University General - Research Publications
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ItemAntibody responses following incident anal and penile infection with human papillomavirus in teenage men who have sex with men(WILEY, 2016-08-01)Men who have sex with men (MSM) are at risk for human papillomavirus (HPV)-related anal cancer. Few data exist on antibody responses following incident anogenital infection with HPV in teenage MSM. A cohort of 200 MSM aged 16-20 years from Melbourne, Australia were assessed at baseline, 3, 6 and 12 months. At each visit anal and penile swabs were collected for HPV DNA and serum for HPV antibodies for genotypes 6, 11, 16 and 18 (Merck's Multiplex Assays using Luminex). The main outcome, seroconversion, was defined as the detection of HPV antibodies following a negative antibody result for the same HPV type at baseline. The seroincidence rates for HPV types 6, 11, 16 and 18 were: 19 (95% CI 12-26), 7 (3-12), 4 (1-8) and 6 (3-11) per 100 person-years, respectively. Men who experienced incident anal HPV infections from types 6/11 were significantly more likely to develop serum antibodies to the same HPV type(s) than those who experienced incident anal infections from types 16/18 [73 vs. 18%, odds ratio (OR) = 15, 95% CI: 2-118]. The median time between incident anal HPV infection and seroconversion for HPV 6, 11, 16 and 18 was: 91, 38, 161 and 182 days, respectively. Antibody responses against HPV types 6/11 were significantly more likely to occur following incident anal compared with incident penile infection with HPV types 6/11 (OR = 6, 95% CI: 2-21). The likelihood of antibody responses following anogenital HPV infections depends on the HPV type and site of infection.
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ItemIs There a Role for the ThinPrep Imaging System in Reporting Anal Cytology?(WILEY, 2016-05)BACKGROUND: The ThinPrep Imaging System (TIS) is an accurate time-saving method of reading cervical ThinPrep slides in screening programs. As anal and cervical cytology are morphologically similar, TIS can potentially be used for anal cytology. We assessed the performance of TIS on anal ThinPrep slides from homosexual men in a natural history study of human papillomavirus-related anal abnormalities. METHODS: Four hundred nineteen anal cytology slides were processed by TIS and classified by a cytologist as either No further review (slide archived) or Manual review (slide requiring full manual screen). The results were compared with the original manual screening report for all slides and specifically for those screening episodes accompanied by a high-grade squamous intraepithelial lesion (HSIL) on concurrent biopsy. RESULTS: One hundred seventy six of 419 (42.0%) slides were classified as No further review, with a trend of decreasing proportions as the degree of severity of the cytological abnormality increased. Thirteen (27.7%) slides with an original unsatisfactory report were classified as No further review. Eighty two (92.1%) of those with biopsy HSIL and cytological abnormality were classified for Manual review, including all 45 (100%) with cytological HSIL. CONCLUSION: The cervical algorithm of TIS performed best on anal samples when HSIL was present both cytologically and histologically. The 27.7% unsatisfactory slides classified as No further review may indicate need for use of different criteria from cervical cytology. Because of the high prevalence of abnormalities, and hence the large proportion of slides needing manual review, the cytologist time-saving would compare unfavorably with use of TIS in cervical screening.
