Distribution of intestinal parasitic infections among the residence of Porto Novo municipality of Cape Verde

Background

Intestinal parasitic diseases are among the
most common diseases globally and for this reason, it is very
important to study its occurrence and its degree of risk in
contamination. No previous record is available in the
municipality of Porto Novo, hence the necessity of this
study.

AIMS: To obtain the
occurrence of common intestinal parasites among the inhabitants
of Porto Novo municipality.

KEY WORDS: Distribution,
Intestinal Parasites, Municipality, Porto Novo, Cape
Verde.

ABSTRACT

Stool testing performed on
391 subjects between March to June, 2011 age ranging from 11
months to 82 years old, 141 (36.06%) were infected with one or
more of the intestinal parasites. Among protozoa, Entamoeba coli
(22.51%), Entamoeba Histolytica/Dispar (7.67%) and Giardia
Lamblia (5.90%) were the most isolated intestinal parasites and
among the helminths, Hymenolepis nana(2.30%), Ancylostoma
Duodenale(1.28%) and Trichuris Trichuria(0.51%) were
isolated.

Age distribution did not
show a definite pattern of infectivity rather females(24.60%)
were mainly infected than males(11.50%) , thus concluded that
intestinal parasites pose a serious public health problem in the
municipality of Porto Novo and that its degree of contamination
is still high, therefore, treatment measures, National deworming
programs at schools and sanitary improvement strategies is
advocated for the population of the municipality to reduce and or
eradicate this sporadic problem.

KEY WORDS: Distribution,
Intestinal Parasites, Municipality, Porto Novo, Cape
Verde.

Introduction

A parasite is an organism that is entirely
dependent on another organism, referred to as its host for all or
part of its life cycle and metabolic requirements. Parasitism is
therefore a relationship in which a parasite benefits and the
host provides the benefit. The degree of dependence of a parasite
on its host varies.

An obligatory parasite is one that must
always live in contact with its host. The term free- living
describes the non parasitic stages of existence which are lived
independently of a host for example, hookworms, have active free
living stages in the soil.

Definitive host is the host in which sexual
reproduction takes place or in which the most highly developed
form of a parasite occurs. When the most mature form is not
obvious, the definitive host is the mammalian host. However, the
intermediate host refers to the host which alternates with the
definitive host and in which the larval or asexual stages of a
parasite are found. Some parasites require two intermediate hosts
in which to complete their life cycle.

The reservoir host is an animal host
serving as a source from which other animals can become infected.
Epidemiological speaking, reservoir hosts are important in the
control of parasitic diseases. The can maintain a nucleus of
infection in an area. The term zoonosis is used to describe an
animal infection that is naturally transmissible to humans either
directly or indirectly via a vector (insect).

Gastrointestinal parasites are frequently
transmitted via food and contaminated drinking water but may also
be spread from person to person through faecal- oral contact. It
is believed that over 70 species of protozoan and helminthic
parasites can infect human through food and water
contamination(Pozio 2003).

A third of the world´s population
most of them children may be infected with intestinal worms,
principal among them are Ascaris Lumbricoides, Hookworms, and
Trichuris Trichuria which cause a variety of conditions including
malnutrition, iron deficiency anaemia, malabsorption syndrome,
intestinal obstruction and mental and physical growth retardation
(Allen & Maizel 1996).

The protozoan Entamoeba Histolytica cause
of amoebiasis and life threatening liver abscess is a leading
cause of death due to parasites second only to malaria(Stanley
2003). Although many intestinal parasites, particularly the
geohelminths have virtually disappeared from industrialized
countries, screening for parasitic infections remains a public
health priority in the United States of America health care
settings serving refugees and immigrants(Walker & Jaranson
1999), most of whom may have emigrated from countries where
intestinal parasitic diseases are endemic(Larson
2003).

Helminthes and protozoan infections differ
importantly both in host immune response and in
epidemiology.Helminths are macroparasites that reproduce sexually
within the definitive host, where the can persist for many years,
whereas protozoa are microparasites that are capable of direct
reproduction within the host, often at high rates and cause
relatively short lived infection (Maizel 1993).

