CHAPTER ONE
Introduction
Background to the Study
Diarrhoea accounts for high levels of mortality in young children in developing countries like Nigeria, despite worldwide efforts to improve overall child health levels. Each year, in the developing countries of Asia, Africa and Latin America, approximately five million children under five years of age die from acute diarrhoea. About 80 per cent of these deaths are in the first two years of life (Lucas & Gilles, 2009) In the developing world as a whole, about one-third of infant and child deaths are due to diarrhoea and approximately 70 per cent of diarrhoeal deaths are caused by dehydration – the loss of large quantity of water and salts from the body, which needs water to maintain blood volume and other fluids to function properly (Gupta & Mahajan, 2005). UNICEF (2002) submitted that in Nigeria, infant mortality rates are twice as high in rural settings as they are in urban ones due to poor hygiene and poor sanitation. Of the annual 3 million infant births in Nigeria, approximately 170,000 result in deaths that are mainly due to poor knowledge and management practices of childhood diarrhoea. Several factors are likely to contribute to the very high diarrhoea morbidity and mortality rates, in children under-five years including poverty, female illiteracy, poor water supply and sanitation, poor hygiene practices and inadequate health services (Park, 2009). Malnutrition is another established risk factor for mortality among children with diarrhoea disease. This may be due to inadequate case management. The first line of management of diarrhoea, is therefore, the prevention of dehydration. This can be achieved at home using Oral Rehydration Therapy (ORT).
Diarrhoea is the disturbance of the gastrointestinal tract comprising of changes in intestinal motility and absorption, leading to increase in the volume of stools and in their consistency (Ballabriga, Hilpert & Isliker, 2000). In diarrhoea, stool contains more water than normal stool and is often called loose or watery stool. In certain cases, they may contain blood in which case the diarrhoea is called dysentery (Obionu, 2001). Any passage of three or more watery stools within a day (24 hours) is referred to as diarrhoea (Tauxe, 1997). The consistency and the volume of stool constitute how to classify diarrhoea.
World Health Organization – WHO (1993) classified diarrhoea as acute or persistent based on its duration. An episode of diarrhoea that lasts less than two weeks is acute diarrhoea, while diarrhoea that lasts more than two weeks is persistent. Morley (2000) further classified diarrhoea according to its typology: Secretary diarrhoea, osmotic diarrhoea and exudative diarrhoea. Secretary diarrhoea results from active process in the intestinal epithelium stimulated by the presence of toxin, chemical or nutritional product in the intestinal linning. Osmotic diarrhoea is caused by the presence of the intestinal linning of osmotically active solutes that are poorly absorbed by the injection of laxatives such as magnesium sulphate or magnesium hydroxide. Exudative diarrhoea is associated with damage to the mucosa lining leading to outpouring of mucus, blood and plasma protein among other substances. However, it is important to note that the classification of diarrhoea does not influence the cause.
Diarrhoea is a symptom of infection caused by a host of bacterial, viral and parasitic organisms most of which can be spread by contaminated water. Diarrhoea in most cases is caused by three major groups of micro-organisms namely; Viruses, bacteria and protozoa or parasites (Lucas & Gilles, 2009). The main agents of diarrhoea according to them are enteroviruses (e.g. rotavirus, escherichia coli, campylobacter spp, shigella, vibrio cholera, salmonella (non typhoid), entamoeba histolytica, giardia lamblia, cryptosporidium). These are further grouped in the following ways: Viruses (e.g. Rota virus); Bacteria (e.g. shigella, escherichia coli, vibrio cholerae, salmonella non typhoid, campylobacter spp). Parasites (e.g. entamoeba histolytica, crytosporidium and giardia lamblia). All over the world, viruses especially rotavirus has been identified as the major cause of acute diarrhoea in children. Studies in Nigeria also found viruses as the major causes of diarrhoea in 60 per cent of cases with bacteria responsible for about only 3-20 per cent. Most of these pathogens are transmitted by faeco-oral route. Childhood diarrhoea within the context of this study refers to any type of loose, watery stool that occurs more frequently than usual in a child. The various causative agents vary according to the signs and symptoms manifesting from the disease.
The main consequence of diarrhoea are frequent loose or watery stools, the risk of dehydration, damage to intestine (especially when there is bloody diarrhoea) and loss of appetite with or without vomiting. However, Victoria, Bryce, Fountaine and Monasch (2000) asserted that signs of dehydration are not evident until there is acute fluid loss of approximately 4-5 per cent of body weight. The signs and symptoms of dehydration include sunken fontanelle, dry mouth and throat, fast and weak pulse, loss of skin elasticity and reduced amount of urine.