Prevalence and Risk Factors of Trichomonas vaginalis Among Female Sexual Workers in Nairobi, Kenya.

BACKGROUND: Trichomonas vaginalis (TV) is the most common curable sexually transmitted infection (STI) worldwide. Trichomonas vaginalis infection is associated with an increased risk of pelvic inflammatory disease, human immunodeficiency virus transmission, and preterm birth in women. Data on the prevalence and risk factors for TV infection in sub-Saharan African countries remain scarce. METHODS: A total of 350 Kenyan female sex workers, aged 18 to 50 years, participated in a 2-year longitudinal study of the acquisition of STIs, including TV infection. Every 3 months, cervical and vaginal brush samples were collected for STI testing. At baseline, a sociodemographic and behavior questionnaire was administered. Testing for TV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae, Mycoplasma genitalium, and high-risk human papillomavirus was performed using APTIMA assays. RESULTS: The TV baseline prevalence was 9.2% (95% confidence interval [95% CI], 6.3-12.7%) and 2-year cumulative TV incidence was 8.1 per 1000 person months (6.9-9.3). Risk factors for higher TV prevalence at baseline were CT infection (adjusted prevalence ratio [PR], 8.53; 95% CI, 3.35-21.71), human immunodeficiency virus seropositivity (PR, 3.01; 95% CI, 1.45, 6.24) and greater than 4 years of sex work (PR, 2.66; 95% CI, 1.07-6.60). Risk factors for elevated 2-year TV incidence were CT (hazard ratio [HR], 4.28; 95% CI, 1.36-13.50), high-risk human papillomavirus infection (HR, 1.91; 95% CI, 1.06-3.45) and history of smoking (HR, 2.66; 95% CI, 1.24-5.73). DISCUSSION: CT infection was positively associated with both prevalent and 2-year incident TV infections.

Prospective Evaluation of Cervicovaginal Self- and Cervical Physician Collection for the Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium Infections.

BACKGROUND: This study aimed to examine the agreement between sexually transmitted infection (STI) screening using self-collected specimens and physician-collected specimens, and to investigate the acceptability of self-collection for screening in an 18-month study of female sex workers in a high-risk, low-resource setting. METHODS: A total of 350 female sex workers in Nairobi, Kenya, participated in a prospective study from 2009 to 2011. Women self-collected a cervicovaginal specimen. Next, a physician conducted a pelvic examination to obtain a cervical specimen. Physician- and self-collected specimens were tested for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium (MG) using Aptima nucleic acid amplification assays (Hologic). Specimens were collected at 3-month intervals over 18-month follow-up. κ Statistics measured agreement of positivity between self-collection and physician collection. RESULTS: Baseline STI prevalence was 2.9% for N. gonorrhoeae, 5.2% for C. trachomatis, 9.2% for T. vaginalis, and 20.1% for MG in self-collected samples, and 2.3%, 3.7%, 7.2%, and 12.9%, respectively, in physician-collected samples. κ Agreement was consistently strong (range, 0.66-1.00) for all STIs over the 18-month study period, except for MG, which had moderate agreement (range, 0.50-0.75). Most participants found self-collection easy (94%) and comfortable (89%) at baseline, with responses becoming modestly more favorable over time. CONCLUSIONS: Self-collected specimen screening results showed strong agreement to clinical-collected specimens, except for MG, which was consistently detected more commonly in self-collected than in physician-collected specimens. Acceptability of the self-collection procedure was high at baseline and increased modestly over time. In high-risk, low-resource settings, STI screening with self-collected specimens provides a reliable and acceptable alternative to screening with physician-collected specimens.

Epstein-Barr Virus, High-Risk Human Papillomavirus and Abnormal Cervical Cytology in a Prospective Cohort of African Female Sex Workers.

BACKGROUND: High-oncogenic-risk human papillomavirus (hrHPV) is necessary, although insufficient, to promote cervical cancer. Like HPV, Epstein-Barr virus (EBV) is a common pathogen with the capacity to promote epithelial neoplasms. We examined the association between cervical EBV, hrHPV, and cytology in female sex workers in Nairobi, Kenya. METHODS: Women (n = 332) with known cervical cytology and hrHPV mRNA results were evaluated for cervical EBV DNA by conventional polymerase chain reaction. Prevalence ratios (PRs) were calculated to assess the relationships between EBV, hrHPV, and cervical cytology. Prospective analyses used risk ratios and time-to-event analyses to determine the association of EBV with hrHPV clearance and with abnormal cytology outcomes. RESULTS: Baseline prevalence of hrHPV and EBV was 29% and 19%, respectively. Higher EBV prevalence was found among women with older age, HIV, hrHPV, abnormal cytology, Mycoplasma genitalium infection, smoking habits, younger age at sexual debut, and less frequent condom use. At baseline, women with EBV had a higher prevalence of hrHPV infection than did EBV-negative women (52% vs. 24%; HIV-adjusted PR [95% confidence interval], 1.8 [1.3-2.6]). Epstein-Barr virus-positive women had a higher prevalence than did EBV-negative women of high-grade precancer (15% vs. 2%) and abnormal cytology (37% vs. 15%), although HIV- and hrHPV-adjusted associations were not significant (high-grade precancer: PR, 2.0 [0.7-5.9]; abnormal cytology: PR, 1.4 [0.9-2.2]). In prospective analyses, a marginal association was observed between baseline EBV detection and delayed hrHPV clearance. CONCLUSIONS: Our data support a possible role for EBV as a high-risk marker or cofactor for HPV-mediated cervical cancer development.

