Malaria has been a serious global public health problem for several decades, especially in Africa and other endemic regions [1,2,3]. It is a fatal disease that is preventable and treatable and is transmitted to humans by female Anopheles mosquitoes [4, 5]. Malaria is an infectious disease caused by 5 protozoan species, namely; Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, Plasmodium ovale, and Plasmodium knowlesi. Among these species, P. falciparum is the most lethal pathogen and is found mostly in sub-Saharan Africa (SSA) [2, 3, 6, 7]. Generally, severe outcomes of malaria in children could result in seizures and coma, anaemia due to repeated infection and low birth weight during pregnancy, increasing the risk of death in the first month of life [8].
Malaria has continued to be the foremost cause of morbidity and mortality in children under 5 years old in sub-Saharan Africa [9, 10]. In 2022, globally, there were 249 million cases of malaria with 75% being children under 5 years of age [8]. Under-five children are more vulnerable to malaria infection than adults due to their lower immunity, thereby making them more susceptible to severe malaria due to repeated malaria infections [7]. A study in Nigeria showed that age, mosquito bed net usage, availability of health infrastructure, source of drinking water, distance to waste disposal points and window protection were significant determinants of malaria infection in children under 5 years of age [7, 11].
In 2020, 95% of all malaria cases and 96% of malaria deaths were reported in the African region with 80% of these deaths reported in children younger than 5 years. 6 sub-Saharan African countries, namely Nigeria (27%), the Democratic Republic of Congo (12%), Uganda (5%), Mozambique (4%), Angola (3.4%), and Burkina Faso (3.4%), bore 55% of the global malaria burden [12].
Nigeria has a high incidence of malaria mortality in children under 5 years, which is largely attributable to a health financing system that ignores uninsured individuals. This results in high out-of-pocket (OOP) medical expenditures that discourage healthcare-seeking behaviour, especially among these individuals [13]. The percentage of out-of-pocket expenditure medical expenditure in Nigeria in 2021 was 76% compared to 66% in 2005 [14]. The rate of care-seeking for suspected cases of malaria in Nigeria is among the lowest globally, as just under 20% of all children under 5 years with fever are taken for clinical consultation and parasitological testing in health facilities [13]. According to the Malaria Indicator Survey (MIS) 2021 in Nigeria, 22% of children tested positive for malaria parasites within 6–59 months according to microscopy results [15].
In the last two decades, many policies and interventions have been implemented to control malaria at the global and regional levels, which have resulted in a significant reduction in malaria-related morbidity and mortality [2]. The WHO Global Technical Strategy for Malaria 2016–2030 (GTS), the complementing Roll Back Malaria (RBM), and the Action and Investment to Defeat Malaria 2016–2030 (AIM) are notable malaria control initiatives that have been put into place in Nigeria and other malaria-endemic countries [16]. By 2030, they hope to eradicate malaria in 35 countries, decrease malaria mortality and case incidence by 90%, and stop the reintroduction of the disease into previously malaria-free areas [16].
However, despite these remarkable successes, there is still a high disease burden and mortality among children under 5 years of age [17]. This study aimed to identify the factors associated with the risk of malaria and to determine the predictors of malaria among children under 5 years in Nigeria.
