Toscana virus infection

Sandfly

Toscana virus is an arthropod-borne virus transmitted by sand flies in Mediterranean countries. Toscana virus infection commonly occurs during the warm season although there are important variations in risk exposure (e.g. seasonality, endemicity, local ecologic conditions) as assessed by seroprevalence rates ranging from <1% to 45% in human populations [1].

Because of the behaviour of the sand fly vectors and their limited mobility, at-risk areas can be small and focal activity is expected. Most cases of infection result in asymptomatic or pauci-symptomatic forms, with mainly febrile illness, leading to a massive underestimation of cases.

In south-western Europe, Toscana virus infection accounts for the most frequent cause of aseptic meningitis together with enteroviruses and herpesviruses [2]. Mortality is exceptional but neuro-invasive manifestation is often associated with encephalitis. Due to the lack of specificity of clinical symptoms, virological diagnostic is needed and relies on molecular detection of viral RNA combined with serology.

Case definition

Toscana virus infection is not a notifiable disease at the EU/EEA level and there is no EU case definition.

However, Toscana virus infection case definitions have been proposed in the literature [3]. By analogy with other arboviruses such as Tick-borne encephalitis virus, West Nile virus, Zika virus and Chikungunya virus, several points could be applied for Toscana virus such as epidemiological conditions (history of travel to, or residence in, an area with documented on-going transmission within the two-week period prior the onset of symptoms). Laboratory criteria for direct diagnosis such as virus isolation or viral RNA detection in blood or cerebrospinal fluid (CSF) that are used for the aforementioned viruses could also be applied to Toscana virus. Serological data such as seroconversion or a four-fold increase in paired sera would also be applicable to Toscana virus as well as the presence of IgM in a unique serum sample is indicative of a probable case of infection.

The pathogen

Phleboviruses are enveloped viruses with a genome consisting of three single-stranded RNA molecules. Toscana virus has four structural proteins:

  • two outer glycoproteins encoded by the M segment;
  • a nucleocapsid protein and a nonstructural protein encoded by the S segment, and
  • an RNA-dependent viral polymerase encoded by the L segment.

The terminal nucleotides of each genomic RNA segment are base-paired to form non-covalently closed circular RNAs. The terminal sequences of the genomic segments are conserved.

Virions are spherical or pleomorphic (80-120 nm in diameter) and present projections of surface glycoproteins (5-10 nm) embedded in a lipid bilayer envelope. They are sensitive to heat, lipid solvents, formaldehyde and detergents [4].

Toscana virus can present serological cross-reactions with other phleboviruses, particularly those included in the Naples phlebovirus species (sandfly fever Naples virus, Granada virus, and to a lesser extent Arrabida, Balkan, Fermo, Saddaguia viruses) or Punique phlebovirus.

Toscana virus was first isolated in 1971 from sand flies collected in the Tuscany region of Italy and first evidence for its propensity to cause human disease was reported in 1983 [5].

Toscana virus belongs to the Toscana phlebovirus species within the Phlebovirus genus in the Phenuiviridae family  [6,7]. Species demarcation within the genus is dictated by at least a 5% difference in polymerase gene sequences. Other human pathogenic viruses within this genus are phlebovirus and Sicilian phlebovirus (all transmitted by sand flies), but also Rift Valley fever phlebovirus transmitted by mosquitoes; other diseases related to tick-borne viruses that were previously included in the Phlebovirus genus (Uukkuniemi virusDabie bandavirusHeartland bandavirus) and are now reclassified either in the Uukuvirus or in the Bandavirus genera. There are three genotypes within the species Toscana phlebovirus, also called lineages A, B and C that are more or less assigned to specific geographic areas although overlap can exist. There is no association between severity of the disease or specific manifestations and genotype. Toscana virus distribution is driven by its vector’s geographic distribution. To date, Toscana virus has been identified in Europe and in Northern Africa [8].