Clinical characteristics associated with Mycoplasma genitalium among female sex workers in Nairobi, Kenya.

The prevalence of Mycoplasma genitalium is high in vulnerable populations of women in low-resource settings. However, the epidemiology of infection in these populations is not well established. To determine the prevalence of Mycoplasma genitalium and its association with cervical cytology and other correlates, we recruited 350 female sex workers (FSW) who were 18 to 50 years old in Nairobi, Kenya, for a cross-sectional study. A questionnaire was administered at baseline to obtain information on sociodemographics and sexual behaviors. Women underwent a pelvic exam, during which a physician collected cervical-exfoliation samples for conventional cytology and sexually transmitted infection (STI) testing. Samples were tested for M. genitalium and other STI organisms (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis) and the E6/E7 mRNA of human papillomavirus (HPV) by Aptima nucleic amplification assays. The prevalence of M. genitalium was 12.9%. FSW who engaged in sexual intercourse during menses were less likely to have M. genitalium infection than those who did not (odds ratio [OR], 0.3; 95% confidence interval [95% CI], 0.1, 0.9). M. genitalium was also less prevalent among FSW who had worked in prostitution for >5 years (6.2%) than among those who had worked for <3 years (17.6%) (OR, 0.3; 95% CI, 0.1, 0.8). FSW who reported more frequent condom use were more likely to be infected with M. genitalium than those who reported less frequent use (OR, 3.8; 95% CI, 1.2, 11.6). These correlates differ from those found in M. genitalium studies conducted with FSW from West Africa and China. Further longitudinal analyses assessing associations with persistent M. genitalium infection are needed.

High-risk human papillomavirus messenger RNA testing in physician- and self-collected specimens for cervical lesion detection in high-risk women, Kenya.

BACKGROUND: Little is known about the performance of physician-versus self-collected specimens for high-risk human papillomavirus (hrHPV) messenger RNA (mRNA) testing or risk factors for hrHPV mRNA positivity in physician- versus self-collected specimens. We compared the performance of hrHPV mRNA testing of physician- and self-collected specimens for detecting cytological high-grade squamous intraepithelial lesions or more severe (≥HSIL) and examined risk factors for hrHPV mRNA positivity in female sex workers in Nairobi. METHODS: From 2009 to 2011, 344 female sex workers participated in this cross-sectional study. Women self-collected a cervicovaginal specimen. A physician conducted a pelvic examination to obtain a cervical specimen. Physician- and self-collected specimens were tested for hrHPV mRNA and sexually transmitted infections using APTIMA nucleic acid amplification assays (Hologic/Gen-Probe Incorporated, San Diego, CA). Cervical cytology was conducted using physician-collected specimens and classified according to the Bethesda criteria. RESULTS: Overall hrHPV mRNA prevalence was similar in physician- and self-collected specimens (30% vs. 29%). Prevalence of ≥HSIL was 4% (n = 15). Overall sensitivity of hrHPV testing for detecting ≥HSIL was similar in physician-collected (86%; 95% CI, 62%-98%; 13 cases detected) and self-collected specimens (79%; 95% CI, 55%-95%; 12 cases detected). Overall specificity of hrHPV mRNA for ≥HSIL was similar in both physician-collected (73%; 95% CI, 68%-79%) and self-collected (75%; 95% CI, 70%-79%) specimens. High-risk HPV mRNA positivity in both physician- and self-collected specimens seemed higher in women who were younger (<30 years), had Trichomonas vaginalis or Mycoplasma genitalium infections, or had more than 8 years of educational attainment. CONCLUSIONS: Self-collected specimens for hrHPV mRNA testing seemed to have similar sensitivity and specificity as physician-collected specimens for the detection of ≥HSIL among high-risk women.

High-risk HPV-RNA screening of physician- and self-collected specimens for detection of cervical lesions among female sex workers in Nairobi, Kenya.

