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Dive into the research topics where Avril Swarts is active.

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Featured researches published by Avril Swarts.


PLOS ONE | 2013

Validation of Cervical Cancer Screening Methods in HIV Positive Women from Johannesburg South Africa

Cynthia Firnhaber; Nomtha Mayisela; Lu Mao; Sophie Williams; Avril Swarts; Mark Faesen; Simon Levin; Pam Michelow; Tanvier Omar; Michael G. Hudgens; Anna-Lise Williamson; Bruce Allan; David A. Lewis; Jennifer S. Smith

Background HIV-infected women are at increased risk for developing cervical cancer. Women living in resource-limited countries are especially at risk due to poor access to cervical cancer screening and treatment. We evaluated three cervical cancer screening methods to detect cervical intraepithelial neoplasia grade 2 and above (CIN 2+) in HIV-infected women in South Africa; Pap smear, visual inspection with 5% acetic acid (VIA) and human papillomavirus detection (HPV). Methods HIV-infected women aged 18–65 were recruited in Johannesburg. A cross-sectional study evaluating three screening methods for the detection of the histologically-defined gold standard CIN-2 + was performed. Women were screened for cervical abnormalities with the Digene HC2 assay (HPV), Pap smear and VIA. VIA was performed by clinic nurses, digital photographs taken and then later reviewed by specialist physicians. The sensitivity, specificity and predictive valves for CIN-2 + were calculated using maximum likelihood estimators. Results 1,202 HIV-infected women participated, with a median age of 38 years and CD4 counts of 394 cells/mm3. One third of women had a high grade lesion on cytology. VIA and HPV were positive in 45% and 61% of women respectively. Estimated sensitivity/specificity for HPV, Pap smear and VIA for CIN 2+ was 92%/51.4%, 75.8%/83.4% and 65.4/68.5% (nurse reading), respectively. Sensitivities were similar, and specificities appeared significantly lower for the HPV test, cytology and VIA among women with CD4 counts ≤200 cells/mm3 as compared to CD4 counts >350 cells/mm3. Conclusions Although HPV was the most sensitive screening method for detecting CIN 2+, it was less specific than conventional cytology and VIA with digital imaging review. Screening programs may need to be individualized in context of the resources and capacity in each area.


Sexually Transmitted Diseases | 2012

Effect of trichomoniasis therapy on genital HIV viral burden among African women.

Brenna L. Anderson; Cynthia Firnhaber; Tao Liu; Avril Swarts; Maureen Siminya; Jessica Ingersoll; Angela M. Caliendo; Susan Cu-Uvin

Background: Our objective was to test the hypothesis that treatment for trichomoniasis among HIV-infected women not taking antiretrovirals in South Africa would be associated with decreased HIV genital shedding. Methods: HIV-infected women presenting for routine HIV care were screened for trichomoniasis using self-collected vaginal swabs with a rapid point-of-care immunochromatographic antigen test. Women testing positive were offered enrollment into a prospective cohort study, if they had documented HIV infection, were aged 18 to 50 years, and were not receiving antiretroviral therapy. Recent use of postexposure prophylaxis or antibiotic therapy, active genital ulcers, or systemic illness were exclusion criteria. Cervical swabs were collected for gonococcal and chlamydial testing, and those testing positive were excluded. Women were treated with directly observed oral therapy with 2 g of oral metronidazole. A follow-up visit was scheduled 1 month after therapy, and partner letters were provided. Paired cervical wicks and plasma were collected for viral load measurement. Results: In all, 557 women were screened. Sixty tested positive for trichomoniasis, 10 subsequently met exclusion criteria, and 4 were lost to follow-up. Of 46 women evaluated at follow-up, 37 (80.4%) were cured. Plasma viral load was not significantly different after therapy (P = 0.93). Genital tract viral load decreased by 0.5 log10 (P < 0.01). The mean genital tract viral load (log10) decreased from 4.66 (<3.52–6.46) to 4.18 (<3.52–6.48) (P < 0.01) after therapy. Conclusions: Screening and treatment of vaginal trichomoniasis decrease genital shedding of HIV among South African women not receiving antiretrovirals at 1 month after therapy.