Helminth infections are well known to
elicit a type-2 (th-2) non inflammatory T-cell response, a
hallmark of which is IgE elevation with eosinophilia and which
may be strong enough to exert biasing effects on concomitant
infections (Pit DS 2001), as well as host response to Th-1
mediated chronic infections, including intracellular parasites.
By contrast, many protozoa like bacteria act through manipulation
of Th-1 pathways.

In developing countries, particularly those
with tropical climates and at low altitudes, such infections
remain a serious medical and public health concern. They are more
prevalent among the poor, who are negatively affected by low
socio- economic conditions, poor personal and environmental
hygiene, overcrowding and limited access to clean water (Mengistu
et al 2007).

In Cape Verde and elsewhere, food vendors
and restaurants are noted for selling foods and drinks at reduced
rate, so providing more affordable means for people to obtain the
balanced diets outside the home. An estimated 2.5 billion people
patronize food vendors worldwide (Nyarango et al 2003). Although
street food has become an indispensable part of both urban and
rural diets, however, in developing countries, some public health
risks are associated with the consumption of street food. While
it is surely expected that street food meets the nutritional
needs of consumers, it is also vital to ensure its safety from
contaminants and microorganisms (Chakravarty 2001).

Illness due to contaminated food has also
been reported by the World Health Organization (WHO) as the most
widespread health problem in the contemporary world and an
important cause of reduced economic productivity (Kaferstein
2003). Food borne illness can therefore be considered a major
international health problem and an important cause of reduced
economic growth (FAO/WHO 1983).

These parasitic diseases whether food
borne, water borne, vector borne, soil transmitted or those that
result from some poor sanitary or social habits provide some of
the many public health problems in the tropics (Woodrouff,1965
& Odutan, 1974).

The disease process which emanates may be
the consequences of the reactions of human host to the parasites
invading the host´s tissue, causing destruction and damage
to the tissues, or the result of the parasites depriving the
human host of some essential nutrients. Parasitic diseases create
morbidity and sometimes mortality. Estimates of these parasitic
disease in the Population of Porto Novo thus become a matter of
necessity for the surveillance of public health, proper health
care delivery and people´s welfare.

Materials and
methods

STUDY AREA

This study was undertaken in the medical
laboratory section of Central Hospital Porto Novo.

SUBJECTS

They subjects were taken from the
municipality of Porto Novo. They are apparently healthy
individuals from all around the municipality and those visiting
the Hospital.

COLLECTION OF
SAMPLE

Each patient were given a clean, dry, well
labeled specimen container and asked to collect and submit two
samples of stool on different days of the week and or during the
period of the research, which started 1-March 2011 to 30-June,
2011.

LABORATORY TESTING OF
STOOL

In the laboratory, each specimen was first
examined macroscopically for its consistency, colour and presence
of blood, mucus, adult worm and proglottids of taenia spp.With
the aid of an applicator stick, normal saline and Lugol´s
iodine preparation were made for direct examination or wet mount
examination. The sodium chloride floatation method or the
technique of Willis and the modified Ziel Neelsen staining method
were used according to Cheesbrough and also WHO standard testing
for Helminth ovas were used. The antigen test for the
differentiation of Entamoeba Histolytica and Entamoeba Dispar
were not possible.

Results

Out of a total of 391 subjects examined,
141 (36.06%) were infected with one or more intestinal parasites.
Age distribution did not show a definite pattern but infection
rate were higher among the age range of 32 to 47 years old with
12.53% prevalence, although this is not statistically significant
(p<0.05). Despite that the subjects were not diarrheal
patients and do not manifest major symptoms of intestinal
parasitic disease, infection rate was relatively high.

Entamoeba coli was the most occurred
parasite( 22.51%) while Giardia lamblia (5.90%), Entamoeba
Histolytica/Dispar (7.67%), Iodamoeba butschlli(4.09%),
Balantidum coli and Endolimax nana were 0.30% and 0.51%
respectively. The helminths isolated were Hymenolepis nana
(2.30%), Ancylostoma duodenale (1.28%) and Trichuris Trichuria
(0.51%).

