Human papillomavirus prevalence among Australian men aged 18-35 years in 2015-2018 according to vaccination status and sexual preference.

BACKGROUND: Australia introduced a national HPV vaccination program for girls in 2007 and boys in 2013, achieving high coverage in both populations. We assessed HPV prevalence among men who have sex with women (MSW) and men who have sex with men (MSM) aged 18-35 years and examined program effects by vaccination status. METHODS: Men recruited between 2015-2018 self-collected a penile or intra-anal swab for HPV genotyping. HPV vaccination status was confirmed with the National Register. HPV prevalence was examined by age groups and vaccination status. RESULTS: Of 1,625 men included (median age 27 years; IQR [23-30]), 231 (14.2%) were vaccinated, and 1,370 (84.3%) were unvaccinated. Among 984 MSW, the prevalence of quadrivalent vaccine-targeted HPV types (6,11,16,18) was 10.6% (95%CI: 8.7-12.8) in unvaccinated and 10.7% (5.7-19.3%) in vaccinated men (p=0.96). Prevalence was lowest in the youngest age groups regardless of vaccination status. Among MSM, quadrivalent HPV type prevalence was 40.3% (36.0-44.8%) in unvaccinated and 29.9% (23.1-37.8%) in vaccinated men (p=0.02). In unvaccinated MSM, prevalence was high regardless of age, whereas among vaccinated MSM, prevalence was lowest in the youngest age-group (p=0.001). Among those with confirmed doses, quadrivalent HPV types were detected in 0% (0-7.7%; n=46) of men who had their first dose at 13-19 years and 37.2% (27.5-47.8%; n=94) of those who received their first dose at 20 years or older. CONCLUSION: Our data demonstrates the importance of universal adolescent HPV vaccination to ensure MSM receive the same benefits as MSW.

Performance of Human Papillomavirus Attribution Algorithms to Predict Causative Genotypes in Anal High-Grade Lesions.

BACKGROUND: Gay and bisexual men (GBM) are at increased risk of human papillomavirus (HPV)-associated anal high-grade squamous intraepithelial lesions (HSILs). Understanding the fractions of HSILs attributable to HPV genotypes is important to inform potential impacts of screening and vaccination strategies. However, multiple infections are common, making attribution of causative types difficult. Algorithms developed for predicting HSIL-causative genotype fractions have never been compared with a reference standard in GBM. METHOD: Samples were from the Study of the Prevention of Anal Cancer. Baseline HPV genotypes detected in anal swab samples (160 participants) were compared with HPV genotypes in anal HSILs (222 lesions) determined by laser capture microdissection (LCM). Five algorithms were compared: proportional, hierarchical, maximum, minimum, and maximum likelihood estimation. RESULTS: All algorithms predicted HPV-16 as the most common HSIL-causative genotype, and proportions differed from LCM detection (37.8%) by algorithm (with differences of -6.1%, +20.9%, -20.4%, +2.9%, and +2.2% respectively). Fractions predicted using the proportional method showed a strong positive correlation with LCM, overall (R = 0.73 and P = .002), and by human immunodeficiency virus (HIV) status (HIV positive, R = 0.74 and P = .001; HIV-negative, R = 0.68 and P = .005). CONCLUSIONS: Algorithms produced a range of inaccurate estimates of HSIL attribution, with the proportional algorithm performing best. The high occurrence of multiple HPV infections means that these algorithms may be of limited use in GBM.

Human Papillomavirus Antibody Levels Following Vaccination or Natural Infection Among Young Men Who Have Sex With Men.

