Objectives The Dual Path Platform (DPP) detects treponemal and lipoidal antibodies at the point of care, with an automated reader generating quantitative optical density (OD) values. We assessed the association between DPP OD and RPR titers and post-treatment DPP OD trajectories according to serological cure. Methods We conducted an observational study comprising cross-sectional and longitudinal analyses. The cross-sectional analysis assessed the association between DPP OD and RPR titers in anonymized serum samples. The longitudinal analysis assessed post-treatment changes in DPP OD according to RPR-based serological cure. Results The cross-sectional analysis included 1,222 samples. DPP OD increased with RPR titer, with a quadratic model showing attenuation of the increase at higher titers. Differences between consecutive RPR categories were significant through 1:64 but not at higher titers, with substantial overlap between categories. The longitudinal analysis included 118 participants. Mean DPP OD declined from 89.1 at baseline to 32.4 at week 12, 20.8 at week 24, and 17.0 at week 48. DPP OD declined after treatment in cases with serological cure and increased during recurrent RPR increases. Conclusions DPP OD was quantitatively associated with RPR titer and longitudinal changes reflected RPR-based serological response, supporting further evaluation as a complementary approach for treatment monitoring.

Neisseria meningitidis clonal complex 11 (cc11) is a hyperinvasive lineage associated with global dissemination and outbreaks, including the 'South American/UK' sublineage. In Spain, cc11 serogroup W cases have increased in recent years; however, the evolutionary dynamics of circulating variants remain insufficiently characterized. This study aimed to assess the clonal diversity, temporal evolution and antimicrobial resistance profiles of cc11 isolates recovered in Spain between 2011 and 2025. A total of 1,226 isolates (406 invasive and 820 non-invasive) were collected across 8 Spanish regions, from which cc11 isolates were selected for analysis. Whole-genome sequencing (WGS) was used to perform core-genome multilocus sequence typing and SNP-based Bayesian phylogenetics to characterize population structure. Antimicrobial susceptibility was assessed using gradient diffusion, and genetic determinants of resistance were identified by WGS. We identified 179 cc11 isolates, mostly belonging to genogroup W (73.7%) and lineage 11.1 (85.5%). The 'South American/UK' sublineage was the main sublineage and displayed extensive diversification. A previously undescribed variant, designated the '2020 strain', emerged with an estimated most recent common ancestor in 2017 and accounted for 77.2% of 'South American/UK' sublineage isolates recovered between 2023 and 2025. This variant was mainly identified in respiratory samples from men who have sex with men but was also associated with invasive meningococcal disease in other population groups. The '2020 strain' exhibited resistance to penicillin and azithromycin, likely driven by penicillin-binding protein 2 and MtrCDE alterations. The emergence of this antimicrobial-resistant variant highlights the adaptive capacity of cc11 and the importance of genomic surveillance to monitor its evolution and public health relevance.

BackgroundSexually transmitted infections (STIs) rates have increased in the last two decades in Western world, including syphilis. Higher rates of syphilis lead to the emergence of atypical or less common manifestations like Follmann's balanitis. Follmann's balanitis is an atypical presentation of primary syphilis characterized as erythematous, erosive lesions on the glans penis.MethodsThe aim of the study is to describe the cases of the Follmann 's diagnosed in Vall d'Hebron-Drassanes STI Unit over 20 years (2003-2023). Retrospectively, the epidemiological, clinical and microbiological data were collected.ResultsIn total 20 cases of Follmann's balanitis were diagnosed. The clinical presentation was heterogeneous, with erosive balanitis being the most frequent presentation. Fifteen per cent had also a chancre and 50% presented with lymphadenopathy. Dark field microscopy and Treponema pallidum NAAT were positive in 41% and 92% respectively, and the median RPR titre was 1/4 (IQR 1/2-1/16).ConclusionsFollmann's balanitis is a rare presentation of primary syphilis which has to be suspected in case of erosive balanitis, especially in key populations as MSM or persons with previous STIs, where syphilis is more frequent.

