Martin Rudbeck Jepsen

Human papillomavirus transmission and cost-effectiveness of introducing quadrivalent HPV vaccination in Denmark

OBJECTIVES The objective of this study was to simulate human papillomavirus (HPV) infection in a heterosexual population and subsequently analyze the incremental costs and effects of introducing a vaccination program against HPV types 6, 11, 16, and 18 in Denmark compared with screening alone. METHODS The analysis was performed in two phases. First, an agent-based transmission model was developed that described the HPV transmission without and with HPV vaccination. Second, an analysis of the incremental costs and effects was performed. The results of prevalence estimates of HPV, genital warts, cervical intraepithelial neoplasia (CIN1-3), and cervical cancer in the model simulations before and after introduction of HPV vaccination were extrapolated to the Danish population figures. Incremental costs and effects were then estimated. Future costs and effects were discounted. RESULTS Cost-effectiveness ratios for annual vaccination of 12-year-old girls, with a vaccination rate of 70 percent without a catch-up program, were estimated at approximately 1,917 euro per quality-adjusted life-year (QALY, 3 percent discount rate) and 10,846 euro/QALY (5 percent discount rate), given a 62-year time horizon. CONCLUSIONS A vaccination program would incur extra vaccination costs but would save treatment costs and improve both quality of life and survival.

Population-level impact, herd immunity, and elimination after human papillomavirus vaccination: a systematic review and meta-analysis of predictions from transmission-dynamic models

Summary Background Modelling studies have been widely used to inform human papillomavirus (HPV) vaccination policy decisions; however, many models exist and it is not known whether they produce consistent predictions of population-level effectiveness and herd effects. We did a systematic review and meta-analysis of model predictions of the long-term population-level effectiveness of vaccination against HPV 16, 18, 6, and 11 infection in women and men, to examine the variability in predicted herd effects, incremental benefit of vaccinating boys, and potential for HPV-vaccine-type elimination. Methods We searched MEDLINE and Embase for transmission-dynamic modelling studies published between Jan 1, 2009, and April 28, 2015, that predicted the population-level impact of vaccination on HPV 6, 11, 16, and 18 infections in high-income countries. We contacted authors to determine whether they were willing to produce new predictions for standardised scenarios. Strategies investigated were girls-only vaccination and girls and boys vaccination at age 12 years. Base-case vaccine characteristics were 100% efficacy and lifetime protection. We did sensitivity analyses by varying vaccination coverage, vaccine efficacy, and duration of protection. For all scenarios we pooled model predictions of relative reductions in HPV prevalence (RRprev) over time after vaccination and summarised results using the median and 10th and 90th percentiles (80% uncertainty intervals [UI]). Findings 16 of 19 eligible models from ten high-income countries provided predictions. Under base-case assumptions, 40% vaccination coverage and girls-only vaccination, the RRprev of HPV 16 among women and men was 0·53 (80% UI 0·46–0·68) and 0·36 (0·28–0·61), respectively, after 70 years. With 80% girls-only vaccination coverage, the RRprev of HPV 16 among women and men was 0·93 (0·90–1·00) and 0·83 (0·75–1·00), respectively. Vaccinating boys in addition to girls increased the RRprev of HPV 16 among women and men by 0·18 (0·13–0·32) and 0·35 (0·27–0·39) for 40% coverage, and 0·07 (0·00–0·10) and 0·16 (0·01–0·25) for 80% coverage, respectively. The RRprev were greater for HPV 6, 11, and 18 than for HPV 16 for all scenarios investigated. Finally at 80% coverage, most models predicted that girls and boys vaccination would eliminate HPV 6, 11, 16, and 18, with a median RRprev of 1·00 for women and men for all four HPV types. Variability in pooled findings was low, but increased with lower vaccination coverage and shorter vaccine protection (from lifetime to 20 years). Interpretation Although HPV models differ in structure, data used for calibration, and settings, our population-level predictions were generally concordant and suggest that strong herd effects are expected from vaccinating girls only, even with coverage as low as 20%. Elimination of HPV 16, 18, 6, and 11 is possible if 80% coverage in girls and boys is reached and if high vaccine efficacy is maintained over time. Funding Canadian Institutes of Health Research.

Dengue Outbreaks in High-Income Area, Kaohsiung City, Taiwan, 2003–2009

Cases distribute in a clustered pattern, and elderly persons have the highest risk for illness and death.

