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African Journal of Biomedical Research
Ibadan Biomedical Communications Group
ISSN: 1119-5096
Vol. 5, Num. 1-2, 2002, pp. 5-8
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African Journal of Biomedical
Research, Vol. 5, No. 1-2, Jan & May, 2002, pp. 5-8
PREVALENCE AND SOCIOECONOMIC
FACTORS IN SCHISTOSOMA
HAEMATOBIUM INFECTION IN A GHANIAN COMMUNITY.
J. O. AWOTUNDE,
E O. OKANLA AND B.
N. AGBA
Department of Biological
Sciences,
University of llorin, llorin, Nigeria.
Received: June 2001
Accepted in final form: February 2002
Code Number: md02002
Prevalence of Schistosoma haematobium
infections was
assessed among 160 students of Twohofo Holy International School. Cape
Coast, Ghana. Overall prevalence was 34.4%, with males and
females having prevalence of 32.3% and 35.8% respectively. Ago group 6-B years
had 30%, while 24.2% were infected in age group 9-11 years.
Prevalence was 48.2% in age
group 12-14 years and 50% in age group 15-17 years. Parental occupation had
affect on prevalence with children of self-employed parents showing significantly
higher prevalence then children of salaried employees of government and private
companies. Knowledge of the
disease was very low among the subjects.
Keywords: Schistosoma haematobium,
infection, prevalence,
socio-economic factors
INTRODUCTION
Schistosomiasis is a disease caused
by blood flukes of the family Schistosomatidae. They infect different vertebrates,
but three of them
in particular cause disease in man. These are Schistosoma mansoni, S.
japonicum and S . haematobium (Adams and Maegraith, 1976).The first
two are found in the veins of the large intestine and small intestine respectively,
while haematobium is found in the veins of the bladder among
other places. S. haematobium is found widespread in Africa. Many factors
influence the epidemiology of schistosomiasis. Edungbola (1980) reported the
relationship between water utilization and schistosomiasis; while Okanla (1991)
reported
that parental occupation may be a factor in contracting schistosomiasis.
Surveillance for schistosomiasis
is very important in establishing endemicity and in the planning of control
operations. Many areas of the world are yet unsampled while some have been
sampled without making definite data available on the socio-economic factors
that have influence on prevalence in such localities. This study was designed
to look at a number of parameters including socio-economic contributors to
the prevalence of S. haematobium infections among the students of Twohofo Holy International School in Cape
Coast, Ghana.
MATERIALS AND METHODS
Study area: Akotokyir is
in the Cape Coast district of the Central Region, Ghana. It is located between
latitude
5°30 N and longitude 10 15 and 10 13 W of the Greenwich
Meridian. It lies 2.2 km from University of Cape Coast. The
vegetation is mainly Savannah. The Kakum River flows through the area. This attracts
activities such as bathing, swimming, laundry and other activities. Information
obtained from the Regional Health office indicated that urinary schistosomiasis
is prevalent in the area, but
useful data were not available.
Pre-sampling formalities:
A total of 160 pupils comprising 68 males and 92 females were involved in the
study. They included students in Basic 1 to Basic 6 (i.e. Primary 1 to Primary
6) of the Basic Educational System, as it is known
in Ghana. Weeks before sampling started, a letter was sent to the Head teacher
of the School to give him an idea of what the study was about and to seek his
cooperation. Students were given letters of consent to be signed by their parents,
as only those who obtained parental consent were included in the study. A day
before the sampling, further notification was made to the Head teacher. On the
day of sampling, the Head teacher had got the students ready and a brief explanation
was made to the students to let them know what schistosomiasis is and to instruct
them on how
to obtain the samples correctly.
Collection of samples: All
samples were collected between 12.00 noon and 2.00 p.m. (Mahmoud, 1987). Urine
samples were collected in graduated plastic bottles. Subjects were told to
empty their bladder completely into the bottle and put on the lid light. Each
student was given a serial number. This was immediately pasted on the corresponding
sample also.
Collection of other data: The
weight in kilograms and height in centimeters was obtained for each subject
Information on age parental occupation and residence history (i.e. whether
subject lived in Akotokyir or elsewhere) were also obtained. Further information
was obtained on whether subjects had any knowledge of the disease, and on the
subjects history of water contact.
