Stools from primary School pupils in Asata Enugu
were analysed for parasitic worms. The analyses
were conducted at the Microbiology Laboratory Department of National
Orthopaedic Hospital, Enugu. A total of
hundred (100) samples collected randomly form Udi road primary School in the
process of the examination brine floatation method was used, normal saline and
stool samples were examined for the parasitic worms.
Out of the hundred (100) pupils examined 46 cases
showed positive while 54 cases showed negative and is showed hookworm while 31
showed Ascaris Ova, Cysts in their faeces.
CHAPTER ONE INTRODUCTION
1.1 Sources of Infection
1.2 Life cycle of Worms Helminths
1.3 Patyhogenicity of Hookworm
1.4 Diseases Cause by Parasitic Worms and their
1.5 Parasite and Worm found in Stool
1.6 Control and Prevention Of Enteric Parasitic
1.7 Diagnosis of Worm Infection
2.0 LITERATURE REVIEW
2.1 Epidemiology of Worms
2.2 Clinical Manifestations
2.3 diagnostic Methods
2.4 food-Borne Helminthiasis
3.0 STUDY METHODOLOGY
3.1 Materials used
3.2 Study Area
3.3 Sample Collection
3.4 Method Used
4.2 Distribution of Helminth Egg Positives
4.3 Comparative Prevalence of Hook Worm
5.1 Summary and Conclusion
5.3 Method of Achieving a Hook Worm Free
1.0 DEFINITION OF ENTERIC WORM
Enteric worm are define as organisms that live in
the intestine of humans or animals and invest their food from the intestine to
grow. The most common of the
parasitic-worms that infect the human intestine are viz.:
Worms (-Asearis spp)
Worms (Ancycostoma duodenate
and Necator spp).
worms (Irichuris trichiura)
The presence of these various types of worms in
large numbers coupled with the poor living habits of large segments of the
world population has made the control of these worms difficulty and their
eradication nearly impossible. That
human life and the worms have been in separately interrelated is quite a
challenge to mouth transmission dynamics and also that man cannot control the
entry into his mouth of materials that pass through his anus is a puzzle. Here, helminthiasis (literally means
infections and parasites caused by worms) is the worst culprite.
1.1 SOURCES OF INFECTION
The primary source of worm infestation is the food
or water contaminated with infected faeces.
When these parasites are passed out through the anus, some of them find
their way to food used by man and get it contaminated. Examples are Ascaris eggs on vegetables such
as Solanium, lettuce, Cabbage and other vegetables eaten raw or poorly washed. So when men feed on such contaminated foods
they get infected. Another source is the
soil, that is the soil borne infections stage.
Here the eggs of these wormshatch in the soil and the third stage larva
(Lz) find its way into the host by actively boring into the skin. Examples are the hookworms (Necator, strongy
bodies, Ancylostoma etc.). Some
soil-borne infective larval stage exploits human behavioural pattern for its
entry. The soil transmitted intestinal
nematodes – round worms Ascaris Lumbricoides, ancylostoms duodenele
and Nectator americanus rank highest among all the helminthes and
their prevalence in different communities serves as an index of socio-economic
status. Ascaris and Trichuris affect the
health of children especially, the former being a frequent cause of
complications and death in many parts of the world, the later causing severe
and stubborn – dysentery. The hookworms
are recognized as important causes of anaemia particularly in older children
and young adults. The obvious high rank
of hookworm infection as a cause of debilating disease placed it first among
helminthiasis to be attacked on a wide scale.
1.2 LIFE CYCLE OF WORMS HELMINTHES
These enteric parasitic worms all pass through a
series of development stage before the adult stage is reached where the –
organism becomes sexually mature and a new life cycle develop. These are several live cycles depending on
the organisms involved. Within the life
cycle, one on several phases of parasitic multiplication may occur depending
one species it may be sexual or asexual.
DIRECT AND INDIRECT LIFE CYCLES
There are two types of life cycle viz.:
i. Direct life cycle
ii. Indirect life cycle
DIRECT LIFE CYCLE
Here a single host species is required for the
parasite to complete it development example Trichuris trichiura and ancylostoma
INDIRECT LIFE CYCLE
Here two or more species of host are required for
the parasite to complete its life cycle example – Taenis Saginata
– requires two hoots for it to complete its life cycle. In the life cycle of ascaris, Trichuris,
ancylostoma, Necator and other helminthes that commonly infect human being, the
soil received the faecal contamination stages which are not infective i.e. free
living then the soil provides conditions under which development to the
infective stage can take place. It
provides protection for the infective stage for a period during which it
fortuitously may be brought into contact with a susceptible individual whom it
may enter by mouth (Ascaris, Trichuria and Ancylostoma) or
by skin (Necator). This the soil serves
the parasite essentially the same manner as an intermediate host. In the life cycle of Ascaris or in Ascariasis
infection – ingesting worm eggs contamining infective larvae inside infects A
patient. The eggs hatch in the small
intestine, then the larvae are liberated and then penetrated the intestinal
wall, gain entrance into muscular system.
