Sexual Behaviour and HPV Infections in 18 to 29 Year Old Women in the Pre-Vaccine Era in the Netherlands

Contains fulltext : 71058.pdf ( ) (Open Access)BACKGROUND: Infection with Human Papillomavirus (HPV) is a necessary event in the multi-step process of cervical carcinogenesis. Little is known about the natural history of HPV infection among unscreened young adults. As prophylactic vaccines are being developed to prevent specifically HPV 16 and 18 infections, shifts in prevalence in the post vaccine era may be expected. This study provides a unique opportunity to gather baseline data before changes by nationwide vaccination occur. METHODS AND PRINCIPAL FINDINGS: This cross-sectional study is part of a large prospective epidemiologic study performed among 2065 unscreened women aged 18 to 29 years. Women returned a self-collected cervico-vaginal specimen and filled out a questionnaire. All HPV DNA-positive samples (by SPF(10) DEIA) were genotyped using the INNO-LiPA HPV genotyping assay. HPV point prevalence in this sample was 19%. Low and high risk HPV prevalence was 9.1% and 11.8%, respectively. A single HPV-type was detected in 14.9% of all women, while multiple types were found in 4.1%. HPV-types 16 (2.8%) and 18 (1.4%) were found concomitantly in only 3 women (0.1%). There was an increase in HPV prevalence till 22 years. Multivariate analysis showed that number of lifetime sexual partners was the most powerful predictor of HPV positivity, followed by type of relationship, frequency of sexual contact, age, and number of sexual partners over the past 6 months. CONCLUSIONS AND SIGNIFICANCE: This study shows that factors independently associated with HPV prevalence are mainly related to sexual behaviour. Combination of these results with the relative low prevalence of HPV 16 and/or 18 may be promising for expanding the future target group for catch up vaccination. Furthermore, these results provide a basis for research on possible future shifts in HPV genotype prevalence, and enable a better estimate of the effect of HPV 16-18 vaccination on cervical cancer incidence

A second generation cervico-vaginal lavage device shows similar performance as its preceding version with respect to DNA yield and HPV DNA results

Contains fulltext : 118480.pdf (publisher's version ) (Open Access)BACKGROUND: Attendance rates of cervical screening programs can be increased by offering HPV self-sampling to non-attendees. Acceptability, DNA yield, lavage volumes and choice of hrHPV test can influence effectiveness of the self-sampling procedures and could therefore play a role in recruiting non-attendees. To increase user-friendliness, a frequently used lavage sampler was modified. In this study, we compared this second generation lavage device with the first generation device within similar birth cohorts. METHODS: Within a large self-sampling cohort-study among non-responders of the Dutch cervical screening program, a subset of 2,644 women received a second generation self-sampling lavage device, while 11,977 women, matched for age and ZIP-code, received the first generation model. The second generation device was different in shape, color, lavage volume, and packaging, in comparison to its first generation model. The Cochran's test was used to compare both devices for hrHPV positivity rate and response rate. To correct for possible heterogeneity between age and ZIP codes in both groups the Breslow-Day test of homogeneity was used. A T-test was utilized to compare DNA yields of the obtained material in both groups. RESULTS: Median DNA yields were 90.4 mug/ml (95% CI 83.2-97.5) and 91.1 mug/ml (95% CI 77.8-104.4, p= 0.726) and hrHPV positivity rates were 8.2% and 6.9% (p= 0.419) per sample self-collected by the second - and the first generation of the device (p= 0.726), respectively. In addition, response rates were comparable for the two models (35.4% versus 34.4%, p= 0.654). CONCLUSIONS: Replacing the first generation self-sampling device by an ergonomically improved, second generation device resulted in equal DNA yields, comparable hrHPV positivity rates and similar response rates. Therefore, it can be concluded that the clinical performance of the first and second generation models are similar. Moreover, participation of non-attendees in cervical cancer screening is probably not predominantly determined by the type of self-collection device

Tuberculosis chemotherapy: current drug delivery approaches

Tuberculosis is a leading killer of young adults worldwide and the global scourge of multi-drug resistant tuberculosis is reaching epidemic proportions. It is endemic in most developing countries and resurgent in developed and developing countries with high rates of human immunodeficiency virus infection. This article reviews the current situation in terms of drug delivery approaches for tuberculosis chemotherapy. A number of novel implant-, microparticulate-, and various other carrier-based drug delivery systems incorporating the principal anti-tuberculosis agents have been fabricated that either target the site of tuberculosis infection or reduce the dosing frequency with the aim of improving patient outcomes. These developments in drug delivery represent attractive options with significant merit, however, there is a requisite to manufacture an oral system, which directly addresses issues of unacceptable rifampicin bioavailability in fixed-dose combinations. This is fostered by the need to deliver medications to patients more efficiently and with fewer side effects, especially in developing countries. The fabrication of a polymeric once-daily oral multiparticulate fixed-dose combination of the principal anti-tuberculosis drugs, which attains segregated delivery of rifampicin and isoniazid for improved rifampicin bioavailability, could be a step in the right direction in addressing issues of treatment failure due to patient non-compliance

Long-Term Impact of the Dutch Colorectal Cancer Screening Programme on Cancer Incidence: Exploration of the Serrated Pathway

