Beyond risk compensation : clusters of antiretroviral treatment (ART) users in sexual networks can modify the impact of ART on HIV incidence

Introduction : Concerns about risk compensation-increased risk behaviours in response to a perception of reduced HIV transmission risk-after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence. Methods : We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily-a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART. Results : ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (approximate to 10%), ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (approximate to 35% HIV prevalence), ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH) have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting. Conclusions : Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes

Lift Not the Painted Veil! To Whom Are Directors’ Duties Really Owed?

In this article, we identify a fundamental contradiction in the law of fiduciary duty of corporate directors across jurisdictions, namely the tension between the uniformity of directors’ duties and the heterogeneity of directors themselves. American scholars tend to think of the board as a group of individuals elected by shareholders, even though it is widely acknowledged (and criticized) that the board is often a largely self-perpetuating body whose inside members dominate the selection of their future colleagues and eventual successors. However, this characterization is far from universally true internationally, and it tends to be increasingly less true even in the United States. Directors are often formally or informally selected by specific shareholders (such as a venture capitalist or an important shareholder) or other stakeholders of the corporation (such as creditors or employees), or they are elected to represent specific types of shareholders (e.g. minority investors). The law thus sometimes facilitates the nomination of what has been called “constituency” directors. Once in office, legal rules tend nevertheless to treat directors as a homogeneous group that is expected to pursue a uniform goal. We explore this tension and suggest that it almost seems to rise to the level of hypocrisy: Why do some jurisdictions require employee representatives that are then seemingly not allowed to strongly advocate employee interests? Why can a director representing a specific shareholder not advance this shareholder’s interests on the board? Behavioral research indicates that directors are likely beholden to those who appointed them and will seek to pursue their interests in order to maintain their position in office. We argue that for many decision-making processes, it does not matter all that much what specific interest directors are expected to pursue by the law, given that across jurisdictions, enforcement of the corporate purpose is highly curtailed

Age differences between sexual partners, behavioural and demographic correlates, and HIV infection on Likoma Island, Malawi

Patterns of age differences between sexual partners-"age-mixing"-may partially explain the magnitude of HIV epidemics in Sub-Saharan Africa. However, evidence of age-disparity as a risk factor for HIV remains mixed. We used data from a socio-centric study of sexual behaviour in Malawi to quantify the age-mixing pattern and to find associations between relationship characteristics and age differences for 1,922 participants. Three age difference measures were explored as predictors of prevalent HIV infection. We found that for each year increase in male participant age, the average age difference with their partners increased by 0.26 years, while among women it remained approximately constant around 5 years. Women in the study had larger within-individual variation in partner ages compared to men. Spousal partnerships and never using a condom during sex were associated with larger age differences in relationships of both men and women. Men who were more than five years younger than their partners had 5.39 times higher odds ( 95% CI: 0.93-31.24) of being HIV-infected than men 0-4 years older. The relationship between HIV-infection and age-asymmetry may be more complex than previously described. The role that women play in HIV transmission should not be underestimated, particularly in populations with large within-individual variation in partner ages

Should home-based HIV testing and counseling services be offered periodically in programs of ARV treatment as prevention? A case study in Likoma (Malawi).

To reduce HIV incidence, prevention programs centered on the use of antiretrovirals require scaling-up HIV testing and counseling (HTC). Home-based HTC services (HBHTC) increase HTC coverage, but HBHTC has only been evaluated during one-off campaigns. Two years after an initial HBHTC campaign ("round 1"), we conducted another HBHTC campaign ("round 2") in Likoma (Malawi). HBHTC participation increased during round 2 among women (from 74 to 83%, P < 0.01). New HBHTC clients were recruited, especially at ages 25 and older. Only 6.9% of women but 15.9% of men remained unreached by HBHTC after round 2. HIV prevalence during round 2 was low among clients who were HIV-negative during round 1 (0.7%), but high among women who received their first ever HIV test during round 2 (42.8%). The costs per newly diagnosed infection increased significantly during round 2. Periodically conducting HBHTC campaigns can further increase HTC, but supplementary interventions to enroll individuals not reached by HBHTC are needed