Clinical manifestations and sequelae

The majority of infections are thought to be asymptomatic although the exact proportion is not known. Toscana virus can cause febrile illness and neuroinvasive infection, potentially leading to death.

In most instances, the incubation period lasts from three to seven days but can last up to two weeks; after that period, there is a sudden onset of symptoms typically characterised by high fever, headache, rash, nausea, vomiting, malaise and/or myalgia. Neck stiffness is reported in nearly 90% of the cases and encephalitis is observed in nearly 40% of the cases [9,10]. In addition, focal deficits (e.g., cranial neuropathy, hemiparesis, aphasia, ataxia) are often reported [11-13]. In rare instance, fatal encephalitis has been reported [14].

Particular clinical manifestations have been often described such as:

  • sensory polymyeloradiculopathy [15],
  • Guillain-Barré syndrome [8,16],
  • testicular involvement [17,18],
  • myositis and fasciitis [19],
  • hydrocephalus [20,21],
  • lymphadenopathy [22],
  • personality disorders [23],
  • neurological sequelae related to ischemic complications [24] and
  • deafness [25].

In a study gathering over 1000 cases from Croatia, France, Greece, Italy, Malta, Portugal, Romania, Spain and Turkey, the median age of the cases was 45 years, with the youngest reported patient being three months old and the oldest was 95 years old (Ayhan & Charrel unpublished work).

Differential diagnosis cannot be made based on clinical criteria only. Virological investigations are required to establish the diagnosis of Toscana virus infection and to perform differential diagnoses (e.g., West Nile virus infections, enterovirus and herpesviruses infections).

Epidemiology

Toscana virus circulates in several countries in southern Europe (from west to east, Portugal, Spain, France, Italy, Malta, Croatia, Bosnia Herzegovina, Kosovo*,Greece, Cyprus, and Turkey) and in Northern Africa (Morocco, Tunisia, Algeria) where it causes human infections. In France, Italy and Tunisia, Toscana virus ranks within the three most common causes of summer meningitis after enteroviruses and herpesviruses (herpes simplex virus, varicella-zoster virus) [5,26-30]. It is likely that the same situation applies in several other Mediterranean countries where Toscana virus circulate in sand fly populations. Seroprevalence studies in several countries (i.e., Portugal, Spain, France, Italy, Croatia, Bosnia-Herzegovina, Kosovo*, Malta, Greece, Turkey, Cyprus, Morocco, Tunisia, Algeria) show that Toscana virus is among the most prevalent endemic arboviruses, with seroprevalences of up to 77% reported in forestry workers in Italy [1,31-35]. An estimated 250 million people are living in regions where they might be exposed to Toscana virus [36].

Cases of Toscana virus infection are reported exclusively during the period of sand fly activity, from April through November in the Mediterranean, with a peak observed during the hottest period (July to September). To date, only Phlebotomus (P.) perniciosus and P. perfiliewi have been formally identified as vectors. However, it is highly probable that other species belonging to the subgenus Larroussius (P. ariasi, P. longicuspis, P. neglectus, P. tobbi, etc.) are also vectors of Toscana virus. Toscana virus geographic distribution is much wider than was assumed a decade ago [8]. The geographic extension of Toscana virus circulation area might be apparent because of increased attention during the last decade and/or might be due to climate change and the increase of annual mean temperatures causing the expansion of the sandfly’s habitat. The extension of the Toscana virus circulation area suggests that in addition to the two recognised vector species (P. perniciosus and P. perfiliewi), alternative species of sand flies must be considered as competent vectors for the virus such as P. longicuspis, P. sergenti, P. tobbi, P. neglectus and Sergentomyia minuta [37,38].

At present, the reservoir for maintenance of Toscana virus circulation is not known. There is no evidence that either humans or other vertebrates, including dogs, can be amplifying host or reservoir host. They are commonly considered as dead-end hosts. Healthy domestic dogs are not highly susceptible to experimental infection by Toscana virus and do not develop significant viremia or excrete virus following infection although they can mount significant titres of neutralising antibodies [1,39,40]. Consequently, healthy dogs are not likely to play a significant role in Toscana virus transmission cycles. There are no published studies reporting experimentations in other species of vertebrates.

