CHAPTER ONE

1.0                                                                       INTRODUCTION

Malaria is an internationally devastating disease and continues to be one of the most devastating infectious diseases of our time, rivaling Human Immunodeficiency Virus/ Acquired Immune Deficiency Disease Syndrome (HIV/AIDS) and Tuberculosis as killer diseases in tropical and subtropical regions (WHO, 2005) Figure 1. Around 3.2 billion people are at risk of malarial attack each year, with around 500 million people proceeding to clinical disease and 2-3 million deaths occurring (Snow et al, 2005). Over 90% of these deaths occur in sub-Saharan Africa (WHO, 2005). The burden of morbidity and mortality is biased towards young children, not yet immuned to clinical symptoms (Snow et al, 2005) and pregnant women, where parasites are sequestered in the placenta (Rowe and Keys, 2004).

In Africa, Anopheles gambiae and An. melas breeding in sunlit habitats and An. funestus in shades and An. phorensis in Upper Egypt and Sudan are responsible for the transmission of malaria parasite. In Nigeria, Anopheles gambiae complex, An. funestus and An. arabiensis have been incriminated for malaria transmission with major impact (Oguoma and Ikpeze, 2008) and Ekanem (1991).

The parasites that cause malarial disease are protozoan organisms that also infect many animal species including primates, lizards and birds. Four Plasmodium species are responsible for human malaria: Plasmodium falciparum; P. vivax, P. ovale, and P. malariae. Plasmodium falciparum is the most virulent parasite, and is responsible for the majority of malaria – related mortality. It is found in all malaria endemic regions of the world, and is the most common human malaria parasite in Africa (WHO, 2005). Plasmodium vivax is rarely

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found in Africa, but it is the most common species outside Africa (Mendis et al, 2001; Carter and Mendis, 2002).

Anaemia is a fairly common problem encountered in malaria and it poses special problems in pregnancy and in children. The easiest measures of anaemia are the haemoglobin and Packed Cell Volume levels. The haematological parameters of the study community was assessed using haemoglobin and Packed Cell Volume.

Aguowa community is a slum with about 5000 inhabitants within Trans-Ekulu area of Enugu Metropolis, Enugu-East Local Government Area of South-Eastern Nigeria. It is inhabited by mostly farmers, artisans, students, traders and civil servants. There are no pipe borne water, health, facilities, schools, tarred roads, with poor sanitary conditions.

1.1       THE OBJECTIVES OF THE STUDY

The main objective of the study is to sample mosquito vectors of malaria, determine the prevalent plasmodium species in humans, as well as blood parameters related to malaria pathology in some inhabitants of Aguowa community.

1.2       THE SPECIFIC OBJECTIVES

A.           Entomological

i)             Larval survey of Anopheles mosquitoes.

ii)            Indoor survey of adult Anopheles mosquitoes using the Pyrethrum Knockdown Collection (PKC) method.

iii)          Dissection of adult Anopheles mosquitoes collected indoors to demonstrate the presence of sporozoites in the salivary glands or gametocytes in the stomach.

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B.           Parasitological

i)             To determine the prevalence of infecting Plasmodium species in the human community, through examination of blood films using both thick and thin smears

C.           Haematology

i)             To estimate the Haemoglobin (Hb) level

ii)            To determine the packed cell volume (PCV) of the inhabitants of Aguowa community

1.3       EXPECTATIONS OF THE STUDY

This study, if successfully completed is expected to provide information and data on:

i)             The malaria vectors’ composition in the Aguowa Community