PATTERNS OF TRANSMISSION, PREVALENCE AND INTENSITY OF SOIL TRANSMITTED HELMINTHIASIS IN NSUKKA ZONE, ENUGU STATE, NIGERIA

ABSTRACT
The study assessed the prevalence, intensity and environmental risk factors affecting the
transmission of soil transmitted helminthiasis in eleven randomly selected communities in
Nsukka and Uzouwani Local Government Areas of Enugu State, Nigeria. It also determined
the effect of peoples’ knowledge of mode of transmission of the diseases and access to
facilities for water supply and sanitation in each of the communities. This is with a view to
gaining insight into the patterns of transmission and endemicity of the diseases in the area.
Fifty households were systematically selected in eleven randomly selected communities in
Nsukka zone. A health structured questionnaire was administered to consenting member of
each selected households to collect information on personal bio-data (age, sex, state of origin,
etc.), personal hygiene (toilet habits such as anal cleansing and hand washing patterns after
toilet use), knowledge of mode of transmission, signs and symptoms of each disease as well
as management of infected persons (type of treatment received and where). Faecal samples
were collected from each individual once every 3 months for 12 months and analysed for
presence and number of helminth eggs using the concentration by gravity method and the
40X magnification of the compound microscope Soil samples were collected from three
sites in each community and analysed for chemical and physical properties using standard
methods. Presence and number of helminth eggs in each soil sample was determined using
the concentration by gravity method. Data were analysed using appropriate descriptive and
inferential statistical methods. Hookworm and ascariasis were the only soil transmitted
helminth infections observed in the communities. Out of a total of 2055 persons examined in
all communities, overall prevalence of hookworm was 52.8%, ascariasis 74.3% and double
infection 50%, while 76.7% were infected with either hookworm or ascariasis suggesting that
less than a quarter were free of infection. Prevalence of hookworm ranged from 38..9% at
Margaret Cartwright to 64.7% at Nkpunato; 50% in males to 55% in females; and 30.5% to
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82.6 in 40+ and 10-19 years age groups. Corresponding values for ascariasis were 61.9% and
82.6% at New Anglican Road and Ogurugu; 69.5% - 71.9% in males and females; and 67.8 -
86.6% in 30-39 and 10-19 years age brackets. Overall mean intensity of hookworm was
125.6 ± 129.8 eggs per gramme faeces (epg) and ascariasis 310.6 ± 234.8 epg. Intensity of
hookworm ranged from 82.4±101.3 to 160.3±153.2 epg at Foulton and Nkpunato,
respectively; 121.7±141.5 in males to 128.9±134.9 epg in females; and 76.2±126.7 to
198.8±120.8 epg in the 40+ and 10-19 years age groups respectively. For ascariasis, intensity
ranged from 232.6±175.5 to 429.4±261.6 epg at Nkpologu and Nkpunato; 288.3±238.4 -
328.5±237.7 in males and females; and 237.7±229.0 -396.3±234.5 in 40+ and 1-9 years age
groups. Thus, prevalence and intensity of both hookworm and ascariasis varied significantly
(p< 0.05) among the communities, sexes and age groups. They also varied with educational
background, marital status, seasons and access to different facilities for water supply and
sanitation. Soil texture was sandy to sandy loam and total porosity, exchangeable base (1.46
to 1.78 cmol kg-1s) and organic carbon (1.04 g kg-1) contents were relatively low. The soils
were also strongly (3.70 ± 0.17) to weakly (6.33 ± 0.15) acidic. Mean hookworm and Ascaris
egg concentration in soil were 750.00±633.37 and 763.64±458.56 respectively and varied
between communities, soil types and seasons. Logistic regression analysis showed that
among other factors, hookworm infection was significantly explained by footwearing habits
and ascariasis by hand washing and anal cleansing habits after toilet use.
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TABLE OF CONTENT
Title Page ………………………………………………………………………………. i
Approval page………………………………………………………………………….. ii
Dedication ……………………………………………………………………………… iii
Certification ……………………………………………………………………………. iv
Acknowledgement………………………………………………………………………. v
Abstract ……………………………………………………………………………….... vi
Table of Contents………………………………………………………………………. vii
Pages
CHAPTER ONE (INTRODUCTION AND LITERATURE REVIEW)
1 Introduction ………………………………………………………………… 1
1.1 Objectives of The Study. …………………………………………………… 3
1.2 Literature Review……………………………………………………………. 3
1.3 Ascaris lumbricoides (Roundworm): ……………………………………… 3
1.3.1 Morphology and Life Cycle………………………………………………… 3
1.3.2 Epidemiology………………………………………………………………… 6
1.3.3 Clinical Manifestation: ……………………………………………………… 7
1.3.4 Pathology and Pathogenesis: ………………………………………………… 7
1.4 Enterobius vermicularis (Pinworm) ………………………………………… 9
1.4.1 Morphology and Life Cycle…………………………………………………. 9
1.4.2 Epidemiology: ……………………………………………………………… 11
1.4.3 Clinical Manifestation: ……………………………………………………… 11
1.4.4 Pathology and Pathogenesis: ………………………………………………… 11
1.5 Ancylostoma duodenale, and Necator americanus (Hookworms): ………… 11
