Malaria Seasonality and Epidemiology in Burundi: A Non-Parametric Approach

Introduction: Malaria is a disease caused by parasites of the Plasmodium genus. It is transmitted to humans through the bites of Anopheles mosquitoes, which are themselves infected by the Plasmodium parasite. Malaria is primarily a tropical disease and is most prevalent in Africa. In Burundi, malaria remains a major public health issue and one of the country’s top health priorities. The objective of this study is to analyze the time series of confirmed malaria cases to determine its seasonality and epidemic characteristics. Methods: The data used in this study consists of monthly confirmed malaria cases in Burundi, reported across all health districts in the country. A non-parametric Haar wavelet decomposition approach was used as the assumptions of the parametric decomposition model were not met. The Haar wavelet model provides two parameters, mean and variation, which can characterize the epidemic magnitude and seasonality of malaria. Results: The decomposition model results show that periods of the year, such as February to June and August to December are characterized by high malaria transmission. Similarly, the periods from January to July and October to December record average malaria cases exceeding 500,000. Conclusion: The objective of this study was to determine the existence of a seasonal effect on malaria cases in Burundi over a monthly observation period from January 2019 to December 2023. The results show that a seasonal effect exists, which may contribute to malaria epidemics in Burundi. Malaria seasonality follows a cyclical pattern, lasting for four months, followed by a two-month period of decreased cases. The key question that arises is whether the seasonal effect of malaria is uniform across the entire Burundian territory. To address this, a further study could focus on the level of malaria transmission across different geographical strata of the country.