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ItemAssociation between visual inspection of the cervix with acetic acid examination and high-risk human papillomavirus infection, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis in Papua New Guinea(WILEY, 2018-10)BACKGROUND: Papua New Guinea (PNG) has among the highest estimated burdens of cervical cancer globally but currently has no national cervical screening program. Visual inspection of the cervix with acetic acid (VIA) is a low-cost screening strategy endorsed by the World Health Organization that has been adopted in many low-resource settings but not previously evaluated in PNG. AIM: To evaluate the association between VIA examination findings and high-risk HPV (hrHPV) infection; and the impact of concomitant genital Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis on the interpretation of VIA findings. METHODS: A prospective clinical cohort study among women aged 30-59 years attending Well Woman Clinics in PNG. Main outcome measures were VIA examination findings and laboratory-confirmed hrHPV, C. trachomatis, N. gonorrhoeae and T. vaginalis. RESULTS: A total of 614 women were enrolled, of whom 87.5% (537/614) underwent VIA, and 12.5% (77/614) did not due to pre-existing cervicitis or inability to visualise the transformation zone. Among the 537 women who underwent VIA, 21.6% were VIA positive, 63.7% VIA negative, and 14.7% had indeterminate findings. The prevalence of hrHPV infection (n = 614) was 14.7%; C. trachomatis, 7.5%; N. gonorrhoeae, 8.0%; and T. vaginalis, 15.0%. VIA positive women were more likely to have HPV16 (odds ratio: 5.0; 95%CI: 1.6-15.6; P = 0.006) but there was no association between HPV18/45, all hrHPV types (combined), C. trachomatis, N. gonorrhoeae or T. vaginalis. CONCLUSIONS: VIA positivity was associated with HPV16, but not with other hrHPV infections, nor with genital C. trachomatis, N. gonorrhoeae or T. vaginalis in this setting.
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ItemIncreasing Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium(CENTERS DISEASE CONTROL, 2017-05)Escalating resistance to azithromycin and moxifloxacin is being reported for Mycoplasma genitalium in the Asia-Pacific region. Analyzing 140 infections, we found pretreatment fluoroquinolone-resistance mutations in parC (13.6%) and gyrA (5%). ParC S83 changes were associated with moxifloxacin failure. Combined macrolide/fluoroquinolone-resistance mutations were in 8.6% of specimens, for which recommended therapies would be ineffective.
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ItemPopulation-Level Effects of Human Papillomavirus Vaccination Programs on Infections with Nonvaccine Genotypes(CENTERS DISEASE CONTROL & PREVENTION, 2016-10)We analyzed human papillomavirus (HPV) prevalences during prevaccination and postvaccination periods to consider possible changes in nonvaccine HPV genotypes after introduction of vaccines that confer protection against 2 high-risk types, HPV16 and HPV18. Our meta-analysis included 9 studies with data for 13,886 girls and women ≤19 years of age and 23,340 women 20-24 years of age. We found evidence of cross-protection for HPV31 among the younger age group after vaccine introduction but little evidence for reductions of HPV33 and HPV45. For the group this same age group, we also found slight increases in 2 nonvaccine high-risk HPV types (HPV39 and HPV52) and in 2 possible high-risk types (HPV53 and HPV73). However, results between age groups and vaccines used were inconsistent, and the increases had possible alternative explanations; consequently, these data provided no clear evidence for type replacement. Continued monitoring of these HPV genotypes is important.
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ItemThe Potential of Metatranscriptomics for Identifying Screening Targets for Bacterial Vaginosis(PUBLIC LIBRARY SCIENCE, 2013-09-27)BACKGROUND: The ribosomal RNA content of a sample collected from a woman with bacterial vaginosis (BV) was analysed to determine the active microbial community, and to identify potential targets for further screening. METHODOLOGY/PRINCIPAL FINDINGS: The sample from the BV patient underwent total RNA extraction, followed by physical subtraction of human rRNA and whole transcriptome amplification. The metatranscriptome was sequenced using Roche 454 titanium chemistry. The bioinformatics pipeline MG-RAST and desktop DNA analysis platforms were utilised to analyse results. Bacteria of the genus Prevotella (predominately P. amnii) constituted 36% of the 16S rRNA reads, followed by Megasphaera (19%), Leptotrichia/Sneathia (8%) and Fusobacterium (8%). Comparison of the abundances of several bacteria to quantitative PCR (qPCR) screening of extracted DNA revealed comparable relative abundances. This suggests a correlation between what was present and transcriptionally active in this sample: however distinct differences were seen when compared to the microbiome determined by 16S rRNA gene amplicon sequencing. To assess the presence of P. amnii in a larger pool of samples, 90 sexually active women were screened using qPCR. This bacterium was found to be strongly associated with BV (P<0.001, OR 23.3 (95%CI:2.9-190.7)) among the 90 women. CONCLUSIONS/SIGNIFICANCE: This study highlighted the potential of metatranscriptomics as a tool for characterising metabolically active microbiota and identifying targets for further screening. Prevotella amnii was chosen as an example target, being the most metabolically active species present in the single patient with BV, and was found to be detected at a high concentration by qPCR in 31% of cohort with BV, with an association with both oral and penile-vaginal sex.
