CHAPTER ONE
INTRODUCTION
Gastroenteritis is a disease condition due to the inflammation of the mucous of the stomach and intestine. Many microorganisms contaminating food and water can cause acute gastroenteritis. In most cases it runs its own course over several (days. However it can be a serious condition if the fluid loss is sever enough to cause dehydration. When food is the source of the pathogen the condition is often called food  poisoning (Archeson 200)
Gastroenteritis can arise in two ways the microorganisms may actually produce a food borne infection, that is, they may first colonize the gastrointestinal tract and grow within it, then either invade host tissues or secrete exo- toxins (Johnson, 1999).
Alternatively the pathogens may secrete an exo- toxins that contaminates the food and is ingested by the host. This is some times reffered to as food intoxication because the toxins ingested and the presence of the living microorganisms is not required. Because theses toxins of the disrupt the functioning  of intestinal mucosa they are called enterotoxins (Sanders and sanders 1997)
Most cases of gastroenteritis are due to viral infection about a half are caused by the rotavirus, first discovered and described at the royal children’s Hospital university of Melbourne in the early 1970 various other  virus may cause the same symptoms as well as bacteria like campylobacter protozoa and helminthes. In most cases the precise infective agent is not identified. It is only when symptoms are persisting that stools are sent for microscopy and culture in the laboratory (Nachamkin 1992).
On a global scale gastroenteritis is a massive health problem. About 5 million people die each year, mainly young children in underdevloped countries most deaths are due to dehgdration, in adequate fluid replacement and cirulatory collapse. In Australia, Asia, African and South America an occasional fatality still occurs with gastroenteritis again mainly due to complication of sever dehydration A rotavirus vaccine has been developed in Australia and may eventually have  extensive world wide application (Prescott et al 2005).
The main symptoms of gastroenteritis are vomiting diarliea and cramping abdominal pain. Sometimes of fever may also be present. In more severe cases, signs of dehydration may appear a young child may look floppy  and pale and  the   urine out put may be reduced. these signs means that urgent medical assessments and treatment are required.
1.1              AIMS  AND OBJECTIVES
-                      to determine the prevalenble of gastroenteritis  in primary  school children
-                      also to implicate in gastroenteritis .
-                      to relate the environment of the pupil to the types of diseases which they acquire from it.
1.2              STATEMENT OF PROBLEMS
There are factors in the environment which iduce pior sanitation and the filthy habits of the children ideal for transmission of gastroenteritis, therefore infection rate is expected high.
1.3              HYPOTHESIS
H0 -      prevalence of gastroenteritis caused by bacteria and protozoa is common in primary school children
H1 -      Although environment favours infection prevalence is not common in primary school children .