The mucosal immune system plays a fundamental role in maintaining microbial balance. Microbial imbalance in the female genital tract increases the risk for adverse health outcomes in women and may increase susceptibility to local infections. Myeloid-derived suppressor cells (MDSCs) remain understudied in the context of female genital tract conditions. Here we show that frequency of polymorphonuclear (PMN-) MDSCs increased in the cervical mucosa of women with Chlamydia trachomatis infection, bacterial vaginosis, or with a coinfection, but not in women with human papillomavirus infection. Mucosal PMN-MDSC frequencies correlated with mucosal IL-1β in C. trachomatis patients and ex vivo exposure of cervical tissue to C. trachomatis elevated both PMN-MDSC frequencies and IL-1β secretion. Likewise, exposure of cervical tissue to cervicovaginal lavage fluid from C. trachomatis and bacterial vaginosis patients also enhanced PMN-MDSC frequencies. Lastly, cervical MDSCs expressed suppressive mediators and functionally suppressed cytotoxic T-cell responses. Our study identifies IL-1β-stimulated PMN-MDSCs as immunosuppressive mediators in female genital tract infections, potentially modulating susceptibility to local secondary infections.

BACKGROUND:In 2019, Trichophyton mentagrophytes genotype VII (TMVII) was identified in Germany as a cause of sexually transmitted tinea. Since 2023, it has been described in men who have sex with men (MSM) in France, Italy, and the United States. No cases have been reported in Spain. OBECTIVES:Our study aimed to assess the occurrence of TMVII in an STI clinic in Barcelona. PATIENTS/METHODS:We identified TMVII cases among all positive mycological skin/hair cultures between January 2020 and January 2025 by sequencing the internal transcribed spacer on isolates of T. mentagrophytes-interdigitale. We retrospectively collected demographic, clinical and treatment data and analysed the association between treatment received and outcome (cure vs. recurrence). RESULTS:Among 21 positive cultures, we obtained 15 isolates of T. mentagrophytes-interdigitale, of which 14 were sequenced and identified as TMVII. Patients with TMVII were all MSM; most were HIV positive (7) or negative on preexposure prophylaxis (6). Main sites of infection were pubogenital (6), buttocks-perianal (5) and beard (2). Six patients required multiple courses of treatment due to recurrence. Twenty-one courses of antifungal therapy were analysed, with an observed cure rate of 45% (5/11) for oral terbinafine vs. 80% (7/10) for topical agents (p = 0.39), and 0% (0/6) for ≤ 2-week courses vs. 80% (12/15) for 3-to-8-week courses (p < 0.01). CONCLUSIONS:Our study confirms the presence of TMVII in Spain, supporting its circulation across Europe. Epidemiological profile and site of infection support sexual transmission. Patients responded to systemic or topical terbinafine but required longer-than-usual periods of treatment.

A 64 year old cisgender man attended to our genito-urinary clinic with a 1 week history of a painful genital ulcer after travelling to Madagascar. On physical examination, we observed two small ulcers, each with a fibrinous base and erythematous borders, without associated lymphadenopathy. The initial diagnosis was a genital herpes outbreak. Thus, a seven-day course of Valaciclovir 500 mg twice daily orally was prescribed. An ulcer sample was collected for NAATs including C. trachomatis L1-L3, Herpes simplex virus 1 and 2, Varicella-zoster virus, Treponema pallidum and Haemophilus ducreyi. The ulcer NAATs was positive for H. ducreyi. Considering the result and the epidemiological background, diagnosis confirmed chancroid. Ceftriaxone 1 g STAT intramuscular was administered with subsequent improvement. Chancroid, caused by H. ducreyi is very rare in Europe. Its prevalence in STI clinics has varied from 0% to 0.5%. It must be suspected, especially in travellers to endemic countries in the first days of their return due to its short incubation period.

•En el 2020 hubo 82 millones de casos de gonorrea en el mundo.•La Neisseria gonorrhoeae (N. gonorrhoeae) es una bacteria que ha generado mecanismos de resistencia a los tratamientos antibióticos utilizados, desde las sulfonamidas que fueron las primeras que se utilizaron, hasta las cefalosporinas, tratamiento de elección en estos momentos y que en las últimas décadas se han aislado cepas con sensibilidad reducida.•Se ha estudiado el uso de tratamientos ya existentes con otras indicaciones para el tratamiento de la gonorrea, como son el ertapenem, gemifloxacino y delafloxacino.•Se están estudiando nuevos fármacos como la zoliflodacina, la solitromicina y la gepotidacina, todas ellas en fase III.

