OROV or the “sloth virus”: will it come to Europe?

Medical Review (Med. pregled), 2025, 61(2), 14-17.

V. Velev

Department of Epidemiology and Hygiene, Medical University – Sofia

Abstract. Oropouche virus (OROV) was first identified in 1955. Since then, reported cases of OROV infection have continuously increased and expanded their geographic range. Oropouche fever is thought to be one of the most common transmissible infections in Latin America. More than 30 epidemics and more than half a million sporadic cases are thought to have developed in the last 60 years – mainly in Brazil, Peru, Panama, Trinidad and Tobago. In Brazil, OROV infection is the second most common transmissible infection after dengue. Fever is transmitted by several families of anthropophilic biting midges. In most cases, the disease is subsymptomatic or with non-specific flu-like symptoms. The variety of vectors that transmit the virus, the multitude of mammalian reservoirs, the best known of which is sloths (Bradypus tridactylus), as well as birds, and the often negligible, mild illness are serious prerequisites for the spread of infection outside its classical ranges. In early 2024, multiple cases were reported in North America, and in the summer of that year, 19 imported cases were reported in Europe. In view of the appearance of OROV in until recently unsuspected territories, the existing knowledge in the etiology, clinic and spread of the disease has been examined, and some still unclear points related to prevention and therapy have been taken into account.

Key words: OROV, transmissible infection, fever, meningoencephalitis, Culicoides paraensis

Address for correspondence: Assoc. Prof. Valeri Velev, MD, PhD, e-mail: