Project – Environmental Risk Factors Associated with Mosquito Breeding and Their Implications for Community Health in Selected Communities in Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Mosquitoes are among the most important disease vectors affecting human populations, particularly in tropical and subtropical regions. Through their bites, different mosquito species transmit parasites, viruses and other pathogens capable of causing serious diseases, including malaria, dengue, yellow fever, chikungunya, lymphatic filariasis and other vector-borne infections. The World Health Organization (WHO) identifies vector-borne diseases as major public health problems, accounting for a substantial proportion of the global burden of communicable diseases and causing more than 700,000 deaths annually. The burden is particularly concentrated in tropical and subtropical environments where climatic and ecological conditions support vector survival and reproduction (World Health Organization [WHO], 2017).

Mosquito-borne diseases are not produced by mosquitoes in isolation. Their transmission results from a complex interaction involving mosquito vectors, infectious agents, human hosts and the physical environment. Consequently, environmental conditions constitute an important determinant of mosquito abundance and disease transmission. Factors such as rainfall, temperature, relative humidity, vegetation, water bodies, drainage conditions, soil characteristics, housing conditions, waste disposal practices and water-storage behaviours can influence mosquito breeding and the subsequent risk of human infection. Research conducted in Nigeria has demonstrated that environmental and climatic variables, including temperature, vegetation, water bodies, rainfall, relative humidity, elevation and slope, can influence the spatial distribution of malaria morbidity (Adeleke et al., 2023).

Among mosquito-borne diseases, malaria remains one of the most significant public health challenges in Nigeria. Malaria is caused by Plasmodium parasites and transmitted primarily through the bites of infected female Anopheles mosquitoes. The disease remains endemic throughout Nigeria, with transmission occurring throughout the year, although intensity varies geographically and seasonally. The country’s malaria burden is exceptionally high. The WHO reported that in 2023 Nigeria accounted for approximately 55% of estimated malaria cases in the West African subregion, while the country continues to carry one of the largest malaria burdens globally (WHO, 2024).

More recent WHO estimates indicate that approximately 282 million malaria cases and 610,000 malaria deaths occurred globally in 2024. The African Region accounted for approximately 95% of malaria cases and deaths globally, and Nigeria alone accounted for about 31.9% of malaria deaths in the African Region (WHO, 2025). This situation demonstrates that malaria prevention remains an important component of community health in Nigeria and that environmental approaches to vector control deserve continued attention.

Although malaria receives considerable attention, environmental mosquito breeding can have implications beyond malaria. Different mosquito genera occupy different ecological niches and transmit different diseases. Anopheles mosquitoes are important vectors of malaria, while Aedes species can transmit diseases such as yellow fever, dengue and chikungunya. Culex species are associated with several diseases, including lymphatic filariasis and other arboviral infections. The WHO Global Vector Control Response therefore advocates an integrated approach that addresses multiple vectors and diseases rather than relying exclusively on disease-specific interventions (WHO, 2017).

The environmental conditions that permit mosquito breeding are often associated with human activities. Mosquitoes generally require water for their immature stages, meaning that any environmental condition that creates suitable aquatic habitats can contribute to mosquito proliferation. Such habitats may include stagnant pools, blocked drainage channels, open gutters, discarded tyres, plastic containers, abandoned vessels, construction pits, uncovered water-storage containers, ponds, flooded areas and other water-holding receptacles. The WHO has specifically recognised poor solid-waste management and inadequate water infrastructure as factors that can create mosquito breeding sites (WHO, 2017).

In urban and semi-urban communities, environmental changes caused by rapid population growth, housing development, road construction, poor drainage and inadequate waste disposal can create additional opportunities for mosquito breeding. Urbanisation does not necessarily eliminate mosquito-borne disease risk. Rather, it may change the nature and distribution of mosquito habitats. The WHO has noted that urbanisation, environmental change and inadequate infrastructure can increase opportunities for mosquito vectors to reproduce and come into contact with human populations (WHO, 2017).

