PREVALENCE OF SCHISTOSOMIASIS AMONG PRIMARY SCHOOL CHILDREN IN DAKACE DISTRICT, ZARIA LOCAL GOVERNMENT AREA, KADUNA STATE, NIGERIA

ABSTRACT

Urine and stool samples were collected from 540 students (9-14 years) in at Dakace district in Zaria Local Government Area of Kaduna State. The samples were examined for urinary and intestinal Schistosomiasis infection. Each student was interviewed and data collectors used a structured pre-tested questionnaire that included questions on socioeconomic status of the family and risk factors that may be associated with schistosomiasis infection. A standard filtration technique was used to diagnose and quantify ova of S. haematobium and S. mansoni. Ten millitre (10 ml) of urine was filtered through 13 mm diameter in 12 μm pore size of nylon mesh filter using plastic syringe. The filter containing the filtrate was removed and placed on a clean microscopic slide and examined under a middle power objective (X40). After examining the whole field, microscopic slides containing eggs of S. haematobium were recorded as positive while absence of eggs was taken as negative. Stool samples were tested for the presence of S. mansoni eggs using the standard Kato Katz technique. Two slides from the same stool samples were prepared and examined for infection. Odds ratio and Pearson Chi square test was used to determine the association and relationship between age, school, risk factor and sex with schistosoma infection. An overall prevalence of 120 (22.22%) was recorded with S. haematobium and S. mansoni in all. Schistosoma haematobium recorded the highest prevalence of 14 (28.15%) in urine, while S. mansoni accounted for only 46 (17.04%) in stool samples examined. There were significant difference (p<0.05) in the infection of schistosomiasis among different schools in Dakace district with the highest (34.44%) and lowest (7.78%) infection were obtained from Nagoyi Local Government Education Authority (L. G. E. A.) primary school and Kith and Kin Academy respectively. The age specific prevalence of schistosomiasis ranged between 23 (12.78%) in ages 9-10 to 54 (30.00%) in 13-14 years age group. The prevalence of schistosomiasis was higher in males (14.07%) than their females (8.15%) counterpart. There were significant (p<0.05) association between prevalence infection with source water (Well; OR 529; Tap; OR = 2.053 and stream/river; OR = 2.125) and faecal disposal using pit latrines, OR = 1.117 and water systems, OR = 1.992. Schistosomiasis was not associated with fishing, swimming and washing in the river/stream. The prevalence of 22.22% was established in the selected schools in Dakace district of Zaria. Health education and large-scale chemotherapy for all school children to decrease the prevalence and intensity of infection would be highly suitable.

CHAPTER ONE

INTRODUCTION

1.1         Background of the Study

Schistosomes are important human and animal parasites throughout Africa, Asia and South America, predominantly in rural areas that support agriculture and inland fisheries. The distribution of Schistosomes are linked to that of their snail intermediate hosts (Bulinus and Biomphlaria spp.), which differ in their habitat preferences for slow-flowing or still waters (CDC, 2011). The impact of schistosomiasis has long been underestimated (Bergquist, 2002). It ranks second only to malaria as the most common parasitic disease, killing an estimated 280,000 people each year in the African region alone (CDC, 2011). The prevalence of schistosomiasis, like most parasitic disease is related to poverty and poor living conditions (Engels et al., 2002).

Despite intensive efforts to control the disease, it has been found to affect nearly 240 million people worldwide each year and more than 700 million people live in endemic areas (WHO, 2010). Nonetheless, 85% of the cases reported annually occur in sub-Saharan Africa and over 150,000 deaths are associated with chronic infection caused by S. haematobium in the African region (Hotez and Kamath, 2009; WHO, 2010). Schitosomiasis with soil-transmitted helminthiasis continue to represent more than 40% of the disease burden caused by all tropical diseases, excluding malaria (Hotez and Kamath, 2009). The disease is common in the Niger basin and is found in every country within the West African sub-region (Brown and Wright, 1985; Hegertun et al., 2013).

In Nigeria, one of the most severely affected countries in Africa, it is estimated that 101.28 million people are at risk of infection while 25.83 million are infected with Schistosoma haematobium, Schistosoma mansoni and Schistosoma intercalatum (Chitsulo et al., 2000). The risk and reemergence of urinary schistosomiasis is attributed to the range of snail habitats promoted by water development schemes such as dam construction (WHO, 2010). Furthermore, school age children who have frequent water contact are more vulnerable to schistosomiasis, and hence this age group that are often associated more frequently with schistosomiasis problems (Deribe et al., 2011; Bala et al., 2012).

Urogenital or urinary schistosomiasis is caused by Schistosoma haematobium while intestinal schistosomiasis is caused by S. guineensis, S. intercalatum, S. mansoni, S. japonicum, and S. mekongi (Hotez and Kamath, 2009). Other Schistosomes of veterinary importance reported in man include Schistosoma bovis, Schistosoma mathei, Schistosoma hippopotami, Schistosoma sprinadalis and Schistosoma rohhaini (Noble and Glem, 1982; Taylor and Naidu, 2013).

The intermediate snail host of S. mansoni is Biomphalaria spp. Bulinus snails are intermediate host for S. haematobium and Oncomelania snail for S. japoniacum (Ukoli, 1984). The parasitic larvae of Schistosoma species live in fresh water. It has the ability to penetrate host skin, predisposing people to the risk of infection due to everyday activities such as washing laundry or fetching water. Human contact with water is thus necessary for infection by schistosomes. Animals such as dogs, cats, rodents, pigs, horses and goats serve as reservoirs for Schistosoma spp.

Various socio-epidemiological factors are responsible for transmission of the disease and level of infection; some of which include distance from transmission site, migration and emergence of new foci, urbanization, socio-economic status, sanitation, water supply patterns and level of faecal contamination of water source (Sammy et al., 2011).

The provision of civilized swimming pools which is for recreational activities could serve as a good control measure for the spread of the disease (Gracio et al., 1992). Wearing of footwear to protect the legs could also be a good protective measure against active penetration by the cerceriae of the Schistosoma (Sammy et al., 2011). The geographical distribution of schistosomiasis in any locality depends on the distribution of the snail hosts and opportunities for infection of both the snail and human (Luka et al., 2005; Pillay et al., 2014).

School aged children are mostly infected with this silent destructive disease because it is easily contracted while bathing or swimming in water contaminated with the parasite that is shed by snails (Kabatereine et al., 2004; Kanwai et al., 2011). It has been estimated that every year, a child‟s risk of infection increases, peaking between the ages of 10 and 20 (Kabatereine et al., 2004). However, the intensity of their infection, as measured by quantitative egg counts of faeces or urine, shows the heaviest burden in the youngest age group. The morbidity associated with childhood infection can result in cognitive and growth stunting that is irreversible (Nokes et al., 1999).

Clinical manifestations of schistosomiasis are associated with the species-specific oviposition sites and the burden of infection (WHO, 2006). This parasitic infection imposes significant economic burdens on individuals, communities and nations (Blas et al., 2006). Urinary schistosomiasis is a chronic disease usually characterised by haematuria, dysuria, urinary frequency but in highly endemic areas, more than 50% of children show moderate to severe urinary pathology (van der Werf, 2003). A survey in the year 2000 of the disease-specific mortality, reported that 70 million individuals, out of 682 million, had experienced haematuria and 32 million, dysuria associated with S. haematobium infection (van der Werf, 2003; Pillay et al., 2014). It is associated with bladder and uretral fibrosis, sandy patches in the bladder mucosa and hydronephrosis that are commonly seen in chronic cases while bladder cancer is possible at late stage complication (Gryseels, 2006). The WHO estimates that out of these infected individual 18 million suffered cancers of the bladder and 10 million hydronephrosis (King et al., 2005).

On the other hand, intestinal clinical manifestations include abdominal pain, diarrhoea, and blood in the stool. In advanced cases, hepatosplenomegaly is common and is repeatedly associated with ascites and other signs of portal hypertension (Mostafa, 1999). Genital disease is present in approximately one third of infected women (Poggensee et al., 2001), resulting in a variety of vulvar and perineal disease, including ulcerative, fistulous, or wart-like lesions. Vulvar schistosomiasis may also facilitate hepatosplenomegaly (Stephenson et al., 1989; Feldmeier et al., 1995).

PREVALENCE OF SCHISTOSOMIASIS AMONG PRIMARY SCHOOL CHILDREN IN DAKACE DISTRICT, ZARIA LOCAL GOVERNMENT AREA, KADUNA STATE, NIGERIA

1.2         Statement of the Research Problems

The global burden of schistosomiasis has been estimated at 1.7–4.5 million disability-adjusted life years lost per annum (Molyneux et al., 2005), but new research suggests that this estimate is a considerable underestimation of the true burden of schistosomiasis (Jia et al., 2007). Children born in Nigerian villages are highly exposed to parasitic infection almost throughout their lifetime. According to the National Schistosomiasis Control Programme, the lack of adequate studies on schistosomiasis prevalence in some developing countries such as Nigeria and under developed countries has stalled the implementation of a treatment strategy. Schistosomiasis disease burden needs to be identified as a health problem in Dakace district, Zaria Local Government Area of Kaduna State, particularly among school children. The information on schistosomiasis disease in Dakace district is sketchy and therefore remains unknown.

1.3 Justification

Schistosomiasis is the most prevalent of the waterborne diseases and constitutes a serious health risk in rural areas of developing countries (Van der Werf, 2003; Pillay et al., 2014). Children under 18 years of age are reported to be highly susceptible to the scouge of this disease. Schistosomiasis as a public health problem and has not been properly researched and documented in Dakace district of Zaria Local Government Area, Kaduna State. The information obtained may therefore serve as a guide to the schistosomiasis Control Programme of the State Ministry of Health in Kaduna State Nigeria and applying treatment plans for schistosomiasis in Dakace district.

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1.4   Aim

To access the prevalence of schistosomiasis among primary school pupils in Dakace district, Zaria Local Government Area, Kaduna State.

PREVALENCE OF SCHISTOSOMIASIS AMONG PRIMARY SCHOOL CHILDREN IN DAKACE DISTRICT, ZARIA LOCAL GOVERNMENT AREA, KADUNA STATE, NIGERIA

1.5         Objectives

1. To determine the prevalence of Schistosoma mansoni among primary school pupils in six selected primary schools in Dakace district of Zaria Local Government Area.
2. To determine the prevalence of Schistosoma haematobium in primary school pupils of six selected primary schools in Dakace district of Zaria Local Government Area
3. To determine the risk factors associated with schistosomiasis among primary school pupils in Dakace district.

1.6         Hypotheses

1. There is no significant difference in the prevalence of Schistosoma mansoni in primary school pupils of six selected primary schools in Dakace district of Zaria Local Government Area
2. Schistosoma haematobium is not prevalent among primary school pupils in Dakace district of Zaria Local Government Area.
3. There are no risk factors associated with schistosomiasis infections among primary school pupils in Dakace district of Zaria Local Government Area.

See also: SENEGALENSIS (DESR. A. JUSS.) AGAINST EIMERIA TENELLA IN BROILER CHICKENS