Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project

BACKGROUND

Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil.

METHODS

A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included.

RESULTS

A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86).

CONCLUSION

This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

Lactobacillus gasseri and Gardnerella vaginalis produce extracellular vesicles that contribute to the function of the vaginal microbiome and modulate host-Trichomonas vaginalis interactions

Trichomonas vaginalis is an extracellular protozoan parasite of the human urogenital tract, responsible for a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a dysbiotic microbiome that is characterised by the depletion of host-protective commensals such as Lactobacillus gasseri, and the flourishing of a bacterial consortium that is comparable to the one seen for bacterial vaginosis, including the founder species Gardnerella vaginalis. These two vaginal bacteria are known to have opposite effects on T. vaginalis pathogenicity. Studies on extracellular vesicles (EVs) have been focused on the direction of a microbial producer (commensal or pathogen) to a host recipient, and largely in the context of the gut microbiome. Here, taking advantage of the simplicity of the human cervicovaginal microbiome, we determined the molecular cargo of EVs produced by L. gasseri and G. vaginalis and examined how these vesicles modulate the interaction of T. vaginalis and host cells. We show that these EVs carry a specific cargo of proteins, which functions can be attributed to the opposite roles that these bacteria play in the vaginal biome. Furthermore, these bacterial EVs are delivered to host and protozoan cells, modulating host-pathogen interactions in a way that mimics the opposite effects that these bacteria have on T. vaginalis pathogenicity. This is the first study to describe side-by-side the protein composition of EVs produced by two bacteria belonging to the opposite spectrum of a microbiome and to demonstrate that these vesicles modulate the pathogenicity of a protozoan parasite. Such as in trichomoniasis, infections and dysbiosis co-occur frequently resulting in significant co-morbidities. Therefore, studies like this provide the knowledge for the development of antimicrobial therapies that aim to clear the infection while restoring a healthy microbiome.

Construction a novel detection method for Trichomonas vaginalis based on recombinant enzyme polymerase amplification targeting the Actin gene

Trichomoniasis is a common and curable sexually transmitted disease worldwide. The rapid, convenient, and accurate diagnosis of trichomoniasis is an important link in the prevention and treatment of the disease. The current detection methods of Trichomonas vaginalis are mainly wet mount microscopy, culture, nested PCR, and loop-mediated isothermal amplification. However, these detection methods have some shortcomings. In this study, a recombinant enzyme polymerase amplification (RPA) assay had been conducted to detect T. vaginalis. The target gene and the corresponding primers were screened, and the reaction system and conditions were optimized in the assay of RPA. The sensitivity and specificity of this detection method were analyzed. The detection efficiency of wet mount microscopy, culture, nested PCR, and RPA was compared by testing 53 clinical samples from vaginal secretions. By screening, the actin gene of T. vaginalis could be used as a target gene for RPA detection of T. vaginalis, and the optimum reaction condition to amplify the actin gene by RPA was at 39°C for 30 min. The detection limit of T. vaginalis DNA using RPA was 1 pg, corresponding to a sensitivity of approximately five trophozoites. The RPA assay demonstrated high specificity for T. vaginalis, and there was no cross-reactivity with Giardia lamblia, Escherichia coli, Lactobacillus, Toxoplasma gondii, Staphylococcus aureus, and Candida albicans. Of the 53 clinical samples, the positive rates of T. vaginalis detected by wet mount microscopy, culture, nested PCR and RPA were 50.9 4% (27/53), 71.7% (38/53), 71.7% (38/53), and 69.81% (37/53), respectively. Compared with culture which was used as the gold standard for diagnosing trichomoniasis, testing clinical samples by wet mount microscopy showed 71.05% sensitivity, 100% specificity, and moderate diagnostic agreement with the culture (K = 0.581, Z = 4.661, p < 0.001). The nested PCR showed 100% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 1, Z = 7.28, p < 0.001), while RPA displayed 97.37% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 0.954, Z = 6.956, p < 0.001). At the present study, rapid amplification of actin gene by RPA could be used as a tool for detection of T. vaginalis. The detection method of RPA was more sensitive than wet mount microscopy and displayed excellent specificity. Moreover, RPA amplification of actin gene did not require a PCR instrument and the amplification time was shorter than that of ordinary PCR. Therefore, the RPA assay was proposed in this study as a point-of-care examination and a diagnostic method of T. vaginalis infection, which exhibited the potential value in the treatment and prevention of trichomoniasis.

Demographic and behavioural risk factors associated with Trichomonas vaginalis among South African HIV-positive men with genital ulcer disease: a cross-sectional study

OBJECTIVES

Demographic and risky sexual behaviours may increase the risk for Trichomonas vaginalis (TV) infection and, thus, enhance HIV transmission to uninfected partners. We assessed the demographic and behavioural risk factors associated with TV among South African HIV-positive men with genital ulcer disease.

METHODS

We conducted a cross-sectional study with data from a randomised controlled trial conducted by the Centers for Disease Control and Prevention and the London School of Hygiene and Tropical Medicine. The data were obtained from three primary healthcare clinics in South Africa. At baseline (n=387), participants reported on demographics, sexual behaviour, history of sexually transmitted infections and clinical ulcers. The outcome TV was measured using real-time multiplex PCR assays and a Rotor-gene 3000 platform from the first and past urine samples of all participants. Logistic regression model estimated ORs and 95% CIs adjusted for demographics, sexual risk behaviours and ulcer conditions.

RESULTS

An estimated 11.4% of TV was detected among the men. The odds of TV infection were significantly associated with high blister counts (OR 4.0, 95% CI 1.6 to 28, p=0.01), ulcer pain (OR 0.4, 95% CI 0.2 to 0.7, p=0.003), number of days with ulcers (OR 0.4, 95% CI 0.2 to 0.8, p=0.006), sought treatment before coming into clinics (OR 0.07, 95% CI 0.002 to 0.7, p=0.005) and being unqualified worker (OR 2.5, 95% CI 0.9 to 6.7 p=0.05). Multivariate analyses revealed that increased days with ulcers (OR 0.1, 95% CI 0.04 to 0.5, p=0.002) and ulcer pain intensity (OR 0.08, 95% CI 0.007 to 1.1, p=0.05) remained significantly associated with decreased odds of TV infection. Men from the Sotho ethnic group were eight times more likely to have TV infection (OR 8.6, 95% CI 1.3 to 55.7, p<0.02) than men from the other ethnic groups.

CONCLUSION

HIV-positive men with severe ulceration should be screened and treated for TV to minimise HIV transmission to uninfected partners.