Research from Nigeria provides empirical evidence that mosquitoes can adapt to diverse urban environmental conditions. Awolola et al. (2007), for example, investigated Anopheles breeding in polluted water bodies in urban Lagos and found Anopheles gambiae complex larvae in a range of polluted aquatic environments. The study reported associations between mosquito larvae and water characteristics such as pH, turbidity, dissolved oxygen, conductivity, oil and heavy-metal concentrations. This finding demonstrates that environmental degradation does not necessarily prevent mosquito breeding and, in some circumstances, mosquitoes may exploit human-created and polluted habitats.

Similarly, mosquito larval habitats investigated in Abeokuta, Ogun State, included ground pools and ponds, gutters and open drains, tyres, domestic containers and tree holes or leaf axils. Several mosquito species of public health importance were identified, including Aedes aegypti, Aedes albopictus, Culex quinquefasciatus and Anopheles gambiae sensu lato. The researchers concluded that the availability of these habitats creates conditions in which residents may be exposed to mosquito-borne diseases and recommended improved environmental sanitation and public education (Awolola et al., 2008).

Environmental sanitation is consequently an important component of mosquito control. Sanitation practices such as proper refuse disposal, removal of containers that collect rainwater, clearing of blocked drains, elimination of stagnant water and maintenance of clean surroundings can reduce the availability of mosquito breeding habitats. Conversely, indiscriminate waste disposal, accumulation of refuse, poor drainage and uncontrolled vegetation may increase the availability of breeding sites.

Evidence from Nigeria supports the relationship between environmental sanitation and malaria. In a study conducted in a rural town in southwestern Nigeria, Oladepo et al. (2014) found that although most respondents understood that a dirty environment could increase malaria risk, regular environmental cleaning was uncommon. The study reported that respondents identified bushes, stagnant water and unclean drainage systems as environmental factors associated with malaria, while malaria attacks were common among the households studied. The findings demonstrate that awareness of environmental risk does not necessarily translate into appropriate environmental practices.

Agricultural and livelihood activities can also contribute to mosquito breeding. In two rural farming communities in Oyo State, Nigeria, Akinleye et al. (2010) found that farming practices such as trenches, irrigation, fish ponds, water-filled containers and the accumulation of agricultural waste could create mosquito breeding habitats. The study also found gaps in community knowledge about malaria transmission, suggesting that environmental practices and knowledge should be considered together in malaria prevention programmes.

The relationship between environmental conditions and mosquito-borne disease is also influenced by climatic factors. Temperature affects mosquito development, survival and biting behaviour, while rainfall can create breeding habitats. Relative humidity can influence mosquito survival, and vegetation and surface water can provide favourable ecological conditions. A recent spatial analysis of malaria in Ondo State, Nigeria, demonstrated that temperature was an important factor influencing malaria transmission, while vegetation, water bodies, rainfall, relative humidity, elevation and slope also contributed to variations in malaria risk (Adeleke et al., 2023).

These environmental relationships are particularly important in communities where water accumulates during the rainy season or where drainage infrastructure is inadequate. Even relatively small water-holding containers may become productive breeding sites when they remain undisturbed for sufficient periods. Consequently, environmental risk assessment needs to consider both large-scale environmental characteristics and small household-level conditions.

The situation is relevant to Kogi State because the state contains a mixture of urban, semi-urban and rural settlements with diverse environmental and socioeconomic characteristics. Communities located around major rivers, streams, drainage systems, agricultural areas and low-lying locations may experience different environmental exposures. Variations in housing, sanitation, water supply, waste management and economic activities may further influence the distribution of mosquito breeding habitats.

The selected locations for this study—Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe—provide an important basis for comparative assessment of environmental mosquito-breeding risks. These communities are situated within Kogi State but differ in their geographical, ecological, settlement and socioeconomic characteristics. Such differences may create variations in mosquito breeding conditions and, consequently, differences in community health risks.

