Prevalence of Syphilis in Pregnant Women Living With Human Immunodeficiency Virus (HIV) From South Africa Using a Molecular-Based Assay.

BACKGROUND: Syphilis is one of the most common sexually transmitted infections (STIs), and it remains a significant public health concern, particularly in low-resource settings including sub-Saharan Africa. There are limited data on the prevalence of syphilis among pregnant women living with HIV in South Africa. This study determined the prevalence of syphilis infection in pregnant women living with HIV by the polymerase chain reaction (PCR). METHODS: This was a cross-sectional study that included 385 pregnant women living with HIV recruited from the antenatal clinic at the King Edward VIII Hospital in Durban, South Africa between October 2020 and April 2021. Treponema pallidum was detected using the Applied BiosystemsTM TaqMan® Assays from stored DNA samples extracted from vaginal swabs. RESULTS: The prevalence of syphilis was 5.2% (20/385). The overall median (Q1-Q3) age of the women was 30.0 years (25.0-36.0). Of the women who tested positive for syphilis, 60.0% had reported STI symptoms (p = 0.030) and of those, 65.0% did not perceive themselves at risk of contracting STIs (p = 0.019). Women who reported having STI symptoms were more likely to test positive for syphilis when compared to women who reported not having any STI symptoms (OR: 2.810; 95% CI 1.119-7.052; p = 0.028). Women who perceived themselves as being at risk of contracting STIs were less likely to test positive for syphilis when compared to women who did not perceive themselves at risk of contracting STIs (OR: 0.328; 95% CI 0.128-0.842; p = 0.020). CONCLUSION: The study has indicated syphilis is prevalent among pregnant women living with HIV in Durban, South Africa however STI risk perception is low. Educational programs on STIs are essential among pregnant women attending antenatal care clinics in Durban.

Prevalence of Chlamydia trachomatis infection in pregnant women from Durban, South Africa.

INTRODUCTION: The Sub-Saharan African region has some of the world's highest prevalence of sexually transmitted infections (STIs). These infections are considered a major public health concern. Previous studies on the prevalence of C. trachomatis infection in Sub-Saharan Africa have reported rates ranging from 3.1% to 36.8% in pregnant women. This study investigated the prevalence and risk factors associated with C. trachomatis infection in pregnant women. METHODS: This study included 735 stored clinical samples that were collected from pregnant women attending the antenatal clinic at King Edward VIII Hospital in Durban from 2018 -2021. C. trachomatis was detected using the Applied BiosystemsTM TaqMan® Assays from stored DNA samples. RESULTS: A total of 81/735 (11%) samples tested positive for C. trachomatis infection. The overall median (Q1-Q3) age of the women was 29.0 years (24.0-35.0). The majority of the women who tested positive for C. trachomatis were younger, median (Q1-Q3) age 26.0 years (23.0-32.0) vs 30.0 years (25.0-35.0) for the negative women (p < .001). Of the positive women, 96.3% were unmarried (p=0.014). Older women were less likely to test positive for C. trachomatis infection (OR: 0.93; 95% CI 0.89-0.96 p = .001). Women who were married (OR: 0.25; 95% CI 0.06-0.70; p = .022), co-habiting with their partner (OR: 0.60; 95% CI 0.36-0.98; p = .048) and started having sex at older than 15 years (OR:0.26; 95% CI 0.09-0.87; p = .018) were less likely to test positive for C. trachomatis compared to their counterparts. CONCLUSION: This study showed that behavioural and clinical factors were associated with prevalent infections. In order to reduce prevalent infections, stronger risk reduction counselling messages need to be provided from the educational and public health sector.

Detection of metronidazole resistance in Trichomonas vaginalis using uncultured vaginal swabs.