Examination of urine samples
for eggs of S. haematobium: The method of Okanla (1991) was used,
All samples were taken to the laboratory immediately and, the total volume
of urine passed by each subject was recorded Samples were allowed to settle
for 30min. The urine in each sample was drawn off an aspirator leaving the
last 10 ml in the bottle. The content of each bottle was shaken to the sediment
and was emptied into a 20m centrifuge tube The serial number for each sample
was carefully transferred so as not to get the samples mixed up. The tubes
were centrifuged at 1000 rpm for 5 min The top 9ml was aspirated off. The
sediment was resuspended in the remaining 1ml. A Pasteur pipette which was
calibrated to discharge 1 ml in 20 drops was used to release 1 drop of the
sample unto a microscope slide. A cover slip was placed on it and all haematobium
eggs present were counted under the x10 objective of a light microscope.
The number of eggs counted in 1 drop was multiplied by 20 to obtain the number
in 1ml, which is also the total eggs passed in the total volume of urine
originally obtained. The number in 10ml. of urine was then calculated. This
is important for determination of epidemiological implications.
RESULTS
A total of 160 subjects (68 males
and 92 females) were
examined S. haematobium was found in males and females alike A total of
22 males and 33 females were positive. This gave prevalence of 32.3% for the
males and 35.8% for the females. Overall prevalence was 34.4% (Table 1). Prevalence
by age showed increase in S. haematobium infection with age except in
age group 9 -11 years, which showed a decrease (Table 2). Age group 6-8 years
had a prevalence of 30.0%, while age group 9-11 years had 24.2%. Age group 12-14
years had 48.2%. Only 2 subjects were sampled in age group 15-17
years.
One of them was infected giving
a prevalence of 50%.
Prevalence by paternal occupation
is presented in Table 3. Among those whose fathers have white collar/blue collar
jobs, 11.1% of the males, and 34.0% of the females were infected while in the
other jobs group
48.6% of the males and 50.0% of the females were infected.
Also, prevalence by maternal
occupation has 21.8% of the males and 26.0% of the females infected in the
white collar/blue collar group while 41.7% of the males and 47,6% of the females
were infected in the other jobs group (Table 4). Table 5 shows prevalence by
residency. Among the 146 subjects who lived in the study area, 51 (34.9%) were
infected while only 4 out of 14 subjects who lived outside of the study area
Akotokyir were infected. About 66% of those who were infected had egg output
of 50 eggs or more/10ml of urine. One female had an output of 180 eggs/10mI.
of urine.
The relationship between
water contact habits of males and females to prevalence showed that among male
students 41.2% engaged in swimming activities whereas only 29.3% of females
were involved. Also 36.7% of the males and 32.6% of the females actually bathed
in the Kakum River. Other activities in the water like washing of dishes and
clothes attracted 22.0% and 38.0% of males and females respectively.
Knowledge of the disease
was very little, with about 61.2% having no idea of what causes the disease,
while 12,5% thought that it was caused by contact with a body of water. Some
15.6% believed that it was caused by drinking of dirty water. There was no
relationship between prevalence and weight to height ratio. Also there was
no relationship between sex and prevalence. Relationships however existed between
the paternal occupational groups and between the maternal occupational groups
using the Chi square test.
Table 1: Prevalence of urinary
schistosomiasis among pupils
of Twohofo Holy School
-
|
-
|
MALES
|
-
|
FEMALES
|
TOTAL
|
-
|
CLASS
|
NUMBER EXAMINED
|
NUMBER/(%) INFECTED
|
NUMBER EXAMINED
|
NUMBER/(%) INFECTED
|
TOTAL NO. EXAMINED
|
TOTAL NO (%) INFECTED
|
BASIC 1
BASIC 2
BASIC 3
BASIC 4
BASIC 5
BASIC 6
|
12
11
12
16
12
5
|
7 (58.3)*
3 (27.2)*
1 (8.3)*
4 (25.0)*
3(25.0)* 4(80,0)*
|
19
17
10
16
17
13
|
5 (26.3)*
10 (58.8)*
2 (20.0)*
3 (18.7)*
7 (41.2)*
6 (46.1)*
|
31
28
22
32
29
16
|
12 (38.7)**
13(46.4)
3 (13.6)**
7 (21.8)**
10 (34.4)**
10 (55.5)**
|
TOTAL
|
68
|
22
|
92
|
33(358)
|
160
|
55(34.4)
|
*Percentage of students that were
infected; **Total percentage
of infected students.
