CHAPTER ONE: INTRODUCTION

1.0 Background

Fruits and vegetables are essential components of a healthy diet, playing a crucial role in human nutrition due to their rich content of vitamins, minerals, dietary fiber, and antioxidants. They help prevent chronic diseases such as heart disease, cancer, diabetes, and obesity, while also addressing micronutrient deficiencies prevalent in many developing countries (1). The increasing recognition of their health benefits has led to a significant rise in global production and consumption, with fresh produce accounting for 86% of the total market share of food consumption worldwide (2). This surge in demand has been driven by health-conscious lifestyles, government initiatives promoting healthy eating, and eases of access to fresh produce (3). Despite their nutritional benefits, fruits and vegetables are significant vehicles for the transmission of foodborne diseases. According to the World Health Organization (WHO), one in ten people globally falls ill yearly from consuming contaminated food, resulting in over 420,000 deaths (4). Foodborne illnesses associated with fresh produce, such as those caused by pathogens like Escherichia coli, Salmonella, Shigella and Listeria monocytogenes, have increased due to greater consumption and more effective disease surveillance. The open nature of the fresh produce chain exposes these foods to contamination at various stages of production, harvesting, and processing. Microbial contamination of fresh fruits and vegetables occurs through diverse sources and routes, varying based on geographical regions and environmental factors. Pre-harvest contamination sources include soil, irrigation water, manure, and wildlife, while post-harvest contamination arises from human handling, harvesting equipment, rinse water, and processing facilities (5). For instance, contaminated water used for irrigation or rinsing produce can serve as a major source of harmful microorganisms, introducing pathogens such as bacteria, fungi, viruses, and parasites (3). In developing countries, where food safety practices are less stringent, contamination risks are exacerbated by inadequate handling, storage, and packaging technologies.

Fruits and vegetables consumed raw or minimally processed are particularly susceptible to foodborne illnesses due to the lack of cooking, which would otherwise kill pathogens. External damage to the produce, such as bruises or cuts during post-harvest operations, creates entry points for microorganisms to infiltrate and multiply within the nutrient-rich tissues. This process is further influenced by environmental factors such as topography, land use, and interactions with livestock, all of which affect the frequency and severity of contamination (2). Efforts to mitigate contamination have traditionally focused on post-harvest decontamination, including the use of sanitizers during washing. However, research shows that these methods have limited efficacy and may even cause cross-contamination under commercial conditions. As a result, the current emphasis has shifted toward preventing contamination at the source through good agricultural practices (GAP). Despite these preventive measures, the effectiveness of GAP in completely eliminating contamination remains limited, highlighting the need for integrated strategies that address both pre-harvest and post-harvest challenges (5). The economic and health impacts of foodborne illnesses associated with fresh produce are substantial. Contaminated produce leads to significant food losses, negatively affecting economies and consumer trust in food safety. In regions such as Africa and Southeast Asia, where agricultural intensification often places produce fields in close proximity to animal production zones, the risks of contamination are heightened (4). These intertwined ecological connections between wild animals, livestock, and crops underscore the complexity of ensuring microbial safety in fresh produce. Advancing food safety in fruits and vegetables requires a multifaceted approach, including innovative technologies for cultivation, storage, and packaging. For instance, modern disinfection techniques and microbial testing methods can enhance the microbiological quality of fresh produce (3). Additionally, raising awareness and improving knowledge on food safety practices among producers and consumers in developing countries are crucial steps toward reducing contamination risks and improving public health outcomes. In conclusion, while fresh fruits and vegetables are indispensable for a healthy diet, they also pose significant food safety challenges due to microbial contamination. Addressing these challenges necessitates comprehensive strategies that integrate preventive measures at the production level with effective post-harvest interventions. Furthermore, increased research and knowledge dissemination on contamination pathways, sources, and mitigation techniques are vital to ensuring the safe consumption of fresh produce and reducing the global burden of foodborne diseases.

1.1 Problem statement

Despite the nutritional benefits of consuming fresh fruits and vegetables, their contamination with pathogenic Bacteria such as Escherichia coli, Staphylococcus, Shigella and Salmonella, Parasites such as Tricuris tricuria, Ascaris lumbricoides, Gardia lambia and Entamoeba histolytica present a substantial public health concern in many regions, including Bamenda. Studies have demonstrated alarmingly high contamination rates in fresh produce. For instance, research conducted around Egerton University, Kenya, revealed that approximately 80% of salad samples tested positive for E. coli and 70% for Salmonella spp., with contamination levels exceeding regulatory standards [6]. Also other studies conducted in Yaoundé Cameroon resulted in a 28.2% parasitic contamination rate [8] which is similar to a research work conducted in Tiko and Limbe in the south west region of Cameroon, that revealed a 29.5% contamination rate of parasitic microbes in fruits and vegetables [9]. These findings highlight critical deficiencies in hygiene practices and effective contamination control measures across the production, handling, and distribution chains. Despite these contamination studies around the country, comprehensive understanding of fruit and vegetable safety in Bamenda whose economy relies greatly on agriculture is still lacking. Therefore, it becomes important to investigate the diversity and prevalence of microbial contaminants in fruits and vegetables in Bamenda in order to implement appropriate intervention strategies.  

1.2
Fresh fruits and vegetables are integral to a balanced diet and vital for reducing the prevalence of non-communicable diseases. However, they also serve as vehicles for transmitting foodborne pathogens, particularly when grown, harvested, processed, or stored under unhygienic conditions. The Bamenda region, like many urban centers, relies on open markets and informal supply chains for fresh produce, which increases the likelihood of microbial contamination. Understanding the extent and sources of contamination is crucial for developing effective intervention strategies to protect public health. This research will provide valuable data on microbial risks associated with fresh produce at some markets in Bamenda and recommend appropriate measures to mitigate these risks.

1.3 Research questions

1. What is the prevalence of pathogenic microbes in fruits and vegetables sold in Bamenda Markets?
2. What are the most common pathogenic microbial contaminants of fruits vegetables in Bamenda markets?
3. What type of fruits and vegetables are most contaminated by pathogenic microbes in Bamenda markets?
4. What are the predisposing factors to microbial contamination of fruits and vegetables sold in Bamenda markets?

1.4 Main research objective

To determine the prevalence of pathogenic microbes in fruits and vegetables sold at some markets in Bamenda town.

1.4.1 Specific objectives

1. To determine the most common pathogenic microbe contaminants in fruits and vegetables sold in Bamenda markets.
2. To identify the types of fruits and vegetables which are most contaminated by pathogenic microbes in Bamenda markets.
3. To identify predisposing factors that contribute to microbial contamination of fruits and vegetables sold in Bamenda markets.