BACKGROUND: Australia introduced a school-based gender-neutral human papillomavirus (HPV) vaccination program for girls and boys aged 12-13 years in 2013. We examined HPV type-specific antibody levels in unvaccinated young men who have sex with men (MSM) with natural infection and compared these with levels in those vaccinated against HPV. METHODS: Serum specimens at baseline were collected from MSM aged 16-20 years in the HYPER1 (Human Papillomavirus in Young People Epidemiological Research) and HYPER2 studies, conducted in 2010-2013 and 2017-2019, respectively. Merck's 4-plex HPV competitive Luminex Immunoassay was used to quantify HPV6-, HPV11-, HPV16-, and HPV18-specific antibodies. We compared antibody levels for each HPV genotype between unvaccinated men (HYPER1) and vaccinated men (HYPER2) using the Mann-Whitney U test. RESULTS: There were 200 unvaccinated men and 127 vaccinated men included in the analysis. Median antibody levels among vaccinated men were significantly higher than levels among unvaccinated men for HPV6 (223 milli-Merck units per milliliter [mMU/mL] vs 48 mMU/mL, P < .0001), HPV11 (163 mMU/mL vs 21 mMU/mL, P < .0001), HPV16 (888 mMU/mL vs 72 mMU/mL, P < .0001), and HPV18 (161 mMU/mL vs 20 mMU/mL, P < .0001). Antibody levels did not change over time for up to 66 months for all 4 genotypes among vaccinated men. CONCLUSIONS: Among young MSM vaccinated with the quadrivalent HPV vaccine, antibody levels for HPV6, HPV11, HPV16, and HPV18 were significantly higher than those in unvaccinated MSM following natural infection. Antibody levels following vaccination appeared to remain stable over time. CLINICAL TRIALS REGISTRATION: NCT01422356 for HYPER1 and NCT03000933 for HYPER2.

Bacterial biofilm formation on vaginal ring pessaries used for pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: The objective of this study was to characterize the bacterial biofilm on vaginal ring pessaries used to treat pelvic organ prolapse and investigate the relationship between biofilm phenotype and patient symptoms and clinical signs that are suggestive of inflammation. METHODS: This was a cross-sectional observational study of 40 women wearing a ring-shaped pessary continuously for at least 12 weeks. Participants underwent a clinical examination, and the pessary was removed. Clinical signs were recorded. A swab from the pessary surface and a high vaginal swab were collected from each woman. Participants completed a questionnaire on symptoms. Pessary biofilm presence and phenotype were determined by scanning electron microscopy (SEM). Vaginal and pessary bacterial composition was determined by 16S rRNA gene sequencing. The relationship between biofilm phenotype and symptoms and clinical signs was assessed using logistic regression. RESULTS: SEM confirmed biofilm formation on all 40 pessaries. Microbiota data were available for 25 pessary swabs. The pessary biofilm microbiota was composed of bacteria typically found in the vagina and was categorized into Lactobacillus-dominated (n = 10/25 pessaries, 40%) communities and Lactobacillus-deficient communities with high relative abundance of anaerobic/facultative anaerobes (n = 15/25 pessaries, 60%). While increasing age was associated with presence of a Lactobacillus-deficient pessary biofilm (odds ratio = 3.60, 95% CI [1.16-11.22], p = 0.04), no associations between biofilm microbiota composition and symptoms or clinical signs were observed. CONCLUSIONS: Lactobacillus-deficient biofilms commonly form on pessaries following long-term use. However, the contribution of biofilm phenotype to symptoms and clinical signs remains to be determined.

Correction: Defining the genetic susceptibility to cervical neoplasia-A genome-wide association study.

[This corrects the article DOI: 10.1371/journal.pgen.1006866.].

Defining the genetic susceptibility to cervical neoplasia-A genome-wide association study.

A small percentage of women with cervical HPV infection progress to cervical neoplasia, and the risk factors determining progression are incompletely understood. We sought to define the genetic loci involved in cervical neoplasia and to assess its heritability using unbiased unrelated case/control statistical approaches. We demonstrated strong association of cervical neoplasia with risk and protective HLA haplotypes that are determined by the amino-acids carried at positions 13 and 71 in pocket 4 of HLA-DRB1 and position 156 in HLA-B. Furthermore, 36% (standard error 2.4%) of liability of HPV-associated cervical pre-cancer and cancer is determined by common genetic variants. Women in the highest 10% of genetic risk scores have approximately >7.1% risk, and those in the highest 5% have approximately >21.6% risk, of developing cervical neoplasia. Future studies should examine genetic risk prediction in assessing the risk of cervical neoplasia further, in combination with other screening methods.

