An Atlas of surra in Spain: Preliminary results

Abstract

Trypanosoma evansi (T. evansi) is responsible for the form of animal trypanosomosis known as “surra”. This disease causes important socio-economic losses. We collected all available data on T. evansi infections in Spain, with a focus on the Canary Islands, with a view to creating a national atlas. A digital repository was created with information compiled from 30 different published and unpublished sources, covering the period 1997–2022. Data were harmonized, georeferenced and entered in a single database. A total of 9,225 animals were tested, including dromedaries (64 %), goats (15%), sheep (8%), cattle (3%), and equids (10%). A 7,1% prevalence rate was detected, mostly dromedaries (70.3%), followed by sheep (12%), goats (8.4%), equids (5.8%) and cattle (3.5%). Detection was primarily realized using serodiagnostic test (CATT/T.evansi). The samples came mainly from the islands of Gran Canaria, Fuerteventura, and Lanzarote and, to a lesser extent, from Tenerife, La Palma, and Alicante (the latter in mainland Spain). The outbreak on the mainland was caused by the importation of infected camels from the Canary Islands. Over the years, there has been a relevant decrease in the number of positive cases, and the incidence of animal trypanosomosis in Spain is nowadays very low, if any cases occur at all. The creation and regular update of the atlas provides a comprehensive picture on surra in Spain, thus allowing an improved design of surveillance and control activities.