Serologic evidence of widespread Toscana virus infection in Bulgaria

Background Toscana virus (TOSV) is an emerging sandfly-borne virus that is endemic in Mediterranean countries. Methods In order to detect TOSV circulation among the human population of Bulgaria, serum samples from 459 apparently healthy adult individuals, residing in19 out of 28 districts in the country, were tested for the presence of IgG antibodies to TOSV. Results An overall seroprevalence rate of 24.4% was observed, ranging from 4.4% to 53.5% in the districts. Rates were highest in persons over 60 years of age and residing in the southern districts. Conclusion The results of the first TOSV seroprevalence study in Bulgaria revealed that infection is widespread. Physicians should be aware of the virus circulation during summer and consider the diagnosis in cases of febrile illness, meningitis or meningoencephalitis. (c) 2019 The Authors. Published by Elsevier Limited on behalf of King Saud Bin Abdulaziz Universityfor Health Sciences. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).