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Dive into the research topics where Samuel Ayaya is active.

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Featured researches published by Samuel Ayaya.


Journal of Acquired Immune Deficiency Syndromes | 2006

Outcomes of HIV-infected orphaned and non-orphaned children on antiretroviral therapy in western Kenya

Winstone M. Nyandiko; Samuel Ayaya; Esther Nabakwe; Constance Tenge; John E. Sidle; Constantin T. Yiannoutsos; Beverly S. Musick; Kara Wools-Kaloustian; William M. Tierney

Objectives:Determine outcome differences between orphaned and non-orphaned children receiving antiretroviral therapy (ART). Design:Retrospective review of prospectively recorded electronic data. Setting:Nine HIV clinics in western Kenya. Population:279 children on ART enrolled between August 2002 and February 2005. Main Measures:Orphan status, CD4%, sex- and age-adjusted height (HAZ) and weight (WAZ) z scores, ART adherence, mortality. Results:Median follow-up was 34 months. Cohort included 51% males and 54% orphans. At ART initiation (baseline), 71% of children had CDC clinical stage B or C disease. Median CD4% was 9% and increased dramatically the first 30 weeks of therapy, then leveled off. Parents and guardians reported perfect adherence at every visit for 75% of children. Adherence and orphan status were not significantly associated with CD4% response. Adjusted for baseline age, follow-up was significantly shorter among orphaned children (median 33 vs. 41 weeks, P = 0.096). One-year mortality was 7.1% for orphaned and 6.6% for non-orphaned children (P = 0.836). HAZ and WAZ were significantly below norm in both groups. With ART, HAZ remained stable, while WAZ tended to increase toward the norm, especially among non-orphans. Orphans showed identical weight gains as non-orphans the first 70 weeks after start of ART but experienced reductions afterwards. Conclusions:Good ART adherence is possible in western rural Kenya. ART for HIV-infected children produced substantial and sustainable CD4% improvement. Orphan status was not associated with worse short-term outcomes but may be a factor for long-term therapy response. ART alone may not be sufficient to reverse significant developmental lags in the HIV-positive pediatric population.


PLOS ONE | 2014

A Cross-Sectional Study of Disclosure of HIV Status to Children and Adolescents in Western Kenya

Rachel C. Vreeman; Michael L. Scanlon; Ann Mwangi; Matthew Turissini; Samuel Ayaya; Constance Tenge; Winstone M. Nyandiko

Introduction Disclosure of HIV status to children is essential for disease management but is not well characterized in resource-limited settings. This study aimed to describe the prevalence of disclosure and associated factors among a cohort of HIV-infected children and adolescents in Kenya. Methods We conducted a cross-sectional study, randomly sampling HIV-infected children ages 6–14 years attending 4 HIV clinics in western Kenya. Data were collected from questionnaires administered by clinicians to children and their caregivers, supplemented with chart review. Descriptive statistics and disclosure prevalence were calculated. Univariate analyses and multivariate logistic regression were performed to assess the association between disclosure and key child-level demographic, clinical and psychosocial characteristics. Results Among 792 caregiver-child dyads, mean age of the children was 9.7 years (SD = 2.6) and 51% were female. Prevalence of disclosure was 26% and varied significantly by age; while 62% of 14-year-olds knew their status, only 42% of 11-year-olds and 21% of 8-year-olds knew. In multivariate regression, older age (OR 1.49, 95%CI 1.35–1.63), taking antiretroviral drugs (OR 2.27, 95%CI 1.29–3.97), and caregiver-reported depression symptoms (OR 2.63, 95%CI 1.12–6.20) were significantly associated with knowing one’s status. Treatment site was associated with disclosure for children attending one of the rural clinics compared to the urban clinic (OR 3.44, 95%CI 1.75–6.76). Conclusions Few HIV-infected children in Kenya know their HIV status. The likelihood of disclosure is associated with clinical and psychosocial factors. More data are needed on the process of disclosure and its impact on children.


Vulnerable Children and Youth Studies | 2013

Child abuse and neglect among orphaned children and youth living in extended families in sub-Saharan Africa: What have we learned from qualitative inquiry?