Transmission

Toscana virus is transmitted to humans and other vertebrates through the bite of an infected female sand fly belonging to competent species within the genus Phlebotomus. To date there is no other mode of transmission that has been recognised. In particular, blood products have not been identified as at risk for transmission of Toscana virus. However, the presence of Toscana virus RNA in blood products is not tested in countries where virus circulation is established.

Diagnostics

Direct diagnosis: The virus can be detected at the acute phase of infection in CSF and in blood. It is most often detected in the CSF because patients without neurological signs are rarely hospitalised which precludes laboratory investigations. Toscana virus can be isolated in cell culture (Vero, BHK-21, CV-1, SW13). However, direct diagnosis is mainly done using molecular techniques with recommendations for real-time RT-PCR tests [41-44]. The kinetics of viral RNA presence in bodily fluids for RT-PCR detection is largely unknown, but the consensus is that it is short-lived (communication among EVD-LabNet experts).

Serology: The serological diagnosis of an acute infection consists of the detection of a seroconversion or an increase of at least four-fold in antibody titres. In practice, indirect immunofluorescence (IIFA) and ELISA are commonly used due to availability of commercial kits [45,46]. The detection of specific immunoglobulin M can also be performed with IIFA and ELISA. Cross-reactions are to be expected between viruses antigenically close to Toscana virus such as Naples phlebovirus, Massilia phlebovirus, and Punique phlebovirus. Neutralisation assay is less prone to cross-reactions than IIFA or ELISA [47-49].

The humoral response against Toscana virus develops rapidly and is long-lasting [50]. In patients with neuro-invasive manifestations, specific IgM can be detected at the time of hospitalisation, a few days after the onset of the disease; IgM titers start declining one month after hospitalisation; however, IgM are still detectable in 71% of cases after six months, although IgM have disappeared at month 20 [50]. IgG that are also detected early (100% at hospital admission) persist in 100% of cases at month six and 90% of cases at month 20 [50]. There is no difference in IgM and IgG titers according to age, gender and disease severity [50].

Interpretation of the results: By analogy with infections caused by Tick-borne encephalitis, West Nile, Zika and Chikungunya viruses, Toscana virus infection might be considered as laboratory-confirmed in case of (i) viral isolation or detection of RNA in tissue, blood, CSF or other fluids, OR (ii) seroconversion or > four-fold in specific antibody titres in paired sera, whereas detection of specific IgM in a unique serum should be considered indicative of a probable case [3,51]. For serology, techniques displaying the highest specificity (e.g., plaque reduction neutralisation, virus neutralisation or microneutralisation) should be preferred.

In Europe, Toscana virus is a risk group 2 pathogen and clinical specimens, virus isolates should be handled accordingly [52].

Case management and treatment

There is no specific therapy for Toscana virus infections. The treatment is symptomatic and hospitalisation in intensive care is required for the most severe clinical forms.

Infection control, personal protection and prevention

There is no licensed vaccine for Toscana virus.

Personal protective measures against sand fly bites include the use of insecticide-treated bed nets, sleeping or resting in screened or air-conditioned rooms, the wearing of clothes that cover most of the body, and the use of repellent in accordance with the instructions indicated on the product label.

* This designation is without prejudice to positions on status, and is in line with UNSCR 1244 and the ICJ Opinion on the Kosovo Declaration of Independence.

