1.1 Background of the study

Malaria remains a major cause of morbidity and mortality in Nigeria and is a leading contributor to child and maternal ill-health in malaria-endemic areas. Vector control through insecticide-treated nets (ITNs), particularly long-lasting insecticidal nets (LLINs), is one of the most cost-effective interventions for malaria prevention and has been central to national malaria control strategies (World Health Organization, 2022). National surveys show that while household ownership of at least one ITN has improved in recent years, consistent nightly use remains substantially lower than access — an “access-use” gap that undermines population protection (National Malaria Elimination Programme et al., 2022). Recent secondary analyses of the 2021 Nigeria Malaria Indicator Survey and large multi-survey syntheses identify important individual, household and community determinants of ITN use — including household net supply, household size, presence of young children or pregnant women, socio-economic status, religious/ethnic context, seasonal mosquito nuisance and local social norms — indicating that both structural (access, number of nets) and behavioural (perception of risk, discomfort, beliefs about insecticide) barriers shape uptake (Barrow et al., 2025; Solanke et al., 2023; Koenker et al., 2023). In Southeastern Nigeria — including Anambra State — recent net-distribution campaigns and targeted implementation work have focused on raising household access and on social-behavioural communication to promote correct hanging and nightly use (Malaria Consortium, 2021). Despite distribution efforts, state and local post-distribution assessments and program reports show heterogeneous coverage and persistent challenges: insufficient nets per household, nets stored for future use, nets being used for other household purposes, and reported non-use because of heat, perceived low mosquito density (seasonality), and discomfort or concerns about chemicals (Koenker et al., 2023; Malaria Consortium, 2021). These findings underline the need for locality-specific measurement: urban and peri-urban areas such as Onitsha North have distinct living conditions (crowded housing, multiple sleepers per room, informal sleeping arrangements, variable electricity and fan access) that may amplify practical barriers to hanging and nightly use and shift intra-household prioritisation of nets (Solanke et al., 2023). Because ITN effectiveness at a population level requires both access and sustained correct use, programme managers need locally-granular evidence on households’ knowledge (cause of malaria, role of nets), current ownership and patterns of net use (who sleeps under nets, frequency, seasonal variation), and the specific determinants operating in Onitsha North — structural (number of nets per household, net age/condition), behavioural (risk perception, comfort, beliefs about insecticide) and social (gendered allocation, seasonal work patterns) — to design targeted interventions (additional continuous distribution, hanging support visits, tailored behaviour-change communication, and community influencers’ engagement) that will close the access–use gap (Barrow et al., 2025; Koenker et al., 2023).

1.2 Statement of the problem

Although national and state distribution campaigns have increased the supply of ITNs in many parts of Nigeria, gaps remain between ownership and consistent use, and these gaps are not evenly distributed across states or urban neighbourhoods (National Malaria Elimination Programme et al., 2022). Onitsha North LGA — a densely populated commercial and residential area of Anambra State — is likely to face specific constraints: overcrowded sleeping arrangements, high indoor temperatures without adequate ventilation or fans, and household resource pressures that can lead to nets being prioritized for certain family members or repurposed for other uses. Programmatic post-distribution reports from Anambra and evaluation literature from similar Nigerian settings suggest that socio-economic factors, household composition, risk perception and seasonal mosquito nuisance are important predictors of use, while qualitative studies across the region document common behavioural barriers such as “too hot”, “no mosquitoes (perceived low risk)”, “saving net for later”, concerns about chemicals, and damaged/old nets (Solanke et al., 2023; Koenker et al., 2023; Malaria Consortium, 2021). Without a community-level assessment in Onitsha North that measures caregivers’/householders’ knowledge, observed net availability and condition, reported use (last-night and usual), and the social and practical reasons for non-use, local malaria control actors lack the evidence needed to choose the most efficient mix of interventions (for example, additional continuous distribution to increase nets-per-person vs. targeted behaviour change for correct hanging and use). This gap undermines efforts to reduce malaria transmission and protect the most vulnerable groups (young children and pregnant women) in Onitsha North (National Malaria Elimination Programme et al., 2022; Solanke et al., 2023).

1.3 Aim and Objectives of the study

Aim: To assess household knowledge and use of insecticide-treated nets and identify individual, household and community determinants of ITN uptake among households in Onitsha North LGA, Anambra State.

Specific objectives:

1. Estimate the proportion of households owning at least one ITN and the proportion of individuals (children under five, pregnant women, and adults) who slept under an ITN the previous night.
2. Describe household knowledge, attitudes and practices (KAP) about malaria and ITNs (cause of malaria, perceived efficacy of nets, concerns about chemicals, net care practices).
3. Measure structural supply indicators: number of nets per household, nets per sleeping place, net age/physical integrity, and the proportion of households with adequate nets (?1 net per 2 people).
4. Identify behavioural and social determinants of net use (heat/discomfort, perceived mosquito nuisance, seasonal variation, intra-household allocation priorities, alternative net uses, and beliefs about insecticide) using mixed quantitative and qualitative measures.
5. Assess associations between household/individual predictors (wealth proxy, caregiver education, household size, number of rooms, electricity/fan access) and reported net use (last-night use) using multivariable regression.
6. Generate actionable recommendations — for example, targeted continuous distribution, home-visit hanging support, seasonally timed SBC campaigns, or distribution of fans/ventilation guidance — tailored for Onitsha North.