Gillian Morantz; Donald C. Cole; Rachel C. Vreeman; Samuel Ayaya; David Ayuku; Paula Braitstein

Researchers and aid organizations have reported that orphans in sub-Saharan Africa (SSA) are particularly vulnerable to abuse and neglect. This article is a review of qualitative studies that address experiences of maltreatment among orphaned children and youth living in extended families in SSA. It aims to inform policy and programming by providing a better understanding of the types of maltreatment encountered and the perceived risk factors. A literature search was carried out using Google, PubMed, Scholars Portal Search and Scopus. Searches of relevant bibliographies and publications of authors were also undertaken. Studies from peer-reviewed journals and the grey literature were reviewed for relevance and quality. Eligible studies had to include orphans living with extended family in SSA as participants, explore their maltreatment experiences and employ a sound qualitative methodology. Findings were coded, extracted, compared and synthesized. Twenty articles, representing 15 studies, were selected. These studies, from diverse SSAn countries, reported similar forms of maltreatment among orphaned children and youth: experiences of intra-household discrimination; material and educational neglect; excessive child labour; exploitation by family members and psychological, sexual and physical abuse. The perceived risk factors were poverty, living with a non-biological caregiver, stigma and alcohol abuse. The findings of the included studies suggest that awareness, prevention and intervention initiatives aimed to curb child abuse and neglect within communities in SSA are needed and should be coupled with efforts to promote education and reduce poverty and stigma.


BMC Public Health | 2013

Harnessing the power of the grassroots to conduct public health research in sub-Saharan Africa: a case study from western Kenya in the adaptation of community-based participatory research (CBPR) approaches

Allan Kamanda; Lonnie Embleton; David Ayuku; Lukoye Atwoli; Peter Gisore; Samuel Ayaya; Rachel C. Vreeman; Paula Braitstein

BackgroundCommunity-based participatory research (CBPR) is a collaborative approach to research that involves the equitable participation of those affected by an issue. As the field of global public health grows, the potential of CBPR to build capacity and to engage communities in identification of problems and development and implementation of solutions in sub-Saharan Africa has yet to be fully tapped. The Orphaned and Separated Children’s Assessments Related to their Health and Well-Being (OSCAR) project is a longitudinal cohort of orphaned and non-orphaned children in Kenya. This paper will describe how CBPR approaches and principles can be incorporated and adapted into the study design and methods of a longitudinal epidemiological study in sub-Saharan Africa using this project as an example.MethodsThe CBPR framework we used involves problem identification, feasibility and planning; implementation; and evaluation and dissemination. This case study will describe how we have engaged the community and adapted CBPR methods to OSCAR’s Health and Well-being Project’s corresponding to this framework in four phases: 1) community engagement, 2) sampling and recruitment, 3) retention, validation, and follow-up, and 4) analysis, interpretation and dissemination.ResultsTo date the study has enrolled 3130 orphaned and separated children, including children living in institutional environments, those living in extended family or other households in the community, and street-involved children and youth. Community engagement and participation was integral in refining the study design and identifying research questions that were impacting the community. Through the participation of village Chiefs and elders we were able to successfully identify eligible households and randomize the selection of participants. The on-going contribution of the community in the research process has been vital to participant retention and data validation while ensuring cultural and community relevance and equity in the research agenda.ConclusionCBPR methods have the ability to enable and strengthen epidemiological and public health research in sub-Saharan Africa within the social, political, economic and cultural contexts of the diverse communities on the continent. This project demonstrates that adaptation of these methods is crucial to the successful implementation of a community-based project involving a highly vulnerable population.


PLOS ONE | 2014

Impact of Domestic Care Environment on Trauma and Posttraumatic Stress Disorder among Orphans in Western Kenya

Lukoye Atwoli; David Ayuku; Joseph W. Hogan; Julius Koech; Rachel C. Vreeman; Samuel Ayaya; Paula Braitstein

