Seasonal trend analysis of sporotrichosis with zoonotic potential

Abstract

Sporotrichosis is a zoonotic subcutaneous mycosis caused by fungi of the genus Sporothrix. It is considered a neglected disease, already reported in almost all Brazilian states in both animals and humans, highlighting the urgent need to understand the disease's behavior to guide public control and surveillance policies. Therefore, the objective of this study was to elucidate the hypothesis of seasonality in sporotrichosis based on the cases recorded in the municipality of Guarulhos, where notification is mandatory. For this purpose, animal sporotrichosis cases from 2016 to 2023 were provided by the Guarulhos Zoonosis Control Center, along with the date of the first consultation, and analyzed through observation of time series and their moving averages, and statistical comparisons between the seasons. Two models were used for time series decomposition: classical decomposition and seasonal trend decomposition (STL). Both models revealed a seasonal component with a uniform and repetitive pattern, showing little correlation with the residuals of the decomposition. The moving averages displayed annual fluctuations, with more cases recorded in the central months of the year (autumn and winter), supporting the hypothesis of a seasonal pattern of the disease. However, the comparison of case numbers between seasons using an ANOVA test indicated no statistical difference between the seasons, with p = 0.810. It is concluded there is a indication of potential seasonality, which reinforces the importance of implementing preventive and control measures targeting feline populations.