ABSTRACT

Hookworm infection is the leading cause of maternal and child morbidity in the tropics and

subtropics. The most serious consequence of hookworm infection is anaemia, secondary to loss

of iron and protein of gut. The complexity of the hookworm life cycle offers numerous

opportunities for the parasite and host to interact at the molecular level. Infection with human

hookworms is usually chronic, with adult worms surviving an average of 2–4 years, with a

maximum of 18 years and it triggers a series of immune responses in the host. Despite repeated

exposure, protective immunity does not seem to develop in humans, so that infections occur in

all age groups (depending on exposure patterns) and tend to be prolonged. In this study, the

prevalence and the immunological response to hookworm infection were studied among patients

attending some selected hospitals in Kano state. A total of four hundred (400) blood and stool

samples were collected. Microscopy was carried out to establish the presence of hookworm egg

in the stool samples, Enzyme linked immunosorbent assay (ELISA) was used to determine C3b

and IgM levels in the patients’ serum samples. The PCV of the study population was also

determined. Statistical package for social science (SPSS) version 21 was used to test for the

associated risk factors for the infection. Twenty one patients representing 5.3% were positive for

hookworm and were mainly children. The following results were obtained using questionnaire;

age group 6-10 years had the highest prevalence of 17.8% followed by 1-5 years (13.3%) while

those within the age group 16-20 years had the least prevalence (2%), hence, the distribution was

statistically significant (P<0.05). There was increase in IgM level in all the participants but the

participants that were infected with hookworm showed slightly higher level (9.8mg/ml). PCV

was determined for all participants, 19 (35%) of the positive participants had PCV within the

range of 1-20% and 2 (0.57%) participants were within the range 21-above (%), a significant

relationship was observed between PCV and hookworm infection (p<0.05).

CHAPTER ONE

1.0 INTRODUCTION

1.1 Hookworm Infection

Parasitic diseases have contributed immensely in undermining the health status of people and

jeopardizing the economic development of nations in the tropics (Adeyeba and Tijjani, 2002).

Human hookworm infection causes such parasitic diseases. Human hookworm infection is

caused by both Ancylostoma duodenale and Necator americanus, which are blood feeding

nematode (Yulan et al., 2009). They live in the small intestine where they attach to the mucosa

via teeth or cutting plates and feed on the host mucosa and blood (Hotez et al., 2004). They

infect over one billion people around the globe mostly in tropical and subtropical climates,

especially in communities with low socio-economic status (Furst et al., 2012; Fenwick, 2012;

Halpenny et al., 2013).

Hookworm infection is one of the commonest infections in Nigeria, with most persons having an

episode of infestation in their lifetime with far reaching disabling and debilitating effects on the

individual victims (Bala and Yakubu, 2010). Hookworm infection thrives in areas where sanitary

and environmental conditions favor the development of filariform larvae and infection of the

host (Halpenny et al., 2013; Abah and Woken, 2016).

The infection of the host is caused by the infective larvae that penetrate the skin of individuals

walking bare footed through areas contaminated with faecal matter. The most important medical

feature of hookworm infectiom is iron deficiency anaemia and this is as a result of loss of iron

and protein in the gut. The extent of iron deficiency anaemia resulting from hookworm is also

connected to the number of hookworm which infects the individual, particularly in people with

inadequate iron reserves or intake (Hotez et al., 2011).

The most vulnerable and high risk group of individuals to acquiring the infection is children and

pregnant women (Liabsuetrakul et al., 2009). In addition, heavy infection in children causes

stunted growth and impairment of intellectual and cognitive development (Jardim-Botelho et al.,

2008). Anaemia remains one of the most prevalent causes of morbidity suffered by these

individuals in the developing world and is a critical co morbid factor contributing to the excess

mortality in these regions (WHO, 2001).

In most developing countries for instance, anaemia in pregnancy has been associated with worm

disease, especially hookworm (Hotez, 2009). Women and young children have the lowest iron

levels and are therefore most vulnerable to chronic blood loss as the result of hookworm

infection (Brooker and Bundy, 2009).

1.2 Hookworm and Host Cell Responses

The complexity of the hookworm life cycle offers numerous opportunities for the parasite and

host to interact at the cellular level. Further, natural attrition of larvae at critical barriers, such as

during skin invasion, and transit through lung tissues, as well as arrival in the gut and penetration

of its mucosa, presents the host with an extensive diversity of antigenic challenge, immune

stimulation and, most probably, immune modulation. Hence, host immune responses can be said

to be triggered by larval invasion of the skin, larval migration through the circulation and lungs,

and worm establishment in the intestine, where adult worms feed on blood and mucosa while