Kathryn J. Fiorella

Extra-couple HIV transmission in sub-Saharan Africa: a mathematical modelling study of survey data

BACKGROUND The proportion of heterosexual HIV transmission in sub-Saharan Africa that occurs within cohabiting partnerships, compared with that in single people or extra-couple relationships, is widely debated. We estimated the proportional contribution of different routes of transmission to new HIV infections. As plans to use antiretroviral drugs as a strategy for population-level prevention progress, understanding the importance of different transmission routes is crucial to target intervention efforts. METHODS We built a mechanistic model of HIV transmission with data from Demographic and Health Surveys (DHS) for 2003-2011, of 27,201 cohabiting couples (men aged 15-59 years and women aged 15-49 years) from 18 sub-Saharan African countries with information about relationship duration, age at sexual debut, and HIV serostatus. We combined this model with estimates of HIV survival times and country-specific estimates of HIV prevalence and coverage of antiretroviral therapy (ART). We then estimated the proportion of recorded infections in surveyed cohabiting couples that occurred before couple formation, between couple members, and because of extra-couple intercourse. FINDINGS In surveyed couples, we estimated that extra-couple transmission accounted for 27-61% of all HIV infections in men and 21-51% of all those in women, with ranges showing intercountry variation. We estimated that in 2011, extra-couple transmission accounted for 32-65% of new incident HIV infections in men in cohabiting couples, and 10-47% of new infections in women in such couples. Our findings suggest that transmission within couples occurs largely from men to women; however, the latter sex have a very high-risk period before couple formation. INTERPRETATION Because of the large contribution of extra-couple transmission to new HIV infections, interventions for HIV prevention should target the general sexually active population and not only serodiscordant couples. FUNDING US National Institutes of Health, US National Science Foundation, and J S McDonnell Foundation.

Wildlife decline and social conflict

Policies aimed at reducing wildlife-related conflict must address the underlying causes U.S. President Obamas recent creation of an interagency task force on wildlife trafficking reflects growing political awareness of linkages between wildlife conservation and national security (1). However, this and similar new initiatives in Europe and Asia promote a “war on poachers” that overlooks the ecological, social, and economic complexity of wildlife-related conflict. Input from multiple disciplines is essential to formulate policies that address drivers of wildlife decline and contexts from which associated conflicts ignite.

Antiretroviral concentrations in small hair samples as a feasible marker of adherence in rural Kenya.

Abstract:Antiretroviral hair levels objectively quantify drug exposure over time and predict virologic responses. We assessed the acceptability and feasibility of collecting small hair samples in a rural Kenyan cohort. Ninety-five percentage of participants (354/373) donated hair. Although median self-reported adherence was 100% (interquartile range, 96%–100%), a wide range of hair concentrations likely indicates overestimation of self-reported adherence and the advantages of a pharmacologic adherence measure. Higher nevirapine hair concentrations observed in women and older adults require further study to unravel behavioral versus pharmacokinetic contributors. In resource-limited settings, hair antiretroviral levels may serve as a low-cost quantitative biomarker of adherence.

Around the Table: Food Insecurity, Socioeconomic Status, and Instrumental Social Support among Women Living in a Rural Kenyan Island Community

The objective of this study was to investigate the relationship among socioeconomic status, social support, and food insecurity in a rural Kenyan island community. A cross-sectional random sample of 111 female heads of households representing 583 household members were surveyed in Mfangano Island, Kenya from August to October 2010 using adaptations of the Household Food Insecurity Access Scale and the Medical Outcomes Study Social Support Survey. In multiple linear regression models, less instrumental social support, defined as concrete direct ways people help others (B = –0.81; 95% confidence interval [CI] –1.45 to –0.17), and decreased ownership scale based on owning material assets (B = –2.93; 95% CI –4.99 to –0.86) were significantly associated with increased food insecurity, controlling for age, education, marital status, and household size. Social support interventions geared at group capacity and resilience may be crucial adjuncts to improve and maintain the long term food security and health of persons living in low-resource regions.

Implementation and Operational Research: Pulling the Network Together: Quasiexperimental Trial of a Patient-Defined Support Network Intervention for Promoting Engagement in HIV Care and Medication Adherence on Mfangano Island, Kenya.