From here they enter the liver, heart and finally
the lungs. It is in the latter organ
that they reside for a week or more and induce preumonitis reactions. Following this they ascend the respiratory
tract to the pharynx where the larvae are swallowed and then mature into adult
worms in small intestine after several – weeks.
The eggs are released in the faeces in a non-embryonated condition and
they are incubated in the soil for a few weeks in order that the infective
larva may develop. In children
ascariosis seems to be more of a hand-to-mouth kind of transmission, whereas in
adult the contamination of food with infective eggs is probably the chief
source of infection Muller (1989). In
the case of Hookworms i.e. Ancylostoma and especially Necator, a
patient becomes infected by the contact of his/her skin to infective
Penetration of the skin by infective hookworm larva
produces a dermatitis known as dewitch or ground itch. After skin penetration, the larvae are
eventually carried to the heart, then enter the arterial circulation, and
within a day or two, filter out in the lung capillaries. After growth and development in the lungs for
about a week, the larvae break into the alveolar sacs, ascend the respiratory
tract and are swallowed and then develop into mature hookworms in the small
intestine in a mouth or two. Here the
worms mate and the female lays eggs, which pass out in the faeces. Necator lays about 10,000 eggs daily while
Ancylostoma lays 10,000 eggs daily.
(Havard Dictionary 35th Edition).
Under suitable conditions of the soil, the eggs
develop and hatch into rhabdit form larva, which then grows and develop and
then hatch into filariform larva of the worm.
1.3 PATHOGENICITY OF HOOK WORM
Pathogenicity describes the origin of damage caused
by parasites and how these damage originated through the activities of
parasites. The pathogenicity of
different enteric worms. Cestodes and
intestinal parasitic nematodes are briefly described here:
The first sign of hookworm infection is frequently a
skin reaction at the site of larval penetration. This is known as “ground itch” and is usually
more severe in those individuals previously infected. On the entering the host the larvae migrate
through the heart and lungs and mild respiratory symptoms may devel9op. After migrating up to the traches the larvae
are swallowed. They reach the small
intestine and develop into mature worms.
The adult hookworm causes chronic blood loss. It has been estimated that a single
Ancylostoma – duodenals worm ingests about 150 ML (0.15ml) of blood per
day and a Necator americanus worm about 30 ML (0.03ml). the Chronic loss of blood cause anaemia and
Oedema, resulting in severe cases in retardation of growth and mental.
The fertile egg is avoid, non-embyonated and the egg
shell has an outside rugose – layer of material while the infertile egg is
ellipsoid, being longer and narrower than fertile eggs. Eggs will obviously not be present if the
infection is only with male worm and in such cases radiographic detection is
AIMS AND OBJECTIVE OF THE STUDY
examines the prevalence level of parasitic worm infection in Enugu State, using
Asata Zone as a case study.
know the most frequently occurring worms in our pupils in primary schools.
STATEMENT OF PROBLEM
The human environment and human – behaviour are
highly synchronized with the life cycle of worms and other parasites such that
there are very high chance of infection.
The primary school pupils are more exposed because of their careless
habit and ignorance.
Ho - Very wormy
environment signifies high infections rate
detectable from school samples.
Hi - Although
habit is synchronized with transmission, worm
infestation if any, can n0t be detected from stool
SIGNIFICATION OF STUDY
A parasitological stool analysis can be used to
diagnose intestinal infections with endoparasites such as helminthes worms, by
identification of their segments, ova, or whole worm in the stool.
LIMITATION OF STUDY
This study will be focused on parasitic helminthes
(worms) that are enteric. Such parasitic
worm infections, which are among major disease of mankind. Include giant round worm caused by Ascaris
lumbricodides, Hook worm etc.
1.4 DISEASES CAUSED BY PARASTIC WORMS
(ENTERIC) AND THEIR TRANSMISSION MODES
LOCATION IN HOST
Adults in small intestine larvae in muscle, brain
Ingestion of uncookal pork
Taeniasis (adult) Cysticercosis (larvae)
Anal-oval transfer of eggs or Ingestion of
Plerocercoid in fish
Adults in small intestine migratory larvae in
river, lungs, trachea Ectopic infection
Eating viable eggs from faeces contaminated soil
Ingestion of eggs from – feaces contaminated soil.
Small intestine, larvae through lungs.
Through skin, infected soil from drinking
1.5 PARASITE AND WORM FOUND IN STOOL
WORM IN STOOL
1.6 CONTROL AND PREVENTION OF ENTERIC
The control of infectious diseases generally is not
concerned basically with a person who is sick, but with preventing the spread
of the disease in a community. The
methods adopted for each disease are based on knowledge of the natural history
of the parasite involved and attempts to break its life cycle at as many points
or stages as possible. The cure of a
disease is the province of the medical doctor, but prevention can follow on
understanding of the basic scientific principles underlying the cause and
spread of diseases in man and animals.
