Impact of temperature on the incidence of dengue fever in an endemic urban area

Abstract Background Dengue is the most important arbovirus worldwide, with approximately 2.5 billion people at risk, mainly in tropical countries. Objectives The present study evaluated the influence of climatic variables on the incidence of dengue fever in in Belo Horizonte, Brazil, an endemic urban area. Methodology A time series study was carried out with all confirmed cases of dengue fever in Belo Horizonte, southeastern Brazil, from 2001 to 2023. The five climatic explanatory variables obtained from the National Institute of Meteorology (total precipitation, maximum temperature, minimum temperature, mean temperature and relative humidity) were evaluated together with the month of the year as a random effect. The same variables were then averaged per year and compared across the time series to test the overall effect of year on the incidence of dengue, as temporal autocorrelation was not detected. Results Our results suggest that the increase in the average maximum temperature of the current month and the previous month contributed to an increase in dengue incidence, and the average minimum temperatures had the opposite effect. Between years, an increase in average temperature significantly increased the number of dengue cases. In both models, precipitation was not significantly associated. In addition, the resurgence and emergence of new serotypes, although important in defining epidemic years, cannot be considered the most relevant determinant of such years, since they require a combination of climatic conditions that increase the population of insect vectors and promote virus transmission. Conclusion Thus, monitoring temperature and the use of predictive models through epidemiological surveillance can optimize prevention, control, and action efforts to address cases of the disease in the warmer periods to come.