Background:Despite progress in the global scale-up of antiretroviral therapy, sustained engagement in HIV care remains challenging. Social capital is an important factor for sustained engagement, but interventions designed to harness this powerful social force are uncommon. Methods:We conducted a quasiexperimental study evaluating the impact of the Microclinic Social Network intervention on engagement in HIV care and medication adherence on Mfangano Island, Kenya. The intervention was introduced into 1 of 4 similar communities served by this clinic; comparisons were made between communities using an intention-to-treat analysis. Microclinics, composed of patient-defined support networks, participated in 10 biweekly discussion sessions covering topics ranging from HIV biology to group support and group HIV status disclosure. Nevirapine concentrations in hair were measured before and after study. Results:One hundred thirteen (74%) intervention community participants joined a microclinic group, 86% of whom participated in group HIV status disclosure. Over 22-month follow-up, intervention community participants experienced one-half the rate of ≥90-day clinic absence as those in control communities (adjusted hazard ratio: 0.48; 95% confidence interval: 0.25 to 0.92). Nevirapine hair levels declined in both study arms; in adjusted linear regression analysis, the decline was 6.7 ng/mg less severe in the intervention arm than control arm (95% confidence interval: −2.7 to 16.1). Conclusions:The microclinic intervention is a promising and feasible community-based strategy to improve long-term engagement in HIV care and possibly medication adherence. Reducing treatment interruptions using a social network approach has important implications for individual patient virologic suppression, morbidity, and mortality and for broader community empowerment and engagement in healthcare.

Pulling the network together: quasi-experimental trial of a patient-defined support network intervention for promoting engagement in HIV care and medication adherence on Mfangano Island, Kenya

Background:Despite progress in the global scale-up of antiretroviral therapy, sustained engagement in HIV care remains challenging. Social capital is an important factor for sustained engagement, but interventions designed to harness this powerful social force are uncommon. Methods:We conducted a quasiexperimental study evaluating the impact of the Microclinic Social Network intervention on engagement in HIV care and medication adherence on Mfangano Island, Kenya. The intervention was introduced into 1 of 4 similar communities served by this clinic; comparisons were made between communities using an intention-to-treat analysis. Microclinics, composed of patient-defined support networks, participated in 10 biweekly discussion sessions covering topics ranging from HIV biology to group support and group HIV status disclosure. Nevirapine concentrations in hair were measured before and after study. Results:One hundred thirteen (74%) intervention community participants joined a microclinic group, 86% of whom participated in group HIV status disclosure. Over 22-month follow-up, intervention community participants experienced one-half the rate of ≥90-day clinic absence as those in control communities (adjusted hazard ratio: 0.48; 95% confidence interval: 0.25 to 0.92). Nevirapine hair levels declined in both study arms; in adjusted linear regression analysis, the decline was 6.7 ng/mg less severe in the intervention arm than control arm (95% confidence interval: −2.7 to 16.1). Conclusions:The microclinic intervention is a promising and feasible community-based strategy to improve long-term engagement in HIV care and possibly medication adherence. Reducing treatment interruptions using a social network approach has important implications for individual patient virologic suppression, morbidity, and mortality and for broader community empowerment and engagement in healthcare.

Socio-demographic and health associations with body mass index at the time of enrollment in HIV care in Nyanza Province, Kenya

Low body mass index (BMI) at the time of enrollment into HIV care has been shown to be a strong predictor of mortality independent of CD4 count. This study investigated socio-demographic associations with underweight (BMI < 18.5) among adults in Nyanza Province, Kenya, upon enrollment into HIV care. BMI, socio-demographic, and health data from a cross-sectional sample of 8254 women and 3533 men were gathered upon enrollment in the Family AIDS Care and Education Services (FACES) program in Nyanza Province, Kenya, between January 2005 and March 2010. Overall, 27.4% of adults were underweight upon enrollment in HIV care. Among each women [W] and men [M], being underweight was associated with younger age (W: adjusted odds ratio [AOR], 2.90; 95% confidence interval [CI], 1.85–4.55; M: AOR, 5.87; 95% CI, 2.80–12.32 for those aged 15–19 compared to ≥50 years old), less education (W: AOR, 2.92; 95% CI, 1.83–4.65; M: AOR, 1.55; 95% CI, 1.04–2.31 for primary education compared to some college/university), low CD4 count (W: AOR, 2.13; 95% CI, 1.50–3.03; M: AOR, 1.43; 95% CI, 0.76–2.70 for 0–250 compared to ≥750 cells/mm3), and poor self-reported health status (W: AOR, 1.72; 95% CI, 0.89–3.33; M: AOR, 9.78; 95% CI, 1.26–75.73 for poor compared to excellent). Among all enrollees to HIV care, low BMI was associated with male gender, lower educational attainment, younger age, and poor self-reported health. HIV care and treatment programs should consider using socio-demographic and health risk factors associated with low BMI to target and recruit patients with the goal of preventing late enrollment into care.

