CHAPTER ONE
INTRODUCTION
Intestinal parasites are parasites that populate the gastrointestinal tract, typically protozoa and helminthes are the two major types of intestinal parasites (D. R. Arora, and B. A. Brij, 2012). Gastrointestinal parasitic infections are endemic worldwide and have been described as constituting the greatest single worldwide cause of illness and disease (Mehraj V, Hatcher J, Beg MA .2008). These infections are associated with poor sanitary habits, lack of access to safe water and improper hygiene, thereby occurring where there is poverty (Stekee R.W.J Nutr.2003).Current estimates by World Health Organization(WHO) shows that about 3.5 billion people are infected with intestinal parasites, majority of which are children (WHO 2002). The helminthesT.trichiura, A. lumbricoides and the hookworms as well as the protozoa E. histolyticahave been observed to cause infection in 800, 1000, 900 and 48 million people respectively worldwide (WHO 2002). Gastroenteritis is a disease condition due to theinflammation of the mucousof the stomach and intestine. Many microorganisms contaminating food and watercan 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 exotoxins (Johnson, 1999).
Alternatively the pathogens may secrete an exotoxin that contaminates the food and is ingested by the host. This is sometimes referred to as food intoxication because the toxins ingested and the presence of the living microorganisms is not required. Because these toxins 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 underdeveloped countries most deaths are due to dehydration, in adequate fluid replacement and circulatory collapse. In Australia, Asia, African and South America an occasional fatality still occurs with gastroenteritis again mainly due to complication of severe dehydration. A rotavirus vaccine has been developed in Australia and may eventually have extensive worldwide application (Prescott 2005).
The main symptoms of gastroenteritis are vomiting diarrhea and cramping abdominal pain. Sometimes of fever may also be present. In more severe cases, signs of dehydration that may appear in a young child may look floppy and pale and the urine output may be reduced. These signs mean that urgent medical assessments and treatment are required.
Intestinal helminthes and protozoan infections have been recognized as significant causes ofillnesses and diseases worldwide ( Ngui R, Ishaka S, Lim YAL 2011). These are among the most common human parasiticinfections and have been associated with important morbidity and economic loss in endemicareas. Current estimates show that at least more than one quarter of the world’s populationis chronically infected with intestinal parasites and most of the infected individuals live indeveloping countries (Brooker S, Hotez PJ, Montresor A 2003). The prevalence of intestinal parasitic infections is 50% indeveloped countries, whereas it reaches up to 95%in some developing countries (E chacon-czuz 2003)
These infections are usually highly prevalent among the resource poor and socioeconomicallydeprived communities where overcrowding, poor environmental sanitation, low level ofeducation and lack of access to safe water are prevalent (Mehraj V, Hatcher J, Beg MA 2008) The infected people experience a vicious cycle of under nutrition and repeated infections leading to excess morbidity withchildren being the worst affected
For example soil transmitted helminthes (Ascarislumbricoides, Trichuristrichiuraand hookworm) have been recognized as an important public health problem and are the mostprevalent of intestinal parasitic infections among poor communities. In 2009, Hotez PJ., estimated that approximately one third of the world population is infected with at leastone species of soil transmitted helminthes, with A. lumbricoides infecting 800 million people,T. trichiura 600 million, hookworm 600 million and resulting in up to 133,000 deaths annually .With regards to intestinal protozoan infections, giardiasis caused by Giardia intestinalis, isthe most prevalent protozoa infection with estimated prevalence rates ranging from 2 to 7%in developed countries but 20 to 30% in most developing countries and affectingapproximately 200 million people worldwide (Mineno T, Avery MA 2003). Amoebiasis caused by Entamoebahistolyticais another important pathogenic protozoa affecting approximately 180 millionpeople resulting in a reported annual mortality rate of 40,000 to 110,000 (World Health Organization 2003).
Intestinal parasitic infections cause various intestinal symptoms including abdominal bloating, cramps, constipation, diarrhea, lack of appetite and vomiting. Most of thesesymptoms are non-specific and are similar to those of other pathogens such as viruses,bacteria and other non-infectious conditions affecting the intestinal system including irritablebowel syndrome, ulcerative colitis, pancreatitis and peptic ulcer disease (Gordon C. Cook 2009).
Intestinal parasites are common in areas with poor sanitation, dirty water, substandardcrowded housing and in warm and humid environments (Micheal O Harhay, John Horton 2010). In 2008 the World Bankestimated that 1.29 billion people were living in absolute poverty, 47% of whom were in sub-Saharan Africa. These figures correlate with the high prevalence of helminthes infectionsin the region (Brooker S, Clement AC, Bundy DA 2006). In Kenya, depending on the city, 60-80% of Kenyan urban population livesin slums that are characterized by lack of access to water and sanitation, lack of adequatehousing and poor environmental conditions which are predisposing factors for infectionswith intestinal parasites. For instance in Nairobi, 60% of the population lives in slumsthat occupy only 5% of the total land area. Kibera is a slum in Nairobi where it has beendemonstrated that, poor environmental sanitation leads to water and vector borne diseasesincluding intestinal parasites. Although entire populations in such areas are at risk,children carry the greatest burden of infection due to their behavioral and biologicalexposure (Bethony J, Brooker S, Albonico M 2006). For example, children tend to play in contaminated environments and areimmunologically vulnerable to infections. They also are normally crowded together for largeperiods of time for example in schools, orphanages or slums, thereby increasing thelikelihood of transmission or environmental contamination with the parasite. Inagreement with this, in the year 2006 it was estimated that of the 181 million school-aged children in sub-Saharan Africa, almost half (89 million) were infected with one or more ofthese parasitic worms.In general and compared to the intestinal nematodes, the epidemiological data for intestinalprotozoa, and nematodes excluding schistosomiasis, is limited and has not been studied systematically or included in the studies on global burden of disease accuratefigures for the prevalence of these infections have been challenging to obtain, and despitetheir relative low frequency compared to the nematodes, they can cause significant morbidityand mortality in a large number of individuals ( Miceal O Harhay, John Horton 2010).