Very Low Prevalence of Vaccine Human Papillomavirus Types Among 18- to 35-Year Old Australian Women 9 Years Following Implementation of Vaccination.

Introduction: A quadrivalent human papillomavirus vaccination program targeting females aged 12-13 years commenced in Australia in 2007, with catch-up vaccination of 14-26 year olds through 2009. We evaluated the program's impact on HPV prevalence among women aged 18-35 in 2015. Methods: HPV prevalence among women aged 18-24 and 25-35 was compared with prevalence in these age groups in 2005-2007. For women aged 18-24, we also compared prevalence with that in a postvaccine study conducted in 2010-2012. Results: For the 2015 sample, Vaccination Register-confirmed 3-dose coverage was 53.3% (65.0% and 40.3% aged 18-24 and 25-35, respectively). Prevalence of vaccine HPV types decreased from 22.7% (2005-2007) and 7.3% (2010-2012), to 1.5% (2015) (P trend < .001) among women aged 18-24, and from 11.8% (2005-2007) to 1.1% (2015) (P = .001) among those aged 25-35. Conclusions: This study, reporting the longest surveillance follow-up to date, shows prevalence of vaccine-targeted HPV types has continued to decline among young women. A substantial fall also occurred in women aged 25-35, despite lower coverage. Strong herd protection and effectiveness of less than 3 vaccine doses likely contributed to these reductions.

A Prospective Study of the Incidence of Juvenile-Onset Recurrent Respiratory Papillomatosis After Implementation of a National HPV Vaccination Program.

Background: Recurrent respiratory papillomatosis is a rare but morbid disease caused by human papillomavirus (HPV) types 6 and 11. Infection is preventable through HPV vaccination. Following an extensive quadrivalent HPV vaccination program (females 12-26 years in 2007-2009) in Australia, we established a method to monitor incidence and demographics of juvenile-onset recurrent respiratory papillomatosis (JORRP) cases. Methods: The Australian Paediatric Surveillance Unit undertakes surveillance of rare pediatric diseases by contacting practitioners monthly. We enrolled pediatric otorhinolaryngologists and offered HPV typing. We report findings for 5 years to end 2016. Results: The average annual incidence rate was 0.07 per 100000. The largest number of cases was reported in the first year, with decreasing annual frequency thereafter. Rates declined from 0.16 per 100000 in 2012 to 0.02 per 100000 in 2016 (P = .034). Among the 15 incident cases (60% male), no mothers were vaccinated prepregnancy, 20% had maternal history of genital warts, and 60% were first born; 13/15 were born vaginally. Genotyped cases were HPV-6 (n = 4) or HPV-11 (n = 3). Conclusion: To our knowledge, this is the first report internationally documenting decline in JORRP incidence in children following a quadrivalent HPV vaccination program.

HLA and KIR Associations of Cervical Neoplasia.

Background: Cervical cancer is the fourth most common cancer in women, and we recently reported human leukocyte antigen (HLA) alleles showing strong associations with cervical neoplasia risk and protection. HLA ligands are recognized by killer immunoglobulin-like receptors (KIRs) expressed on a range of immune cell subsets, governing their proinflammatory activity. We hypothesized that the inheritance of particular HLA-KIR combinations would increase cervical neoplasia risk. Methods: Here, we used HLA and KIR dosages imputed from single-nucleotide polymorphism genotype data from 2143 cervical neoplasia cases and 13858 healthy controls of European decent. Results: The following 4 novel HLA alleles were identified in association with cervical neoplasia, owing to their linkage disequilibrium with known cervical neoplasia-associated HLA-DRB1 alleles: HLA-DRB3*9901 (odds ratio [OR], 1.24; P = 2.49 × 10-9), HLA-DRB5*0101 (OR, 1.29; P = 2.26 × 10-8), HLA-DRB5*9901 (OR, 0.77; P = 1.90 × 10-9), and HLA-DRB3*0301 (OR, 0.63; P = 4.06 × 10-5). We also found that homozygosity of HLA-C1 group alleles is a protective factor for human papillomavirus type 16 (HPV16)-related cervical neoplasia (C1/C1; OR, 0.79; P = .005). This protective association was restricted to carriers of either KIR2DL2 (OR, 0.67; P = .00045) or KIR2DS2 (OR, 0.69; P = .0006). Conclusions: Our findings suggest that HLA-C1 group alleles play a role in protecting against HPV16-related cervical neoplasia, mainly through a KIR-mediated mechanism.