Further reading

  • Charrel RN, Gallian P, Navarro-Mari JM, Nicoletti L, Papa A, Sánchez-Seco MP, Tenorio A, de Lamballerie X. Emergence of Toscana virus in Europe. Emerg Infect Dis. 2005 Nov;11(11):1657-63.
  • Cusi MG, Savellini GG, Zanelli G. Toscana virus epidemiology: from Italy to beyond. Open Virol J. 2010 Apr 22;4:22-8.
  • Jaijakul S, Arias CA, Hossain M, Arduino RC, Wootton SH, Hasbun R. Toscana meningoencephalitis: a comparison to other viral central nervous system infections. J Clin Virol. 2012 Nov;55(3):204-8.
  • Vocale C, Bartoletti M, Rossini G, Macini P, Pascucci MG, Mori F, Tampieri A, Lenzi T, Pavoni M, Giorgi C, Gaibani P, Cavrini F, Pierro AM, Landini MP, Viale P, Sambri V. Toscana virus infections in northern Italy: laboratory and clinical evaluation. Vector Borne Zoonotic Dis. 2012 Jun;12(6):526-9.
  • Dupouey J, Bichaud L, Ninove L, Zandotti C, Thirion-Perrier L, de Lamballerie X, Charrel RN. Toscana virus infections: A case series from France. J Infect. 2014 Mar;68(3):290-5.