The public health importance of gastrointestinal parasites includes high morbidity in children and in women during their child bearing years (J. I. Mbanugo and O.C Abaziri 2002). Children are mostly infected because of their vulnerability to nutritional deficiency. Intestinal parasitic diseases remain a serious public health problem in many developing countries especially due to fecal contamination of water and food (Jimenez-Gonzalez et al., 2009; Odu et al., 2011a; Odu et al., 2013). The degree of each factor and the prevalence of Infections vary from one region to another.
1.1 AIMS AND OBJECTIVES
This study was carried out to determine the prevalence of gastrointestinal parasites among children in Okigwe, Imo State, Nigeria.
1.2 STATEMENT OF PROBLEMS
There are factors in the environment which induce poor 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 helminthes and protozoa is common in babies.
H1 - prevalence of gastroenteritis caused by helminthes and protozoa is not common in babies
1.4 SCOPE LIMITATION OF STUDY
- Limited to helminthes and protozoa involved in gastroenteritis as
Identified by the method used
1.5 LITERATURE REVIEW
Gastrointestinal parasitic infections (GIPI’s) enjoy a wide global distribution. They are estimated to affect 3.5 billion people, most of whom are children residing in developing countries (WHO 2000). The major intestinal parasitic infection of global public health concern are the protozoal species Entamoebahistolytica and Giardia intestinalis and the soil transmitted helminthes Ascarislumbricoides, Trichuristrichiura, and hookworm (WHO l999;WHO 2000). The incidence and prevalence of these parasitic pathogens varies both between and within countries.
Diarrhea is the condition of having three or more loose of liquid stool per day or more frequent than normal (WHO 2007). Prolonged diarrhea may lead to excessive loss of fluid salt and nutrient in the feaces. The main cause of death from acute diarrhea is dehydration, which result from loss of fluid and electrolyte in stool. Another important cause of death is dysentery and under nutrition (Sinclair 2003). Diarrhea is an important cause of under nutrition because patients eat less during diarrhea and their ability to absorb nutrients is reduced. Moreover, nutrient required is increased as a result of infection (Sinclair 2003). Risk factors that predispose children to diarrhea include poor sanitation, poor social and economic status and malnutrition (Andu2002). Diarrhea diseases are major attendance at health facilities, a common cause of admission to many of the hospitals in the country, and a significant and often preventable cause of death. The clinical symptoms of diarrhea include the passage of frequent loose or watery stool without visible blood (Bahal 2001) vomiting may occur and fever may be present. The most important cause of acute watery diarrhea in young children in Nigeria include rotavirus, enteropathogenic, Shegella, Campylobacterjejuji, Cryptosporidia,vibrio cholera, salmonella and enteropathogenic Escherichia coli (Bahal et al; 2001).
Another clinical symptom of diarrheaincluderapid weight loss and damage to the intestinal mucosa by invasive bacteria. The organisms implicated in these types of diarrhea include Shigella, Campylobacter jejuni, Salmonella, and rarely Entamoebahistolytica(Bahal2001).
Transmission of agent that cause diarrhea are usually by the faecal oral route, which include the ingestion of faecal contaminated water or food, person to person contact and direct contact with infected faeces.
Host factors that increase susceptibility to diarrhea include under nutrition, current or recent measles and immune deficiency or immunosuppression (Audu 2002). Diarrhea disease is part of social problem in Nigeria and in developing countries in the tropics. Diarrhea disease is a leading cause of morbidity and mortality among young children in low income countries. Infections are major cause of severe morbidity and mortality among children worldwide (lawn 2005). Diarrheal illness stands as an important case of infections morbidity in children which exceeded by respiratory tract infections, and mortality in currently associated with cases that evolve in infants without proper feeding or rehydration care, invasive diarrhea with extra intestinal or systemic involvement or persistent diarrhea that occur especially in infants from low level socioeconomic groups, who suffer pervious deficiencies and develop severe enteric infection (Torres 2001).
In Nigeria, available reports indicate that more than 313,000 deaths of preschool age children are recorded annually from diarrhea disease (Alabi 1998; Babiniyi, 1999) nevertheless, despite the public health care delivery system by infantile diarrhea illness in the country there is still paucity of information on epidemiology and etiology of infantile diarrhea in many regions including the South-Eastern part of the country, since pathogens responsible for diarrhea infections employ ingenuous mechanisms to establish disease, regional variation in the microbiological profile may exist even in the same country (Synder and Mersion, 1982; the Thaper and Sanderson, 2004).
Studies have shown that bacterial agent are important causes of infantile diarrhea in many developing countries, prolonged diarrhea persisting for more than 2days maybe a sign of a more serious problems and the risk of dehydration (Katribe 2008).
