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Dive into the research topics where Bettina Shell-Duncan is active.

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Featured researches published by Bettina Shell-Duncan.


Social Science & Medicine | 2011

Dynamics of change in the practice of female genital cutting in Senegambia: testing predictions of social convention theory.

Bettina Shell-Duncan; Katherine Wander; Ylva Hernlund; Amadou Moreau

Recent reviews of intervention efforts aimed at ending female genital cutting (FGC) have concluded that progress to date has been slow, and call for more efficient programs informed by theories on behavior change. Social convention theory, first proposed by Mackie (1996), posits that in the context of extreme resource inequality, FGC emerged as a means of securing a better marriage by signaling fidelity, and subsequently spread to become a prerequisite for marriage for all women. Change is predicted to result from coordinated abandonment in intermarrying groups so as to preserve a marriage market for uncircumcised girls. While this theory fits well with many general observations of FGC, there have been few attempts to systematically test the theory. We use data from a three year mixed-method study of behavior change that began in 2004 in Senegal and The Gambia to explicitly test predictions generated by social convention theory. Analyses of 300 in-depth interviews, 28 focus group discussions, and survey data from 1220 women show that FGC is most often only indirectly related to marriageability via concerns over preserving virginity. Instead we find strong evidence for an alternative convention, namely a peer convention. We propose that being circumcised serves as a signal to other circumcised women that a girl or woman has been trained to respect the authority of her circumcised elders and is worthy of inclusion in their social network. In this manner, FGC facilitates the accumulation of social capital by younger women and of power and prestige by elder women. Based on this new evidence and reinterpretation of social convention theory, we suggest that interventions aimed at eliminating FGC should target womens social networks, which are intergenerational, and include both men and women. Our findings support Mackies assertion that expectations regarding FGC are interdependent; change must therefore be coordinated among interconnected members of social networks.


American Journal of Human Biology | 2009

Evaluation of iron deficiency as a nutritional adaptation to infectious disease: an evolutionary medicine perspective.

Katherine Wander; Bettina Shell-Duncan; Thomas W. McDade

An evolutionary perspective suggests that iron deficiency may have opposing effects on infectious disease risk, decreasing susceptibility by restricting iron availability to pathogens, and increasing susceptibility by compromising cellular immunocompetence. In some environments, the trade‐off between these effects may result in optimal iron intake that is inadequate to fully meet body iron needs. Thus, it has been suggested that moderate iron deficiency may protect against acute infection, and may represent a nutritional adaptation to endemic infectious disease stress. To test this assertion, we examined the association between infection, reflected by C‐reactive protein, a biomarker of inflammation, and iron status, reflected by transferrin receptor (TfR) and zinc protoporphyrin to heme ratio (ZPP:H), among school‐age Kenyan children, and evaluated the hypothesis that moderate iron deficiency is associated with lower odds of infectious disease. TfR > 5.0 mg/l, with sensitivity and specificity for iron deficiency (ZPP:H > 80 μmol/mol) of 0.807 and 0.815, was selected as the TfR definition of iron deficiency. Controlling for age and triceps skinfold thickness (TSF), the odds ratio (OR) for acute viral or bacterial infection associated with iron deficiency (compared to normal/replete) was 0.50 (P = 0.11). Controlling for age and TSF, the OR for infection associated with an unequivocally iron replete state (compared to all others) was 2.9 (P = 0.01). We conclude that iron deficiency may protect against acute infection in children. Am. J. Hum. Biol, 2009.