Cost-effectiveness of human papillomavirus vaccine in reducing the risk of cervical cancer in Ireland due to HPV types 16 and 18 using a transmission dynamic model

We evaluated the cost-effectiveness of combining a cervical cancer screening programme with a national HPV vaccination programme compared to a screening programme alone to prevent cervical dysplasia and cervical cancer related to HPV types 16 and 18 in the Irish healthcare setting. The incremental cost effectiveness of vaccination strategies for 12-year-old females (base-case) and 12-26-year-old catch-up vaccination strategies were examined. The base-case incremental cost-effectiveness ratio was euro17,383/LYG. Using a probabilistic sensitivity analysis about the base-case, the 95% CI for cost per LYG was (euro3400 to euro38,400). This suggests that vaccination against HPV types 16 and 18 would be cost-effective from the perspective of the Irish healthcare payer.

Hotspots of land use change in Europe

Assessing changes in the extent and management intensity of land use is crucial to understanding land-system dynamics and their environmental and social outcomes. Yet, changes in the spatial patterns of land management intensity, and thus how they might relate to changes in the extent of land uses, remains unclear for many world regions. We compiled and analyzed high-resolution, spatially-explicit land-use change indicators capturing changes in both the extent and management intensity of cropland, grazing land, forests, and urban areas for all of Europe for the period 1990–2006. Based on these indicators, we identified hotspots of change and explored the spatial concordance of area versus intensity changes. We found a clear East–West divide with regard to agriculture, with stronger cropland declines and lower management intensity in the East compared to the West. Yet, these patterns were not uniform and diverging patterns of intensification in areas highly suitable for farming, and disintensification and cropland contraction in more marginal areas emerged. Despite the moderate overall rates of change, many regions in Europe fell into at least one land-use change hotspot during 1990–2006, often related to a spatial reorganization of land use (i.e., co-occurring area decline and intensification or co-occurring area increase and disintensification). Our analyses highlighted the diverse spatial patterns and heterogeneity of land-use changes in Europe, and the importance of jointly considering changes in the extent and management intensity of land use, as well as feedbacks among land-use sectors. Given this spatial differentiation of land-use change, and thus its environmental impacts, spatially-explicit assessments of land-use dynamics are important for context-specific, regionalized land-use policy making.

Agent‐based modelling of shifting cultivation field patterns, Vietnam

Shifting cultivation in the Nghe An Province of Vietnams Northern Mountain Region produces a characteristic land‐cover pattern of small and larger fields. The pattern is the result of farmers cultivating either individually or in spatially clustered groups. Using spatially explicit agent‐based modelling, and relying on empirical data from fieldwork and observations for parameterization of variables, the level of clustering in agricultural fields observed around a study village is reproduced. Agents in the model act to maximize labour productivity, which is based on potential yield and labour costs associated with fencing of fields, and are faced with physical constraints. The simulation results are compared with land‐cover data obtained from remote sensing. Comparisons are made on patterns as detected visually and using the mean nearest‐neighbour ratio. Baseline simulation outputs show high degrees of spatial clustering and similarity to the land‐cover data, but also a need for further calibration of model variables and controls.

Mapping dynamics of deforestation and forest degradation in tropical forests using radar satellite data

Mapping anthropogenic forest disturbances has largely been focused on distinct delineations of events of deforestation using optical satellite images. In the tropics, frequent cloud cover and the challenge of quantifying forest degradation remain problematic. In this study, we detect processes of deforestation, forest degradation and successional dynamics, using long-wavelength radar (L-band from ALOS PALSAR) backscatter. We present a detection algorithm that allows for repeated disturbances on the same land, and identifies areas with slow- and fast-recovering changes in backscatter in close spatial and temporal proximity. In the study area in Madre de Dios, Peru, 2.3% of land was found to be disturbed over three years, with a false positive rate of 0.3% of area. A low, but significant, detection rate of degradation from sparse and small-scale selective logging was achieved. Disturbances were most common along the tri-national Interoceanic Highway, as well as in mining areas and areas under no land use allocation. A continuous spatial gradient of disturbance was observed, highlighting artefacts arising from imposing discrete boundaries on deforestation events. The magnitude of initial radar backscatter, and backscatter decrease, suggested that large-scale deforestation was likely in areas with initially low biomass, either naturally or since already under anthropogenic use. Further, backscatter increases following disturbance suggested that radar can be used to characterize successional disturbance dynamics, such as biomass accumulation in lands post-abandonment. The presented radar-based detection algorithm is spatially and temporally scalable, and can support monitoring degradation and deforestation in tropical rainforests with the use of products from ALOS-2 and the future SAOCOM and BIOMASS missions.