Use of Pristinamycin for Macrolide-Resistant Mycoplasma genitalium Infection.

High levels of macrolide resistance and increasing fluoroquinolone resistance are found in Mycoplasma genitalium in many countries. We evaluated pristinamycin for macrolide-resistant M. genitalium in a sexual health center in Australia. Microbiologic cure was determined by M. genitalium-specific 16S PCR 14-90 days after treatment began. Of 114 persons treated with pristinamycin, infection was cured in 85 (75%). This percentage did not change when pristinamycin was given at daily doses of 2 g or 4 g or at 3 g combined with 200 mg doxycycline. In infections with higher pretreatment bacterial load, treatment was twice as likely to fail for each 1 log10 increase in bacterial load. Gastrointestinal side effects occurred in 7% of patients. Pristinamycin at maximum oral dose, or combined with doxycycline, cured 75% of macrolide-resistant M. genitalium infections. Pristinamycin is well-tolerated and remains an option where fluoroquinolones have failed or cannot be used.

Gut microbiota of preterm infants supplemented with probiotics: sub-study of the ProPrems trial.

BACKGROUND: The ProPrems trial, a multi-center, double-blind, placebo-controlled randomized trial, previously reported a 54% reduction in necrotizing enterocolitis (NEC) of Bell stage 2 or more from 4.4 to 2.0% in 1099 infants born before 32 completed weeks' gestation and weighing < 1500 g, receiving probiotic supplementation (with Bifidobacterium longum subsp. infantis BB-02, Streptococcus thermophilus TH-4 and Bifidobacterium animalis subsp. lactis BB-12). This sub-study investigated the effect of probiotic supplementation on the gut microbiota in a cohort of very preterm infants in ProPrems. RESULTS: Bifidobacterium was found in higher abundance in infants who received the probiotics (AOR 17.22; 95% CI, 3.49-84.99, p < 0.001) as compared to the placebo group, and Enterococcus was reduced in infants receiving the probiotic during the supplementation period (AOR 0.27; 95% CI, 0.09-0.82, p = 0.02). CONCLUSION: Probiotic supplementation with BB-02, TH-4 and BB-12 from soon after birth increased the abundance of Bifidobacterium in the gut microbiota of very preterm infants. Increased abundance of Bifidobacterium soon after birth may be associated with reducing the risk of NEC in very preterm infants.

Detection of human papillomavirus in urine among heterosexual men in relation to location of genital warts and circumcision status.

