A STUDY ON MOSQUITO AS A PRIMARY MALARIA VECTOR

A STUDY ON MOSQUITO AS A PRIMARY MALARIA VECTOR

CHAPTER ONE

1.1     INTRODUCTION 
Mosquitoes are vectors of Plasmodium parasite that cause malaria, nematode worms that cause filariasis for example Wuchereria bancrofti, and a large number of arbo-viruses e.g yellow fever and dengue viruses including two of great impacts in the tropical ad sub-tropical regions (Ifeyinwa et al, 2012). They belong to the Order:Diptera and possess short elongated and slender body, long many-segmented antennae, long slender legs and an elongated proboscis with piercing and sucking mouth parts (Jordan et al, 2007).
Mosquitoes exploit almost all types of lentic aquatic habitats for breeding and some have been found to thrive in aquatic bodies such as fresh or salt water marshes, mangroves swamps, rice fields, grassy ditches, edge of streams and rivers and small temporary pools, (Oyewole et al, 2009). Many species prefer habitats with vegetations while some breed in open, sunlit pools. A few species breed in tree holes or the leaf axils of some plants (CDC, 2004).
Vector-borne diseases particularly mosquito-borne diseases have been the most important worldwide health problems for many years still represents a constant and serious risk to a large part of the world’s population. Mosquitoes rank as man’s important pest and most of the challenges posed by mosquito-borne diseases consist not only in their cosmopolitan nature and ability to survive in air, aquatic and terrestrial habitats, but their ability to breed in any collection of standing water such as wheel barrow, cesspits, flower vest and drainage systems make such a prolific source of mosquito production (Ifeyinwa et al, 2012).
Mosquito – transmitted diseases are the major cause of morbidity and mortality in sub Saharan Africa for example, there are up to 500 million clinical cases about deaths due to malaria globally (Olaleye et al, 2001).
1.2     MOSQUITO BREEDING SITES FOR DIFFERENT MOSQUITO TYPES
Breeding site is a place where mosquito can find all the physical and chemical requirements necessary for their growth, development and survival. Breeding sites vary according to types of mosquito. For example many species of Anopheles prefer habitats with vegetation while some breed in open, sunlit pools. A few species breed in tree holes or the leaf axils of some plants (CDC, 2004).
Anopheline species are known to be ground pool breeders, although large numbers have been observed in gutters, periodomestic run off and domestic containers (Mafiana et al, 1998; Aigbodion et al, 2003). Anopheles mosquito has been found to breed in clear water of suitable PH, temperature and nutrient composition (Okorie et at, 1978).
Aedes mosquito usually breeds in natural habitats especially in tree holes, leafs axils, rock pools and similar sites (Hawley, 1988). Wide spread deforestation, climate change and increase in global trade has forced this mosquito worldwide to adapt to breeding in domestic and semi-domestic artificial container habitats (Gubler et al, 2001; Delatte et al,2008).
The unplanned and haphazard growth of urban settlement, stagnant water in ditches and drains, cesspits, septic tanks, water tanks, barrels and all sorts of containers have increased the culex breeding surface area (WHO/TDR, 1975).
Culex species are found breeding in fresh water habitats such as pools, ditches, ponds and even in effluents of sewage treatment plants. Ochlerotatus species are found in temporary flood water pools, fresh and brackish marshes, and natural artificial containers. Psorophora species breed primarily in temporary flood water such as woodland pools, road side ditches and pastures. Deranotaenia species are most commonly found in ground pools, swamps and grassy edges of lakes. They feed primarily on reptiles and amphibians and are not known to bite humans (PHPC, 2001).
1.3     AIMS AND OBJECTIVES 
The aims and objectives of this study are:
1.       To identify the breeding sites of mosquitoes.
2.       To know the species of mosquitoes that are highly prevalent in Uyo urban.
3.       To determine the physico-chemical parameters of the breeding sites.
4.       To know their various control measures.