Table-1: Occurrence of parasites in 391
stool samples from the residence of Porto Novo municipality of
Cape Verde, March to June, 2011.

*Commensal, non-pathogenic.

Table-2. Age-related occurrence of
intestinal parasitic infection of a total of 391 stool specimen
obtained during the Porto Novo municipality study, March to June,
2011

Table- 3: Sex related distribution of
intestinal parasitic infections of the 391 faecal samples from
the residence of Porto Novo municipality study, March to June,
2011.

Table-4: Occurrence of mono and
Polyparasitism of 391 faecal specimen of the inhabitants of
municipality of Porto Novo between March to June,
2011.

Discussion and
conclusion

The results of 36.06% showed in this study
confirmed that intestinal parasitic infection is still a major
public health problem in Porto Novo municipality. The commonest
parasites isolated was Entamoeba coli (22.51%) and Entamoeba
Histolytica /Dispar 7.67%, Giardia lamblia infection was 5.90%
and this occurred mainly in children aged 11 months to 8 years
old. The helminths accounted for 4.0% which was not statistically
significant (p<0.05), among the worms, Hymenolepis Nana was
2.30%, Ancylostoma Duodenale registered 1.28% and Trichuris
Trichuria was 0.51%.

The Porto Novo municipality experiment
showed that parasitic infection due to helminths is not common.
Although, World Health Organization stated that intestinal
protozoan parasites are age dependent and greater severity of the
infection is found in children. This could be attributed to the
different host responses and nutritional status. The Porto Novo
experience showed that age related occurrence of parasitic
infection is not statistically significant (p<0.05). However,
Giardia lamblia infection was in children than in adults possibly
due to daycare schools allow the children to be exposed to the
infecting forms and this was noted in age 11 months to 8 years
old. The hygienic conditions and the low immune responses of
these children to the parasites could also be a determining
factor to them been infected. According to the Porto Novo testing
on parasites, females (24.60%) were more infected than males
(11.50%) and this is directly in agreement to the work of Atu et
al(2006) that reported higher occurrence of intestinal parasites
in females than males. Also in this study, 27.37% of those
infected were Monoparasitism whereas 8.70% were of
Polyparasitism.

The high occurrence of Entamoeba coli
(22.51%), a commensal parasite is indicative of the population`s
precarious sanitary conditions and of elevated environmental
contamination, highlighting the need for education focused on
hygiene measures, along with investments on
sanitation.

The water supply is really an important
risk factor for amoebiasis and giardiasis and several large
outbreaks have resulted from the contamination of municipal water
supplies with human waste as was reported by Wilson et al
(1998).

In view of the occurrence of intestinal
parasitic infections of 36.06% recorded in this work, preventive
measures becomes imperative to prevent dissemination of infection
and or to reduce opportunities for the exposure ,by increasing
the level of knowledge about personal and community health and
hygienic sanitary control of water and waste disposal and
reduction of the source of infection by therapeutic
means.

In conclusion, treatment measures should be
taken for those already infected. Sanitary improvements such as
safe, efficient and dynamic hygienic management of drinking water
and disposal of excreta should be undertaken. Regular hand
washing with soap and water should become a habit and taught at
the basic schools and other sectors and the necessary materials
for this should be provided. Hygienic food preparation, handling,
storage and health education by the public health officers to
encourage individuals to adopt behavioral change is advocated.
Regular inspection of all food processing and or selling areas by
the public health officers of the local council should be
encouraged and or practiced.

The program of intermittent deworming of
school children by the ministry of health of Cape Verde or its
delegated health officers should be re-enforced and this could be
effected twice in a year. At all it seems that a multisectoral
control approach is needed in the Porto Novo municipality of Cape
Verde to control, screen and totally eradicate intestinal
parasitic infection in our region.

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Autor:

Peter Ubah Okeke

Medical Technologist, Dept. of Medical
laboratory Science, Hospital of Porto Novo- Cape Verde. Direct
Phone:00238 9899292,

PORTO NOVO, 2011