Economic empowerment and various preventive strategies play a role in reducing asymptomatic malaria towards the end of the rainy season.

Background: Asymptomatic malaria is responsible for persistent malaria transmission. The prevalence of malaria in children under 5 years in Anambra State, Nigeria, is declining. The sustained transmission of malaria threatens to reverse this decline, as indicated by the high severe malaria cases during the rainy transmission season. We ascertained the prevalence of asymptomatic malaria using the malaria Rapid Diagnostic Test (mRDT) and the determinants of asymptomatic malaria.

Methods: A community-based cross-sectional study was conducted at the end of the rainy season in November 2024 among 130 consenting apparently healthy adults aged 18 years and above residing in the Nnewi North Local Government Area of Anambra State using a standardised self-administered questionnaire and a P. falciparum mRDT. The questionnaire sought information on the participants' sociodemographic and socioeconomic factors, malaria healthcare-seeking behaviour, use of malaria prevention measures, environmental conditions, and perceptions of malaria risk. A finger-prick was used for the mRDT kit. Data were analysed using Stata 17/BE. Binary logistic regression was used to identify the factors associated with asymptomatic malaria.

Results: Of the 130 participants, 26.15% (34/130) were confirmed to be infected with Plasmodium falciparum. There was an overreliance on personal feelings for malaria diagnosis. Covering water containers around a house could be an effective protective measure against asymptomatic malaria. The odds (odds ratio (OR): 0.29/0.27, 95% (CI): 0.07/0.06 - 1.24) of having asymptomatic malaria were lower in those who agreed that 'the cost of malaria prevention tools, such as Insecticide-treated nets (ITNs), insecticides and mosquito repellents, is reasonable' compared to those who did not.

Conclusion: The prevalence of asymptomatic malaria among semi-immune adult participants residing in the Nnewi North Local Government Area (LGA) was 26.15%. Having the financial means to access resources for malaria prevention can lead to healthier behaviours and actions that reduce malaria transmission.