OBJECTIVE: Human papillomavirus (HPV) surveillance is important to monitor the effectiveness of national HPV vaccination programmes. Positivity of HPV in urine in men varies with different sampling methods. We aimed to determine the positivity for detection of HPV-6/11 in urine samples among men in relation to the position of genital warts and circumcision status. METHOD: We analysed stored chlamydia-positive urine specimens in young heterosexual men aged less than 25 years attending Melbourne Sexual Health Centre, Australia, between 2004 and 2015, for HPV genotypes. Positivity of HPV-6/11 and high-risk genotypes were stratified according to the position of genital warts and circumcision status. Positivity of HPV-6/11 was calculated using diagnosis of warts as the gold standard. Warts were classified as proximal penile warts from suprapubic area to midshaft of penis, and distal penile warts from distal shaft of penis to meatus. RESULTS: Of the 934 specimens, 253 (27.1%) men were positive for any HPV and 82 men (8.8%) had genital warts. The ORs of HPV-6/11 detection in urine were 4.63 (95% CI: 1.68 to 12.78) and 40.20 (95% CI: 19.78 to 81.70) times higher among men who had proximal penile warts and distal penile warts, respectively, compared with men who did not have genital warts. Circumcised men were less likely to have high-risk HPV (OR 0.31; 95% CI: 0.14 to 0.65) than uncircumcised men. Uncircumcised men were more likely to have distal penile warts than circumcised men (OR 8.22; 95% CI: 1.34 to 337.46). CONCLUSION: Positivity of HPV-6/11 in urine increases greatly in men with distal penile warts. Circumcised men are less likely to have distal penile warts, any HPV or high-risk HPV detected. Urine is likely to be an alternative sampling method for HPV-6/11 surveillance programme in men in countries with low circumcision rates.

Contaminated fingers: a potential cause of Chlamydia trachomatis-positive urine specimens.

OBJECTIVES: The detection of an STI agent in a urogenital tract (UGT) specimen from a young child is regarded as being indicative of sexual abuse. However, the probabilities of contamination events that could conceivably lead to STI positive specimens in the absence of sexual contact are unclear. The objective was to estimate the potential for fingers that have come in contact with Chlamydia trachomatis-positive urine to detectably contaminate C. trachomatis-negative urine. METHODS: The study design was based on self-experimentation. Dilutions of C. trachomatis elementary bodies (EBs) were prepared. A participant contacted an EB dilution then a urine surrogate specimen. The experiment was performed by three participants using three C. trachomatis isolates, of genotype E, F and B. Two surrogate urine contact methods were used to mimic contamination of a carer assisting with a child's urine collection. All EB dilutions and urine surrogate specimens were subjected to C. trachomatis assay and quantification in a real-time PCR-based diagnostic system. RESULTS: The amplimer crossing point (Cq) for EB dilutions was 10.0±1.6 less than for corresponding finger contacted urine specimens, which corresponds to ~10 µL of EB suspension transferred. This was largely independent of participant identity, C. trachomatis strain or EB dilution. Hand decontamination led to large reductions in EBs transferred, but transfer remained consistently detectable. Recent Cq data from C. trachomatis-positive clinical urine specimens were collated, and 20% clearly contained sufficient C. trachomatis to detectably contaminate another specimen by finger-mediated transfer, as in this experiment. CONCLUSIONS: This study directly demonstrated the potential for urine contaminated fingers to convert a C. trachomatis-negative urine specimen to C. trachomatis positive as a result of contact. Accordingly, procedures for urine specimen collection, particularly from children, need to be designed to prevent contamination.

Molecular test for chlamydia and gonorrhoea used at point of care in remote primary healthcare settings: a diagnostic test evaluation.

OBJECTIVES: A new molecular test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) (GeneXpert CT/NG) has been demonstrated to be as accurate as conventional nucleic acid amplification tests (NAAT), but performance has not been evaluated in routine primary care, performed at the point of care by clinicians. We aimed to examine its diagnostic performance when used by clinicians in remote community health services in Australia with high prevalences of CT and NG infection. The trial was registered with the Australian and New Zealand Clinical Trials Registry (#12613000808741) METHODS: At 12 health services, training was provided to 99 clinicians in the use of the GeneXpert CT/NG assay who tested specimens from all patients undergoing STI screening. Specimens were also sent in parallel for conventional laboratory-based NAATs and the concordance of results was evaluated. RESULTS: Clinicians conducted 2486 tests: CT concordance was 99.4% (95% CI 99.1 to 99.7) with a positive concordance of 98.6% (95% CI 95.9 to 99.7) and negative concordance of 99.5% (95% CI 99.1 to 99.8); NG concordance was 99.9% (95% CI 99.7 to 100.0) with a positive concordance of 100.0% (95% CI 97.5 to 100.0) and negative concordance of 99.9% (95% CI 99.7 to 100.0). CONCLUSIONS: In this first study reporting routine point-of-care use of GeneXpert CT/NG by primary care clinicians, we found excellent concordance with conventional NAATs. The use of the GeneXpert CT/NG at the point of care could potentially transform management and control of these infections in many endemic settings, including low/middle-income countries.