Semantically based reclassification of Danish land-use and land-cover information

In recent years, the availability of georeferenced data has increased substantially, as have the number of producers and users of this information. As a consequence, there is a growing need for harmonization of data, not least in its classification descriptions. Unfortunately, inadequate metadata hampers understanding of how data sets are produced and what data classes represent. This study describes how five different categorical geodata sets for Denmark, ranging from habitat registrations through maps of agricultural land use to national topographic data, are integrated and how the integrated data set is reclassified to land-use and land-cover classes. All five data sets differ with respect to data acquisition, and description and classification methodologies, and none of the data distinguish between land use and land cover. The purpose of the reclassification was to produce maps of land use and land cover, with classes being compatible with the land cover classification system (LCCS) from the Food and Agriculture Organization of the United Nations. We identified land-cover and land-use classes from the LCCS that matched Danish conditions and cross-tabulated those classes with classes from the integrated Danish data set. Based on the semantic meaning of the class names from the integrated data set, we used heuristic associational knowledge to estimate their membership in the land-use and land-cover classes. The results are three land-use maps and five land-cover maps, indicating qualitative estimates of the presence of land-cover classes measured on an ordinal scale.

Conceptual and Empirical Approaches to Mapping and Quantifying Land-Use Intensity

Land use is a pervasive driver of change in the earth system (Steffen et al., Ambio 36:614–621, 2007; Turner et al., Proceedings of the National Academy of Sciences of the United States of America 104:20666–20671, 2007). Today, the majority of the ice-free terrestrial surface has been affected in one way or another by human land use (McCloskey and Spalding, Ambio 18:221–227, 1989; Sanderson et al., BioScience 52:891–904, 2002), and since the beginning of agriculture, more than one third of all pristine terrestrial ecosystems have been converted to human-controlled, permanently managed ecosystems with fundamentally altered ecological characteristics (Erb et al., Journal of Land Use Science 2:191–224, 2007). By using the land, human societies alter structures and processes in ecosystems and thereby substantially affect global land cover, biodiversity, biogeochemical cycles of carbon, water, nitrogen, and many other patterns and processes, with far-reaching consequences for ecosystems and human well-being (Millennium Ecosystem Assessment, Ecosystems and human well-being: Current state and trends, 2005). Land use, on the one hand, provides the basis of nutrition, an array of resources and many essential ecosystem services to society. On the other hand, land use is increasingly jeopardising ecosystem functioning and thus threatens the biophysical basis of humanity. This fundamental trade-off related to land use leads to the emergence of an interdisciplinary research agenda, land-system science (Global Land Project, Science plan and implementation strategy. IGBP Report No. 53/ IHDP Report No. 19, 2005), which seeks to improve the observation of land changes as well as the understanding of these changes in a systemic context, including the interactions and feedback loops among social and natural systems (Turner et al., Annals of the Association of American Geographers, 67, 384–396, 2007).

Greenlandic sheep farming controlled by vegetation response today and at the end of the 21st Century

The spatial heterogeneity of vegetation greenness and potential aboveground biomass production for sheep farming has been assessed for Southwest Greenland. A Multi-Criteria Evaluation (MCE) model was set up to identify biophysical constraints on the present spatial distribution of farms and fields based on all existing sheep farms in a detailed study area. Time-integrated NDVI (TI-NDVI) from MODIS and observed temperatures (2000-2012) have been combined with a downscaled regional climate model (HIRHAM5) in order to establish a spatio-temporal model for future TI-NDVI, thus forecasting the dry biomass production available for sheep farming in steps of decades for the next 85 years. The model has been validated against observed biomass production and the present distribution of fields. Future biomass production is used to discuss the expansion of current farms and to identify new suitable areas for sheep farming. Interestingly, new suitable areas are located where sheep farms were situated during the Norse era more than 1000 years ago; areas which have been abandoned for the past 500 years. The study highlights the potential of establishing new areas for sheep farming in Arctic Greenland, where current and future climate changes are markedly amplified compared to global trends. However, for the study area the MCE model clearly indicates that the potential of expansion relies on contemporary infrastructural development.