Movement between facilities for HIV care among a mobile population in Kenya: transfer, loss to follow-up, and reengagement

ABSTRACT HIV treatment is life-long, yet many patients travel or migrate for their livelihoods, risking treatment interruption. We examine timely reengagement in care among patients who transferred-out or were lost-to-follow-up (LTFU) from a rural HIV facility. We conducted a cohort study among 369 adult patients on antiretroviral therapy between November 2011 and November 2013 on Mfangano Island, Kenya. Patients who transferred or were LTFU (i.e., missed a scheduled appointment by ≥90 days) were traced to determine if they reengaged or accessed care at another clinic. We report cumulative incidence and time to reengagement using Cox proportional hazards models adjusted for patient demographic and clinical characteristics. Among 369 patients at the clinic, 23(6%) requested an official transfer and 78(21%) were LTFU. Among official transfers, cumulative incidence of linkage to their destination facility was 91% at three months (95%CI (confidence intervals) 69–98%). Among LTFU, cumulative incidence of reengagement in care at the original or a new clinic was 14% at three months (95%CI 7–23%) and 60% at six months (95%CI 48–69%). In the adjusted Cox model, patients who left with an official transfer reengaged in care six times faster than those who did not (adjusted hazard ratio 6.2, 95%CI 3.4–11.0). Patients who left an island-based HIV clinic in Kenya with an official transfer letter reengaged in care faster than those who were LTFU, although many in both groups had treatment gaps long enough to risk viral rebound. Better coordination of transfers between clinics, such as assisting patients with navigating the process or improving inter-clinic communication surrounding transfers, may reduce delays in treatment during transfer and improve overall clinical outcomes.

Considering the Complexity in HIV/AIDS and the Environment

The recent article by Talman et al.1 brings to light the intersection between the health of people, their livelihoods, and the environment in which they live. The framework provides considerable insight into the effect of environmental change on people living with HIV/AIDS, and vice versa. Talman et al. show that the links between HIV/AIDS and the environment require both further study and improved interventions to address this syndemic. As we move toward a joint understanding of HIV/AIDS and the environment, we need to fully appreciate not only the complexity of the human dimensions of HIV/AIDS and the range of ways people interact with the environment, but also the complexity of the environment itself. For example, the Lake Victoria ecosystem, noted for its eutrophication, pollution, and deforestation, has further experienced introductions of nonnative species,2 a tremendous number of extinctions of native cichlid species,3 changing food webs,4 and shifting interactions among its fish species.5 The dimensions of ecosystems and the effects of changes that ripple through them are as complex and multifaceted as those of human systems. To truly understand the ramifications and cyclical nature of this syndemic, we must fully consider the range of factors represented by “global environmental change.” Furthermore, environments remain as varied as social systems. An environment’s characteristics further affect HIV/AIDS–environment interactions. For example, gender dynamics may impact who interacts with the environment most directly. In many agricultural systems, women do most of the work, whereas in some fisheries only men go out fishing. Time horizons may also differ; hunters may be successful in a short time frame, whereas agriculturalists must invest further ahead to reap a harvest. Temporal, gender, and other dynamics that affect how the environment is used, when, and by whom are likely to further complicate interactions between HIV/AIDS, livelihoods, and the environment. To continue improving our understanding and response to how HIV/AIDS and the environment interact, we must apply and question a syndemic framework across varied environments while considering the complexity of both the human and environmental systems.

Human health alters the sustainability of fishing practices in East Africa

Significance We accept that the environment influences human health, but we know little about how human health affects the environment. However, millions of people around the world rely on natural resources for food and livelihoods and confront a high burden of illness. Experience of illness may change people’s physical capacities, outlook, and planning horizons and shape how they engage with the environment. We analyze these impacts in fishing communities of Lake Victoria, Kenya. Although illness may cause the sickest individuals not to fish, many fishers continue fishing but shift their methods. When sick, fishers use methods that are less physically demanding but illegal and environmentally destructive. Our findings suggest that environmental sustainability may be integrally shaped by the health of resource users. Understanding feedbacks between human and environmental health is critical for the millions who cope with recurrent illness and rely directly on natural resources for sustenance. Although studies have examined how environmental degradation exacerbates infectious disease, the effects of human health on our use of the environment remains unexplored. Human illness is often tacitly assumed to reduce human impacts on the environment. By this logic, ill people reduce the time and effort that they put into extractive livelihoods and, thereby, their impact on natural resources. We followed 303 households living on Lake Victoria, Kenya over four time points to examine how illness influenced fishing. Using fixed effect conditional logit models to control for individual-level and time-invariant factors, we analyzed the effect of illness on fishing effort and methods. Illness among individuals who listed fishing as their primary occupation affected their participation in fishing. However, among active fishers, we found limited evidence that illness reduced fishing effort. Instead, ill fishers shifted their fishing methods. When ill, fishers were more likely to use methods that were illegal, destructive, and concentrated in inshore areas but required less travel and energy. Ill fishers were also less likely to fish using legal methods that are physically demanding, require travel to deep waters, and are considered more sustainable. By altering the physical capacity and outlook of fishers, human illness shifted their effort, their engagement with natural resources, and the sustainability of their actions. These findings show a previously unexplored pathway through which poor human health may negatively impact the environment.