American Journal of Human Biology | 2009

Women's Autonomy and its Relationship to Children's Nutrition Among the Rendille of Northern Kenya

Emily K. Brunson; Bettina Shell-Duncan; Matthew S. Steele

This study explores the effect of womens autonomy on childrens health. Research was conducted among the Rendille, a traditionally nomadic pastoralist population living in northern Kenya. Using data collected from 435 women and 934 of their children, we tested the hypothesis that women with higher levels of autonomy would have children with better nutrition. Results of our study indicated that while womens autonomy had no effect on younger—ages 0–35 months—childrens nutrition as measured by WHZ scores, greater levels of womens autonomy were significantly associated with improved nutrition among older—ages 3–10 years—children. These results suggest that womens autonomy is an important factor in relation to childrens health in some circumstances. In addition to exploring the applied aspects of our findings, we also suggest how considering the concept of womens autonomy may add to the existing literature on parental investment. Am. J. Hum. Biol., 2009.


AIDS | 2014

'If I am given antiretrovirals I will think I am nearing the grave': Kenyan HIV serodiscordant couples' attitudes regarding early initiation of antiretroviral therapy.

Kathryn Curran; Kenneth Ngure; Bettina Shell-Duncan; Sophie Vusha; Nelly Mugo; Renee Heffron; Connie Celum; Jared M. Baeten

Objectives:Early initiation of antiretroviral therapy (ART) – that is, at higher CD4+ cell counts (>350 cells/&mgr;l) – is a potent HIV prevention strategy. The WHO recommends ART initiation by all HIV-infected individuals in HIV serodiscordant relationships to prevent HIV transmission, yet the acceptability of early ART among couples has not been well studied. Design:Qualitative study exploring HIV serodiscordant couples’ attitudes toward early initiation of ART. Methods:We conducted eight focus group discussions and 20 in-depth interviews with members of heterosexual HIV serodiscordant couples in Kenya. Investigators iteratively applied inductive and deductive codes, developed matrices to identify patterns in codes, and reached consensus on key attitudes (motivations and barriers) related to early ART and one central, emerging theme. Results:Most participants expressed interest in early initiation of ART, with maintaining health and preventing HIV transmission as key benefits. However, many identified personal concerns and potential barriers to wider community acceptance, including side-effects, adherence to life-long treatment, and stigma. The meaning of ART emerged as a fundamental consideration, with initiating therapy perceived as emblematic of the final stage of AIDS, when one was ‘nearing the grave.’ One particular challenge was what early ART might signify for someone who looks and feels healthy. Conclusion:HIV serodiscordant couples recognized the potential benefits of early ART, but ART was frequently viewed as signifying AIDS and approaching mortality. Potential implementation of early ART presents challenges and an opportunity to re-orientate individuals toward a new image of ART as health-preserving for patients and partners.


American Journal of Physical Anthropology | 2000

Child nutrition in the transition from nomadic pastoralism to settled lifestyles: individual, household, and community-level factors.

Bettina Shell-Duncan; Walter O. Obiero

The research reported here examines child nutrition in a population that is currently experiencing a transition in subsistence, shifting from nomadic pastoralism to a variety of settled lifestyles. We investigate the range of nutritional consequences of settlement both within and between communities by examining individual, household, and community-level predictors of child nutritional status. Data are drawn from the Rendille Demographic and Health Survey, which contains anthropometric data from 1,088 children ages 6 months to 10 years, as well as socioeconomic data from 640 households drawn from one nomadic and four economically and ecologically diverse settled communities. Comparisons allow us to test the widely held assumption that settlement results in nutritional improvements. The examination of individual and household-level factors highlights several important influences on child nutrition. We find a complex interaction between gender and birthorder, whereby firstborn sons have significantly higher weight-for-height scores than other children, potentially reflecting preference under a system of primogeniture. We also find a complex interaction between defacto female-headed households, where males are absent for over half of the year, and economic status. Young children from poor female-headed households have significantly lower weight-for-height than other children, possibly due to the fact that these households are amongst the poorest in the entire community. However, young children from economically sufficient female-headed households actually fare better than their counterparts in male headed households, suggesting that in households with any discretionary resources, female heads prioritize food acquisition relative to other concerns. Finally, our comparison of child nutritional status across communities, while controlling for individual and household-level variation, does not support the contention that settlement is associated with nutritional improvements. Rather, the effect of community, and its associated changes in subsistence and lifestyle, results in either no nutritional changes, or in the case of young children in the lowland desert community of Korr, diminished nutritional status. Our results underscore the importance of considering variation in sample composition and socioeconomic status when performing community comparisons, and highlight the central role of women in influencing the nutritional welfare of their families.