Current Microbiology | 1998

Flow Cytometry Demonstrates Bacteriocin-Induced Injury to Listeria monocytogenes

Avril Swarts; John W. Hastings; Robert F. Roberts; Alexander von Holy

Abstract. Flow cytometry was used to study the effect of the bacteriocin leucocin B-TA11a on Listeria (L.) monocytogenes. Mixed proportions of dead and live control populations were analyzed by flow cytometry to determine detection limits of the Dead/Live Baclight Bacterial Viability KitTM. High correlations for flow cytometric detection of defined proportions of live or dead cells in mixtures between 10 and 100% of dead (r2 = 0.97) or live (r2 = 0.99) cells were obtained. However, mixtures containing less than 10% of either live or dead control cells gave correlations below 0.72. The growth of L. monocytogenes in the absence and presence of leucocin B-TA11a was analyzed by flow cytometry with Baclight, plate counts, and optical density measurements. Although leucocin B-TA11a initially inhibited listerial growth, the uptake of both Baclight dyes suggested that cells remained viable but became leaky, possibly indicating bacteriocin-induced pore formation in the target membranes.


Journal of Lower Genital Tract Disease | 2015

Evaluation of a cervicography-based program to ensure quality of visual inspection of the cervix in HIV-infected women in Johannesburg, South Africa

Cynthia Firnhaber; Lu Mao; Simon Levin; Mark Faesen; David A. Lewis; Bridgette Goeieman; Avril Swarts; Ntombiyenkosi Rakhombe; Pam Michelow; Sophie Williams; Jennifer S. Smith

Objective To determine whether a quality assurance (QA) program using digital cervicography improved the performance of a visual inspection with acetic acid (VIA) to detect cervical intraepithelial neoplasia grade 2 or worse (CIN 2+) in HIV-infected women in Johannesburg, South Africa. Materials and Methods Visual inspection with acetic acid was performed among HIV-infected women, aged 18 to 65 years, in Johannesburg, South Africa. Nurses received 2 weeks of training on the VIA procedure. The VIA interpretation was performed in real time. The VIA results were then photographed using a retail available digital camera. A gynecologist and medical officer reviewed the VIA digital images within 2 weeks of the procedure. Colposcopic biopsy was performed on all women with positive VIA and 25% negative VIA results. Sensitivity and specificity of VIA for the detection of CIN 2+ were compared between the nurses and physicians at the beginning and at the end of the study. Results Positive VIA results were found in 541 (45%) of the 1,202 participating women. The sensitivity of VIA to predict CIN 2+ was improved from 65% to 75% (p = .001) with the addition of digital cervicography and specialist review. There was no statistical difference in the sensitivity of the VIA readings when comparing the first 600 participants to the final 593 participants between the nurses (p = .613) and physicians (p = .624). Conclusions Quality assurance performed by specialists using digital cervicography improved the sensitivity of VIA. There was no difference in sensitivity in interpreting VIA between the beginning and the end of the study. Quality assurance should form a cornerstone of any VIA program to improve sensitivity in detecting CIN 2+ lesions.


Journal of Acquired Immune Deficiency Syndromes | 2017

Prevalence of Anal Hpv and Anal Dysplasia in Hiv-infected Women From Johannesburg, South Africa

Bridgette Goeieman; Cynthia Firnhaber; Eefje Jong; Pam Michelow; Avril Swarts; Anna-Lise Williamson; Bruce Allan; Jennifer S. Smith; Patricia Kegorilwe; Timothy Wilkin

Background: Anal cancer is a relatively common cancer among HIV-infected populations. There are limited data on the prevalence of anal high-risk human papillomavirus (HR-HPV) infection and anal dysplasia in HIV-infected women from resource-constrained settings. Methods: A cross-sectional study of HIV-infected women aged 25–65 years recruited from an HIV clinic in Johannesburg, South Africa. Cervical and anal swabs were taken for conventional cytology and HR-HPV testing. Women with abnormal anal cytology and 20% of women with negative cytology were seen for high-resolution anoscopy with biopsy of visible lesions. Results: Two hundred women were enrolled. Anal HR-HPV was found in 43%. The anal cytology results were negative in 51 (26%); 97 (49%) had low-grade squamous intraepithelial lesions (SIL), 32 (16%) had atypical squamous cells of unknown significance, and 19 (9.5%) had high-grade SIL or atypical squamous cells suggestive of high-grade SIL. On high-resolution anoscopy, 71 (36%) had atypia or low-grade SIL on anal histology and 17 (8.5%) had high-grade SIL. Overall, 31 (17.5%) had high-grade SIL present on anal cytology or histology. Abnormal cervical cytology was found in 70% and cervical HR-HPV in 41%. Conclusions: We found a significant burden of anal HR-HPV infection, abnormal anal cytology, and high-grade SIL in our cohort. This is the first study of the prevalence of anal dysplasia in HIV-infected women from sub-Saharan Africa. Additional studies are needed to define the epidemiology of these conditions, as well as the incidence of anal cancer, in this population.


