Sandfly Virus Encephalitis in Israel: Two Case Reports and a Review

Abstract

Background: Infections due to Sand-fly virus (SFV) are common in the Mediterranean region, but are rarely diagnosed in Israel. Until recently, no cases of severe neuro-invasive SFV infections were reported. In this study, we describe two cases of encephalitis associated with seroconversion to SFV acquired in Israel. We further try to postulate about the infecting strain of the SFV, its local phlebotomine vector, and the reasons for the emergence of this infection in Israel. Methods: Clinical data were collected from hospital records. Laboratory diagnosis was obtained using mosaic indirect immunofluorescence tests (IFT) against several SFVs. Results: Two patients with severe encephalitis presented during the same 2014 summer season. Both have acquired their infection in Hasharon district of central coastal Israel. Their encephalitis developed after a prolonged prodrome of 7 and 14 days, and was associated with severe neurological complications. Both patients exhibited a late seroconversion beyond twenty days from symptom onset. Conclusion: SFVs are possible etiological agents of febrile illnesses and central nervous system infections in Israel. The SFV we report is suspected to be a Toscana virus-like strain, and is probably transmitted by Phlebotomus perfiliewi. A review of the spread of phlebotomine vectors is presented.