Public Health Nutrition | 2008

Feasibility of using retinol-binding protein from capillary blood specimens to estimate serum retinol concentrations and the prevalence of vitamin A deficiency in low-resource settings.

Jonathan Gorstein; Omar Dary; Pongtorn; Bettina Shell-Duncan; Tim Quick; Emorn Wasanwisut

Vitamin A deficiency (VAD) is a significant public health problem in many countries. While cost-effective interventions are available to control VAD, reliable information is needed to the track progress of control programmes. However, assessment of VAD is uncommon because current approaches are expensive and not feasible in low-resource settings. The present study explores the utility of retinol-binding protein (RBP), analysed by enzyme-linked immunosorbent assay from capillary blood, as an alternative measure of serum retinol concentrations in populations. The study collected matched panels of venous and capillary blood from pre-school children in Chiang Mai, Thailand. Of a total sample of 195 children, there were no differences between RBP from venous blood, RBP from capillary blood or retinol from capillary blood relative to retinol from venous blood. Receiver-operating characteristic curve analysis suggested a cut-off of RBP < 0.825 micromol l(-1) had optimal screening proficiency relative to retinol <0.70 micromol l(-1). For the purpose of population assessment, all three parameters performed well in screening for VAD relative to retinol from venous blood. There were no differences in the estimates of VAD between children stratified by inflammation status. Lower RBP concentrations were found in children in the early convalescent stage of infection than in children with no infection or in the late convalescent stage. This study provided evidence of the biological comparability between retinol and RBP estimated from venous blood and capillary blood. This is a critical observation as it provides empirical evidence that RBP from capillary blood is a surrogate measure of serum retinol concentrations.


Food and Nutrition Bulletin | 2005

Cultural and environmental barriers to adequate iron intake among northern Kenyan schoolchildren

Bettina Shell-Duncan; Thomas W. McDade

The purpose of this study was to examine the context of iron deficiency and feeding patterns of iron-rich foods among northern Kenyan school-aged children. A nutrition survey was conducted among 300 subjects in two Rendille communities, Korr and Karare. The objectives were to determine the prevalence of iron deficiency as it relates to parasitic infection, dietary intake, and sociodemographic factors, as well as cultural food proscriptions influencing child feeding. Sociodemographic and qualitative data on food beliefs and child-feeding practices were obtained from the primary caretaker of each subject. From pediatric subjects, 24-hour dietary recall data were obtained with the help of the primary caretaker, and capillary blood from a fingerstick was used to detect iron deficiency based on measures of hemoglobin, the zinc protoporphyrin-to-heme ratio, C-reactive protein, and transferrin receptor. With an overall prevalence of 31.2%, iron deficiency was found to be associated with dietary iron intakes constrained by diverse economic, cultural, and environmental factors among Rendille children. In Karare, where childrens iron intake approached recommended levels, iron deficiency was found to be attributable to low bioavailability of iron (only 4.3% of total iron intake), rather than low dietary intake per se. By contrast, in Korr the average daily iron intake was estimated at only 65% of recommended allowances, indicating that iron deficiency was the outcome not merely of low bioavailability, but rather of overall inadequate iron intake. Sociodemographic analysis showed a significant interaction between sex and economic status, revealing that girls in economically sufficient households were 2.4 times as likely to have iron deficiency as boys. This difference in risk parallels culturally defined gender-based proscriptions for child feeding: girls are believed to benefit from “soft foods,” including rice, maize porridge, and tea, whereas boys benefit from “hard foods,” including meat, blood, and beans. Consequently, in households economically able to purchase iron-rich foods, these foods are being preferentially fed to boys. Economic development may result in improved iron status for boys, but it will be unlikely to benefit girls in the absence of a dietary modification intervention. A modification of culturally acceptable “soft foods” to include iron-rich foods may provide a sustainable approach to controlling and preventing iron deficiency in this population.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2014