Of particular importance is Koton Karfe, where previous research has specifically examined malaria risk. Ifatimehin, Laah and Toluhi (2019) assessed malaria risk in the Koton Karfe watershed catchment using ground surveys, questionnaires and health-facility data. Their study reported substantial variation in malaria incidence across the watershed and identified poverty as an important factor associated with malaria risk. The researchers also highlighted the need for stronger interventions to reduce malaria burden in the population.

Earlier work by Musa, Mohammed and Emeka (2014) also investigated environmental and socioeconomic factors associated with malaria risk in Koton Karfe. The study found considerable variation in malaria incidence across the watershed catchment and identified poverty as a major factor influencing malaria risk. The existence of this earlier evidence makes Koton Karfe particularly relevant to the present research, while also demonstrating the need to examine environmental mosquito breeding conditions as a specific public health issue.

However, the fact that Koton Karfe has previously been studied does not eliminate the need for further research. Previous studies have focused largely on malaria risk, incidence and socioeconomic conditions, whereas the present study seeks to examine environmental risk factors specifically associated with mosquito breeding and their implications for community health across multiple selected communities. This broader approach can provide evidence on whether environmental conditions that facilitate mosquito breeding are common across the selected communities or vary according to local circumstances.

The public health implications of mosquito breeding extend beyond the occurrence of individual malaria episodes. Repeated exposure to mosquitoes can contribute to recurrent illness, household expenditure on healthcare and medicines, loss of working days, school absenteeism, reduced productivity and pressure on health facilities. Malaria particularly affects vulnerable groups such as young children and pregnant women, although all individuals living in endemic areas can be exposed. WHO identifies children under five years and pregnant women among populations requiring particular attention in malaria control (WHO, 2024, 2025).

At the community level, mosquito-borne diseases can place pressure on already constrained health systems. Frequent cases can increase demand for diagnosis and treatment, while recurrent illness can affect household economic stability. Consequently, environmental prevention should be viewed not simply as a mosquito-control activity but as an important component of community health promotion.

Environmental management has long been recognised as an important vector-control approach. Measures such as drainage, elimination of breeding sites, improved sanitation and appropriate management of water-holding containers can reduce opportunities for mosquito reproduction. WHO describes larval source management as including the manipulation and modification of aquatic mosquito habitats, larviciding and biological control, with container and waste management also recognised as important components of controlling mosquito larvae (WHO, 2026).

Modern vector control increasingly emphasises integrated approaches. The WHO Global Vector Control Response identifies four major pillars: strengthening inter- and intra-sectoral collaboration, engaging and mobilising communities, enhancing vector surveillance and monitoring, and scaling up and integrating appropriate vector-control tools (WHO, 2017). This approach is important because mosquito breeding cannot be addressed effectively by health workers alone. Environmental sanitation, drainage, waste management, housing, water supply, urban planning and community behaviour all contribute to the risk environment.

Community participation is particularly important because many breeding sites occur around people’s homes and neighbourhoods. Residents can contribute significantly to vector control by removing stagnant water, covering water containers, clearing blocked drains, disposing of waste appropriately and maintaining clean surroundings. However, community participation depends on knowledge, attitudes, available resources, social organisation and local environmental conditions.

There is therefore a need to move beyond simply documenting malaria cases to understanding the environmental circumstances that may facilitate mosquito breeding. Identifying these environmental risk factors can provide an evidence base for preventive action before disease transmission occurs. Such an approach is consistent with the public health principle of prevention, which seeks to address risk factors before they result in disease.

The present study is therefore designed to assess environmental risk factors associated with mosquito breeding and examine their implications for community health in selected communities of Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe. By examining environmental conditions such as stagnant water, drainage, refuse disposal, vegetation, water-storage practices, discarded containers, construction activities and other potential breeding sites, the study will provide a clearer understanding of the environmental determinants of mosquito-related health risks within the selected communities.

