High prevalence of the Mediterranean spotted fever agent Rickettsia aeschlimannii in Hyalomma marginatum ticks from Pianosa island, Italy

Tick-borne rickettsioses, caused by bacteria of the spotted fever group (SFG) Rickettsia , are emerging diseases influenced by climate and land-use changes. Hyalomma spp. ticks in the protected area of Pianosa island, Tuscany (Italy), a renowned touristic location, were monitored and investigated in their bacterial community composition (575 specimens, composed in 120 pools) through metabarcoding sequencing. In our study, we report the high prevalence of Rickettsia aeschlimannii (58% glt-, and 75% 17kDa-Ag protein-positive pools), an agent of the SFG group in H. marginatum . These findings rise the warning on the risk of transmission of Spotted Fever rickettsiosis to residents and to international travellers and underline the need for enhanced surveillance, public awareness, and preventive measures.