1.5.1 Morphology and Life Cycle. ………………………………………………… 11
1.5.2 Epidemiology: ……………………………………………………………… 15
1.5.3 Clinical Manifestation: ……………………………………………………… 15
1.5.4 Pathology and Pathogenesis: ……………………………………………….. 16
1.6 Trichuris trichiura (whipworm): …………………………………………… 17
1.6.1 Parasitology: ………………………………………………………………… 17
1.6.2 Morphology and Life Cycle: ………………………………………………… 17
1.6.3 Epidemiology: ……………………………………………………………… 18
1.6.4 Clinical Manifestation: ……………………………………………………… 19
1.6.5 Pathology and Pathogenesis: ………………………………………………… 19
1.7 Strongyloides stercoralis: ……………………………………………………. 19
1.7.1 Morphology and Life Cycle. ………………………………………………… 19
1.7.2 Epidemiology: ……………………………………………………………… 22
1.7.3 Clinical Manifestation: ……………………………………………………… 22
1.7.4 Pathology and pathogenesis: ………………………………………………… 22
1.8 Toxocara Species (Toxocara spp). …………………………………………… 23
1.8.1 Morphology and life cycle …………………………………………………… 23
1.8.2 Epidemiology: ………………………………………………………………… 23
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1.8.3 Clinical Manifestations: ……………………………………………………… 23
1.8.4 Pathology and pathogenesis …………………………………………………… 24
1.9 Laboratory Diagnosis of Soil Transmitted Helminths ………………………… 25
1.9.1 Transmission of Soil-Transmitted Helminthes. …………………………………. 26
1.9.2 Factors Affecting Transmission ………………………………………………. 27
1.9.2.1 Occupation…………………………………………………………………….. 27
1.9.2.2 Educational Background.. ……………………………………………………... 28
1.9.3 Health Education ……………………………………………………………… 28
1.9.4 Management. ………………………………………………………………….. 29
1.9.4.1 Hygiene ………………………………………………………………………… 29
1.9.5 Environmental Control of Soil-transmitted Helminthes. ………………………. 29
1.9.6 Chemotherapy ………………………………………………………………… 35
1.9.6.1 Orthodox……………………………………………………………………….. 35
1.9.6.2 Drugs of Choice: ………………………………………………………………. 35
1.9.6.3 Alternative Therapy: …………………………………………………………… 35
1.9.6.4 General Preventive Measures: ………………………………………………… 36
1.9.6.5 Mass Chemotherapy: ………………………………………………………… 36
1.9.6.6 Group- Targeted Chemotherapy: …………………………………………….. 36
1.9.6.7 Treatment of Individual Cases: ……………………………………………… 37
1.9.6.8 Herbal ………………………………………………………………………… 37
1.9.6.9 Immunosuppressed Hosts: …………………………………………………… 38
1.9.7 Water Supply and Sanitation………………………………………………… 38
Chapter Two (Materials And Method)
2.1 Study Area: …………………………………………………………………… 40
2.2 Questionnaire Administration and Faecal Sample Collection ……………….. 42
2.3 Collection of Soil Samples …………………………………………………… 42
2.4 Analysis of Faecal Samples …………………………………………………. 43
2.5 Statistical Analysis…………………………………………………………… 45
Chapter Three (Results)
3.1: Demographic and Socio-economic Characteristics …………………………… 46
3.1.1 Personal Characteristics………………………………………………………… 46
3.1.2 Water supply and sanitation…………………………………………………….. 46
3.1.3 Health Condition Ranking and Perception …………………………………….. 49
3.2 Prevalence and Intensity Patterns. …………………………………………….. 51
3.2.1 Prevalence and intensity of infection in communities………………………….. 51
3.2.2 Age and sex prevalence and intensity of infection …………………………….. 55
3.2.3 Prevalence and Intensity of Infection by educational background. …….. 60
3.2.4 Prevalence and intensity of infection by seasons ……………………………… 61
3.2.5 Prevalence and intensity of infection by marital status ……………………….. 64
3.2.6 Prevalence and intensity of infection by latrine type. ………………………….. 66
3.2.7 Prevalence and intensity of infection according to cleaning habits after toilet use. 68
3.2.8 Prevalence and intensity of infection in relation to Occupation………………… 72
3.2.9 Prevalence and intensity of infection by dry season water source (2006-2007) …. 72
3.2.10 Prevalence and intensity of infection by water source during the rainy season …. . 73
3.2.11 Prevalence and intensity of infection according to footwear and type 2006-2007... 74
3.2.12 Knowledge of the people concerning the infection of hookworm and ascariasis
diseases (2006-2007). ……………………………………………………………... 77
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3.2.13 Prevalence and intensity of infection according to treatment method. ………… 79
3.2.14 Prevalence and intensity of infection according to treatment type (2006-2007)… 81
3.2.15 Prevalence and intensity of infection in relation to common signs and symptoms.. 82
3.2.16 Prevalence and intensity of infection according to hospital visit and rate…….. 85
3.3 Environmental Characteristics…………………………………………………… 90
3.3.1 Soils Physical Properties ……………………………………………………….. 90
3.3.2 Chemical Properties of Soils …………………………………………………… 92
3.3.3 Summary of Helminth Egg Concentration in soil ……………………………… 94
3.3.4 Summary of Helminth Egg Concentration in sites……………………………… 95
3.3.5 Relationship between soil characteristics and geohelminthes contamination:…. 96
3.30 Relationship between soil characteristics and Geohelminthes contamination…. 97
Chapter Four (Discussion) ……………………………………………………………… 98
4.1 Demorgraphic and socio-economic characteristics……………………………… 98
4.2 Prevalence and intensity patterns of the infections………………………………. 101
4.3 Environmental factors that influence the infections……………………………… 104
4.4 Conclusion and Recommendation………………………………………………... 106
Reference…………………………………………………………………………………. 108