Trichomonas vaginalis (T. vaginalis) is the most prevalent sexually transmitted infection (STI) globally. Metronidazole is the drug of choice for treating T. vaginalis infections although metronidazole-resistant T. vaginalis has been reported in clinical isolates. The purpose of this study was to determine the presence of mutations in nitroreductase genes associated with metronidazole resistance in vaginal swabs testing positive for T. vaginalis. This study included 385 human immunodeficiency virus (HIV)-positive pregnant women. Vaginal swabs were collected from consenting pregnant women and used for the detection of T. vaginalis using the TaqMan assay. From the vaginal swabs, nitroreductase genes ntr4 and ntr6 containing mutations associated with metronidazole resistance were amplified using a quantitative polymerase chain reaction (PCR) assay. To validate the PCR assay, T. vaginalis cultured isolates with known metronidazole resistance profiles were used as controls in the mutation detection assays. The prevalence of T. vaginalis in the study population was 12.2% (47/385). Mutations associated with resistance to metronidazole were detected in more than 40% of the samples tested, i.e. 21/47 (45%) and 24/47 (51%) for ntr4 and ntr6, respectively. A total of 19 samples (40%) carried mutations for both ntr4 and ntr6 genes associated with metronidazole resistance. The validation assays showed a positive correlation between phenotypic and genotypic resistance profiles. This study found a high prevalence of mutations associated with metronidazole resistance. This is concerning since metronidazole is currently used in the syndromic management of STIs in South Africa. Molecular-based assays for monitoring metronidazole resistance profiles using nitroreductase genes may serve as a feasible method for antimicrobial surveillance studies for T. vaginalis.

A review on Trichomonas vaginalis infections in women from Africa.

BACKGROUND: Trichomoniasis is the most common sexually transmitted infection (STI) with an estimated annual incidence of 276.4 million cases globally and about 30 million cases in sub-Saharan Africa. Trichomoniasis has been found to be associated with various health complications including pelvic inflammatory disease (PID), significant pregnancy complications, cervical cancer, prostatitis, infertility and the acquisition of human immunodeficiency virus (HIV). AIM: Despite being a highly prevalent infection in the African continent, there is no review article published that solely focusses on Trichomonas vaginalis (T. vaginalis) infections in women from Africa. This review aims to fill this gap in the literature. METHOD: An electronic search of online databases was used to identify and extract relevant research articles related to the epidemiology, health complications and treatment associated with T. vaginalis in women from Africa. RESULTS: Within the African continent, South Africa has reported the highest prevalence rate for this infection. A combination of sociodemographic, behavioural and biological factors has been shown to be associated with infection. Trichomonas vaginalis infection is associated with the acquisition of HIV, cervical cancer and PIDs in various female populations across the continent. Emerging patterns of resistance to metronidazole have been reported in women from South Africa. Currently, there is no effective vaccine against this pathogen despite efforts at vaccine development. CONCLUSION: Based on the high prevalence and health consequences associated with T. vaginalis, there is a need for improved screening programmes that will lead to early diagnosis, detection of asymptomatic infections and effective treatment regimens.

Distribution of genotypes in relation to metronidazole susceptibility patterns in Trichomonas vaginalis isolated from South African pregnant women.

Reports on metronidazole resistance of Trichomonas vaginalis strains have been on the increase. This study investigated the in vitro metronidazole resistance patterns in T. vaginalis isolates obtained from South African pregnant women and the genotypes of these isolates. This study included 362 pregnant women recruited from a hospital in Durban, South Africa. The women provided self-collected vaginal swabs for the detection of T. vaginalis by culture in Diamonds media. Cultured isolates were then subjected to anaerobic susceptibility assays to metronidazole. For the genotyping assays, the actin gene was digested by HindII, MseI, and RsaI. The banding patterns obtained after digestion was used to determine the genotypes. A total of 21/362 (5.8%) pregnant women tested positive for T. vaginalis infection. Of the 21 T. vaginalis isolates tested for metronidazole susceptibility, 9.5% (2/21) had a minimum inhibitory concentration (MIC) of 4 µg/ml (resistant), 38.1% (8/21) had a MIC of 2 µg/ml (intermediate), and 52.4% (11/21) had a MIC ≤ 1 µg/ml (susceptible). The dominant genotype that was identified across the isolates was genotype G. There was no correlation between genotype harboured and metronidazole susceptibility patterns. In this study, resistance to metronidazole was observed in clinical isolates of T. vaginalis. This study did not find a correlation between genotype harboured and metronidazole susceptibility patterns. Despite the lack of association, our study provides data on an area of research that is currently lacking in our setting.