OBJECTIVE: To compare accuracy of detecting high-grade cervical lesions (squamous intraepithelial lesions or greater, HSIL+) by high-risk HPV messenger RNA (hrHPV-RNA) testing between physician- and self-collected specimens, and by conventional cytology. METHODS: The present prospective longitudinal study included data collected among female sex workers (FSWs) in Nairobi, Kenya, between December 2, 2009, and February 15, 2013. Participants self-collected cervico-vaginal specimens for hrHPV-RNA testing, and a physician collected cervical specimens for hrHPV-RNA testing and conventional cytology. hrHPV-RNA testing was conducted every 3 months, and conventional cytology every 6 months. RESULTS: Overall, 350 FSWs aged 18-50 years participated. hrHPV-RNA prevalence decreased slightly from 29.9% (103/344) at baseline to 24.3% (53/218) at 24 months for physician-collected, and 28.5% (98/344) to 24.3% (53/218) for self-collected specimens. Agreement between the sampling methods appeared to increase over time (baseline κ 0.55, 95% confidence interval [CI] 0.45-0.65; 24 months κ 0.83, 95% CI 0.74-0.91). Among 21 patients with HSIL+ over 24 months, 18 (86%) and 17 (81%) had hrHPV-RNA-positive results at baseline in physician- and self-collected specimens, respectively; and 20 (95%) had baseline hrHPV-RNA-positive results or cytology anomalies. CONCLUSION: Overall agreement between physician- and self-collected hrHPV-RNA results was moderate and appeared to increase over time. Baseline physician- and self-collected hrHPV-RNA tests were similarly strong indicators of cumulative HSIL+ over 24 months.

Increased levels of inflammatory cytokines in the female reproductive tract are associated with altered expression of proteases, mucosal barrier proteins, and an influx of HIV-susceptible target cells.

Elevated inflammatory cytokines (EMCs) at mucosal surfaces have been associated with HIV susceptibility, but the underlying mechanisms remain unclear. We characterized the soluble mucosal proteome associated with elevated cytokine expression in the female reproductive tract. A scoring system was devised based on the elevation (upper quartile) of at least three of seven inflammatory cytokines in cervicovaginal lavage. Using this score, HIV-uninfected Kenyan women were classified as either having EMC (n=28) or not (n=68). Of 455 proteins quantified in proteomic analyses, 53 were associated with EMC (5% false discovery rate threshold). EMCs were associated with proteases, cell motility, and actin cytoskeletal pathways, whereas protease inhibitor, epidermal cell differentiation, and cornified envelope pathways were decreased. Multivariate analysis identified an optimal signature of 16 proteins that distinguished the EMC group with 88% accuracy. Three proteins in this signature were neutrophil-associated proteases that correlated with many cytokines, especially GM-CSF (granulocyte-macrophage colony-stimulating factor), IL-1ß (interleukin-1ß), MIP-3α (macrophage inflammatory protein-3α), IL-17, and IL-8. Gene set enrichment analyses implicated activated immune cells; we verified experimentally that EMC women had an increased frequency of endocervical CD4(+) T cells. These data reveal strong linkages between mucosal cytokines, barrier function, proteases, and immune cell movement, and propose these as potential mechanisms that increase risk of HIV acquisition.

Early HIV-1 infection is associated with reduced frequencies of cervical Th17 cells.

BACKGROUND: The hallmark of HIV infection is progressive but variable rates of systemic and mucosal CD4 depletion, leading to immunodeficiency. The impact of early HIV infection on cervical CD4 T-cell populations in humans remains poorly described. METHODS: We analyzed cytobrush-derived immune cells by flow cytometry and cytokines in cervicovaginal lavage from participants in early HIV (<6 months postinfection), chronic HIV, and HIV-uninfected controls. RESULTS: CD4:CD8 ratios declined rapidly in both the cervix and the blood following HIV infection. In contrast, absolute cervical CD4 T-cell counts in early HIV were comparable to HIV-uninfected participants, declining only in chronic infection. Early HIV infection was associated with increases in RANTES and MIP3a in cervicovaginal fluids. Concurrently, slight increases in activated cells (CD38HLA-DR) and higher levels of CTLA4 expression on Tregs in the cervix were observed. Although study groups did not differ with respect to levels of CCR5, integrin B7, or CD69, the frequencies of Th17 cells (defined as CCR6CCR10) was reduced by >10-fold in early HIV infection and Th1 cells (defined as CCR6CXCR3) were reduced by >2-fold. Although CCR6CCR10 cells did not differ in HIV receptor expression, these cells produced higher levels of interferon gamma and interleukin 17. CONCLUSIONS: These data support the model of initial CD4 T-cell depletion followed by overall T-cell influx in response to infection and concomitant increases in immune activation, inflammation, and regulatory markers. These data are among the earliest characterization of the cellular milieu in the female genital tract following male-to-female HIV transmission.