BACKGROUND:Management of syphilis, a sexually transmitted infection (STI) with increasing incidence, is challenged by drug shortages, scarcity of randomised trial data, an absence of non-penicillin alternatives for pregnant women with penicillin allergy (other than desensitisation), extended parenteral administration for neurosyphilis and congenital syphilis, and macrolide resistance. Linezolid was shown to be active against Treponema pallidum, the causative agent of syphilis, in vitro and in the rabbit model. We aimed to assess the efficacy of linezolid for treating early syphilis in adults compared with the standard of care benzathine penicillin G (BPG). METHODS:We did a multicentre, open-label, non-inferiority, randomised controlled trial to assess the efficacy of linezolid for treating early syphilis compared with BPG. We recruited participants with serological or molecular confirmation of syphilis (either primary, secondary, or early latent) at one STI unit in a public hospital and two STI community clinics in Catalonia (Spain). Participants were randomly allocated in a 1:1 ratio using a computer-generated block randomisation list with six participants per block, to receive either oral linezolid (600 mg once per day for 5 days) or intramuscular BPG (single dose of 2·4 million international units) and were assessed for signs and symptoms (once per week until week 6 and at week 12, week 24, and week 48) and reagin titres of non-treponemal antibodies (week 12, week 24, and week 48). The primary endpoint was treatment response, assessed using a composite endpoint that included clinical response, serological response, and absence of relapse. Clinical response was assessed at 2 weeks for primary syphilis and at 6 weeks for secondary syphilis following treatment initiation. Serological cure was defined as a four-fold decline in rapid plasma reagin titre or seroreversion at any of the 12-week, 24-week, or 48-week timepoints. The absence of relapse was defined as the presence of different molecular sequence types of T pallidum in recurrent syphilis. Non-inferiority was shown if the lower limit of the two-sided 95% CI for the difference in rates of treatment response was higher than -10%. The primary analysis was done in the per-protocol population. The trial is registered at ClinicalTrials.gov (NCT05069974) and was stopped for futility after interim analysis. FINDINGS:Between Oct 20, 2021, and Sept 15, 2022, 62 patients were assessed for eligibility, and 59 were randomly assigned to linezolid (n=29) or BPG (n=30). In the per-protocol population, after 48 weeks' follow-up, 19 (70%) of 27 participants (95% CI 49·8 to 86·2) in the linezolid group had responded to treatment and 28 (100%) of 28 participants (87·7 to 100·0) in the BPG group (treatment difference -29·6, 95% CI -50·5 to -8·8), which did not meet the non-inferiority criterion. The number of drug-related adverse events (all mild or moderate) was similar in both treatment groups (five [17%] of 29, 95% CI 5·8 to 35·8 in the linezolid group vs five [17%] of 30, 5·6 to 34·7, in the BPG group). No serious adverse events were reported during follow-up. INTERPRETATION:The efficacy of linezolid at a daily dose of 600 mg for 5 days did not meet the non-inferiority criteria compared with BPG and, as a result, this treatment regimen should not be used to treat patients with early syphilis. FUNDING:European Research Council and Fondo de Investigaciones Sanitarias.

Worldwide, more than 90% of contemporary syphilis strains belong to SS14-like clade. This study aimed to describe the molecular profile of circulating Treponema pallidum subsp. pallidum (TPA) strains in Barcelona, Spain, from 2021 to 2023 building upon our report in 2015 which showed that 94.8% of typed strains belonged to the SS14 clade. Multilocus sequence typing (MLST) was conducted on TPA-positive samples obtained from swab samples by sequencing the tp0136, tp0548, and tp0705 loci. Strains were classified as Nichols-like or SS14-like clade. Macrolide and tetracycline resistance‑associated mutations were determined through analysis of 23S rDNA and 16S rRNA gene sequences. Of the 96 typeable samples, 47.9% belonged to SS14-like and 52.1% to the Nichols-like. Fourteen haplotypes were identified, with ST26 representing 43.8% of the samples, distributed across 11 haplotypes in the SS14-like and 3 haplotypes in the Nichols-like. All the samples showed macrolide resistance-associated mutations, while none exhibited tetracycline-associated mutations. Our findings revealed a substantial shift in the proportion of TPA clades within the Barcelona population from 2021 to 2023, characterized by a higher proportion of Nichols-like strains compared to 2015 and international trends. The varying temporal and geographical trends underscore the need for regular surveillance to understand regional variations in syphilis and strengthen control programs.