List of references

  1. Alkan C, Bichaud L, de Lamballerie X, Alten B, Gould EA, Charrel RN. Sandfly-borne phleboviruses of Eurasia and Africa: epidemiology, genetic diversity, geographic range, control measures. Antiviral Res. 2013 Oct;100(1):54-74. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23872312
  2. Charrel RN, Gallian P, Navarro-Mari JM, Nicoletti L, Papa A, Sanchez-Seco MP, et al. Emergence of Toscana virus in Europe. Emerg Infect Dis. 2005 Nov;11(11):1657-63. Available at: https://www.ncbi.nlm.nih.gov/pubmed/16318715
  3. The Centers for Disease Control and Prevention. Arboviral Diseases, Neuroinvasive and Non-neuroinvasive 2015 Case Definition. 2022. Available at: https://ndc.services.cdc.gov/case-definitions/arboviral-diseases-neuroinvasive-and-non-neuroinvasive-2015/
  4. Plyusnin A, Beaty BJ, Elliott RM, Goldbach R, Kormelink R, Lundkvist Å, et al. Bunyaviridae Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses 2011  Available at: http://www.sciencedirect.com/science/book/9780123846846
  5. Charrel RN, Bichaud L, de Lamballerie X. Emergence of Toscana virus in the mediterranean area. World J Virol. 2012 Oct 12;1(5):135-41. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24175218
  6. Kuhn JH, Adkins S, Agwanda BR, Al Kubrusli R, Alkhovsky SV, Amarasinghe GK, et al. 2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales. Arch Virol. 2021 Dec;166(12):3513-66. Available at: https://www.ncbi.nlm.nih.gov/pubmed/34463877
  7. International Committee on Taxonomy of Viruses. Current ICTV Taxonomy Release. Available at: https://ictv.global/taxonomy
  8. Ayhan N, Charrel RN. An update on Toscana virus distribution, genetics, medical and diagnostic aspects. Clin Microbiol Infect. 2020 Aug;26(8):1017-23. Available at: https://www.ncbi.nlm.nih.gov/pubmed/31904562
  9. Dupouey J, Bichaud L, Ninove L, Zandotti C, Thirion-Perrier L, de Lamballerie X, et al. Toscana virus infections: a case series from France. J Infect. 2014 Mar;68(3):290-5. Available at: https://www.ncbi.nlm.nih.gov/pubmed/2424706
  10. Doudier B, Ninove L, Million M, de Lamballerie X, Charrel RN, Brouqui P. [Unusual Toscana virus encephalitis in southern France]. Med Mal Infect. 2011 Jan;41(1):50-1. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21050685
  11. Glaser CA, Gilliam S, Schnurr D, Forghani B, Honarmand S, Khetsuriani N, et al. In search of encephalitis etiologies: diagnostic challenges in the California Encephalitis Project, 1998-2000. Clin Infect Dis. 2003 Mar 15;36(6):731-42. Available at: https://www.ncbi.nlm.nih.gov/pubmed/12627357
  12. Granerod J, Ambrose HE, Davies NW, Clewley JP, Walsh AL, Morgan D, et al. Causes of encephalitis and differences in their clinical presentations in England: a multicentre, population-based prospective study. Lancet Infect Dis. 2010 Dec;10(12):835-44. Available at: http://www.ncbi.nlm.nih.gov/pubmed/20952256
  13. Mailles A, Stahl JP, Steering C, Investigators G. Infectious encephalitis in france in 2007: a national prospective study. Clin Infect Dis. 2009 Dec 15;49(12):1838-47. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19929384
  14. Bartels S, de Boni L, Kretzschmar HA, Heckmann JG. Lethal encephalitis caused by the Toscana virus in an elderly patient. J Neurol. 2012 Jan;259(1):175-7. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21656341
  15. Gonen OM, Sacagiu T. Sensory polymyeloradiculopathy associated with Toscana virus infection. J Neurovirol. 2013 Oct;19(5):508-10. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24081884
  16. Rota E, Morelli N, Immovilli P, De Mitri P, Guidetti D. Guillain-Barre-like axonal polyneuropathy associated with Toscana virus infection: A case report. Medicine (Baltimore). 2017 Sep;96(38):e8081. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28930847
  17. Baldelli F, Ciufolini MG, Francisci D, Marchi A, Venturi G, Fiorentini C, et al. Unusual presentation of life-threatening Toscana virus meningoencephalitis. Clin Infect Dis. 2004 Feb 15;38(4):515-20. Available at: https://www.ncbi.nlm.nih.gov/pubmed/14765344
  18. Zanelli G, Bianco C, Cusi MG. Testicular involvement during Toscana virus infection: an unusual manifestation? Infection. 2013 Jun;41(3):735-6. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23160838
  19. Mosnier E, Charrel R, Vidal B, Ninove L, Schleinitz N, Harle JR, et al. Toscana virus myositis and fasciitis. Med Mal Infect. 2013 May;43(5):208-10. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23701922