1.2 Statement of the Problem

Mosquito-borne diseases continue to constitute a major public health problem in Nigeria despite the availability of effective prevention and control measures. Nigeria remains one of the countries with the highest malaria burden globally, and transmission occurs throughout the country. WHO estimates indicate that Nigeria continues to account for a very substantial proportion of malaria deaths in the African Region (WHO, 2025). The continued burden raises questions about the extent to which environmental conditions that support mosquito breeding are being adequately controlled at community level.

One major concern is the persistence of mosquito breeding habitats within residential and community environments. Stagnant water, blocked drains, open gutters, discarded tyres, abandoned containers, water-filled receptacles, poorly managed refuse and overgrown vegetation can create conditions suitable for mosquito reproduction. In many communities, these environmental conditions may persist because of inadequate sanitation services, poor drainage infrastructure, irregular waste collection, inappropriate water-storage practices or limited community participation in environmental management.

The problem is particularly important because mosquito breeding can occur in environments that residents may not recognise as significant public health hazards. A discarded plastic container, used tyre, blocked drainage channel or uncovered water-storage vessel may appear insignificant but can provide an aquatic habitat for mosquito larvae. Research in Nigeria has demonstrated that mosquito larvae can occur in a wide range of natural and artificial habitats, including gutters, ground pools, tyres and domestic containers (Awolola et al., 2008).

Another concern is that environmental sanitation knowledge may not necessarily translate into appropriate practice. Oladepo et al. (2014) found that a very high proportion of respondents in a Nigerian community recognised that dirty environments could increase malaria risk, yet regular environmental cleaning was uncommon. This gap between awareness and practice represents an important public health challenge because effective environmental control depends on consistent implementation of preventive measures.

The problem may be more complicated in communities with different ecological and socioeconomic conditions. Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe may differ in settlement patterns, topography, vegetation, water sources, drainage, waste management, agricultural activities, construction and household characteristics. Consequently, the environmental factors responsible for mosquito breeding may not be uniform across the communities.

For instance, communities with inadequate drainage may experience water accumulation after rainfall, while areas with poor waste disposal may have numerous containers capable of retaining rainwater. Communities involved in agricultural activities may have irrigation channels, ponds, trenches or other water-holding areas. In more densely settled locations, inadequate drainage and waste management may create numerous artificial breeding habitats. These differences make it inappropriate to assume that a single mosquito-control strategy will have the same effectiveness across all communities.

Koton Karfe provides a particularly important example. Previous research has established that malaria constitutes a significant health risk in the Koton Karfe watershed catchment. Ifatimehin et al. (2019) found considerable variation in malaria incidence across the catchment and identified socioeconomic factors as important contributors to risk. However, existing studies have not sufficiently addressed the current environmental conditions that facilitate mosquito breeding across Koton Karfe and the other selected communities in the present study.

A further problem is that the environmental dimension of mosquito-borne disease is sometimes overshadowed by emphasis on treatment and individual protection. Insecticide-treated nets, indoor residual spraying and appropriate malaria case management are important, but they do not eliminate mosquito breeding habitats in the external environment. The WHO Global Vector Control Response emphasises the need for integrated vector control involving surveillance, environmental action, community mobilisation and collaboration across sectors (WHO, 2017).

Inadequate environmental management may also have implications beyond malaria. The presence of multiple mosquito breeding habitats can support different mosquito genera and potentially increase the risk of other mosquito-borne diseases. Research in Nigerian urban environments has documented Anopheles, Aedes and Culex species in different breeding habitats (Awolola et al., 2008). Therefore, an environmental assessment of mosquito breeding should not be limited exclusively to malaria transmission.

Climate and environmental changes further complicate the problem. Variations in rainfall, temperature, humidity and surface water can alter the availability and suitability of mosquito habitats. Research in Nigeria has shown that climatic and environmental factors influence the geographical and temporal pattern of malaria morbidity (Adeleke et al., 2023). Consequently, environmental risk assessment must take into account the local ecological characteristics of the communities under investigation.