American Journal of Obstetrics and Gynecology | 2017

A randomized clinical trial comparing cervical dysplasia treatment with cryotherapy vs loop electrosurgical excision procedure in HIV-seropositive women from Johannesburg, South Africa

Jennifer S. Smith; Busola Sanusi; Avril Swarts; Mark Faesen; Simon Levin; Bridgette Goeieman; Sibongile Ramotshela; Ntombiyenkosi Rakhombe; Anna L. Williamson; Pam Michelow; Tanvier Omar; Michael G. Hudgens; Cynthia Firnhaber

BACKGROUND: Mortality associated with cervical cancer is a public health concern for women, particularly in HIV–seropositive women in resource‐limited countries. HIV‐seropositive women are at a higher risk of high‐grade cervical precancer, which can eventually progress to invasive carcinoma as compared to HIV‐seronegative women. It is imperative to identify effective treatment methods for high‐grade cervical precursors among HIV‐seropositive women. OBJECTIVE: Randomized controlled trial data are needed comparing cryotherapy vs loop electrosurgical excision procedure treatment efficacy in HIV‐seropositive women. Our primary aim was to compare the difference in the efficacy of loop electrosurgical excision procedure vs cryotherapy for the treatment of high‐grade cervical intraepithelial neoplasia (grade ≥2) among HIV‐seropositive women by conducting a randomized clinical trial. STUDY DESIGN: HIV‐seropositive women (n = 166) aged 18‐65 years with histology‐proven cervical intraepithelial neoplasia grade ≥2 were randomized (1:1) to cryotherapy or loop electrosurgical excision procedure treatment at a government hospital in Johannesburg. Treatment efficacy was compared using 6‐ and 12‐month cumulative incidence posttreatment of: (1) cervical intraepithelial neoplasia grade ≥2; (2) secondary endpoints of histologic cervical intraepithelial neoplasia grade ≥3 and grade ≥1; and (3) high‐grade and low‐grade cervical cytology. The study was registered (ClinicalTrials.gov NCT01723956). RESULTS: From January 2010 through August 2014, 166 participants were randomized (86 loop electrosurgical excision procedure; 80 cryotherapy). Cumulative cervical intraepithelial neoplasia grade ≥2 incidence was higher for cryotherapy (24.3%; 95% confidence interval, 16.1–35.8) than loop electrosurgical excision procedure at 6 months (10.8%; 95% confidence interval, 5.7–19.8) (P = .02), although by 12 months, the difference was not significant (27.2%; 95% confidence interval, 18.5–38.9 vs 18.5%; 95% confidence interval, 11.6–28.8, P = .21). Cumulative cervical intraepithelial neoplasia grade ≥1 incidence for cryotherapy (89.2%; 95% confidence interval, 80.9–94.9) did not differ from loop electrosurgical excision procedure (78.3%; 95% confidence interval, 68.9–86.4) at 6 months (P = .06); cumulative cervical intraepithelial neoplasia grade ≥1 incidence by 12 months was higher for cryotherapy (98.5%; 95% confidence interval, 92.7–99.8) than loop electrosurgical excision procedure (89.8%; 95% confidence interval, 82.1–95.2) (P = .02). Cumulative high‐grade cytology incidence was higher for cryotherapy (41.9%) than loop electrosurgical excision procedure at 6 months (18.1%, P < .01) and 12 months (44.8% vs 19.4%, P < .001). Cumulative incidence of low‐grade cytology or greater in cryotherapy (90.5%) did not differ from loop electrosurgical excision procedure at 6 months (80.7%, P = .08); by 12 months, cumulative incidence of low‐grade cytology or greater was higher in cryotherapy (100%) than loop electrosurgical excision procedure (94.8%, P = .03). No serious adverse effects were recorded. CONCLUSION: Although rates of cumulative cervical intraepithelial neoplasia grade ≥2 were lower after loop electrosurgical excision procedure than cryotherapy treatment at 6 months, both treatments appeared effective in reducing cervical intraepithelial neoplasia grade ≥2 by >70% by 12 months. The difference in cumulative cervical intraepithelial neoplasia grade ≥2 incidence between the 2 treatment methods by 12 months was not statistically significant. Relatively high cervical intraepithelial neoplasia grade ≥2 recurrence rates, indicating treatment failure, were observed in both treatment arms by 12 months. A different treatment protocol should be considered to optimally treat cervical intraepithelial neoplasia grade ≥2 in HIV‐seropositive women.


