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 135,000 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 315,000 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).