Human intestinal spirochetosis: an entity associated with sexual transmitted infections.

Introduction: Human intestinal spirochetosis (HIE) is a poorly studied clinical entity with variable clinical manifestations. However, in recent years it has gained special relevance because an increasing number of cases have been described in people living with HIV (PWH) and in patients with a history of sexually transmitted infections (STI) or immunosuppression.

Methods: Retrospective review of all HIE cases identified in a tertiary level hospital (Hospital Universitario la Paz, Madrid) between 2014 and 2021.

Results: 36 Cases of HIE were identified. Most cases corresponded to males (94%) with a median age of 45 years. 10 patients (29.4%) were PWH and 20 (56%) were men who had sex with men. Although the clinical manifestations were very heterogeneous, the most frequent was chronic diarrhea (47%), and up to 25% of the subjects had clinical proctitis. 39% percent of patients had been diagnosed with an STI in the previous two years, this characteristic being more frequent in PWH (90% vs. 28%; p < 0.01) than in patients without HIV infection. The STI most frequently associated with a diagnosis of HIE was syphilis (31%).

Conclusion: HIE is frequently diagnosed with other STIs and affects mostly men who have sex with men, which supports that this entity could be considered as a new STI.