Vaccines against smallpox are known to have cross-protective activity against monkeypox, and smallpox and monkeypox infections are believed to generate permanent immunity. Nevertheless, there are scarce data about the possibility of reinfection or reactivation. Recently, a case of apparent monkeypox reinfection has been reported. We present a suspected case of second episode of monkeypox in a healthy and previously vaccinated man, with a confirmed primary monkeypox infection occurring three months before the second confirmed presentation.

BackgroundWhole-genome sequencing (WGS) of Neisseria gonorrhoeae isolates combined with epidemiological and phenotypic data provides better understanding of population dynamics.AimThe objective of this study was to investigate the molecular epidemiology of N. gonorrhoeae isolates from three centres in Spain and determine associations of antimicrobial resistance.MethodsGenetic characterization was performed in 170 N. gonorrhoeae isolates. WGS was carried out with the HiSeq platform (Illumina). Genome assemblies were submitted to the PubMLST Neisseria database website to determine NG-MAST, MLST and NG-STAR. Antimicrobial resistance genes and point mutations were identified with PubMLST. Phylogenomic comparison was based on whole-genome single nucleotide polymorphism analysis.ResultsTwenty-six MLST, 49 NG-MAST and 41 NG-STAR sequence types were detected, the most prevalent being MLST-ST9363 (27.1%), NG-MAST ST569 (12.4%) and NG-STAR ST193 (14.7%). Phylogenetic analysis identified 13 clusters comprising 69% of the isolates, with two of note: one involved cefixime-resistant isolates from Barcelona presenting a mosaic penA X and belonging to MLST-ST7363 and the other involved azithromycin-resistant isolates from Mallorca that possessed the C2611T mutation in the four 23S rRNA alleles belonging to MLST-ST1901.ConclusionThe population of N. gonorrhoeae is quite heterogeneous in Spain. Our results agree with previous data published in Europe, albeit with some differences in distribution between regions. This study describes the circulation of two gonococcal populations with a specific resistance profile and sequence type in a specific geographic area. WGS is an effective tool for epidemiological surveillance of gonococcal infection and detection of resistance genes.

ABSTRACT To assess the feasibility of oral fosfomycin-tromethamine (FT) for the management of acute bacterial prostatitis (ABP) caused by multidrug-resistant (MDR) Enterobacterales. An observational study of adult patients diagnosed with ABP from Vall d’Hebron University Hospital (Barcelona, Spain), treated with oral FT. The primary outcome was clinical cure defined as symptom relief at the control visit, 2–4 weeks post-end of treatment. Secondary outcomes included microbiological cure, relapse, and adverse events related to the treatment. Eighteen patients with ABP caused by Enterobacterales (15 Escherichia coli and three Klebsiella pneumoniae) were included. Microorganisms were MDR bacteria [14 extended-spectrum beta-lactamase (ESBL) producers and two carbapenemase producing K. pneumoniae]. Patients received treatment with FT 3 g/48 hours during a median of 14 days (Q25–Q75, 12–17.75). Fifteen patients received a lead-in phase of intravenous suitable antimicrobial during a median of 7 days (Q25–Q75, 3.75–8). No patient had to stop treatment due to adverse events, and the only side effect reported in two patients was diarrhea. Clinical cure was achieved in all (18/18) patients and microbiological cure in 11/12 patients. After a median of follow-up of 5 months (Q25–Q75, 2–11), 2/18 patients relapsed with an orchitis and a new episode of ABP. FT is an attractive step-down therapy for ABP in patients with resistance or side effects to first-line drugs. The availability of oral treatment could reduce the use of the carbapenems, with a benefit in the quality of life of the patient, health costs, and an ecological impact. IMPORTANCE We present a brief but largest and interesting experience in which we use fosfomycin-tromethamine (FT) for the treatment of acute bacterial prostatitis (ABP) due to multiresistant bacteria. Our study provides new data that help to consider FT as a plausible alternative for treating ABP in patients with resistance or side effects to first-line drugs. The availability of an alternative oral treatment to avoid the use of the carbapenems could have important benefits in terms of quality of life of the patient, health costs, and an ecological impact.

