Toscana virus (TOSV) is an

arbovirus Arbovirus is an informal name for any virus that is Transmission (medicine), transmitted by arthropod Vector (epidemiology), vectors. The term ''arbovirus'' is a portmanteau word (''ar''thropod-''bo''rne ''virus''). ''Tibovirus'' (''ti''ck-''bo ...

(

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

-borne virus) belonging to '' Bunyaviricetes'', a class of negative-stranded, enveloped

RNA virus An RNA virus is a virus characterized by a ribonucleic acid (RNA) based genome. The genome can be single-stranded RNA (ssRNA) or double-stranded (Double-stranded RNA, dsRNA). Notable human diseases caused by RNA viruses include influenza, SARS, ...

es. The virus can be transmitted to humans by the bite of an infected

sandfly Sandfly or sand fly is a colloquial name for any species or genus of flying, biting, blood-sucking dipteran (fly) encountered in sandy areas. In the United States, ''sandfly'' may refer to certain horse flies that are also known as "greenhea ...

of the genus '' Phlebotomus''. Toscana is not normally associated with disease, as indicated by high seroprevalence rates (up to 25%) in endemic areas, but in common with other sandfly transmitted viruses such as '' Naples virus'' and '' Sicilian virus'', infection may result in Pappataci fever, an illness with mild fever,

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

and

myalgia Myalgia or muscle pain is a painful sensation evolving from muscle tissue. It is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, espec ...

. In serious cases that go undiagnosed, acute

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

meningoencephalitis Meningoencephalitis (; from ; ; and the medical suffix ''-itis'', "inflammation"), also known as herpes meningoencephalitis, is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the mening ...

and

encephalitis Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include se ...

may occur. There is no specific treatment for infection, so treatment is supportive, reducing the severity of symptoms until the immune system has cleared the infection. The virus is found in most countries that border the Mediterranean Sea, with the highest incidence in Italy. Infection rates peak during the summer time as sandfly populations grow more abundant.

Virology

Structure and genome

TOSV has a spherical, enveloped body with an 80–120 nm diameter. The genome is encased in a nucleocapsid and consists of negative-sense RNA broken into three segments, termed L, M and S. L is about 6,400 nucleotides in length, M about 4,200 nucleotides in length, and S about 1,900 nucleotides in length. L encodes for the viral polymerase, M encodes for structural glycoproteins and S encodes for nucleic proteins.

Diagnosis

Laboratory diagnosis of TOSV infection can be performed through the use of

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay is a solid-phase type of enzyme immunoassay (EIA) to detect the presence of ...

immunofluorescence Immunofluorescence (IF) is a light microscopy-based technique that allows detection and localization of a wide variety of target biomolecules within a cell or tissue at a quantitative level. The technique utilizes the binding specificity of anti ...

and/or neutralization tests, but reverse transcription,

real-time polymerase chain reaction A real-time polymerase chain reaction (real-time PCR, or qPCR when used quantitatively) is a laboratory technique of molecular biology based on the polymerase chain reaction (PCR). It monitors the amplification of a targeted DNA molecule durin ...

assays are preferred because they are less time-consuming and reduce the risk of contamination.

History

Toscana virus (TOSV) was first isolated in 1971 from '' Phlebotomus perniciosus'' and '' Phlebotomus perfiliewi'' in Monte Argentario (

Grosseto Grosseto () is a city and a ''comune'' in the central Italian region of Tuscany, the capital of the province of Grosseto and the main city of the Maremma region. The city lies from the Tyrrhenian Sea, at the centre of an alluvial plain on the ...

Tuscany Tuscany ( ; ) is a Regions of Italy, region in central Italy with an area of about and a population of 3,660,834 inhabitants as of 2025. The capital city is Florence. Tuscany is known for its landscapes, history, artistic legacy, and its in ...

References

{{DEFAULTSORT:Toscana Virus Phleboviruses