Objectives The Netherlands has recently started with the stepwise implementation of biennial faecal immunochemical testing for colorectal cancer (CRC). We evaluated the impact of the transition to, and the fully implemented screening programme on the long-term CRC incidence and colonoscopy demand. Methods The previously reported and calibrated ASCCA model was set up to simulate the Dutch CRC screening programme between 2014 and 2044. We adopted an open-model approach by simulating multiple birth cohorts and combining the results while accounting for the ageing of the population. Besides a no screening scenario, we evaluated the impact of screening under three sets of natural history assumptions which differed in the contribution of the serrated pathway to the CRC incidence (0%, 15% and 30%). Model-predicted outcomes were CRC incidence and colonoscopy demand per year. Results Due to ageing, the model-predicted CRC incidence in the no screening scenario increased from 77/100,000 in 2014 to 109/100,000 in 2044. Under screening, the predicted CRC incidence in 2014 was between 105/100,000 (assuming all CRCs originate from adenomas) and 109/100,000 (assuming that 30% of CRCs arises from serrated lesions) due to the detection of asymptomatic, prevalent tumours. After this peak, the predicted incidence gradually decreased until in 2039 a new equilibrium was reached, ranging between 65/100,000 and 71/100,000 assuming that 100% versus 70% of CRCs originate from adenomas, respectively. Due to the stepwise implementation, the predicted number of colonoscopies required for the screening programme increased gradually over time from 38,000 (752,199 invitees) in 2014 to 117,000 (2,154,875 invitees) in 2044. Conclusions The Dutch screening programme will markedly decrease CRC incidence in the next 25 years. The conclusions about the impact of screening were robust to key natural history assumptions. With the results of this study, decision-makers can anticipate the expected change in CRC-related health care use and colonoscopy demand

Inclusion of the benefits of enhanced cross-protection against cervical cancer and prevention of genital warts in the cost-effectiveness analysis of human papillomavirus vaccination in the Netherlands

<p>Background: Infection with HPV 16 and 18, the major causative agents of cervical cancer, can be prevented through vaccination with a bivalent or quadrivalent vaccine. Both vaccines provide cross-protection against HPV-types not included in the vaccines. In particular, the bivalent vaccine provides additional protection against HPV 31, 33, and 45 and the quadrivalent vaccine against HPV31. The quadrivalent vaccine additionally protects against low-risk HPV type 6 and 11, responsible for most cases of genital warts. In this study, we made an analytical comparison of the two vaccines in terms of cost-effectiveness including the additional benefits of cross-protection and protection against genital warts in comparison with a screening-only strategy.</p><p>Methods: We used a Markov model, simulating the progression from HPV infection to cervical cancer or genital warts. The model was used to estimate the difference in future costs and health effects of both HPV-vaccines separately.</p><p>Results: In a cohort of 100,000 women, use of the bivalent or quadrivalent vaccine (both at 50% vaccination coverage) reduces the cervical cancer incidence by 221 and 207 cases, corresponding to ICERs of (sic)17,600/QALY and (sic)18,900/QALY, respectively. It was estimated that the quadrivalent vaccine additionally prevents 4390 cases of genital warts, reducing the ICER to (sic)16,300/QALY. Assuming a comparable willingness to pay for cancer and genital warts prevention, the difference in ICERs could justify a slightly higher price (similar to 7% per dose) in favor of the quadrivalent vaccine.</p><p>Conclusions: Clearly, HPV vaccination has been implemented for the prevention of cervical cancer. From this perspective, use of the bivalent HPV vaccine appears to be most effective and cost-effective. Including the benefits of prevention against genital warts, the ICER of the quadrivalent HPV vaccine was found to be slightly more favourable. However, current decision-making on the introduction of HPV is driven by the primary cervical cancer outcome. New vaccine tenders could consider the benefits of cross-protection and the benefits of genital warts, which requires more balanced decision-making.</p>

The Impact of Vehicles on the Mucoadhesive Properties of Orally Administrated Nanoparticles: a Case Study with Chitosan-4-Thiobutylamidine Conjugate

The aim of this study was to evaluate the impact of various vehicles on mucoadhesive properties of thiolated chitosan nanoparticles both in vitro and in vivo. Nanoparticles (NPs) were prepared by in situ gelation technique followed by labeling with fluorescein diacetate. Comparative studies on mucoadhesion were done with these thiolated chitosan NPs and unmodified chitosan NPs (control). The obtained nanoparticles displayed a mean diameter of 164.2 ± 6.9 nm and a zeta potential of 21.5 ± 5 mV. In an in vitro adhesion study, unhydrated thiolated NPs adhered strongly to freshly excised porcine small intestine, which was more than threefold increase compared to the control. In contrast, in the presence of various vehicles (PEG 300, miglyol 840, PEG 6000, cremophor EL, and caprylic triglyceride), the mucoadhesive properties of thiolated NPs were comparatively weak. Thiolated NPs suspended in caprylic triglyceride, for example, had a percent mucoadhesion of 22.50 ± 5.35% on the mucosa. Furthermore, results from in vivo mucoadhesion studies revealed that the dry form of nanoparticles exhibits the strongest mucoadhesion, followed by nanoparticles suspended in PEG 300, miglyol, and 100 mM phosphate buffer, in that order. Three hours after administration, the gastrointestinal residence time of the dry form of thiolated NPs was up to 3.6-fold prolonged. These findings should contribute to the design of highly effective oral mucoadhesive nanoparticulate drug delivery systems