1.4 Research questions

1. What proportion of households in Onitsha North own at least one ITN and what proportion of children under five, pregnant women and other household members slept under an ITN the previous night?
2. What is the level of household knowledge about malaria transmission and the protective role of ITNs in Onitsha North?
3. What structural factors (nets per person, net age/condition, number of sleeping rooms) and household characteristics (household size, wealth proxy, access to fans/electricity) are associated with last-night ITN use?
4. What behavioural and social reasons do households report for non-use of available nets (too hot, saving net, repurposing, fear of chemicals, not hung), and how common is each reason?
5. Which locally feasible interventions (continuous distribution, hanging assistance, targeted SBC, community influencer engagement) are most likely, according to community feedback, to increase consistent ITN use in Onitsha North?

1.5 Scope of the study

Design: Cross-sectional, mixed-methods household survey combined with targeted qualitative interviews and direct observation of net condition and hanging status.

Area of study (single area): Onitsha North Local Government Area, Anambra State.

Population & inclusion criteria: Households with at least one resident for ?6 months; respondents: primary caregiver or household head aged ?18 years; sub-modules for pregnant women and households with at least one child under five.

Sampling & sample size (outline): Two-stage cluster sampling of enumeration areas (EA) in Onitsha North, with probability-proportional-to-size (PPS) selection of clusters and systematic selection of households within clusters. Sample size will be calculated to estimate the key indicator (proportion of children under five sleeping under ITN last night) with ±5 percentage-point precision at 95% confidence, adjusted for design effect (typical design effect 1.5–2.0) and anticipated non-response. Oversampling of households with pregnant women will be considered to allow separate estimates.

Instruments & measures:

• Household questionnaire: roster, demographic characteristics, socio-economic proxy (assets), malaria knowledge items, ITN ownership and source (campaign, ANC, purchase), reported last-night use for each household member, usual use and seasonal variation, net care (washing frequency), and reasons for non-use (pre-coded with “too hot”, “no mosquitoes”, “saved for later”, “net not hung”, “concern about chemicals”, “net damaged”, “used for other purpose”, plus open response).

• Observation checklist: count of ITNs, physical integrity (holes/repairs), presence and status of hanging points, evidence of nets being used for other purposes, and presence of fans/ventilation.

• Qualitative: in-depth interviews with purposive sample of caregivers (users and non-users), focus groups with community health workers and local opinion leaders, and key informant interviews with LGA malaria programme staff to explore explanatory beliefs and feasible interventions.

• Facility key informant mapping to document continuous distribution channels (ANC, school, community channels) in Onitsha North.

Analysis: Weighted descriptive estimates (ownership, last-night use by age group); cross-tabulation of reasons for non-use by net supply status; multivariable logistic regression modelling of individual/household predictors of last-night net use (adjusting for clustering); qualitative thematic analysis to interpret social and behavioural drivers and intervention acceptability. Where possible, stratify results by season or recall of high/low mosquito months.

Ethics & dissemination: Ethical approval from a recognised Institutional Review Board and Anambra State health research authority; community entry via ward leaders and health facilities; written informed consent from adult respondents. Findings will be shared in plain language with Onitsha North LGA malaria programme, community stakeholders, and distributed as a short implementation brief recommending high-impact responses informed by local barriers.

Policy relevance: The study will provide Onitsha North LGA with the local evidence needed to decide whether to prioritise additional net distribution (increase nets per person), targeted post-campaign hanging and follow-up visits, seasonal social-behaviour change communication addressing “too hot” and perceived low risk, or complementary measures (e.g., distribution of hanging kits, promotion of net-care and repair) that are most likely to increase sustained ITN use in this urban setting (Koenker et al., 2023; Solanke et al., 2023; Malaria Consortium, 2021).

References

Barrow, A., Ogidan, O. C., Nzoputam, C. I., & Ekholuenetale, M. (2025). Coverage and contextual factors associated with insecticide-treated net use among women of reproductive age in Nigeria: Evidence from the 2021 Malaria Indicator Survey data. PLOS Global Public Health, 5(2), e0004207. https://doi.org/10.1371/journal.pgph.0004207

Koenker, H., Kumoji, E. K., Erskine, M., Opoku, R., Sternberg, E., Taylor, C., et al. (2023). Reported reasons for non-use of insecticide-treated nets in large national household surveys, 2009–2021. Malaria Journal, 22, Article 61. https://doi.org/10.1186/s12936-023-04490-w

Malaria Consortium. (2021). ITN campaign in Ondo and Anambra states (project webpage/report). Malaria Consortium. Accessed from https://www.malariaconsortium.org/projects/itn-campaign-in-ondo-and-anambra-states

National Malaria Elimination Programme, National Population Commission, National Bureau of Statistics, & ICF. (2022). Nigeria Malaria Indicator Survey 2021 (NMIS 2021). Accessed from https://dhsprogram.com/pubs/pdf/MIS41/MIS41.pdf

Solanke, B. L., Soladoye, D. A., Birsirka, I. A., Abdurraheem, A., Salau, O. R., & others. (2023). Utilization of insecticide-treated nets and associated factors among childbearing women in Northern Nigeria. Malaria Journal, 22, Article 184. https://doi.org/10.1186/s12936-023-04620-4

World Health Organization. (2022). World malaria report 2022. World Health Organization. Accessed from https://apps.who.int/iris/handle/10665/372274