Intro: In mid-May 2022,a monkeypox virus(MPXV) outbreak was identified in the UK,reporting new cases later in Portugal and Spain,and recently being declared a public health emergency by the WHO. The aim of this study was to describe the microbiological characteristics of MPXV infection in Barcelona. Methods: Clinical samples from patients with MPXV infection suspicion attended at Hospital Universitari Vall d'Hebron (HUVH) and Barcelona's primary healthcare centres were collected from May to July 2022. Laboratory-confirmation was initially performed by an in-house Orthopoxvirus RT-PCR assay until June,when commercial LightMix Modular Orthopoxvirus or MPXV-specific RT-PCR assays(RocheApplied Science,Germany)were available. Findings: A total of 802 samples from 511 patients were included. MPXV was laboratory-confirmed in 77.3%(395/511)of cases, 20.4%(104/511) were negative, while the remaining 2.3%(12/511) were unconclusive probably due to inhibitions or low-quality samples. Most confirmed cases were male patients(97.7%;n=386/395) and the median age was 37 years(IQR:31-44). Weekly MPXV incidence constantly increased. Discussion: The MPXV incidence trends reveal a high burden. Secondary related cases are expected when wide circulation occurs into the community. Samples from skin lesions had the best diagnostic performance;genital-chancre,throat and rectal samples also revealed higher viral loads, suggesting active viral replication and source of infection.Urine samples were positive but showing lower viral loads. Conclusion: The 2022 MPXV outbreak has had a high burden in Barcelona.Skin specimens seem to be the sample of choice for diagnosis.Even though MPX pathogenesis in humans is not still well-defined,viral replication seems to occur in oral,genital and rectal mucosa,suggesting a source of infection and playing a role in transmission,in contrast with other fluids like urine.These results are key information for prevention measures.

Objectives: We aimed to determine if starting antiretroviral therapy (ART) in the first 30 days after acquiring HIV infection has an impact on immunovirological response. Methods: Observational, ambispective study including 147 patients with confirmed acute HIV infection (January/1995-August/2022). ART was defined as very early (≤30 days after the estimated date of infection), early (31-180 days), and late (>180 days). We compared time to viral suppression (viral load [VL] <50 copies/ml) and immune recovery (IR) (CD4+/CD8+ ratio ≥1) according to the timing and type of ART using survival analysis. Results: ART was started in 140 (95.2%) patients. ART was very early in 24 (17.1%), early in 77 (55.0%), and late in 39 (27.9%) cases. Integrase strand transfer inhibitor (INSTI)-based regimens were the most used in both the overall population (65%) and the very early ART group (23/24, 95.8%). Median HIV VL and CD4+/CD8+ ratio pre-ART were higher in the very early ART group (P <0.05). Patients in the very early and early ART groups and treated with INSTI-based regimens achieved IR earlier (P <0.05). Factors associated with faster IR were the CD4+/CD8+ ratio pre-ART (hazard ratio: 9.3, 95% CI: 3.1-27.8, P <0.001) and INSTI-based regimens (hazard ratio: 2.4, 95% CI: 1.3-4.2, P = 0.003). Conclusions: The strongest predictors of IR in patients who start ART during AHI are the CD4+/CD8+ ratio pre-ART and INSTI-based ART regimens.

Objectives Culture of Neisseria gonorrhoeae remains essential for antimicrobial resistance (AMR) surveillance. We evaluated the effect of time of specimen collection on culture yield following a positive nucleic acid amplification test (NAAT). Methods We retrospectively assessed N. gonorrhoeae culture yield among asymptomatic individuals (largely men who have sex with men) who attended for sexual health screening and had a positive NAAT. Participants underwent either same-day testing and notification (Drassanes Exprés) or standard screening with deferred testing. Results Among 10 423 screened individuals, 809 (7.7%) tested positive for N. gonorrhoeae . A total of 995 different anatomical sites of infection culture was performed in 583 of 995 (58.6%) of anatomical sites (Drassanes Exprés 278 of 347, 80.1%; standard screening 305 of 648, 47.1%; p<0.001). Recovery was highest when culture specimens were collected within 3–7 days of screening with only a slight drop in recovery when the interval extended to 7 days . Recovery from pharynx was 38 of 149 (25.5%) within 3 days, 19 of 81 (23.4%) after 4–7 days (p=0.7245), 11 of 102 (10.7%) after 8–14 days (p<0.0036) and 1 of 22 (4.5%) with longer delays (p=0.00287). Recovery from rectum was 49 of 75 (65.3%) within 3 days, 28 of 45 (62.2%) after 4–7 days (p=0.7318), 41 of 69 (59.4%) after 8–14 days (p=0.4651) and 6 of 18 (33.3%) with longer delays (p=0.0131). Median culture specimen collection time was 1 day within Drassanes Exprés vs 8 days within standard screening. Consequently, the overall culture yield was slightly higher within Drassanes Exprés (102/278, 36.6% vs 99/305, 32.5%; p=0.2934). Conclusion Reducing the interval between screening and collection of culture specimens increased N. gonorrhoeae recovery in extragenital samples. Implementing a same-day testing and notification programme increased collection of culture samples and culture yield in our setting, which may help AMR surveillance.