  20. Charrel RN, Petzold GC, Oechtering J. Acute hydrocephalus due to impaired CSF resorption in Toscana virus meningoencephalitis. Neurology. 2013 Apr 9;80(15):1444. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23569000
  21. Oechtering J, Petzold GC. Acute hydrocephalus due to impaired CSF resorption in Toscana virus meningoencephalitis. Neurology. 2012 Aug 21;79(8):829-31. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22875097
  22. Ranaldi R, Goteri G, Biagetti S, Cusi MG, Rossini S. Histological description of the lymphadenopathy related to Toscana virus infection. Report of a case. Pathol Res Pract. 2011 Mar 15;207(3):197-201. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21115298
  23. Serata D, Rapinesi C, Del Casale A, Simonetti A, Mazzarini L, Ambrosi E, et al. Personality changes after Toscana virus (TOSV) encephalitis in a 49-year-old man: A case report. Int J Neurosci. 2011 Mar;121(3):165-9. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21126108
  24. Sanbonmatsu-Gamez S, Perez-Ruiz M, Palop-Borras B, Navarro-Mari JM. Unusual manifestation of toscana virus infection, Spain. Emerg Infect Dis. 2009 Feb;15(2):347-8. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19193294
  25. Martinez-Garcia FA, Moreno-Docon A, Segovia-Hernandez M, Fernandez-Barreiro A. [Deafness as a sequela of Toscana virus meningitis]. Med Clin (Barc). 2008 May 3;130(16):639. Available at: https://www.ncbi.nlm.nih.gov/pubmed/18482536
  26. Nicoletti L, Verani P, Caciolli S, Ciufolini MG, Renzi A, Bartolozzi D, et al. Central nervous system involvement during infection by Phlebovirus toscana of residents in natural foci in central Italy (1977-1988). Am J Trop Med Hyg. 1991 Oct;45(4):429-34. Available at: https://www.ncbi.nlm.nih.gov/pubmed/195185
  27. Valassina M, Cusi MG, Valensin PE. Rapid identification of Toscana virus by nested PCR during an outbreak in the Siena area of Italy. J Clin Microbiol. 1996 Oct;34(10):2500-2. Available at: https://www.ncbi.nlm.nih.gov/pubmed/8880508
  28. Valassina M, Cuppone AM, Bianchi S, Santini L, Cusi MG. Evidence of Toscana virus variants circulating in Tuscany, Italy, during the summers of 1995 to 1997. J Clin Microbiol. 1998 Jul;36(7):2103-4. Available at: https://www.ncbi.nlm.nih.gov/pubmed/9650974
  29. Valassina M, Meacci F, Valensin PE, Cusi MG. Detection of neurotropic viruses circulating in Tuscany: the incisive role of Toscana virus. J Med Virol. 2000 Jan;60(1):86-90. Available at: https://www.ncbi.nlm.nih.gov/pubmed/10568768
  30. Sghaier W, Bahri O, Kedous E, Fazaa O, Rezig D, Touzi H, et al. [Retrospective study of viral causes of central nervous system infections in Tunisia (2003-2009)]. Med Sante Trop. 2012 Oct-Dec;22(4):373-8. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23354155
  31. Anagnostou V, Papa A. Seroprevalence of Toscana virus among residents of Aegean Sea islands, Greece. Travel Med Infect Dis. 2013 Mar-Apr;11(2):98-102. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23312503
  32. Anagnostou V, Papa A. Prevalence of antibodies to phleboviruses within the sand fly fever Naples virus species in humans, northern Greece. Clin Microbiol Infect. 2013 Jun;19(6):566-70. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22764837
  33. Fezaa O, Bahri O, Alaya Bouafif NB, Triki H, Bouattour A. Seroprevalence of Toscana virus infection in Tunisia. Int J Infect Dis. 2013 Dec;17(12):e1172-5. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24103332
  34. Punda-Polic V, Jeroncic A, Mohar B, Sisko Kraljevic K. Prevalence of Toscana virus antibodies in residents of Croatia. Clin Microbiol Infect. 2012 Jun;18(6):E200-3. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22512547
  35. Sakhria S, Bichaud L, Mensi M, Salez N, Dachraoui K, Thirion L, et al. Co-circulation of Toscana virus and Punique virus in northern Tunisia: a microneutralisation-based seroprevalence study. PLoS Negl Trop Dis. 2013;7(9):e2429. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24069484
  36. Ayhan N, Baklouti A, Prudhomme J, Walder G, Amaro F, Alten B, et al. Practical Guidelines for Studies on Sandfly-Borne Phleboviruses: Part I: Important Points to Consider Ante Field Work. Vector Borne Zoonotic Dis. 2017 Jan;17(1):73-80. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28055576
