Public Health www.thelancet.com Vol 368 August 5, 2006 505 Background Around 40 million people worldwide are thought to be infected with HIV. Many of these people live in developing countries. Since 2001, the WHO has been promoting a public-health approach to antiretroviral therapy (ART) to improve access in resource-poor settings. Existing guidelines for ART, 1,2 and the prevention of mother-to- child transmission 3 were revised earlier this year, and separate guidelines for treating children were developed. 4–6 Other publications support the public-health approach to ART delivery 7–9 and free 10 and equitable access 11 to ART. The integrated management of adult, adolescent, and childhood illness (IMAI/IMCI) has been developed to support decentralised implementation in resource-poor countries. 12 Treatment options have been consolidated into two sequential ART regimens. 2 International consensus on a simple first-line antiretroviral combination for adults meant that production and supply of ARTs could be scaled-up. Once fixed-dose combinations became widely available, and prices had fallen substantially, the WHO announced its 3 by 5 initiative (to strive for 3 million people in low-income and middle-income countries to be on antiretrovirals by 2005). 13 Although the initiative did not meet its target, by the end of 2005, around 1·3 million people were receiving WHO-recommended first-line regimens, 14 compared with 400 000 in 2003. A recent assessment noted that almost all focus countries for ART scale-up had either adapted or used WHO recommendations to shape national policy; 15 treatment programmes and centres report good initial responses. 16,17 Despite these achievements, there remains considerable uncertainty about what should constitute a public-health approach to ART. We summarise here the WHO’s approach, and clarify its importance for treatment providers, HIV programme managers, and policymakers in developing countries. Why a public-health approach? Extensive evidence shows that combined antiretrovirals can substantially extend the life of those with HIV/AIDS. Guidelines for industrialised countries cover individual patient management delivered by specialist doctors prescribing from the full range of antiretrovirals, supported by routine high-technology laboratory monitoring. 18,19 Such an approach is not feasible in resource-limited settings where doctors are scarce (eg, one per 12 500 population in Uganda 20 ), laboratory infrastructure is inadequate (eg, one working microscope per 100 000 population in central Malawi 21 ), and the procurement and supply-chain management is fragile. This difficulty in translating guidelines from developed to developing nations caused concerns over whether ART scale-up in poor countries was feasible, let alone affordable or cost-effective. Drawing on experience from using the DOTS approach for tuberculosis, the WHO began to develop a public-health approach to providing ART. This approach took into account country requirements, the realities of weak health systems, and the experiences of pioneering ART programmes. 22 The key tenets were standardisation and simplification of regimens to support efficient implementation, ensuring ART programmes were based on the most rigorous scientific data, 1 and equity—aiming to set standards for treatment that should be accessible by all in need. The key conceptual shift was the move from an individual-based approach to a population-based one, recognised as the only way to make ART rapidly accessible to the millions in need. 23 Lancet 2006; 368: 505–10 Department of HIV/AIDS, World Health Organization, Geneva 1211, Switzerland (Prof C F Gilks FRCP, S Crowley MRCP, René Ekpini MD, S Gove MD; Jos Perriens MD, Y Souteyrand PhD, D Sutherland MD, M Vitoria MD, T Guerma MD, K De Cock FRCP) Correspondence to: Prof Charles Gilks gilksc@who.int The WHO public-health approach to antiretroviral treatment against HIV in resource-limited settings Charles F Gilks, Siobhan Crowley, René Ekpini, Sandy Gove, Jos Perriens, Yves Souteyrand, Don Sutherland, Marco Vitoria, Teguest Guerma, Kevin De Cock WHO has proposed a public-health approach to antiretroviral therapy (ART) to enable scaling-up access to treatment for HIV-positive people in developing countries, recognising that the western model of specialist physician management and advanced laboratory monitoring is not feasible in resource-poor settings. In this approach, standardised simplified treatment protocols and decentralised service delivery enable treatment to be delivered to large numbers of HIV-positive adults and children through the public and private sector. Simplified tools and approaches to clinical decision-making, centred on the “four Ss”—when to: start drug treatment; substitute for toxicity; switch after treatment failure; and stop—enable lower level health-care workers to deliver care. Simple limited formularies have driven large-scale production of fixed-dose combinations for first-line treatment for adults and lowered prices, but to ensure access to ART in the poorest countries, the care and drugs should be given free at point of service delivery. Population-based surveillance for acquired and transmitted resistance is needed to address concerns that switching regimens on the basis of clinical criteria for failure alone could lead to widespread emergence of drug-resistant virus strains. The integrated management of adult or childhood illness (IMAI/IMCI) facilitates decentralised implementation that is integrated within existing health systems. Simplified operational guidelines, tools, and training materials enable clinical teams in primary-care and second-level facilities to deliver HIV prevention, HIV care, and ART, and to use a standardised patient-tracking system.