Objective The aim of this study was to determine the impact of the domestic care environment on the prevalence of potentially traumatic events (PTEs) and posttraumatic stress disorder (PTSD) among orphaned and separated children in Uasin Gishu County, western Kenya. Methods A total of 1565 (55.5% male) orphaned and separated adolescents aged 10–18 years (mean 13.8 years, sd 2.2), were assessed for PTSD and PTEs including bullying, physical abuse and sexual abuse. In this sample, 746 lived in extended family households, 746 in Charitable Childrens Institutions (CCIs), and 73 on the street. Posttraumatic stress symptom (PTSS) scores and PTSD were assessed using the Child PTSD Checklist. Results Bullying was the commonest PTE in all domestic care environments, followed by physical and sexual abuse. All PTEs were commonest among the street youth followed by CCIs. However, sexual abuse was more prevalent in households than in CCIs. Prevalence of PTSD was highest among street youth (28.8%), then households (15.0%) and CCIs (11.5%). PTSS scores were also highest among street youth, followed by CCIs and households. Bullying was associated with higher PTSS scores and PTSD odds than either sexual or physical abuse. Conclusion This study demonstrated differences in distribution of trauma and PTSD among orphaned and separated children in different domestic care environments, with street youth suffering more than those in CCIs or households. Interventions are needed to address bullying and sexual abuse, especially in extended family households. Street youth, a heretofore neglected population, are urgently in need of dedicated mental health services and support.


Aids Research and Treatment | 2012

A Systematic Review of Clinical Diagnostic Systems Used in the Diagnosis of Tuberculosis in Children

Emily C. Pearce; Jason F. Woodward; Winstone M. Nyandiko; Rachel C. Vreeman; Samuel Ayaya

Background. Tuberculosis (TB) is difficult to diagnose in children due to lack of a gold standard, especially in resource-limited settings. Scoring systems and diagnostic criteria are often used to assist in diagnosis; however their validity, especially in areas with high HIV prevalence, remains unclear. Methods. We searched online bibliographic databases, including MEDLINE and EMBASE. We selected all studies involving scoring systems or diagnostic criteria used to aid in the diagnosis of tuberculosis in children and extracted data from these studies. Results. The search yielded 2261 titles, of which 40 met selection criteria. Eighteen studies used point-based scoring systems. Eighteen studies used diagnostic criteria. Validation of these scoring systems yielded varying sensitivities as gold standards used ranged widely. Four studies evaluated and compared multiple scoring criteria. Ten studies selected for pulmonary tuberculosis. Five studies specifically evaluated the use of scoring systems in HIV-positive children, generally finding the specificity to be lower. Conclusions. Though scoring systems and diagnostic criteria remain widely used in the diagnosis of tuberculosis in children, validation has been difficult due to lack of an established and accessible gold standard. Estimates of sensitivity and specificity vary widely, especially in populations with high HIV co-infection.


PLOS ONE | 2013

Nutritional status of orphaned and separated children and adolescents living in community and institutional environments in Uasin Gishu county Kenya.

Paula Braitstein; Samuel Ayaya; Winstone M. Nyandiko; Allan Kamanda; Julius Koech; Peter Gisore; Lukoye Atwoli; Rachel C. Vreeman; Corey Duefield; David Ayuku

Objective To describe the nutritional status of orphaned and separated children and adolescents (OSCA) living in households in the community (HH), on the street, and those in institutional environments in western Kenya. Methods The study enrolled OSCA from 300 randomly selected households (HH), 19 Charitable Children’s Institutions (CCIs), and 100 street-involved children. Measures of malnutrition were standardized with Z-scores using World Health Organization criteria; Z-scores ≤-2 standard deviations (sd) were moderate-severe malnutrition. Data were analyzed using multivariable logistic regression adjusting for child age, sex, HIV status, whether the child had been hospitalized in the previous year, time living with current guardian, and intra-household clustering for adequacy of diet and moderate-severe malnutrition. Results Included are data from 2862 participants (1337 in CCI’s, 1425 in HH’s, and 100 street youth). The population was 46% female with median age at enrolment of 11.1 years. Only 4.4% of households and institutions reported household food security; 93% of children in HH reported an adequate diet vs. 95% in CCI’s and 99% among street youth. After adjustment, OSCA in HH were less likely to have an adequate diet compared to those in CCI’s (AOR 0.4, 95% CI 0.2–1.0). After adjustment, there were no differences between the categories of children on weight-for-age, weight-for-height, or BMI-for-age. Children living in HH (AOR 2.6, 95% CI: 2.0–3.4) and street youth (AOR: 5.9, 95% CI: 3.6–9.5) were more likely than children in CCI’s to be low height-for-age. Conclusion OSCA in HH are less likely to have an adequate diet compared to children in CCI’s. They and street children are more likely to be moderately-severely low height-for-age compared to children in CCI’s, suggesting chronic malnutrition among them.


