First case of Oropouche fever in Italy

: Source: Luis E. Escobar

The first European case of Oropouche fever was recently diagnosed in Veneto.

Oropouche fever is a viral disease transmitted by insect vectors, is endemic in some regions of Latin America, but never before it has been diagnosed in Italy.

The patient, a 45 years old man, with a recent history to travel in tropical Caribbean region, showed flu-like symptoms including high fever, headache, muscle and joint pain. The case has been confirmed from the Department of Infectious, Tropical and Microbiological Diseases at IRCCS Sacro Cuore Don Calabria in Negrar di Valpolicella (Verona province) and promptly reported to the relevant health authorities and to the Local Health Agency (ASL) of the Veneto Region as well as to international information and monitoring services. The diagnosis was made in BSL3 laboratory and was confirmed by specific laboratory tests, which showed the presence of Oropouche virus in the patient’s blood. Currently, the patient is under close medical monitoring and his condition is stable.

Oropouche fever is caused by a virus of the genus Orthobunyavirus, family Peribunyaviridae. The virus Oropouche is transmitted to humans by biting midge of the genus Culicoides and specifically Culicoides paraensis, found in South and Central America and the Caribbean.

The oropouche virus transmition occurs in two cycles: wild and urban-epidemic.

In wild cycle, the basin for Oropouche virus is wildlife (i.e. primates, sloths, certain arthropods). In urban-epidemic cycle, human beings are the main reservoir and the infection cycle is between man to man through Culicoides as the vector.

Oropouche fever is one of the most common arbovirosis in South America, with over 500.000 cases diagnosed since 1955, a number underestimated due to the limited diagnostic resources available in the spread area.

First symptoms usually occur 3-8 days after insect bite and are non-specific, similar to those of Dengue and Chikungunya: high fever (>39°C) with headache, retro-orbital pain, illness, myalgia, arthralgia, nausea, vomiting, and photophobia. Rarely, complications such as meningitis and meningoencephalitis may occur.

The prevention of Oropouche fever is based on avoiding the insect bite.

Today, the identified vector, Culicoides paraensis, is not present in Italy and Europe.

WHO recommends that oropouche fever be included in the differential clinical diagnosis for others common febrile arbovirosis infections ( chikungunya , dengue , yellow fever , Zika ) ( 1 ).