An Epidemiology Survey for Schistosomiasis Among Adults
Chapter One
RESEARCH OBJECTIVES
The purpose of this study is to carry out an epidemiology survey for schistosomiasis among adults in Birnin Gwari Local Government Area of Kaduna State. Specifically, the objectives include:
- To determine the prevalence and epidemiology of Schistosomiasis among adults in Birnin Gwari Local Government Area, Kaduna State.
- To determine the age and sex specific prevalence of Schistosomiasis infection in Birnin Gwari Local Government Area, Kaduna State.
- To determine the risk factors associated with the transmission of Schistosomiasis to adults in Birnin Gwari Local Government Area, Kaduna State.
CHAPTER TWO
LITERATURE REVIEW
CONCEPTUAL REVIEW
Schistosomiasis is a parasitic disease caused by blood flukes (Trematodes) of the genus Schistosoma. About 700 million people are at risk of Schistosomiasis infection in 76 countries. The disease is endemic among people whose agricultural work, domestic chores and recreational activities expose them to infested water (WHO, 2010a). Schistosomiasis is the third most devastating tropical disease in the world, out of which 85% of infected individuals live in Africa (WHO, 2010b). Schistosoma species was discovered by Theodore Bilharz, a German surgeon while working in Cairo. He first identified the etiological agent, Schistosoma haematobium in 1851 (Nawal, 2010).
Schistosomes are transmitted to humans through contact with water containing the snail intermediate host that habours the infective stage of the parasite i.e. the cercaria (Shurrock, 2001; Corachan, 2002; WHO, 2010a).
Diversity of Schistosoma Species and their Geographical Distribution
There are about fifteen species of schistosomes that are prevalent in different areas of the world and produce different symptoms. Some of the important species are: Schistosoma mansoni, Schistosoma haematobium, Schistosoma mekongi, Schistosoma japonicum and Schistosoma intercalatum. Schistosoma mansoni is widespread in Africa, the Eastern – Mediterranean, the Caribbean and South America and can only infect humans and rodents. Schistosoma mekongi is prevalent only in the Mekong river basin in Asia. Schistosoma japonicum is limited to China and the Philippines and can infect mammals, such as pigs, dogs and water buffalos, in addition to humans. As a result, it can be more difficult to control disease caused by this species. Schistosoma intercalatum is found in Central Africa. Schistosoma haematobium occurs predominantly in Africa and the eastern Mediterranean (WHO, 1995; Leder and Weller, 2009). Three out of these species are of vast medical importance, these include S. haematobium that causes urinary Schistosomiasis and S. mansoni plus S. japonicum which cause Schistosomiasis.
LIFE CYCLE OF SCHISTOSOMA
The life cycle of schistosomes are different from those of other trematodes. Each of the schistosome species requires a snail intermediate host in order to complete its life cycle because humans become infected by penetration of cercaria through intact skin rather than through the ingestion of matacercaria (Fig. 1). Cercaria consists of a body containing glands whose material is used to penetrate skin and a bifurcated tail that is lost when the cercaria penetrates the skin (Fig.2). Once the cercaria have successfully entered the host, the organism is termed a schistosomulum (Sher and Moser, 1981). The schistosomulum migrates through the tissues and finally invades a blood vessel.
CHAPTER THREE
MATERIALS AND METHODS
STUDY AREA
The study was carried out in Birnin Gwari Local Government Area, which is one of the twenty three (23) Local Government Areas (LGA) of Kaduna State, Nigeria. The LGA is located in the eastern part of the State. It is divided into thirteen (13) districts, and has an area of 6,185Km2 and an estimated population of 252,363 (Census, 2006). The local government lies geographically between latitude 10°44’52″N – 11°19’59″Nand longitude 6°38’32″E – 7°19’59″E (Figure 1). The inhabitants are predominantly farmers, traders and civil servants. Their sources of water include wells, rivers, streams, pipe-borne water and dams. The supply of tap water is periodically.
CHAPTER FOUR
RESULTS AND DISCUSSION
RESULTS
Schistosoma haematobium Survey
The overall prevalence of Schistosoma haematobium infection was 108 out of 300 representing 36.0% of the study population. The prevalence of S. haematobium in males was 88(29.5%) in females 20(6.7%). The infection distribution by age among males showed that the highest prevalence of 9.7% was recorded in the age group 31 – 40 years and above. The age group 26 – 30 ranked second with 7.7% of pupils infected. The age group with the lowest prevalence was the 18 – 25 years age group where 5.3% males were infected. In females, the highest prevalence of 2.7% was recorded in the 26 – 30 years age group followed by 2.0% in the 31 – 40 years and above age group. The lowest prevalence of 0.7% was recorded in the 18-25 years age group (Table 1). On a general note, the highest prevalence of infection was recorded among the males than the females.
CHAPTER FIVE
SUMMARY, CONCLUSION, RECOMMENDATION
SUMMARY
An overall prevalence of Schistosoma haematobium was 36.0% out of 300 adults examined. The prevalence of the disease by age among the males showed that the highest prevalence was recorded in the age group of 36 – 40 years, followed by age group of 26-30 years. While among the females, the highest prevalence was recorded in the 21 – 25 age group followed by in the age group 36 – 40 years. The prevalence of S. mansoni was 20.3% varied from one community to another. The intensity of and it infection was light with the intensity ranging from 1 to 18 eggs per gram of faeces.
With regards to the responses of the adults to the questionnaires, relating the associations between various epidemiological variables and the disease, Odds ratio value greater than 1 indicated associations between fishing, use of pond water, stream water with the disease prevalence.
CONCLUSION
In conclusion, the study had provided an idea on the prevalence of Schistosomiasis infection among adults in Birnin Gwari Local Government Area. The prevalence of Schistosomiasis among adults examined showed that Schistosomiasis is a serious public health problem, The prevalence rate is higher in males than in females.
RECOMMENDATION
Therefore to reduce the morbidity of Schistosomiasis in these areas, target or selective chemotherapy should be carried out using praziquantel. A community health eradication campaign and adequate health education should be promoted on the control of the disease. The community should be educated on the mode of transmission of the disease and the pathology of the disease and therefore encourage them to adopt control measures. Portable water should be provided in the community with other basic amenities to promote the level of good living in the rural communities, thereby avoiding the use of pond, river and stream water.
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