Epidemiological Study Related to the First Outbreak of Ovine Anaplasmosis in Spain.

Delia Lacasta,Cristina Baselga,Luis Miguel Ferrer,Sergio Villanueva-Saz,Marta Ruiz De Arcaute,Miguel Lorenzo,Calasanz Jiménez,José María González,Alfredo Ángel Benito,Nuria Lorenzo,María Eugenia Milian

doi:10.3390/ani11072036

Abstract

Ovine anaplasmosis is a vector-borne disease caused by Anaplasma ovis and mainly transmitted through tick bites. In Spain, the first outbreak of ovine anaplasmosis occurred in 2014. An epidemiological study in fifty-one farms was carried out associated with this outbreak in the affected geographical area. An epidemiological questionnaire was performed. In addition, whole blood samples were taken for molecular analysis in 47 of these farms to determine the prevalence of infection of Anaplasma ovis. A. ovis was present in 44 out of 47 PCR-analysed farms (93.6%). However, only 40.4% of the studied farms showed severe clinical signs. The clinical signs affected mainly young animals, which showed severe anaemia, weakness, anorexia, cachexia and epiphora. The early culling of young animals was more frequently reported by severely affected farms than the analysed farms without clinical signs (71.4% vs. 12.5%, p < 0.001). The geographical area where the farm is located seems to be relevant for the presence of clinical signs of the disease. Ovine anaplasmosis is an emerging disease in Europe that spreads rapidly through tick bites and is capable of causing significant economic losses when it spreads in a naive area and causes an epidemic.

Highlights

Ovine anaplasmosis is an emerging disease in Europe, caused by the bacteria Anaplasma ovis, that is transmitted through tick bites
Twenty-one of the 51 farms surveyed during this study reported currently or previously having animals with clinical signs of severe anaplasmosis (21/51: 41.2%)
There is a lack of epidemiological studies assessing the presence of Anaplasma ovis on small ruminant flocks

Summary

Introduction

Ovine anaplasmosis is an emerging disease in Europe, caused by the bacteria Anaplasma ovis, that is transmitted through tick bites. This disease has great significance in developing countries in tropical and subtropical areas. During the last few decades, climate change has facilitated the wider dissemination of ovine anaplasmosis, which is being spread very quickly throughout Europe. In recent years, it has been reported in many different European countries, such as Bulgaria, France, Germany, Greece, Hungary, Italy, Portugal, Romania and Turkey [1,2,3]. The impacts of A. ovis are on animal welfare, rural livelihoods and farm sustainability but might result in significant wastage of food intended for human consumption

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