Effects of environmental factors on dengue incidence in the Central Region, Burkina Faso: A time series analyses

Background: Dengue is endemic in Burkina Faso with sporadic outbreaks during the decade 2011–2021. Dengue control depends on the ability to predict future outbreaks. This study aimed to forecast dengue cases using historical data between 2016 and 2021. Methods: The study covered the Central Region, Burkina Faso, with dengue monthly data from the National System of Health Information (SNIS) and environmental data from the National Agency of Meteorology (ANAM). The Autoregressive Distributed Lag (ARDL) model was performed to forecast dengue cases between 2022 and 2025. Results: Dengue cases increased gradually between 2016 and 2021, with seasonal spikes during the year. The 95 per cent confidence interval exceeds 5000 cases by 2023 and reaches about 10,000 cases by 2025. From the ARDL results, the lagged variable Dengue cases (-1) showed a strong positive association (coefficient = 0.76; p-value = 0.00) and the variable Dengue cases (-2) a negative association (coefficient = -0.47; p-value = 0.01). The Population statistically impacted dengue incidence (coefficient = 0.00; p-value of 0.01). Relative humidity (-1) and Relative humidity (-4) positively affected dengue cases (coefficient = 114.26; p-value = 0.00 and 90.84; p-value = 0.00 respectively). Furthermore, Rainfall (-4) had a negative influence on dengue incidence (Coefficient = -6.91; p-value = 0.00. D.Minimum temperature (-3) positively influenced dengue cases (Coefficient = 223.20; p-value = 0.01). D.Wind speed showed a negative relationship (Coefficient = -925.31; p-value = 0.02), while D. Wind speed (-3) had a positive relationship (Coefficient = 875.04; p-value = 0.02). In addition, the ARDL long-run results revealed a positive association between dengue cases and population size (p-value = 0.02), Relative humidity (p-value = 0.01), and D.Minimum temperature (p-value = 0.02), and a negative association with Rainfall (p-value = 0.04). Conclusion: Dengue cases are forecasted to increase in the Central Region between 2022 and 2025. It is then crucial to develop long-term interventions against dengue, integrated with interventions for other neglected tropical diseases. Author summary: Dengue fever is a growing global threat, partially due to unplanned urbanization and climatic change. Africa, which is increasingly paying the price, lacks comprehensive data on the disease. Dengue fever has increasingly threatening Burkina Faso in recent years with sporadic outbreaks. We therefore conducted this study in the Central Region of Burkina Faso to better understand its dynamics. According to previous data, dengue cases are expected to continue rising between 2022 and 2023. This was confirmed in 2023, as Burkina Faso declared the largest dengue outbreak ever recorded in Africa. Dengue fever transmission is modulated by climatic factors. Thus, recent weather conditions associated with rainfall, humidity, ambiant temperature and wind speed were found to influence the occurrence of new cases. The influence of climate on the emergence of dengue new cases is also remote. These results highlight the complex dynamics of dengue-climate interactions. In addition to the climate, the growing population of the Region will favour the occurrence of dengue new cases. These data have enabled us to gain a better understanding of the dengue situation in Burkina Faso.