Tropheryma whipplei Colonization in Adults and Children: A Prospective Study.

We conducted a prospective cohort study at the IRCCS Sacro Cuore Don Calabria Hospital in Negrar di Valpolicella from 2019 to 2021 to investigate the duration of T. whipplei colonization. In addition, the correlation between persistent colonization and the continent of origin, current treatment regimen, clinical manifestations, and parasite coinfection was evaluated. The cohort included subjects who were tested in a previous study (years 2014-2016) and found to be positive for T. whipplei DNA in fecal samples. Thirty-three subjects were enrolled in a prospective study between 2019 and 2021. Feces, saliva, urine, and blood were collected at baseline and after 12 months. Medical history, current treatment, and symptoms were recorded. Among them, 25% showed persistent intestinal or oral colonization, 50% had no colonization at both visits, and 25% had intermittent colonization. No association was found between persistent T. whipplei colonization and subjects' continent of origin, current treatment regimen, initial clinical manifestations, and parasite coinfection. The longest duration of persistent T. whipplei intestinal colonization exceeded six years, with 11 subjects presenting persistent positivity for more than three years, including 1 minor. Our research was limited by the lack of a strain-specific identification of T. whipplei that made it impossible to distinguish between persistence of the same T. whipplei strain, reinfection from household exposure, or infection by a new strain. Larger prospective studies are needed to further explore the implications of this persistence and determine the key factors influencing the duration of colonization and its potential health impacts.