Another problem is the limited availability of recent comparative community-level evidence for the selected locations. Although studies have examined malaria risk in Koton Karfe and environmental mosquito habitats in other Nigerian settings, there is limited integrated evidence comparing environmental mosquito-breeding risk across Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe. Without such evidence, it is difficult to determine which environmental factors are most prevalent, which communities have the greatest concentration of potential breeding sites, and what implications these conditions may have for community health.

This lack of evidence can limit the ability of local health authorities, environmental health officers, community leaders and other stakeholders to develop targeted interventions. If the principal problem in one community is blocked drainage while another is dominated by household water-storage containers or refuse accumulation, interventions should be appropriately adapted to the local situation.

The central problem, therefore, is that environmental conditions that may facilitate mosquito breeding continue to exist in communities within Kogi State, while adequate comparative evidence on the specific environmental risk factors and their implications for community health remains limited. The persistence of such environmental conditions may contribute to continued mosquito-human contact and consequently increase the risk of mosquito-borne diseases.

It is against this background that this study seeks to assess the environmental risk factors associated with mosquito breeding and their implications for community health in selected communities in Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe. The findings are expected to provide empirical evidence that can support environmental health planning, community mobilisation, vector surveillance and targeted mosquito-control interventions in the selected communities.

1.3 Purpose of the Study

The main purpose of this study is to assess environmental risk factors associated with mosquito breeding and their implications for community health in selected communities in Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe.

Specifically, the study seeks to:

1. identify the major environmental conditions associated with mosquito breeding in the selected communities;
2. assess the prevalence of potential mosquito breeding sites in the selected communities;
3. examine the relationship between poor environmental sanitation and the presence of mosquito breeding habitats;
4. determine the extent to which stagnant water, poor drainage and improper waste disposal contribute to mosquito breeding

1.4 Research Questions

The following research questions will guide the study:

1. What are the major environmental conditions associated with mosquito breeding in the selected communities?
2. What types of potential mosquito breeding sites are present in the selected communities?
3. What relationship exists between environmental sanitation practices and the presence of mosquito breeding habitats?
4. To what extent do stagnant water, poor drainage and improper waste disposal contribute to mosquito breeding?

1.5 Research Hypothesis

The following null hypothesis will be tested at 0.05 level of significance:

H₀: There is no significant relationship between environmental risk factors and the occurrence of mosquito breeding sites in the selected communities of Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe.

1.6 Significance of the Study

The study will be significant to the following groups:

1.6.1 Kogi State Ministry of Health

The findings will provide the Kogi State Ministry of Health with evidence concerning environmental conditions that may contribute to mosquito breeding. Such evidence may assist in strengthening malaria and vector-control programmes and in designing interventions that are responsive to the conditions of individual communities.

1.6.2 Local Government Health Authorities

The findings will assist health authorities in the selected local government areas to identify environmental conditions requiring attention. The information may support environmental sanitation campaigns, community health education, mosquito surveillance and targeted vector-control activities.

1.6.3 Environmental Health Officers

Environmental health personnel may benefit from evidence concerning the types and distribution of potential mosquito breeding habitats. The findings can assist officers in prioritising environmental inspections and community sanitation activities.

1.6.4 Community Leaders

Traditional leaders, religious leaders, youth organisations and other community stakeholders may use the findings to understand the environmental conditions contributing to mosquito breeding within their communities. This may encourage community-led environmental sanitation, drainage maintenance and removal of mosquito breeding sites.

1.6.5 Residents

The study will increase awareness among residents regarding the relationship between environmental conditions and mosquito breeding. It may encourage households to remove water-holding containers, maintain clean surroundings, properly dispose of waste and participate in community environmental sanitation.

