Raising Awareness of Canine, Feline and Human Dirofilariosis in Aveiro, Portugal: A One Health Perspective

Climatic and various socio-geographical variables have significantly influenced the global spread of <i>Dirofilaria immitis</i>. The coastal district of Aveiro, Portugal, marked by its unique hydrographic structure, Ria de Aveiro, and a concerning rise in heartworm disease, was the focus of our study. We aimed to update the prevalence of <i>D. immitis</i> in dogs and the seroprevalence in cats and humans, correlating these data with epidemiological information. A total of 430 dogs were sampled for <i>D. immitis</i> antigens, and 426 cats and 398 humans for <i>D. immitis</i> and <i>Wolbachia</i> sp. antibodies. In addition, we developed and validated an infection risk map for <i>D.</i> immitis with the geolocation of positive samples. Our results indicate a canine prevalence of 4.7%, peaking at 16.7% in Vagos. Feline and human seroprevalences were 8.9% (26.7% in Espinho) and 3.0% (Vagos presented the most alarming results), respectively. Positive samples were found in both high- and low-risk areas highlighting the need for chemoprophylaxis in all municipalities. Risk factors identified included lack of vaccination and internal deworming in cats, while dogs faced risks from inadequate vaccination and outdoor exposure. Our study identifies Aveiro as an endemic area, with a need for control measures to address this public health threat.