Detection of Chlamydia trachomatis mRNA using digital PCR as a more accurate marker of viable organism.

Spontaneous resolution of urogenital Chlamydia trachomatis (CT) without treatment has previously been described, but a limitation of these reports is that DNA or RNA-based amplification tests used do not differentiate between viable infection and non-viable DNA. We modified a previously published CT mRNA detection (omp2) method to differentiate between viable infection and non-viable DNA in a sample of CT DNA PCR positive women. We modified a CT mRNA detection (omp2) method from reverse transcriptase qPCR (RTqPCR) to digital PCR (dPCR) and evaluated it in samples from CT DNA positive women. Firstly, CT infected McCoy B cells treated with azithromycin in vitro identified detectable mRNA levels disappeared <2 days, while DNA persisted up to 6 days. We used 55 self-collected vaginal swabs from a cohort of women diagnosed as DNA positive for chlamydia obtained pre- and 7 days of post-azithromycin treatment. Concordance with DNA results was higher for dPCR than RTqPCR (74.5% versus 65.5%). At visit 1, there was a strong linear relationship between DNA and mRNA (r = 0.9, p < 0.000); 24 samples had both mRNA and DNA detected (82.8%) and 5 had only DNA detected with a potential false positive proportion of 17.2% (95%CI: 5.8, 35.8). At visit 2, there was poor correlation between DNA and mRNA (r = 0.14, p = 0.55); eight specimens had only DNA detected (42.1%; 95%CI: 20.25, 66.50) and one had mRNA detected. DNA detection methods alone may detect non-viable DNA. Consideration should be given to further develop mRNA assays as ancillary tests to improve detection of viable chlamydia.

Association 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.

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.

Human Papillomavirus Prevalence in Unvaccinated Heterosexual Men After a National Female Vaccination Program.

Background: In Australia, high uptake of the quadrivalent human papillomavirus (4vHPV) vaccine has led to reductions in the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, and 18 in women and girls aged ≤25 years. We evaluated the impact of the program impact on HPV prevalence in unvaccinated male subjects. Methods: Sexually active heterosexual male subjects aged 16-35 years were recruited in 2014-2016. Participants provided a self-collected penile swab sample for HPV genotyping (Roche Linear Array) and completed a demographic and risk factor questionnaire. Results: The prevalence of 4vHPV genotypes among 511 unvaccinated male subjects was significantly lower in those aged ≤25 than in those aged >25 years: 3.1% (95% confidence interval, 1.5%-5.7%) versus 13.7% (8.9%-20.1%), respectively (P < .001); adjusted prevalence ratio, 0.22 (.09-.51; P < .001). By contrast, the prevalence of high-risk HPV genotypes other than 16 and 18 remained the same across age groups: 16.8% (95% confidence interval, 12.6%-21.9%) in men aged ≤25 years and 17.9% (12.4%-25.0%) in those aged >25 years (P = .76); adjusted prevalence ratio, 0.98, (.57-1.37; P = .58). Conclusions: A 78% lower prevalence of 4vHPV genotypes was observed among younger male subjects. These data suggest that unvaccinated men may have benefited from herd protection as much as women from a female-only HPV vaccination program with high coverage.

Sustained Antibody Responses 6 Years Following 1, 2, or 3 Doses of Quadrivalent Human Papillomavirus (HPV) Vaccine in Adolescent Fijian Girls, and Subsequent Responses to a Single Dose of Bivalent HPV Vaccine: A Prospective Cohort Study.

