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Modelling infectious agent transmission using social mixing data
No full textIntroduction
The economic evaluation of new vaccines requires the modelling of infectious disease transmission within a population, which in turn requires making assumptions about specific mixing patterns in the population. In the European POLYMOD project, matrices
generated from social contact studies were determined for 8 European countries. To date, no such data exist for France. The Comes-F study (Contact Matrix Estimation France) aimed to fill this gap.
Methodology
Contact matrices: The survey was carried out over 3 different periods (Feb-Mar, Apr, Apr-May) with 278 participants common to the first and the last periods. Participants had to list all their contacts for 2 consecutive days in a diary, with age, sex, location, frequency, type and duration of the contact, from which we estimated French contact matrices. Outbreak risk : Combining cross-sectional serological surveys from 2009 and 2013 and
vaccine coverage information, we determined an optimal model for the seroprevalence of measles, mumps and rubella for the year of the data collection; age-dependent susceptibility by department was then derived for the year of interest (2016), and effective reproduction number and age-dependent relative incidence of a potential outbreak were estimated using the French contact matrices. Meteorological conditions and mixing patterns: We analysed the influence of meteorological conditions on the temporal variations in mixing patterns. The study population was split according to day and weather at the time the diary was filled in. The mean number of contacts and the potential for transmission summarized by R0 were calculated for type and location of contact under different weather conditions.
Gender and mixing patterns: We conducted a systematic review on gender differences in infection, focusing on influenza, measles, mumps and rubella. Finally, we provided an exploration of the impact of gender on mixing patterns, and eventually the potential implications for modelling.
Results
The 2033 participants reported 38,881 contacts (median [first quartile-third quartile]: 8[5{14] per day), and 54,378 contacts with supplementary professional contacts (9[5{17]). Contrary to age, gender, household size, holidays, weekend and occupation, the period of the year as available in this study had little influence on either the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced the number of contacts dramatically, and as proxies for school closure, reduced R0 by 33% and 28%, respectively. The outbreak risk for mumps and rubella mainly concerned southeastern and south central France, while the risk for measles was more scattered over the country. Risk differed by gender for measles and rubella. Besides infants under 1 year of age, incidence was estimated highest for teenagers and young adults. The weather had a different effect on social mixing according to the type of day, notably weekdays and weekend. But correcting for multiple testing made some results no more
significant, although the trend for a differential effect between weekdays and weekend remained. Gender differences in social mixing might explain some gender differences in infectious disease epidemiology. Using gender-specific susceptibility and gender-specific contact matrices had a significant impact on the result of the modelling.
Conclusion
French contact matrices shared many common aspects with and were qualitatively similar to those of other European countries, despite differences in design and conduct of the survey. Notably, school closures were likely to have a substantial impact on the spread of close contact infections in France. While the risk of a new measles outbreak persists, it predominates for mumps. The effect of weather on social mixing was mild, if not negligible. Gender differences in modelling should be emphasized.UHasselt: BOF BILA: BOF14BL0
Modelling infectious agent transmission using social mixing data
No full textIntroduction
The economic evaluation of new vaccines requires the modelling of infectious disease transmission within a population, which in turn requires making assumptions about specific mixing patterns in the population. In the European POLYMOD project, matrices
generated from social contact studies were determined for 8 European countries. To date, no such data exist for France. The Comes-F study (Contact Matrix Estimation France) aimed to fill this gap.
Methodology
Contact matrices: The survey was carried out over 3 different periods (Feb-Mar, Apr, Apr-May) with 278 participants common to the first and the last periods. Participants had to list all their contacts for 2 consecutive days in a diary, with age, sex, location, frequency, type and duration of the contact, from which we estimated French contact matrices. Outbreak risk : Combining cross-sectional serological surveys from 2009 and 2013 and
vaccine coverage information, we determined an optimal model for the seroprevalence of measles, mumps and rubella for the year of the data collection; age-dependent susceptibility by department was then derived for the year of interest (2016), and effective reproduction number and age-dependent relative incidence of a potential outbreak were estimated using the French contact matrices. Meteorological conditions and mixing patterns: We analysed the influence of meteorological conditions on the temporal variations in mixing patterns. The study population was split according to day and weather at the time the diary was filled in. The mean number of contacts and the potential for transmission summarized by R0 were calculated for type and location of contact under different weather conditions.
Gender and mixing patterns: We conducted a systematic review on gender differences in infection, focusing on influenza, measles, mumps and rubella. Finally, we provided an exploration of the impact of gender on mixing patterns, and eventually the potential implications for modelling.
Results
The 2033 participants reported 38,881 contacts (median [first quartile-third quartile]: 8[5{14] per day), and 54,378 contacts with supplementary professional contacts (9[5{17]). Contrary to age, gender, household size, holidays, weekend and occupation, the period of the year as available in this study had little influence on either the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced the number of contacts dramatically, and as proxies for school closure, reduced R0 by 33% and 28%, respectively. The outbreak risk for mumps and rubella mainly concerned southeastern and south central France, while the risk for measles was more scattered over the country. Risk differed by gender for measles and rubella. Besides infants under 1 year of age, incidence was estimated highest for teenagers and young adults. The weather had a different effect on social mixing according to the type of day, notably weekdays and weekend. But correcting for multiple testing made some results no more
significant, although the trend for a differential effect between weekdays and weekend remained. Gender differences in social mixing might explain some gender differences in infectious disease epidemiology. Using gender-specific susceptibility and gender-specific contact matrices had a significant impact on the result of the modelling.
Conclusion
French contact matrices shared many common aspects with and were qualitatively similar to those of other European countries, despite differences in design and conduct of the survey. Notably, school closures were likely to have a substantial impact on the spread of close contact infections in France. While the risk of a new measles outbreak persists, it predominates for mumps. The effect of weather on social mixing was mild, if not negligible. Gender differences in modelling should be emphasized.UHasselt: BOF BILA: BOF14BL0
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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