Papillomavirus Research | 2016

Xpert human papillomavirus test is a promising cervical cancer screening test for HIV-seropositive women

Zizipho Z. A. Mbulawa; Timothy Wilkin; Bridgette Goeieman; Avril Swarts; Sophie Williams; Simon Levin; Mark Faesen; Jennifer S. Smith; Carla J. Chibwesha; Anna-Lise Williamson; Cynthia Firnhaber

This study investigated the performance of Cepheid Xpert human papillomavirus (HPV) assay in South African human immunodeficiency virus (HIV)-infected women and compared its performance with that of hybrid capture-2 (hc2). Methods: Stored cervical specimens from HIV-infected women that had previously been tested using hc2 were tested using Xpert. Results: The overall HR-HPV prevalence was found to be 62.0% (720/1161) by Xpert and 61.2% (711/1161) by hc2. 13.6% (158/1161) were HPV16 positive, 18.8% (218/1161) were HPV18/45, 37.3% (434/1161) were HPV31/33/35/52/58, 12.7% (147/1161) were HPV51/59 and 23.3% (270/1161) were HPV39/68/56/66. Overall agreement with hc2 was 90%; Cohen’s kappa was 0.78 (95% CI 0.74–0.82) indicating substantial agreement. Detection of HPV16, HPV18/45, and HPV31/33/35/52/58 were independently associated with cervical intraepithelial neoplasia (CIN)−2+ (P<0.0001 for each); while HPV51/59 and HPV39/68/56/66 were not. Women infected with HPV16, HPV18/45 or HPV31/33/35/52/58 were found to have significantly higher amounts of HPV DNA detected for those with CIN2+ compared to those without CIN2+, P<0.0001 for each. Xpert and hc2 were similarly sensitive (88.3% and 91.5%, respectively) and specific (48.4% and 51.0%) for CIN2+ and CIN3 (sensitivity: 95.8% and 97.9%; specificity: 41.4% and 42.8%). Conclusions: Xpert is a promising screening test in HIV-infected women that performs similarly to hc2.


PLOS ONE | 2016

Prospective One Year Follow Up of HIV Infected Women Screened for Cervical Cancer Using Visual Inspection with Acetic Acid, Cytology and Human Papillomavirus Testing in Johannesburg South Africa

Cynthia Firnhaber; Bridgette Goeieman; Mark Faesen; Simon Levin; Sophie Williams; Sibongile Rameotshela; Avril Swarts; Pam Michelow; Tanvier Omar; Anna-Lise Williamson; Bruce Allan; Kate Schnippel; Jennifer S. Smith

Background Cervical cancer is the most common cancer in Sub-Saharan Africa. There are little of HIV-infected women one-year after screening using visual inspection with acetic acid (VIA), HPV or cytology in sub-Saharan Africa. Methods HIV-infected women in Johannesburg South Africa were screened one year later by Pap smear, VIA and human papillomavirus (HPV) testing. Women qualified for the 12 month follow-up visit if they had a negative or cervical intra-epithelial neoplasia (CIN) 1 results at the baseline visit. Modified Poisson regression was used to analyse associations between patient baseline characteristics and progression. Results A total of 688 of 1,202 enrolled at baseline study who were CIN-2+ negative and qualified for a 12 month follow-up visit. Progression to CIN-2+ was higher in women with positive VIA results (12.6%; 24/191) than those VIA-negative (4.4%; 19/432). HPV-positive women at baseline were more likely to progress to CIN-2+ (12.3%; 36/293) than those HPV-negative (2.1%; 7/329). Cytology-positive women at baseline were more likely to progress to CIN-2+ (9.6%; 37/384) than cytology-negative women (2.5%; 6/237). Approximately 10% (10.4%; 39/376) of women with CIN 1 at baseline progressed to CIN 2+. Women who were VIA or HPV positive at baseline were more likely to progress aIRR 1.85, CI 95% (1.46 to 2.36), aIRR 1.41 CI 95% (1.14 to 1.75) respectively. Conclusion Progression to CIN-2+ in HIV-infected women is significant when measured by baseline positive VIA, HPV or Pap and yearly screening by any method should be considered in this population if possible.


