Molecular diagnosis of Dirofilaria immitis in dogs in the eastern Amazon

Dirofilariasis, a heartworm disease, is an emerging anthropozoonosis that poses serious and imminent health risks to animals, in addition to affecting their quality of life and leading to death if not treated appropriately. Humans can also be infected through culicid vectors. Diagnosis is often performed by identifying microfilariae or by detecting antigens in blood samples. Therefore, the objective of this study was to diagnose animals positive for D. immitis using the Polymerase Chain Reaction (PCR) technique. Forty-nine dog samples were used for the agent research from veterinary clinics and laboratories located in Belém do Pará, Brazil, in 2022, of which 33% were positive for D. immitis, with a higher occurrence in males. However, there was no difference in infection when considering the sex of the animals. Considering that the state of Pará has a hot and humid climate, and some cities are bathed by rivers, it can be concluded that the general prevalence in dogs detected by PCR in this study was higher than expected and that this location can be considered an endemic area, and this is due to the presence of the mosquito species that are vectors of D. immitis being very frequent in this region.