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ItemA randomised trial of point-of-care tests for chlamydia and gonorrhoea infections in remote Aboriginal communities: Test, Treat ANd GO- the "TTANGO" trial protocol(BMC, 2013-10-18)BACKGROUND: High prevalence rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been reported in Aboriginal people in remote and regional areas of Australia for well over two decades, and repeat positivity rates are high. To interrupt disease transmission and reduce the risk of complications, early diagnosis and treatment is important. However in many remote and regional areas there are long delays between testing for these curable sexually transmissible infections and providing treatment, due to both physical distance from laboratories and difficulties when recalling patients for subsequent management once results are available. Point-of-care (POC) tests have the potential to provide more timely diagnosis, to increase treatment and contact tracing, and in turn reduce CT and NG infection rates. METHODS/DESIGN: TTANGO (Test, Treat, ANd GO) is a cross-over cluster randomised controlled trial in 12 regional or remote Australian health services, which predominantly provide clinical services to Aboriginal people. The overall aim of TTANGO is to measure the clinical effectiveness, cost-effectiveness and cultural and operational acceptability of molecular POC testing for CT and NG infection. The primary outcome is repeat positivity at three months after treatment of an initial CT or NG infection. Participating health services will undertake the clinical management of CT and NG under two different modalities for one year each. In the first year, six health services will be randomly assigned to manage these infections under current diagnostic guidelines. The other six will supplement current diagnostic guidelines with POC testing, whereby diagnosis is made and subsequent treatment for those with positive POC tests is offered at the initial consultation. In the second year, the health services will cross over to the opposite management modality. TTANGO will be conducted over four years; 1.5 years of trial initiation and community consultation, 2 years of trial conditions and evaluation, and 6 months of data analysis and feedback. DISCUSSION: TTANGO is the first cluster randomised trial of POC testing for CT and NG internationally. The results of this trial will provide crucial information to guide sexual health clinical practice in remote Aboriginal communities and other high prevalence settings. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN12613000808741.
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ItemThe Study of the Prevention of Anal Cancer (SPANC): design and methods of a three-year prospective cohort study(BMC, 2013-10-09)BACKGROUND: The incidence of human papillomavirus (HPV)-associated anal cancer is increasing in men who have sex with men (MSM). Screening for the presumed cancer precursor, high-grade anal squamous intraepithelial lesions (HSIL) in a manner analogous to cervical cancer screening has been proposed. Uncertainty remains regarding anal HPV natural history and the role of anal cytology and high-resolution anoscopy (HRA) as screening tests. Well-designed cohort studies are required to address these issues. METHODS/DESIGN: The SPANC study is a prospective study of the epidemiology of low-risk and high-risk anal HPV infection and related cytological and histological abnormalities in HIV-negative and HIV-positive homosexual men aged 35 years and over. The study aims to recruit 600 men from community-based settings in Sydney, Australia. There are six study visits over three years. At the first five visits men undergo a digital ano-rectal examination (DARE), an anal "Papanicolaou" (Pap) test for HPV detection, genotyping and anal cytology, followed by HRA and directed biopsy of any visible abnormalities. The men also complete a behavioural questionnaire before each visit. Questions include a detailed history of sexual behaviour, of anal symptoms, possible anal cancer risk factors and validated quality of life and psychosocial questions. Questionnaires are also completed 2 weeks and 3 months following the provision of test results and include questions on participant experience during the procedure and post-procedure symptoms, including pain and bleeding in addition to quality of life/ psychosocial outcomes. DISCUSSION: Recruitment for the study began in September 2010 and will conclude in mid-2015, with follow up continuing to 2018. Thus far, over 350 men have been recruited from a variety of community-based settings and are broadly representative of the target screening population. The SPANC study is one of only a small number of cohort studies globally to perform HPV, cytology and HRA screening on all participants over multiple time points. The study results will contribute to understanding of the natural history of anal HPV and inform the possible development of guidelines for implementing anal cancer screening programs in this population.
