Geographical distribution of potential mechanical vectors implicated in Surra transmission in Spain: an entomological perspective.

Background: Haematophagous Diptera can transmit a wide range of diseases to both humans and animals. Some species of the Trypanosoma genus rely on these vectors for transmission, either cyclically or mechanically. Trypanosoma evansi, the causative agent of Surra, is the only African-origin trypanosome species detected in Spain to date, which is mechanically transmitted.

Methods: To assess the occurrence and distribution of potential mechanical vectors at the national level, a systematic review was conducted on the Hippoboscidae, Muscidae and Tabanidae families. The review followed the methodology established by the Food and Agriculture Organization of the United Nations (FAO) and adhered to PRISMA guidelines. Data were compiled from 43 peer-reviewed scientific publications and four citizen science digital databases.

Results: The review identified three genera belonging to the Hippoboscidae, two of the Muscidae and ten of the Tabanidae families. Genus-level distribution maps were generated for each group.

Conclusions: This atlas serves as a valuable tool for the prevention and control of vector-borne animal trypanosomosis in Spain. Nonetheless, further studies on the distribution, ecology and behaviour of haematophagous dipterans are essential to better understand their role in disease transmission and their potential impact on future outbreaks.