ObjectiveTo evaluate whether ethnicity is independently associated with vaginal microbiota (VMB) composition in women living in Amsterdam, the Netherlands, as has been shown for American women.MethodsWomen (18–34 years, non-pregnant, N = 610) representing the six largest ethnic groups (Dutch, African Surinamese, South-Asian Surinamese, Turkish, Moroccan, and Ghanaian) were sampled from the population-based HELIUS study. Sampling was performed irrespective of health status or healthcare seeking behavior. DNA was extracted from self-sampled vaginal swabs and sequenced by Illumina MiSeq (16S rRNA gene V3-V4 region).ResultsThe overall prevalence of VMBs not dominated by lactobacilli was 38.5%: 32.2% had a VMB resembling bacterial vaginosis and another 6.2% had a VMB dominated by Bifidobacteriaceae (not including Gardnerella vaginalis), Corynebacterium, or pathobionts (streptococci, staphylococci, Proteus or Enterobacteriaceae). The most prevalent VMB in ethnically Dutch women was a Lactobacillus crispatus-dominated VMB, in African Surinamese and Ghanaian women a polybacterial G. vaginalis-containing VMB, and in the other ethnic groups a L. iners-dominated VMB. After adjustment for sociodemographic, behavioral and clinical factors, African Surinamese ethnicity (adjusted odds ratio (aOR) 5.1, 95% confidence interval (CI) 2.1–12.0) and Ghanaian ethnicity (aOR 4.8, 95% CI 1.8–12.6) were associated with having a polybacterial G. vaginalis-containing VMB, and African Surinamese ethnicity with a L. iners-dominated VMB (aOR 2.8, 95% CI 1.2–6.2). Shorter steady relationship duration, inconsistent condom use with casual partners, and not using hormonal contraception were also associated with having a polybacterial G. vaginalis-containing VMB, but human papillomavirus infection was not. Other sexually transmitted infections were uncommon.ConclusionsThe overall prevalence of having a VMB not dominated by lactobacilli in this population-based cohort of women aged 18–34 years in Amsterdam was high (38.5%), and women of sub-Saharan African descent were significantly more likely to have a polybacterial G. vaginalis-containing VMB than Dutch women independent of modifiable behaviors.

Introduction: This prospective study aimed to study the composition and structure of the vaginal microbiota prior to Chlamydia trachomatis infection. Methods: A nested case control study was performed in 122 women, half of which acquired C. trachomatis within a year after of their first visit. At the first visit, the composition and structure of vaginal microbial communities were analyzed using 16S-rRNA-sequencing, in the context of the socio-demographic and sexual risk behaviour information using logistic regression. Results: Five vaginal community state types (CSTs) were identified. Four CSTs were dominated by Lactobacillus spp., of which L. crispatus (37%) and L. iners (33%) were the most common. One CST was characterized by the absence of Lactobacillus spp. (25%) and the presence of an array of strict and facultative anaerobes. Multivariate logistic regression analysis revealed that women with a L. iners dominated CST had an increased risk of C. trachomatis infection (P=0.04; OR: 2.6, 95%CI: 1.0–6.6). Conclusions: The distribution of CSTs dominated by Lactobacillus spp. agreed with previous studies. However, the frequency of dysbiosis amongst Caucasian women was relatively high (24%). Having vaginal microbiota dominated by L. iners was associated with an increased risk for C. trachomatis infection. Therefore, we hypothesize that specific signatures of vaginal microbiota are indicative of increased host predisposition to acquiring STIs.

Women who tested positive for Chlamydia trachomatis infection after having been contact-traced by a chlamydia-positive partner were more likely to have CVM dominated by L. iners or by diverse anaerobic bacteria, than by L. crispatus.

Background & AimsSince acute hepatitis C virus (HCV) infection is often asymptomatic, it is difficult to examine the rate and determinants of spontaneous clearance. Consequently, these studies are subject to bias, which can potentially lead to biased rates of viral clearance and risk estimates. We evaluated determinants of spontaneous HCV clearance among HCV seroconverters identified in a unique community-based cohort.MethodsSubjects were 106 drug users with documented dates of HCV seroconversion from the Amsterdam Cohort Study. Logistic regression was used to examine sociodemographic, behavioral, clinical, viral and host determinants, measured around acute infection, of HCV clearance.ResultsThe spontaneous viral clearance rate was 33.0% (95% confidence interval (CI) 24.2–42.8). In univariate analyses female sex and fever were significantly associated with spontaneous clearance. The favorable genotypes for rs12979860 (CC) and rs8099917 (TT) were associated with spontaneous clearance, although borderline significant. In multivariate analysis, females with the favorable genotype for rs12979860 (CC) had an increased odds to spontaneously clear HCV infection (adjustedOR 6.62, 95% 2.69–26.13), whereas females with the unfavorable genotype were as likely as men with the favorable and unfavorable genotype to clear HCV. Chronic Hepatitis B infection and absence of HIV coinfection around HCV seroconversion also favor HCV clearance.ConclusionsThis study shows that co-infection with HIV and HBV and genetic variation in the IL28B region play an important role in spontaneous clearance of HCV. Our findings suggest a possible synergistic interaction between female sex and IL28B in spontaneous clearance of HCV.