Background: The emergence of chemsex has raised several concerns about gay, bisexual, and other men who have sex with men's (GBMSM) health. In this study we aim to analyze illicit drugs and chemsex use, sexual behavior and sexually transmitted infections (STI) in GBMSM who attended to a sexual health clinic and to explore any potential association between drug use and STI. Methods: We conducted an observational study between January and June 2019 among GBMSM population attending to a STI clinic in Barcelona, Spain. An anonymous self-administered questionnaire was given consecutively to all participants older than 18 years who accepted to participate. Results: A total of 514 GBMSM (median age of 34 years-old) were included. The median number of sexual partners in the last year was 20. Seventy-one percent did not use condoms consistently for receptive anal intercourse. Drug abuse prevalence in the preceding year was 64.2%, and 26.5% of the individuals practiced chemsex. Gamma-hydroxibutyrate/gammabutyrolactone, poppers and methamphetamine were the most common drugs in chemsex. Chemsex was associated to group sex (OR 9.8 [95 CI: 4-24]), HIV infection (OR 2.5 [95 CI: 1.1-5.8]), taking pre-exposure prophylaxis (OR 3.2 [95 CI: 1.5-7.1]), developing gonorrhea (OR 3.7 [95 CI: 1.5-8.8]) or syphilis (OR 6.7 [95 CI: 2.4-18.7]). Conclusions: The prevalence of drug use and chemsex was high among GBMSM in Barcelona. Chemsex was associated with group sex, taking PrEP, and contracting syphilis, gonorrhea, and HIV. (C) 2022 Elsevier Espana, S.L.U. All rights reserved.

Aim: To implement the multilocus sequence typing (MLST) methodology in syphilis samples previously characterized by enhanced CDC typing (ECDCT) and macrolide resistance. Materials & methods: MLST was performed on genital ulcer and blood samples by analyzing a region of the tp0136, tp0548 and tp0705loci using Sanger sequencing. Results: Up to 59/85 (69.4%) of genital ulcer and 4/39 (10.3%) of whole blood samples were fully typed. The most frequent profiles were 1.3.1 (56%) and 1.1.1 (11%). All the 1.3.1 samples typed carried the A2058G mutation, responsible for macrolide resistance. MLST and ECDCT showed similar overall typing yields. Conclusion: Several allelic profiles of T. pallidum subsp. pallidum were identified and classified into two major genetic clades in Barcelona. Our results were similar to that described in Europe.

Human intestinal spirochetosis (HIS) is a possible cause of chronic diarrhoea and affects mainly men who have sex with men (MSM) and people living with HIV. Diagnosis is based on colon biopsy, where spirochetes can be observed on the luminal surface, especially with the Warthin-Starry stain or similar silver stains. We conducted a retrospective descriptive study of all HIS cases diagnosed in two sexually transmitted infections (STI) centres in Barcelona from 2009 until 2018. The medical histories were reviewed to gather epidemiological, clinical, and diagnostic variables. Six patients were diagnosed with HIS. All the individuals were MSM, with a median age of 31.5 years (interquartile range [IQR] 29.5;49.25) and half of them were living with HIV. Five patients reported condomless anal intercourse and 4 patients had practised oro-anal sex previously. Concomitantly, two of them had rectal gonorrhoea, one had rectal Chlamydia trachomatis and none of them had syphilis. The predominant clinical symptom was diarrhoea (5 patients). All cases were diagnosed by a Warthin-Starry stain on a colon biopsy specimen, and mild inflammatory changes were found in 5 cases. Five patients were treated with metronidazole and one with benzathine penicillin G. Treatment was successful in all the patients. HIS should be considered in patients with chronic diarrhoea who report risky sexual practices and/or concomitant STI. HIS may also be sexually transmitted according to the context.