Characterization of a sandfly fever Sicilian virus isolated during a sandfly fever epidemic in TurkeyArchived

ECDC comment

Phleboviruses cause sandfly fever but isolates are rare.

Carhan A 1, Uyar Y 1, Ozkaya E 1, Ertek M 1, Dobler G 2, Dilcher M 3, Wang Y 3, Spiegel M 3, Hufert F 3, Weidmann M 3.1 Refik Saydam National Public Health Agency (RSNPHA), Ankara, Turkey2 Institute for Microbiology of the Armed Force, München, Germany3 University Medical Center, Institute of Virology, Kreuzbergring 57, Göttingen 37075, Germany  Journal of Clinical Virology Aug. 2010. 48(4): 264-9.

BACKGROUND: Phleboviruses cause sandfly fever but isolates are rare.

OBJECTIVES: To analyse samples from concurrent outbreaks of suspected sandfly fever in the Mediterranean provinces of Adana, Izmir and the central province of Ankara, Turkey.

STUDY DESIGN: Samples from acute cases were analysed by immunofluorescence assay (IFA). Virus isolation was attempted and pyrosequencing performed.

RESULTS: In IFA 38% of 106 samples tested scored IgM positive for sandfly fever Sicillian virus (SFSV), 12% for SFSV/sandfly fever Cyprus Virus (SFCV) and only 4% for SFCV. A sandfly fever Sicilian type virus designated sandfly fever Turkey virus (SFTV) was isolated. The S-segment sequence of SFTV had a homology of 98% to that of SFCV. The M-segment sequence showed a 91.1% homology to the only SFSV sequence available. The L-segment sequence showed a homology of 58% and 60.3% to Toscana virus and Rift Valley Fever virus sequences, a partial 201nt sequence showed 95.5% homology to the SFSV Sabin strain.

CONCLUSION: A new phlebovirus related to sandfly fever Sicilian virus, SFTV was isolated and characterized from acute patient material. The sandfly fever Sicilian virus activity seems to be changing in Turkey. Entomological studies are needed.

VBORNET comment: 2010-04-12

Carhan et al. report the identification and genomic characterization of a novel variant of sand fly fever Sicilian virus (SFSV), provisionally named the Sandfly Fever Turkish Virus (SFTV), during the investigation for outbreaks of febrile diseases associated with sandfly bites in Izmir (Aegean coast), Adana (Mediterranean coast), and Ankara (Central Anatolia) provinces in 2007-2008. Sandfly fever viruses (SFVs) comprise three major serotypes; SFSV, SFNV and Toscana virus (TOSV). Sandfly fever Cyprus virus (SFCV), a variant of Sicilian serotype, is also responsible for acute febrile disease and TOSV may cause aseptic meningitis/encephalitis in the infected individuals. The S segment of the novel SFTV displayed 98% homology to that of SFCV Cyprus whereas M and partial L segments also showed 91.1% and 95.5% homology to SFSV, respectively. It is generally accepted that SFVs have the capacity to display significant diversity in the sandfly vectors and variants/recombinants, some of which may be capable of inducing human disease which may emerge in the endemic regions. In addition to Carhan et al.’s identification of the SFSV variant in Turkey, another report to support this hypothesis was recently published by Collao et al. who identified in Spain a new member of the phlebovirus genus in sandflies, tentatively named Granada virus (Am J Trop Med Hyg, 83(4): 760–765, 2010). Human exposure to this agent is also demonstrated, although association with a clinical syndrome could not be proven. Interestingly, the genomic analysis of Granada virus revealed that it is likely to be a natural reassortant of the recently described Massilia virus (donor of the long and short segments) with a yet unidentified phlebovirus. See also Ergünay et al., 2011 and Hamarsheh, 2011.