American Journal of Clinical Pathology | 2017

Prevalence of Anal Human Papillomavirus (HPV) and Performance of Cepheid Xpert and Hybrid Capture 2 (hc2) HPV Assays in South African HIV-Infected Women

Zizipho Z. A. Mbulawa; Timothy Wilkin; Bridgette Goeieman; Eefje Jong; Pamela Michelow; Avril Swarts; Jennifer S. Smith; Patricia Kegorilwe; Cynthia Firnhaber; Anna-Lise Williamson

Objectives This study investigated anal high-risk HPV (HR-HPV) prevalence in HIV-infected women using the Cepheid Xpert HPV assay and compares its performance with that of Hybrid Capture-2 (hc2). Methods A total of 199 HIV-infected women were recruited from Helen Joseph Hospital, Johannesburg. Stored ThinPrep anal swabs that had previously been tested using hc2 were tested for HPV using Xpert. Results The HR-HPV prevalence by Xpert was 40.8% and similar to hc2 (41.8%) with overall agreement of 86.7%; Cohens kappa 0.73 (95% CI 0.63-0.82). High grade squamous intraepithelial lesions (HSIL) was associated with increasing number of multiple HPV infection (P < .001). Xpert and hc2 were similarly sensitive (77.4% and 77.4%, respectively) and specific (66.1% and 64.8% respectively) for HSIL detection. HPV16 (OR: 14.0, 95% CI: 3.9-48.0, P < .0001), HPV39/68/56/66 (OR: 4.1, 95% CI: 1.4-12, P = .01) and HPV51/59 (OR: 2.8, 95% CI: 1.1-7.6, P = .04) were independently associated with anal HSIL. Conclusions Xpert HPV typing is a promising anal screening test in HIV-infected women that performs similarly to hc2.


Journal of Acquired Immune Deficiency Syndromes | 2017

Cryotherapy Reduces Progression of Cervical Intraepithelial Neoplasia Grade 1 in South African HIV-Infected Women: A Randomized, Controlled Trial

Cynthia Firnhaber; Avril Swarts; Bridgette Goeieman; Ntombi Rakhombe; Masangu Mulongo; Anna-Lise Williamson; Pam Michelow; Sibongile Ramotshela; Mark Faesen; Simon Levin; Timothy Wilkin

Background: HIV-infected women are at an increased risk of cervical cancer, especially in resource-limited countries. Cervical cancer prevention strategies focus treating cervical high-grade squamous intraepithelial lesions (HSIL). The management of low-grade squamous intraepithelial lesions (LSIL) in HIV-infected women is unknown. Setting: HIV treatment clinic in Johannesburg, South Africa. Methods: We randomized HIV-infected women with histologic cervical LSIL to cervical cryotherapy vs. no treatment (standard of care). Cervical high-risk human papillomavirus testing (hrHPV) was performed at baseline. All women underwent cervical cytology and colposcopic biopsies 12 months after enrollment. The primary end point was HSIL on histology at month 12. Chi-square was used to compare arms. Results: Overall, 220 HIV-infected women were randomized to cryotherapy (n = 112) or no treatment (n = 108). Median age was 38 years, 94% were receiving antiretroviral therapy; median CD4 was 499 cells per cubic millimeter, and 59% were hrHPV positive. Cryotherapy reduced progression to HSIL: 2/99 (2%) in the cryotherapy arm and 15/103 (15%) in the no treatment arm developed HSIL, 86% reduction (95% confidence interval: 41% to 97%; P = 0.002). Among 17 HSIL end points, 16 were hrHPV+ at baseline. When restricting the analysis to hrHPV+ women, HSIL occurred in 2/61 (3%) in the cryotherapy arm vs. 14/54 (26%) in the no treatment arm, 87% reduction (95% confidence interval: 47% to 97%; P = 0.0004). Participants in the cryotherapy arm experienced greater regression to normal histology and improved cytologic outcomes. Conclusions: Treatment of cervical LSIL with cryotherapy decreased progression to HSIL among HIV-infected women especially if hrHPV positive. These results support treatment of LSIL in human papillomavirus test-and-treat approaches for cervical cancer prevention in resource-constrained settings.

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Cynthia Firnhaber

University of the Witwatersrand

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Jennifer S. Smith

University of North Carolina at Chapel Hill

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Pam Michelow

National Health Laboratory Service

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Simon Levin

University of the Witwatersrand

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Bruce Allan

University of Cape Town

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Pamela Michelow

National Health Laboratory Service

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Tanvier Omar

University of the Witwatersrand

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