Influence of season and photoperiod in severe dog attack cases on humans in a Mediterranean climate region

Abstract

Dog bites in humans are a serious public health problem widely documented. Although some studies report a seasonal effect on dog bite incidence, the rationale for these findings is poor. This study aimed to describe the influence of season and photoperiod on the incidence of dog bite injury hospitalizations (DBIH) in Sicily, a Mediterranean climate region, over 10 years (2012-2021). Four hundred and forty-nine cases of severe dog bites that required hospitalization were analyzed. Patients were divided into two age groups: group 1 (0-19 years) and group 2 (≥20 years). A Poisson regression general linear model analysis was used to model incidence data across seasons and photoperiods (short photoperiod [SP] and long photoperiod [LP]). The results revealed that the relative risk for group 1 is higher during summer (2.03; 95%CI 1.30-2.17) and, in general, during LP (1.788; 95%CI 1.274-2.55) when compared with autumn and SP, respectively. Comparing group 2 with group 1, a lower relative risk is observed in both summer (0.42; 95%CI 0.28-0.63) and spring (0.32; 95%CI 0.22-0.45), and in LP (0.41; 95%CI 0.31-0.53). In group 2, results showed a significant increase of DBIH during winter and autumn (P < 0.05) and in both photoperiods with a positive trend over 10 years (P < 0.05). Results from this study suggest an influence of season on DBIH modulated by the age of patients. This aspect should be considered in developing preventive approaches for dog bite injuries.