Table 2: Prevalence of S.
haematobium infection
by age
Age Grp(Yrs)
|
Total Examined
|
Number Infected
|
% Infected
|
6-8
|
40
|
12
|
30.0
|
9-11
|
62
|
15
|
24.2
|
12-14
|
56
|
27
|
48.2
|
15-17
|
2
|
1
|
50.0
|
TOTAL
|
160
|
55
|
34 4
|
Table 3: Prevalence of S. haematobium infection
by paternal occupation
-
|
*Blue/White Collar
|
Other Jobs
|
TOTAL
|
NO EXAMINED
|
89
|
71
|
160
|
MALES
INFECTED
|
45
5(11.1%)
|
35
17(486%)
|
80
22
|
FEMALES
INFECTED
|
44
15(34.0%)
|
36
18(50.0%)
|
60
33
|
TOTAL
INFECTED
|
20
(22.4%)
|
35
(49.3%)
|
55
(34.4%)
|
*Upper class/Lower class salaried
employees of Government
and the private sector
For paternal occupational groups,
calculated c2
= 12. 595
tabulated c2 =
3.841
For maternal occupational groups,
calculated c2 =
tabulated c2 =
3.841
Table 4: Prevalence of S. haematobium infection
by maternal occupation
-
|
*Blue/White Collar
|
Other Jobs
|
TOTAL
|
NO OF PUPILS
|
82
|
78
|
160
|
MALES
INFECTED
|
32
7(21.8%)
|
36
15(41.7%)
|
68
22
|
FEMALES
INFECTED
|
50
13(26,0%)
|
42
20(47.6%)
|
92
33
|
TOTAL INFECTED
|
20(24.3%)
|
35(44.8%)
|
55(34.4%)
|
*Upper class/Lower class salaried
employees of Government
and the private sector
DISCUSSION
Before the onset of this study
information was obtained from
the Regional Health Office that S. haematobium was prevalent in this area,
but recent published data were not available to cover the information obtained
in this study.
This study has indicated
a prevalence of 34.4% among
the students of Twohofo Holy International School. This is high. Parental occupation
has influence on prevalence with children of salaried workers exhibiting less
prevalence than children of those who do other jobs. This observation agrees
with the results obtained by
Okanla (1991) in Ilorin, Nigeria. The relationship between Schistosomiasis and
occupation has long been known (Edungbola, 1980; Fenwick and Jorgensen, 1972).
Also contact with water for recreational or other activities has also been associated
with
infection with schistosomes. (Fernwick and Jorgensen, 1972).
Table 5: Prevalence of urinary schistosomiasis
by residence
Class
|
No. (%) Infected
|
Number From Akotokyir
|
Others
|
% Infected
|
Basic 1
|
31
|
12(38.7)
|
0
|
0(0.0)
|
Basic 2
|
27
|
13(48.1)
|
1
|
0(0.0)
|
Basic 3
|
19
|
3(15.8)
|
3
|
0(0.0)
|
Basic 4
|
27
|
4(14.8)
|
5
|
3(60.0)
|
Basic 5
|
27
|
10(37.0)
|
2
|
0(0.0)
|
Basic 6
|
15
|
9(60.0)
|
3
|
1(33.3)
|
Total
|
146
|
51(34.9)
|
14
|
4 (28.5)
|
Percentage of infected students
This study utilized the centrifugal
sedimentation method to finally determine the number of eggs in 10 ml. or urine
(Okanla 1991). This method is very sensitive since it utilizes the total urine
passed by the subject.. It is however not as fast as the membrane filtration
technique which uses a nylon mesh to filler a sample of 10 ml. drawn from the
total urine passed by each subject. The membrane method is therefore more frequently
used for epidemiological purposes. This study was intended to look at overall
prevalence as well as determine the epidemiological significance of the disease.
The sedimentation method was therefore preferred.
Single urine samples only
were examined in this study,, although multiple examinations may reveal slightly
higher prevalence. Two thirds of the infected subjects passed more than 50
eggs per 10ml. of urine, which is considered to be epidemiologically significant.
One girl passed
180 eggs/10ml), urine. This was very high. S. haematobium infections may
cause discomfort, but rarely lead to death. However, when intensity of infection
is so high mortality may eventually result (Mahmoud, 1987). Significant difference
did not exist in the nutritional status of infected and uninfected subjects.
This agreed with the findings of others (Hiatt et al. 1977; Lehman et al. 1976;
Hiatt 1976; Cook et al. 1974;Okanla 1991). This study also showed that most of
the subjects had no idea of the cause of the disease. Good education is therefore
needed in order to Increase the general awareness
of people in the community.
ACKNOWLEDGEMENT: This
study was supported by Students
Project Funds of (he Faculty of Science, University of Cape
Coast.
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Adams A.R.D. and Maegraith
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EdungboIa L..D. (1980). Water
utilization and its health implication in Ilorin, Kwara state Nigeria.
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Okanla E.O. (1991). Schistosomiasis:
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Lehman, J.S. Jr., Mott, K.E.,
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© 2002 - Ibadan Biomedical
Communications Group
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