My intention was a child but I was very afraid: fertility intentions and HIV risk perceptions among HIV-serodiscordant couples experiencing pregnancy in Kenya

Kenneth Ngure; Jared M. Baeten; Nelly Mugo; Kathryn Curran; Sophie Vusha; Renee Heffron; Connie Celum; Bettina Shell-Duncan

We sought to understand fertility intentions and HIV risk considerations among Kenyan HIV-serodiscordant couples who became pregnant during a prospective study. We conducted individual in-depth interviews (n = 36) and focus group discussions (n = 4) and performed qualitative data analysis and interpretation using an inductive approach. Although most of the couples were aware of the risk of horizontal and vertical HIV transmission, almost all couples reported that they had intended to become pregnant and that the desire for children superseded HIV risk considerations. Motivations for pregnancy were numerous and complex: satisfying desired family size, desire for biological children, maintaining stability of the union, and sociocultural pressures. Couples desired strategies to reduce HIV risk during conception, but expressed hesitation toward assisted reproductive technologies as unnatural. HIV prevention programs should therefore address conception desires and counsel about coordinated periconception risk-reduction strategies.


American Journal of Human Biology | 2011

Vitamin A dynamics in breastmilk and liver stores: A life history perspective

Masako Fujita; Bettina Shell-Duncan; Philip Ndemwa; Eleanor Brindle; Yun Jia Lo; Yeri Kombe; Kathleen A. O'Connor

Newborns are dependent on breastmilk vitamin A for building hepatic stores of vitamin A that will become critical for survival after weaning. It has been documented that vitamin A concentrations in breastmilk decline across the first year postpartum in both well‐nourished and malnourished populations. The reason for this decline has been assumed to be a sign of concurrently depleting maternal hepatic stores. This study investigates this assumption to clarify why the decline occurs, drawing on life history theory.


Sexually Transmitted Infections | 2004

Male genital hygiene beliefs and practices in Nairobi Kenya.

Matthew S. Steele; Elizabeth A. Bukusi; Craig R. Cohen; Bettina Shell-Duncan; King K. Holmes

Objectives: Attitudes and practices concerning genital hygiene may influence topical microbicide use by men. This study examines knowledge and behaviours related to hygiene, genital hygiene, circumcision and hygiene, and to genital hygiene before and after sex among men in Nairobi, Kenya. Methods: We conducted 463 interviews of men recruited by respondent driven sampling techniques and 10 focus group discussions with a subsample of 100 volunteers from this group. Men were asked individual quantitative survey and qualitative group discussion questions about general hygiene behaviours, genital hygiene, and the temporal relation of genital hygiene behaviours to sexual encounters. Results: Bathing once daily was associated with education, income, and inside tap water. Genital washing aside from regular bathing and washing before sex ever were negatively associated with bathroom crowding. Genital hygiene before the most recent sexual encounter was uncommon and negatively associated with HIV risk perception, bathroom crowding, and ethnicity. Men believed genital hygiene before sex would arouse suspicions of infidelity or cool sexual ardour. Genital hygiene after sex was associated with education, religion, and having inside tap water. Genital hygiene after the most recent sexual encounter was associated with age, income, and with men having at least one child. Conclusions: Genital hygiene behaviours were associated with resource access factors and group discussions suggest that they are modulated by interactions in sexual partnerships. Topical microbicides may improve hygiene before and after sex.

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Ylva Hernlund

University of Washington

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Philip Ndemwa

Kenya Medical Research Institute

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Masako Fujita

Michigan State University

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Kenneth Ngure

Jomo Kenyatta University of Agriculture and Technology

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Connie Celum

University of Washington

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