Seroprevalence against Toscana virus in Spain: The case of the autonomous community of Madrid

Background & objectives: The Toscana virus (TOSV) is a neurotropic arbovirus that is transmitted through the bite of some Phlebotomus species. In 2009, the largest outbreak of leishmaniasis described so far in Europe, occurred in the Autonomous Community of Madrid, Spain, which was related to the population increase of P. perniciosus in this region. Methods: A seroprevalence study was conducted to determine the circulation of TOSV among the population of this geographic area. A total of 516 sera were collected in two different stages: 2007 (before the leishmaniasis outbreak) and 2018-19 (representative of the current situation). In the sera, presence of IgG antibodies against TOSV was determined by commercial ELISA. Results: The overall seroprevalence was 34.5%. The anti-TOSV IgG level was significantly higher in the samples collected in 2007 (41.5%) than 2018-19 (27.3%). Interpretation & conclusion: The results of this study show a very active TOSV circulation in the region that is greater than expected. The lower seroprevalence figures in 2018-19 may be related to the vector and environmental control measures that were put in place as a result of the leishmaniasis outbreak of 2009. This highlights the importance of such strategies to reduce the incidence of TOSV infection and other vector-borne diseases.

Automated summary

The study reveals active circulation of Toscana virus in the Autonomous Community of Madrid, Spain. The seroprevalence rate in 2018-19 is lower compared to 2007, potentially due to vector and environmental control measures implemented after the leishmaniasis outbreak.