Tropheryma whipplei colonization in adults and children: A prospective study .

Background: Tropheryma whipplei, the causative agent of Whipple’s disease (WD), has been identified in asymptomatic carriers, including those in close contact with WD patients. However, the persistence of this colonization and it potential clinical impacts are not well understood.

Objectives: Our study aimed to investigate the duration of T. whipplei colonization in both adults and children and to explore if there is any association between persistent colonization, immunosuppressive treatment and the presence of symptoms.

Materials and methods: we conducted a prospective cohort study at the IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella, Verona, from 2019 to 2021. Individuals who had previously tested positive for T. whipplei DNA in stool samples between 2014 and 2016 were reassessed. Biological samples (stool, saliva, urine, and blood) were collected at baseline and after a 12-month follow-up, along with information on medical history, current treatment, and symptoms.

Results: Out of the 33 individuals (17 adults and 16 children), 28 completed the follow-up. The initial and follow-up assessments took place 4.27 and 5.32 years after the initial detection of T. whipplei DNA in stool samples. At the baseline, 14 (42.4%) individuals returned positive for T. whipplei DNA in fecal samples; this number decreased to nine (32.1%) after 12 months. Persistent intestinal colonization was observed in six subjects (18.2%), while 14 (42.4%) showed no colonization at either visit, and the rest had intermittent colonization (39.4%). Saliva tests initially tested positive in five participants (15.2%), decreasing to two (7.1%) by the follow-up. No T. whipplei DNA was detected in blood and urine samples neither at baseline nor at follow –up-. No association was observed between T. whipplei colonization and the presence of symptoms. No cases of Whipple’s disease was observed during the study’s observation period.

The most extended reported duration of persistent T. whipplei intestinal colonization identified in our patients exceeded 6 years. 11 patients presented a persistent positivity longer than 3 years. Among them, 1 minor presented persistent positivity for T. whipplei on stools for 5.9 years.

 Conclusions: These findings indicate that T. whipplei can persist in the intestinal tract for up to five years in adults and children. Larger prospective studies are needed to further explore this persistence's implications and determine which factors influence the duration of colonization and its potential impact on health. Additionally, the absence of established guidelines for managing asymptomatic carriers of T. whipplei highlights the need for developing protocols to address public health recommendations for these individuals.