dietary fibre to the extent that some developed countries have dietary recommendations for them (McGuire, 2010 and Darkwa et al., 2013).
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, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Fruits and vegetables are contaminated with parasites and, some parasitic infections which have direct life cycle and do not need an intermediate host to infect a new host are spread via these faecalorally transmitted parasites. Infections acquired through direct ingestion of infective egg or cyst is ultimately linked with level of hygiene and sanitation in the community.
Factors like lack of latrine, improper hand washing during prayers and other religious activities/practices, and adequate sewage disposal facilities have been known to contribute to the spread of the infective stages of the parasites as well, thereby bringing about a wide spread contamination of foods. Most times, infections can be acquired through preventable attitude of keeping contaminated unwashed fingers by food handlers and vendors, insects, circulation of currency and by wind during dry season. The resistance capacity of the eggs and cysts of these parasites has been identified as a feature of profound influence on its epidemiology. It is now known that eggs of Ascaris can remain viable for up to six years (Eneanya et al., 2003).
The nutritional and economic values of edible fruits and vegetables are very much recognized among the human populations. However, significant prevalence of diseases resulting directly from consumption of parasitological contaminated fruits and vegetables make it alarming, worrisome and a scientific cause of concern. Indigenous fruits and vegetables are known to play major role in the nutritional livelihood of Nigerians, especially in the rural areas and cities where there is poor socio-economic condition (Adeboye et al., 2008). Consumption of raw or unhygienically prepared vegetable is considered a risk factor for human parasitic infection (Orlandi et al., 2002). Some vegetables and most fruits are eaten raw to retain the natural taste and preserve heat labile nutrients but laboratory and epidemiological surveys have implicated this unhygienic practice as well as poor human sanitation as a major risk in the transmission of the parasitic diseases. It has also reported that in certain parts of Nigeria, the consumption of raw vegetable without proper washing is an important route in the transmission of parasitic diseases (Uneke, 2004). In Lokoja, Northcentral Nigeria, and its environs, fresh but raw fruit and vegetables are widely consumed, making it a major route/ mode of transmission of intestinal parasites and spread of high burdened foodborne diseases of great public health importance.
Various other factors contribute to increase in diseases associated with raw fruits and vegetables and intensification of the risk. They include globalization of food supply, introduction of pathogens into new geographical areas through import, use of untreated waste and manure as fertilizer for crop production, irrigation with contaminated water and various agronomic practices and level of hygiene of food handlers. Continued use of untreated waste water and manure as fertilizer and food handling are major contributing factors to contamination that cause numerous food-borne disease outbreaks.
Significant and alarming rates of diseases resulting from parasitological contamination of fruits and vegetables have been reported as well. Studies have shown that high prevalence of parasitic contamination of fruits and vegetables are most common in the tropics and sub-tropics. Geohelminthic infections are most prevalent in tropical and sub-tropical regions of the developing world, where adequate water and sanitation are lacking (Okoronkwo, 2000). Recent estimate suggests that Ascaris lumbriodes infects over one billion people, Trichuris trichuria infects 79 million and hookworm (Ancyclostoma duodenale and Necator americanus) infects 740 million people (WHO, 2008).
Furthermore, amoebiasis is known to cause about 450 million infections per annum in developing countries with an incidence of about 50 million and 100,000 deaths. Giardiasis, which is more common in Children, has a worldwide prevalence of about 1-30%. Ascaris, one of the geohelminthes is the commonest nematode of man especially in tropical Africa, with a prevalence of about 40% in Enugu State and may be as high as 96-100% in the rural community in Enugu state. More recent studies in rural villages of Ebonyi state, southeast Nigeria and other part of Nigeria have corroborated this high prevalence of parasites isolated from edible fruits and vegetables. 40% contamination of a total of 250 samples of edible fruits and vegetables sold in markets in rural villages of Ebonyi state has also been reported. Some of the parasites identified with their stages were ova of Ascaris lumbriodes (54.5%); Strongyloides stercoralis (6.9%); ova of hookworm (23.8%); Trichuris trichuria (8.9%); Enterobius vermicularis (5.9%) (Elom et al., 2012).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Parasitological Profile of Selected Fruits and Vegetables Sold in Four Selected Markets.
1.3 Statement of Problems
Fruits are difficult to keep for a considerable length of time, thus ripe fruits are utilized either as fresh fruit or processed into jam and other types of products. Most fruits are perishable in their natural state after harvest; deterioration sets in almost immediately due to metabolic activities which continue even after harvest.
The perishable nature makes it difficult to store and preserve fruits, hence, there is gradual loss of flavor and nutritional value. Large quantities of fruits are produced and wasted in Nigeria and many other developing tropical countries.
1.4 Aim and Objectives of Study
The aim of the study is to determine the Parasitological Profile of Selected Fruits and Vegetables Sold in Four Selected Markets. In achieving this aim, the following specific objectives were laid out as follows:
- To examine the effectiveness and relevance of a new and locally-adapted technology for control of parasitological contamination of fruits and vegetables.
- To isolate and identify the Parasites on Selected Fruits and Vegetables.
- To assess the number of fruits and vegetables contaminated with parasites in each market.
1.5 Significance of Study
This study 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.
1.6 Scope of Study
The study focuses on the Parasitological Profile of Selected Fruits and Vegetables Sold in Four Selected Markets in Nigeria.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- 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.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- 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).
1.8 Definition of Terms
Bananas: Banana plant is colloquially called a banana tree, it's actually an herb distantly related to ginger, since the plant has a succulent tree stem, instead of a wood one.
Flower: Flower is the seed-bearing part of a plant, consisting of reproductive organs (stamens and carpels) that are typically surrounded by a brightly coloured corolla (petals) and a green calyx (sepals).
Proximate: Proximate is used in the analysis of biological materials as a decomposition of a human-consumable good into its major constituents.
Analysis: Analysis is the process of breaking down a something into its parts to learn what they do and how they relate to one another.
Value: Values are basic and fundamental beliefs that guide or motivate attitudes or actions. They help us to determine what is important to us.
Nutrition: Nutrition is the biochemical and physiological process by which an organism uses food to support its life.
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