Prevalence of toscana and sicilian phlebovirus antibodies in classic Kaposi sarcoma case patients and control subjects in sicily

Exposure to Phlebotomus perniciosus sandfly vectors is positively associated with Toscana virus and Leishmania infantum infection in human blood donors in Murcia Region, southeast Spain

Antibodies against Phlebotomus perniciosus sandfly salivary gland homogenate (SGH) and recombinant protein rSP03B, sandfly-borne Toscana virus (TOSV), Sandfly Fever Sicilian virus (SFSV) and Leishmania, as well as DNA of the latter parasite, were investigated in 670 blood samples from 575 human donors in Murcia Region, southeast Spain, in 2017 and 2018. The estimated SGH and rSP03B seroprevalences were 69% and 88%, respectively, although correlation between test results was relatively low (ρ = 0.39). Similarly, TOSV, SFSV and Leishmania seroprevalences were 26%, 0% and 1%, respectively, and Leishmania PCR prevalence was 2%. Prevalences were significantly greater in 2017, overdispersed and not spatially related to each other although both were positively associated with SGH but not to rSP03B antibody optical densities, questioning the value of the latter as a diagnostic marker for these infections in humans.

Immunoglobulin M seropositivity for Toscana virus in a random population sample in Sicily

OBJECTIVES

High Toscana virus (TOSV) antibody seropositivity rates have been documented in the last decade, especially in the Mediterranean area. It is unclear if these rates are associated with a recent or past exposure to the virus. This is of importance, as primary infection can cause neurologic complications, especially in adults. The aim of the present study was to assess the current active TOSV circulation in western Sicily.

METHODS

A cross-sectional seroprevalence study was conducted on 271 individuals aged 4-92 years, sampled from the general population of a small city. Each participant completed a self-administered questionnaire and provided serum, which was analyzed for the presence of specific anti-TOSV IgM and IgG.

RESULTS

Anti-TOSV IgM was detected in eight (3.0%) participants, of whom only three had anti-TOSV IgG. The prevalence of anti-TOSV IgM was highest in subjects aged 25-34 and 35-44 years (7.1% and 4.8%, respectively). All subjects positive for anti-TOSV IgM were resident in the suburban area.

CONCLUSIONS

The detection of IgM documented the circulation of TOSV, a Phlebovirus, in a random population sample of Sicilian adults. The highest risk of TOSV seroconversion in subjects living in the suburbs appears to suggest a high density of TOSV vectors in peri-urban areas.

Seroprevalence of and risk factors for Toscana and Sicilian virus infection in a sample population of Sicily (Italy)

OBJECTIVE

The present study aimed to assess seroprevalence of and risk factors for Toscana (TOSV) and Sicilian (SFSV) virus infections in a sample of Sicilian subjects.

METHODS

A cross-sectional seroepidemiological study was conducted on 271 individuals. Each participant completed a self-administrated questionnaire and provided a serum sample which was analyzed for the presence of IgG specific anti-TOSV and anti-SFSV viruses.

RESULTS

Overall, 90 subjects (33.2%) were positive for TOSV IgG, 25 (9.2%) were positive for SFSV IgG and 11 (4%) were positive for both the viruses. A higher risk for TOSV seropositivity was found in participants who were older (adjOR = 1.02 per year; 95% CI = 1.01-1.03), having a pet living outdoors (adjOR = 2.62; 95% CI = 1.42-4.83) and being obese (adjOR = 2.37; 95% CI = 1.06-5.30).

CONCLUSIONS

TOSV seroprevalence appears to be relatively high in Sicilian general population, especially in older adults, representing a potential public health concern. The observations that seropositivity for TOSV was not significantly associated with SFSV seropositivity, and none of the risk factors associated with TOSV were associated with SFSV seem to suggest that these two phleboviruses may have different ecology and transmission pathways.