The Likoma Network Study: Context, data collection and initial results

The extent and structure of sexual networks have important consequences for the spread of sexually transmitted diseases such as HIV. However, very few datasets currently exist that allow a detailed investigation of sexual networks in sub-Saharan African settings where HIV epidemics have become generalized. In this paper, we describe the context and methods of the Likoma Network Study (LNS), one of the few studies that have collected extensive information on sexual networks in sub-Saharan Africa. We start by reviewing theoretical arguments and empirical studies emphasizing the importance of network structures in the epidemiology of HIV and other sexually transmitted infections (STI). The island setting of this study is described, and we argue that the choice of an island as a research site limited potential biases that may make the collection of sexual network data difficult. We then document our empirical strategy for the collection of sexual network data and the subsequent identification of sexual network partners. A description of the protocol for the collection of biomarker data (HIV infection) is provided. Finally, we present initial results relating to the socioeconomic context of the island, the size and composition of sexual networks, the quality of the sexual network data, the determinants of successful contact tracing during the LNS, and the prevalence of HIV in the study population.HIV risk factors, HIV transmission, Malawi, sexual behavior, sexual networks

Operating the law in a global context: the multidimensional comparison

O presente texto apresenta uma análise comparativa multidimensional, exemplificando como advogados podem comparar métodos e soluções específicas dentro de direitos nacionais, regionais (p. ex. Direito europeu) e internacional a fim de solucionarem casos em um contexto global. Essa comparação deve centra-se especificamente em duas questões: o escopo dos direitos levados em consideração e as condições em que são invocados.The present paper focuses on the analysis of the multidimensional comparison, i.e. how, in order to solve cases in a global context, lawyers should compare methods and solutions specific to national, international and regional (e.g., European) laws. The comparison should more specifically focus on two questions: the scope of application of the considered laws and the conditions in which they may be invoked

Impact of measles supplementary immunization activities on reaching children missed by routine programs.

BACKGROUND: Measles supplementary immunization activities (SIAs) are vaccination campaigns that supplement routine vaccination programs with a recommended second dose opportunity to children of different ages regardless of their previous history of measles vaccination. They are conducted every 2-4 years and over a few weeks in many low- and middle-income countries. While SIAs have high vaccination coverage, it is unclear whether they reach the children who miss their routine measles vaccine dose. Determining who is reached by SIAs is vital to understanding their effectiveness, as well as measure progress towards measles control. METHODS: We examined SIAs in low- and middle-income countries from 2000 to 2014 using data from the Demographic and Health Surveys. Conditional on a child's routine measles vaccination status, we examined whether children participated in the most recent measles SIA. RESULTS: The average proportion of zero-dose children (no previous routine measles vaccination defined as no vaccination date before the SIA) reached by SIAs across 14 countries was 66%, ranging from 28% in São Tomé and Príncipe to 91% in Nigeria. However, when also including all children with routine measles vaccination data, this proportion decreased to 12% and to 58% when imputing data for children with vaccination reported by the mother and vaccination marks on the vaccination card across countries. Overall, the proportions of zero-dose children reached by SIAs declined with increasing household wealth. CONCLUSIONS: Some countries appeared to reach a higher proportion of zero-dose children using SIAs than others, with proportions reached varying according to the definition of measles vaccination (e.g., vaccination dates on the vaccination card, vaccination marks on the vaccination card, and/or self-reported data). This suggests that some countries could improve their targeting of SIAs to children who miss other measles vaccine opportunities. Across all countries, SIAs played an important role in reaching children from poor households

Sexual behavior and STI/HIV status among adolescents in rural Malawi: An evaluation of the effect of interview mode on reporting

This paper presents the results from an interview-mode experiment conducted by the Population Council with unmarried young women in rural southern Malawi. To collect data on sexual behavior and the dynamics of HIV transmission, respondents were randomly assigned to either an audio computer-assisted self-interview (ACASI) or a conventional face-to-face (FTF) interview. Clear evidence indicates that the mode of interviewing and probing concerning various sexual partnerships affects respondents’ reporting of their sexual activity, yet the results are not always in accordance with expectations. Reporting for “ever had sex” and “sex with a boyfriend” is higher in the FTF mode, whereas, when we ask about other partners as well as multiple lifetime partners, the reporting is consistently higher with ACASI, in many cases significantly so. The interview-administered mode produced more consistent reporting of sexual activity between the main interview and a subsequent interview. Finally, the association between infection status and reporting of sexual behavior is stronger in the FTF mode, although in both modes, some young women who denied ever having had sex tested positive for STIs/HIV