ANAMBRA STATE RECORDS SCHISTOSOMIASIS CASES IN PRIMARY SCHOOLS
The research work carried out by Dr. Ekwunife Chinyelu
Angela and Okafor Fabian Chukwuemeka - both of the Department of Biology,
Nwafor Orizu College of Education, Nsugbe, Anambra State, Nigeria assisted me a
lot in developing this report. Their research revealed how contagious and
infectious the great and revered Agulu lake is and the health implications on
Agulu people and her neighboring communities.
Agulu has different water bodies. Two big major arms of
Agulu Lake are in Agulu town, across which is a bridge and a wide tarred road.
Agulu is a very large semi-urban town with twenty villages. There is pipe borne
water, bore holes in some parts which are far away from the lake. Of the 20
villages in Agulu, 8 or more use the Agulu Lake as source of water for domestic
purposes. Water from the lake is also sold to villages and towns farther from
the lake by water tanker drivers.
Other sources of water for domestic uses in Agulu are spring
water and streams, namely Nemoku and Idemili Streams, Iyi ofu, Iyi Nwaduru,
Mmili Ugwu, Agbana and Iyi Nwangwo. The inhabitants of the area are mainly yam
and cassava farmers. Some are also traders. Most villages have primary schools
located in them. Few without primary schools make use of neighbouring village
schools.
Investigation was made to reveal the state and level of
Schistosomiasis haematobuim infection in the whole of Agulu town in
Anaocha local Government Area of Anambra State, Nigeria where this lake (Agulu
lake) is implicated in the transmission of the disease. Urine sample was
collected from 3029 children for Schistosoma egg identification. This was used
to calculate the level of infection in the different schools. Schistosomiasis prevalence was highest (55.2%) in
Umuowelle primary school and lowest (4.1%) in Obeagu primary school.
Males had higher infection rate than females in the endemic
schools. In Umuowelle,Community and Nneogidi primary schools, infection rates in
males were 36.4%, 13.3% 11.3% respectively while infection
rates in females were 25.2%, 11.7% and 6.8% respectively.
However, the sex differences were not statistically significant at 5%
confidence level (t-test = 2.179, df = 12). Infection levels investigated
in all the schools revealed that the age group 10-14 years recorded the highest
level while 0- 4 years had the lowest. There was also shifts in peaks of
infection within the varous age groups, for instance, in the 10
- 14 years age group of Ifiteani primary school, infection peak was
in 14 years while in Nneogidi primary school it was in 13 year
old pupils.
Schistosomiasis is a parasitic disease caused by flukes
(trematodes) of the genus Schistosoma. After malaria and intestinal
helminthiasis, schistosomiasis is the third most devastating tropical
disease in the world, being a major source of morbidity and mortality for
developing countries in Africa, South America, the Caribbean, the Middle East,
and Asia.
More than 207 million people, 85% of who live in Africa, are
infected with schistosomiasis, and an estimated 700 million
people are at risk of infection in 76 countries where the disease is considered
endemic, as their agricultural work, domestic chores, and recreational
activities expose them to infested water. Globally, 200,000 deaths are
attributed to schistosomiasis annually. Transmission is interrupted in
some countries.
Sometimes referred to as bilharzias, bilharziasis, or snail
fever, schistosomiasis was discovered by Theodore Bilharz, a German surgeon
working in Cairo, who first identified the etiological agent Schistosoma
hematobium in 1851.
Most human schistosomiasis is caused by S
haematobium, S mansoni,
and S japonicum. Less prevalent species, such as S
mekongi and S
intercalatum, may also cause systemic human
disease. Less importantly, other schistosomes with avian or mammalian primary
hosts can cause severe dermatitis in humans (eg, swimmer's itch secondary
to Trichobilharzia ocellata).
Characteristics of schistosomiasis
Schistosomiasis is due to immunologic reactions to Schistosoma eggs trapped in tissues. Antigens released from the
egg stimulate a granulomatous reaction involving T cells, macrophages, and
eosinophils that results in clinical disease. Symptoms and signs depend on the
number and location of eggs trapped in the tissues. Initially, the inflammatory
reaction is readily reversible. In the latter stages of the disease, the
pathology is associated with collagen deposition and fibrosis, resulting in
organ damage that may be only partially reversible.
Eggs can end up in the skin, brain, muscle, adrenal glands,
and eyes. As the eggs penetrate the urinary system, they can find their way to
the female genital region and form granulomas in the uterus, fallopian tube,
and ovaries. Central nervous system (CNS) involvement occurs because of
embolization of eggs from the portal mesenteric system to the brain and spinal
cord via the paravertebral venous plexus.
Snail hosts
The different species of Schistosoma have different types of snails serving as their
intermediate hosts; these hosts are as follows:
- Biomphalaria for
S mansoni
- Oncomelania for S japonicum
- Tricula ( Neotricula
aperta) for S
mekongi
- Bulinus for S haematobium and S intercalatum
At-risk populations
Today, 120 million people are symptomatic with
schistosomiasis, with 20 million having severe clinical disease. More than
200,000 deaths per year are due to schistosomiasis in sub-Saharan
Africa. Women washing clothes in infested water are at risk. Hygiene
and playing in mud and water make children vulnerable to infection. Forty
million women of childbearing age are infected. Approximately 10 million women
in Africa have schistosomiasis during pregnancy. In endemic areas, the
infection is usually acquired as a child.
In Brazil and Africa, refugee movements and migration to
urban areas are introducing the disease to new locations. Increasing population
size and corresponding needs for power and water have led to increased
transmission. Infections are not uniformly distributed within communities. It
has been estimated that 5-10% of an endemic community may be heavily infected,
and the remainder has mild to moderate infections. The risk of infection is
highest amongst those who lived near lakes or rivers. In Uganda, almost no
transmission was found to have occurred at altitudes greater than 1400 m or
where the annual rainfall was less than 900 mm.
With the rise of tourism and travel, an increasing number of
tourists are contracting it. Tourists often present with severe acute infection
and unusual problems including paralysis.
The intensity and prevalence of infection rises with age and
peaks usually between ages 15 and 20 years. In older adults, no significant
change is found in the prevalence of disease, but the parasite burden or the
intensity decreases.The disease is not endemic in United States.
Complications
Complications of schistosomiasis include the following:
- Gastrointestinal
(GI) bleeding
- GI
obstruction
- Malnutrition
- Schistosomal
nephropathy
- Renal
failure
- Pyelonephritis
- Hematuria
- Hemospermia
- Squamous
cell bladder cancer
- Sepsis
( Salmonella)
- Pulmonary
hypertension
- Cor
pulmonale
- Neuroschistosomiasis
- Transverse myelitis, paralysis, and cerebral microinfarcts
- Infertility
- Severe
anemia
- Low ̶
birth-weight babies
- Spontaneous
abortion
- Higher
risk for ectopic pregnancies
- End-organ
disease
- Portal
hypertension
- Obstructive
uropathy
- Pregnancy
complications from vulvar or fallopian granuloma
- Carcinoma
of the liver, bladder, or gallbladder
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