The methods of control of these worms include the prevention of
environmental contamination, prevention of exposure to infection, prevention of
successful maturation and disease, destruction of intermediate hosts and
vectors and integratal control.
Schad (1985), cite appropriate prevention of
exposure to infection is achieved by proper food sanitation, the provision of
safe drinking and bathing water, meat inspection and processing. Meat inspection and processing is a public
health measure taken to avoid eating meat with bladder worm (cysticerci) of T.
Solium, T. Saginata. Prevention of
environmental contamination involves proper environmental sanitation, the
prevention of successful maturation and disease involves the use of
chemotherapentic agents. The control of
taeniasis and cysticercosis is accompanied by through cooking of beef, pork and
pork-by products or other potentially infected food products. Control can also be achieved by maintaining
high standard of sanitation and treatment of cases. In the case of hookworm infections, control
depends on the prevention fo soil form becoming infected by:
- Providing and using adequate latrines
- Avoiding the use of untreated human
faeces as fertilizer
- Treating individuals as part of control
and health education programme
- Preventing infective larvae penetrating
the skin of the feet by wearing
adequate protecting foot wear. Open sandals are not effective barriers to
infection in farm boots are better.
Organised efforts to combat worm infestation have
been extensive and have in divers ways benefited millions of people in many
parts of the world. Control of
intestinal helminthiasis may be viewed as a step wise operation, which begins
with population whose major health problems are related to such basic needs as
foods, housing and sanitation and ends when these needs are so nearly satisfied
that transmission of infection meets natural barriers. Efforts have also been made for the
establishment of public health departments and general health services
installation of toilets, administration, which has served to influence
individuals and community attitudes favourably on matters of sanitation,
nutrition and other aspects of disease prevention. But in general, however, their diorect
effects on the prevalence of infection have been disappointingly slight. Campaigns on worms, more or less continuously
made relatively small though important direct contributions to the reduction of
worm prevalence but without marked progress in the treatment of infected
The climate, water resources and types of
agricultural practices in many parts of the world especially Nigeria are well
suited to the propagation of the various intestinal worms. Again the unhygienic habits and poor
sanitation in the urban and rural areas contribute immensely to the frequent
wide spread of infection.
In general, ascaviasis, trichuriasis and
Anaylostomasis, individually or in combination are important public health
problems through out the tropical regions and are among the major casues of
illness in all the under developed areas.
The prevalence and intensity of the disease vary directly with the
degree of insanitation, and the extent to which indocility extends into
cooler/area depends upon the amount and frequency of faecal contamination of
soil, food and water in the immediate vicinity of permanent inhabitations.
Based on the above statements, the WHO (1982) have
mapped a number of control option. They
are sub-divided into two categories:
(a) Environmental control, which includes
improved sanitation, uninfected
water and food supply, ensuring that diet is free of
parasite eggs and larvae and also
nutritionally balanced. The mass should
be education of in these matters as well as in good personal hygiene and the
reasons for practicing it.
(b) Mass Treatment Control:
This involves treating the whose family with
suitable worms – expeller
The suitable worm expeller should be effective, broad spectrum, in
expensive and relatively safe for all the families.
1.7 DIAGNOSIS OF WORM INFECTION
For hookworm infection, the pneumonitis phase cannot
be diagnosed with certainty, but if there is a history of dermatries in a
patient’s body areas likely to have been in contact with the soil, hookworm
infection would be suspected.
Parasitologically, a stool examination is all that is required for
mature hookworm infection and the microscopic identification of the
characteristic eggs in the faeces – determines definite diagnosis. Clinically, chronic anaemia and debility in
patients living in an endemic areas is suggestive, but may be caused by
malnutrition, malaria, amoebiasis and other helminthiasis. In Ascariasis infection, the pneumonitis casued
by the migrating larvae is often not diagnosed but the accompanying
eosinophilia is suggestive. The adult
worms are some times seen as clear spaces on X-rays after a barium meal (the
gut of the worm may show as a thin central line of contract medium). Parasitologically, eggs are usually plentiful
in the faeces although a distinction must be made between fertile and infertile
eggs. Direct faecal smears using about
2mg of faeces are satisfying and the brine floatation method works as well.
Six million and 6.5% were examined in Japan in 1964
and 6.5% were passing eggs of Ascaris, with about 70 notified deaths, Muller
(1989). Infection rates reported
recently from various countries are 58% in Brazil. 15 – 20% in Columbia. 25 – 40% Surinam, 4% in children in Eastern
Kentucky (USA) and 6% in Ethopia. The
larvas of both parasitic and free living forms are unable to survive
temperatures below 8oc or above 40oc for more than a few days. They have little resistance to drying,
excessive moisture or marked changes in temperature. Strongyloides infections are rarer almost
everywhere than hookworm infection.