BACKGROUND: The duration of antibody response following reduced human papillomavirus (HPV) vaccine doses has not been determined. We compared the antibody responses in girls previously vaccinated with zero, 1, 2, or 3 doses of quadrivalent HPV vaccine (4vHPV; Gardasil, Merck) 6 years previously. METHODS: A prospective cohort study was undertaken in 200 Fijian girls 15-19 years of age. Approximately equal numbers of girls from 2 main ethnic groups (Fijians of Indian descent [FID] and Indigenous Fijians [iTaukei]) in Fiji were recruited for each dosage groups. Blood was drawn before and 28 days following a single dose of bivalent HPV vaccine (2vHPV; Cervarix, GlaxoSmithKline). We measured neutralizing antibodies (NAb) against HPV-6, -11, -16, and -18 using the pseudovirion-based neutralization assay. RESULTS: After 6 years (before a dose of 2vHPV was given), the geometric mean NAb titers for all 4 HPV types were not statistically different between 2-dose (2D) and 3-dose (3D) recipients: HPV-6 (3D: 2216 [95% confidence interval {CI},1695-2896]; 2D: 1476 [95% CI, 1019-2137]; P = .07), HPV-11 (3D: 4431 [95% CI, 3396-5783]; 2D: 2951 [95% CI, 1984-4390]; P = .09), HPV-16 (3D: 3373 [95% CI, 2511-4530]; 2D: 3275 [95% CI, 2452-4373]; P = .89); HPV-18 (3D: 628 [95% CI: 445-888]; 2D: 606 [95% CI, 462-862]; P = .89), and were higher in FID than iTaukei girls. Although 1-dose recipients had significantly lower NAb titers than 2-/3-dose recipients, their NAb titers were 5- to 30-fold higher than unvaccinated girls. Post-2vHPV NAb titers against HPV-16 and -18 were not statistically different between girls who received 1, 2, or 3 doses of 4vHPV previously. CONCLUSIONS: Two doses of 4vHPV provide similar NAb titers as 3 doses for 6 years, although the clinical significance is unknown. A single dose of 4vHPV elicits antibodies that persisted for at least 6 years, and induced immune memory, suggesting possible protection against HPV vaccine types after a single dose of 4vHPV.

Azithromycin 1.5g Over 5 Days Compared to 1g Single Dose in Urethral Mycoplasma genitalium: Impact on Treatment Outcome and Resistance.

BACKGROUND: We evaluated the impact of extended azithromycin (1.5g over 5 days) on selection of macrolide resistance and microbiological cure in men with Mycoplasma genitalium urethritis during 2013-2015 and compared this to cases treated with azithromycin 1g in 2012-2013. METHODS: Microbiological cure was determined for men with M. genitalium urethritis treated with azithromycin 1.5g using quantitative polymerase chain reaction specific for M. genitalium DNA on samples 14-100 days post-treatment. Pre- and post-treatment macrolide resistance mutations were detected by sequencing the 23 S gene. RESULTS: There was no difference in proportions with microbiological cure between azithromycin 1.5g and 1g: 62/106 (58%; 95% confidence interval [CI], 49%, 68%) and 56/107 (52%; 95%CI 42-62%), P = .34, respectively. Also, there was no difference in the proportion of wild-type 23 S rRNA (presumed macrolide sensitive) infections cured after 1.5g and azithromycin 1g: 28/34 (82%; 95%CI 65-92%) and 49/60 (82%; 95%CI 70-90%), P=1.0, respectively. There was no difference between 1.5g and 1g in the proportions of wild-type infections with post-treatment resistance mutations: 4/34 (12%; 95%CI 3-27%) and 11/60 (18%; 95%CI 10-30%), respectively, P = .40. Pre-treatment resistance was present in 51/98 (52%; 95%CI 42-62%) cases in 2013-2015 compared to 47/107 (44%; 95%CI 34-54%) in 2012-2013, P = .25. CONCLUSIONS: Extended azithromycin 1.5g was no more effective than a single 1g dose at achieving cure of M. genitalium urethritis and importantly did not reduce the selection of macrolide resistance. Nonmacrolide and new approaches for the treatment of M. genitalium urethritis are required.