There has been considerable debate over the last 10-15 years as to what constitutes an appropriate standard of health care (SoC) in the context of clinical trials conducted in resource-poor countries [1–3].
HIV prevention trials present a number of unique ethical dilemmas for researchers [4–12]. In many developed and developing countries, such trials are feasible only among vulnerable sub-populations at high-risk of HIV infection and sexually transmitted infections (STIs)[13, 14], where poverty, stigma and social exclusion are significant barriers to local health care access and decisions regarding SoC provision are therefore paramount [15–18].
There is currently no international consensus on researchers' responsibility to meet the health needs of clinical trial participants or their obligations to the wider community from which participants are drawn. In 2000, the World Medical Association (WMA) revised the Declaration of Helsinki, stating in paragraph 29 that the "best current prophylactic, diagnostic and therapeutic methods" i.e. the highest possible SoC should be made available to people participating in clinical research . Guidelines produced subsequently by the UK Nuffield Council on Bioethics , the US National Bioethics Advisory Commission (NBAC) , the Council for International Organization of Medical Sciences (CIOMS)  and UNAIDS  contradict this construct of SoC however and propose that it is ethically justifiable, under certain conditions, to provide less than the worldwide best standard. For example, both the NBAC and CIOMS guidelines recommend that clinical trial participants be given "established effective" therapy as a minimum whilst the Nuffield Council on Bioethics recommends:
"where it is not appropriate to offer a universal [i.e. 'worldwide best'] standard of care, the minimum standard of care that should be offered to the control group is the best intervention available for that disease as part of the national public health system".
More recently, international debate has shifted from these narrow definitions of SoC, in which researchers' obligation to subjects randomised to the placebo or control arms of HIV prevention trials are a particular focus, to a broader conceptualisation of SoC based on the principles of equity, social justice and beneficence that consider the overall health needs of trial participants and the community within which research is conducted [16, 24]. This approach is supported by recent community-based research in East and Southern Africa, India and the United States, which has highlighted the pivotal role of community participation and the importance of open, effective dialogue between researchers and community stakeholders in the on-going SoC debate [12, 17, 18, 25].
Mwanza is one of six centres in sub-Saharan Africa participating in the Microbicides Development Programme (MDP), an international partnership for the development of vaginal microbicides for HIV prevention, funded by the UK Department for International Development and Medical Research Council (MRC). A feasibility study  was carried out among an occupational cohort of women at increased risk of HIV infection and STIs in ten administrative wards in Mwanza City, northwest Tanzania between July 2002 and March 2005 in preparation for the on-going MDP301 randomized placebo-controlled efficacy and safety trial of the candidate vaginal microbicide PRO2000/5 Gel (Indevus Pharmaceuticals, USA), which started in November 2005. Women working in food and recreational facilities, including modern bars, traditional bars (known as vilabu or pombe shops in Tanzania), restaurants, hotels, guesthouses, groceries and as informal food vendors (known locally as mamalishe), are eligible to participate. Research conducted at a number of sites in Tanzania suggests that some women in this occupational group periodically supplement their income through transactional sex [28, 29] and are hence at increased risk of STIs and HIV infection [27, 30–32]
In this paper we describe how a locally-appropriate SoC package was developed by researchers, study participants and community stakeholders in the context of the MDP301 vaginal microbicide trial in Mwanza; present case studies to illustrate some of the ethical issues and dilemmas encountered during implementation; and critically appraise whether the strategies adopted have been successful in this setting.