1.6.6 Public Health Practitioners

Public health practitioners may use the findings to develop health-promotion interventions that address both environmental and behavioural determinants of mosquito-borne disease. This is consistent with WHO’s integrated vector-management approach, which emphasises locally adapted and sustainable vector control (WHO, 2017).

1.6.7 Policymakers

The findings may contribute to policy decisions concerning sanitation, drainage, waste management, environmental health and vector-control activities. Evidence generated from the study may support allocation of resources to communities experiencing greater environmental mosquito-breeding risks.

1.6.8 Researchers and Students

The study will contribute to the literature on environmental health, mosquito ecology, malaria prevention and community health in Nigeria. It may also provide baseline information for future research involving entomological surveillance, GIS-based mapping of breeding sites and evaluation of environmental vector-control interventions.

1.7 Scope of the Study

The study will focus on environmental risk factors associated with mosquito breeding and their implications for community health in selected communities in Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe.

The content scope will cover environmental factors such as:

• stagnant water;
• blocked drainage systems;
• open gutters;
• poor refuse disposal;
• discarded tyres and containers;
• uncovered water-storage containers;
• overgrown vegetation;
• waterlogged areas;
• construction sites;
• ponds and other surface-water bodies;
• household environmental sanitation;
• agricultural activities that may create water-holding habitats; and
• other conditions capable of supporting mosquito breeding.

The study will also examine residents’ knowledge of environmental mosquito-breeding risk and their perception of the health implications of mosquito proliferation.

The geographical scope will cover selected communities within the six locations specified for the study: Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe.

The study will focus primarily on environmental risk factors and community health implications. It will not constitute a laboratory-based entomological study unless mosquito larvae or adult mosquitoes are specifically sampled and identified as part of the methodology. Similarly, the study will not attempt to clinically diagnose malaria or other mosquito-borne diseases among participants unless such clinical data are incorporated into the research design.

1.8 Operational Definition of Terms

Community Health: The health status and well-being of people living within a defined geographical community, including protection from environmental conditions and diseases that threaten collective health.

Environmental Health: The aspect of public health concerned with environmental conditions and factors that influence human health and well-being.

Environmental Risk Factor: Any environmental condition or activity that increases the likelihood of mosquito breeding, mosquito-human contact or mosquito-borne disease transmission.

Environmental Sanitation: Activities undertaken to maintain a clean and healthy physical environment, including proper waste disposal, drainage maintenance, removal of stagnant water and general environmental cleanliness.

Idavi: The geographical community identified by the researcher as one of the selected study locations in Kogi State.

Koton Karfe: A community in Kogi State previously studied in relation to malaria risk and the Koton Karfe watershed catchment.

Mosquito Breeding Site: Any natural or artificial habitat containing environmental conditions, particularly water, that allow mosquitoes to lay eggs and complete their immature developmental stages.

Mosquito-Borne Disease: A disease transmitted to humans through the bite of an infected mosquito, including malaria and other mosquito-transmitted viral or parasitic diseases.

Mosquito Breeding: The process by which mosquitoes reproduce and develop through their aquatic immature stages in suitable water-containing habitats.

Environmental Mosquito-Breeding Risk: The likelihood that specific environmental conditions within a community will provide suitable habitats for mosquito reproduction.

Poor Drainage: A condition in which water does not flow or drain effectively, resulting in water accumulation that may provide mosquito breeding habitats.

Stagnant Water: Water that remains relatively stationary for a period sufficient to potentially support mosquito breeding.

Waste Disposal: The collection, handling, treatment and final disposal of household, commercial or other forms of waste.

Water-Storage Practices: The methods used by households or communities to collect and store water, including whether storage containers are covered or left exposed.

Vector: A living organism capable of transmitting an infectious pathogen between humans or from an animal to a human. Mosquitoes are important vectors of several human diseases.

Project – Environmental Risk Factors Associated with Mosquito Breeding and Their Implications for Community Health in Selected Communities in Okehi, Ajaokuta, Idavi, Okene, Ogori/Magongo and Koton Karfe