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ItemOral Human Papillomavirus in Men Having Sex with Men: Risk-Factors and Sampling(PUBLIC LIBRARY SCIENCE, 2012-11-16)BACKGROUND: Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is becoming more common. We examined prevalence and risk factors for oral HPV among men who have sex with men (MSM) and compared sampling and transport methods. METHODS: In 2010, 500 MSM (249 HIV-positive) attending Melbourne Sexual Health Centre answered a questionnaire, swabbed their mouth and throat and collected a gargled oral rinse sample. Half the oral rinse was transported absorbed in a tampon (to enable postage). HPV was detected by polymerase chain reaction, and genotyped by Roche Linear Array®. Men with HPV 16 or 18 were retested after six months. RESULTS: Any HPV genotype was detected in 19% (95% confidence intervals (CI) 15-25%) of HIV-infected men and 7% (95% CI 4-11%) of HIV-negative men (p<0.001), and HPV 16 was detected in 4.4% (95% CI 2-8%) of HIV-infected men and 0.8% (0.1-2.8%) of HIV-negative men. Oral HPV was associated with: current smoking (adjusted odds ratio (aOR) 2.2 (95%CI: 1.2-3.9)), time since tooth-brushing (aOR per hour 0.87, 95%CI: 0.8-0.96) and number of lifetime tongue-kissing partners aOR 3.2 95%CI: (1.2-8.4) for 26-100 partners and 4.9 95%CI: (1.9-12.5) for>100 partners. Lifetime oral-penile sex partner numbers were significantly associated in a separate model: aOR 2.8(1.2-6.3) for 26-100 partners and 3.2(1.4-7.2) for>100 partners. HPV 16 and 18 persisted in 10 of 12 men after a median six months. Sensitivities of sampling methods compared to all methods combined were: oral rinse 97%, tampon-absorbed oral rinse 69%, swab 32%. CONCLUSIONS: Oral HPV was associated with HIV infection, smoking, recent tooth-brushing, and more lifetime tongue-kissing and oral sex partners. The liquid oral rinse sample was more sensitive than a tampon-absorbed oral rinse or a self-collected swab.
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ItemChlamydia trachomatis Incidence and Re-Infection among Young Women - Behavioural and Microbiological Characteristics(PUBLIC LIBRARY SCIENCE, 2012-05-25)BACKGROUND: This study aimed to estimate rates of chlamydia incidence and re-infection and to investigate the dynamics of chlamydia organism load in prevalent, incident and re-infections among young Australian women. METHODS: 1,116 women aged 16 to 25 years were recruited from primary care clinics in Australia. Vaginal swabs were collected at 3 to 6 month intervals for chlamydia testing. Chlamydia organism load was measured by quantitative PCR. RESULTS: There were 47 incident cases of chlamydia diagnosed and 1,056.34 person years of follow up with a rate of 4.4 per 100 person years (95% CI: 3.3, 5.9). Incident infection was associated with being aged 16 to 20 years [RR = 3.7 (95%CI: 1.9, 7.1)], being employed [RR = 2.4 (95%CI: 1.1, 4.9)] and having two or more new sex partners [RR = 5.5 (95%CI: 2.6, 11.7)]. Recent antibiotic use was associated with a reduced incidence [RR:0.1 (95%CI: 0.0, 0.5)]. There were 14 re-infections with a rate of 22.3 per 100 person years (95%CI: 13.2, 37.6). The median time to re-infection was 4.6 months. Organism load was higher for prevalent than incident infections (p<0.01) and for prevalent than re-infections (p<0.01). CONCLUSIONS: Chlamydia is common among young women and a high proportion of women are re-infected within a short period of time, highlighting the need for effective partner treatment and repeat testing. The difference in organism load between prevalent and incident infections suggests prevalent infection may be more important for ongoing transmission of chlamydia.