  37. European Centre for Disease Prevention and Control. Phlebotomine sand flies - Factsheet for experts. 2020. Available at: https://www.ecdc.europa.eu/en/disease-vectors/facts/phlebotomine-sand-flies
  38. Ayhan N, Prudhomme J, Laroche L, Banuls AL, Charrel RN. Broader Geographical Distribution of Toscana Virus in the Mediterranean Region Suggests the Existence of Larger Varieties of Sand Fly Vectors. Microorganisms. 2020 Jan 14;8(1) Available at: https://www.ncbi.nlm.nih.gov/pubmed/31947561
  39. Muñoz C, Ayhan N, Ortuño M, Ortiz J, Gould EA, Maia C, et al. Experimental Infection of Dogs with Toscana Virus and Sandfly Fever Sicilian Virus to Determine Their Potential as Possible Vertebrate Hosts. Microorganisms. 2020;8(4):596. Available at: https://www.mdpi.com/2076-2607/8/4/596
  40. Dincer E, Gargari S, Ozkul A, Ergunay K. Potential animal reservoirs of Toscana virus and coinfections with Leishmania infantum in Turkey. The American journal of tropical medicine and hygiene. 2015 2015/04//;92(4):690-7. Available at: http://europepmc.org/abstract/MED/25711610
  41. Reusken C, Baronti C, Mogling R, Papa A, Leitmeyer K, Charrel RN. Toscana, West Nile, Usutu and tick-borne encephalitis viruses: external quality assessment for molecular detection of emerging neurotropic viruses in Europe, 2017. Euro Surveill. 2019 Dec;24(50) Available at: https://www.ncbi.nlm.nih.gov/pubmed/31847946
  42. Perez-Ruiz M, Collao X, Navarro-Mari JM, Tenorio A. Reverse transcription, real-time PCR assay for detection of Toscana virus. J Clin Virol. 2007 Aug;39(4):276-81. Available at: https://www.ncbi.nlm.nih.gov/pubmed/17584525
  43. Thirion L, Pezzi L, Pedrosa-Corral I, Sanbonmatsu-Gamez S, de Lamballerie X, Falchi A, et al. Evaluation of a Trio Toscana Virus Real-Time RT-PCR Assay Targeting Three Genomic Regions within Nucleoprotein Gene. Pathogens. 2021 Feb 24;10(3) Available at: https://www.ncbi.nlm.nih.gov/pubmed/33668339
  44. Weidmann M, Sanchez-Seco MP, Sall AA, Ly PO, Thiongane Y, Lo MM, et al. Rapid detection of important human pathogenic Phleboviruses. J Clin Virol. 2008 Feb;41(2):138-42. Available at: https://www.ncbi.nlm.nih.gov/pubmed/18006376
  45. Cusi MG, Savellini GG. Diagnostic tools for Toscana virus infection. Expert Rev Anti Infect Ther. 2011 Jul;9(7):799-805. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21810052
  46. Ergunay K, Litzba N, Lo MM, Aydogan S, Saygan MB, Us D, et al. Performance of various commercial assays for the detection of Toscana virus antibodies. Vector Borne Zoonotic Dis. 2011 Jun;11(6):781-7. Available at: https://www.ncbi.nlm.nih.gov/pubmed/21395410
  47. Charrel RN, Moureau G, Temmam S, Izri A, Marty P, Parola P, et al. Massilia virus, a novel Phlebovirus (Bunyaviridae) isolated from sandflies in the Mediterranean. Vector Borne Zoonotic Dis. 2009 Oct;9(5):519-30. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19055373
  48. Collao X, Palacios G, de Ory F, Sanbonmatsu S, Perez-Ruiz M, Navarro JM, et al. Granada virus: a natural phlebovirus reassortant of the sandfly fever Naples serocomplex with low seroprevalence in humans. Am J Trop Med Hyg. 2010 Oct;83(4):760-5. Available at: https://www.ncbi.nlm.nih.gov/pubmed/20889862
  49. Zhioua E, Moureau G, Chelbi I, Ninove L, Bichaud L, Derbali M, et al. Punique virus, a novel phlebovirus, related to sandfly fever Naples virus, isolated from sandflies collected in Tunisia. Journal of General Virology. 2010 2010-05;91(Pt 5):1275-83. Available at: https://hal-riip.archives-ouvertes.fr/pasteur-00612146
  50. Pierro A, Ficarelli S, Ayhan N, Morini S, Raumer L, Bartoletti M, et al. Characterization of antibody response in neuroinvasive infection caused by Toscana virus. Clin Microbiol Infect. 2017 Nov;23(11):868-73. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28344163
  51. European Commission. Commission implementing decision 2018/945 of 22 June 2018 on the communicable diseases and related special health issues to be covered by epidemiological surveillance as well as relevant case definitions. Luxembourg: Office of the European Union. 6.7.2018:L170/1. Available at: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32018D0945&from=EN#page=13.
  52. European Commission. Commission directive (EU) 2019/1833 of 24 October 2019 amending Annexes I, III, V and VI to Directive 2000/54/EC of the European Parliament and of the Council as regards purely technical adjustments, L 279/54 Brussels: EC. Available at: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32019L1833&from=EN