# Spatial and temporal inequalities in malaria incidence and mortality among children aged 0–4 years in Nigeria: a subnational analysis, 2010–2019

## TL;DR

Malaria rates in young Nigerian children dropped from 2010 to 2019, but northern states still face much higher risks than southern states.

## Contribution

This study quantifies subnational disparities in malaria incidence and mortality among children under five in Nigeria using multiple inequality metrics.

## Key findings

- Malaria incidence and mortality in children under five declined nationally from 2010 to 2019.
- Northern Nigerian states like Zamfara and Kano had consistently higher malaria burdens compared to southern states.
- Subnational inequality metrics showed some improvement in equity but persistent disparities remain.

## Abstract

Malaria remains a leading cause of morbidity and mortality among children under five in Nigeria, with pronounced subnational disparities. This study analyzed the temporal and spatial inequalities in malaria incidence and mortality among children aged 0–4 years across Nigeria’s 36 states and the Federal Capital Territory from 2010 to 2019.

Estimates from the Institute for Health Metrics and Evaluation (IHME) were analyzed using the WHO Health Equity Assessment Toolkit (HEAT). Subnational inequalities were quantified using five metrics: coefficient of variation (COV), difference (D), ratio (R), population-attributable risk (PAR), and population-attributable fraction (PAF).

From 2010 to 2019, national malaria incidence declined from 103 to 74.5 cases (27.7% reduction), while mortality fell from 477.3 to 237.6 deaths per 100,000 (50.2% reduction). However, progress was uneven. Northern states such as Zamfara, Kano, and Katsina had the highest baseline burden in 2010 (incidence > 150 per 1000; mortality > 700 per 100,000) and, despite declines, remained among the most affected in 2019. Southern states including Lagos, Delta, and Anambra consistently recorded lower burdens (incidence < 60 per 1000; mortality < 300 per 100,000). Subnational inequality narrowed over time, with incidence COV peaking at 46.3% in 2013 before falling to 28.1% in 2019, and mortality COV declining from a 2013 peak of 42.9% to 22.3% in 2019.

Nigeria’s malaria incidence and mortality among under-five children have decreased, but subnational disparities persist, particularly in northern states, although a reduction in D and R values indicates modest progress in equity, necessitating geographically targeted interventions.