Lack of association between Mycoplasma hominis and Trichomonas vaginalis symbiosis in relation to metronidazole resistance.

Resistance mechanisms of Trichomonas vaginalis to metronidazole are still not well understood. It has been shown that Mycoplasma hominis has the ability to establish an endosymbiotic relationship with T. vaginalis. This study investigated the association between T. vaginalis and M. hominis symbiosis in relation to metronidazole resistance. This study included 362 pregnant women from the King Edward VIII hospital in South Africa. The women provided self-collected vaginal swabs for the diagnosis of T. vaginalis by culture. Metronidazole susceptibility using the broth-microdilution assay was performed. Detection of the 16S rRNA from M. hominis using T. vaginalis genomic DNA as the template was performed. All statistical analysis was conducted in R statistical computing software. A total of 21 culture positive isolates were obtained resulting in a prevalence of 5.8% for T. vaginalis in the study population. Under anaerobic incubation, 52.4% (11/21) of the isolates were susceptible to metronidazole (MIC ≤ 1 µg/ml). Intermediate resistance (MIC of 2 µg/ml) and full resistance (4 µg/ml) was observed in 38.1% (8/21) and 9.5% (2/21) of the isolates, respectively. The majority of the isolates 95% (19/20) were susceptible to metronidazole under aerobic conditions. Only one isolate had a MIC of 50 µg/ml. M. hominis was shown to be present in 85.7% (18/21) of the T. vaginalis isolates. However, there was no significant association between metronidazole susceptibility and T. vaginalis-M. hominis symbiosis. This study provides evidence of emerging metronidazole resistance in T. vaginalis. However, these resistance profiles were not associated with M. hominis symbiosis.

Genotypic Variation in Trichomonas vaginalis Detected in South African Pregnant Women.

Background: Trichomonas vaginalis is the causative agent of trichomoniasis. The genetic characterisation of T. vaginalis isolates reveals significant genetic diversity in this organism. Data on the prevalence of different genotypes of T. vaginalis in South African populations is lacking. This study investigated the diversity of T. vaginalis in a pregnant population in South Africa. Methods: In this study, 362 pregnant women from the King Edward VIII Hospital in Durban, South Africa, provided vaginal swabs to be tested for the presence of T. vaginalis. T. vaginalis was detected using the TaqMan assay using commercially available primers and probes specific for this protozoan (Pr04646256_s1). The actin gene from T. vaginalis was amplified with gene-specific primers. The actin amplicons were digested with HindII, MseI, and RsaI, and the banding patterns were compared across the three digests for assignment of genotypes. Phylogenetic analysis was conducted using MEGA. Results: The prevalence of T. vaginalis in the study population was 12.9% (47/362). Genotype G was the most frequent genotype in our study population. Genotypes H and I were detected in one sample each. According to the multiple sequence alignments and phylogenetic analysis, a level of diversity was observed across and within genotypes. Four different single-nucleotide changes in the actin gene were detected. Sample TV358 (H genotype) contained a single amino acid substitution from glutamine to lysine. Sample TV184 (G genotype) contained a single amino acid substitution from glutamic acid to arginine. Sample TV357 (G genotype) contained two amino acid substitutions, arginine to leucine and glycine to aspartic acid. Conclusion: Three different genotypes were observed in the pregnant population. Diversity was observed across and within genotypes. The observed diversity can be challenging for future vaccine design and development of antigen-based rapid diagnostic tests for trichomoniasis.