BMC Medical Ethics | 2012

A qualitative study using traditional community assemblies to investigate community perspectives on informed consent and research participation in western Kenya

Rachel C. Vreeman; Eunice Kamaara; Allan Kamanda; David Ayuku; Winstone M. Nyandiko; Lukoye Atwoli; Samuel Ayaya; Peter Gisore; Michael L. Scanlon; Paula Braitstein

BackgroundInternational collaborators face challenges in the design and implementation of ethical biomedical research. Evaluating community understanding of research and processes like informed consent may enable researchers to better protect research participants in a particular setting; however, there exist few studies examining community perspectives in health research, particularly in resource-limited settings, or strategies for engaging the community in research processes. Our goal was to inform ethical research practice in a biomedical research setting in western Kenya and similar resource-limited settings.MethodsWe sought to use mabaraza, traditional East African community assemblies, in a qualitative study to understand community perspectives on biomedical research and informed consent within a collaborative, multinational research network in western Kenya. Analyses included manual, progressive coding of transcripts from mabaraza to identify emerging central concepts.ResultsOur findings from two mabaraza with 108 community members revealed that, while participants understood some principles of biomedical research, they emphasized perceived benefits from participation in research over potential risks. Many community members equated health research with HIV testing or care, which may be explained in part by the setting of this particular study. In addition to valuing informed consent as understanding and accepting a role in research activities, participants endorsed an increased role for the community in making decisions about research participation, especially in the case of children, through a process of community consent.ConclusionsOur study suggests that international biomedical research must account for community understanding of research and informed consent, particularly when involving children. Moreover, traditional community forums, such as mabaraza in East Africa, can be used effectively to gather these data and may serve as a forum to further engage communities in community consent and other aspects of research.


Journal of the International AIDS Society | 2014

Measuring adherence to antiretroviral therapy in children and adolescents in western Kenya

Rachel C. Vreeman; Winstone M. Nyandiko; Hai Liu; Wanzhu Tu; Michael L. Scanlon; James E. Slaven; Samuel Ayaya; Thomas S. Inui

High levels of adherence to antiretroviral therapy (ART) are central to HIV management. The objective of this study was to compare multiple measures of adherence and investigate factors associated with adherence among HIV‐infected children in western Kenya.


Child Abuse & Neglect | 2014

Physical and sexual abuse in orphaned compared to non-orphaned children in sub-Saharan Africa: A systematic review and meta-analysis

J. Nichols; Lonnie Embleton; Ann Mwangi; Gillian Morantz; Rachel C. Vreeman; Samuel Ayaya; David Ayuku; Paula Braitstein

This systematic review assessed the quantitative literature to determine whether orphans are more likely to experience physical and/or sexual abuse compared to non-orphans in sub-Saharan Africa (SSA). It also evaluated the quality of evidence and identified research gaps. Our search identified 10 studies, all published after 2005, from Zimbabwe, South Africa, Kenya and Uganda. The studies consisted of a total 17,336 participants (51% female and 58% non-orphans). Of those classified as orphans (n=7,315), 73% were single orphans, and 27% were double orphans. The majority of single orphans were paternal orphans (74%). Quality assessment revealed significant variability in the quality of the studies, although most scored higher for general design than dimensions specific to the domain of orphans and abuse. Combined estimates of data suggested that, compared to non-orphans, orphans are not more likely to experience physical abuse (combined OR=0.96, 95% CI [0.79, 1.16]) or sexual abuse (combined OR=1.25, 95% CI [0.88, 1.78]). These data suggest that orphans are not systematically at higher risk of experiencing physical or sexual abuse compared to non-orphans in sub-Saharan Africa. However, because of inconsistent quality of data and reporting, these findings should be interpreted with caution. Several recommendations are made for improving data quality and reporting consistency on this important issue.

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