The impact of HIV on cities in the era of treatment: A global perspective

In this paper, we summarize key aspects of the global HIV situation, focusing on HIV care and treatment programs that provide highly active antiretroviral treatment (ART) and their programs' impact on the epidemiology of the disease, with a particular focus on urban areas. Urban populations in both resource-rich and resource-limited settings have been impacted harder by the HIV epidemic than their rural counterparts. We discuss the impact of HIV in cities before and after the introduction of ART using the example of New York City, one of the world's most resource-rich cities affected by HIV, and draw on the available data from resource-limited settings to anticipate the possible impact of HIV care and treatment programs in sub-Saharan Africa and other resource-poor settings, along with strategies that can be used for evaluating impact.By the end of 2003, a total of 142,310 New Yorkers had been diagnosed with AIDS, including the 84,810 who died. The annual number of deaths declined by 66% in the 6 years following the introduction of ART in 1995. However, the decline has since slowed and the annual number of deaths due to HIV remains relatively constant at about 2100 per year. Pediatric infections resulting from maternal to child transmission of HIV peaked at 321 in 1990 and have since been virtually eliminated. Currently, about 92,000 of New York City's population of 8 million (1.2%) are diagnosed and living with HIV and an estimated additional 22,500 persons living with HIV have not yet been diagnosed. Approximately 4500 New Yorkers are diagnosed with HIV each year, though the rate of new HIV infections is not known. There are substantial racial and ethnic disparities in rates of HIV prevalence, and death due to HIV in New York City. In addition to the challenges associated with preventing HIV transmission in a diverse population, the treatment era has brought with it a new set of challenges related to access to and continuity of care and treatment.With several recently launched international HIV treatment initiatives, the authors turn to the HIV epidemic in resource-limited settings and the expected impact of rapid expansion of HIV care and treatment in these settings, given the epidemic's greater magnitude and scope (25.4 million HIV infections in sub-Saharan Africa alone), and the lack of public health and medical infrastructures. With urban settings tending to have higher prevalence rates and rural settings tending to have greater numbers of persons with HIV, the challenges to HIV care and treatment scale up may be different in urban and rural areas. By June 2005, approximately one million of the estimated 6.5 million HIV-positive persons in need of treatment in resource-limited settings were receiving it.We discuss some of the immediate challenges that lie ahead in controlling the HIV epidemic and providing access to care and treatment in resource-limited countries, drawing on the experience of cities in resource-rich countries. In particular, we focus on the challenges associated with diagnosing HIV in resource-limited settings and facilitating the entry of HIV-positive persons into HIV care and treatment.Finally, the crucial challenge of monitoring and evaluating the progress of HIV care and treatment programs in resource-limited settings is discussed. Epidemiologists have relied on conventional HIV/AIDS case-reporting systems for monitoring and evaluation in resource-rich settings; however, due to resource constraints and lack of medical and public health infrastructure in resource-poor settings, the authors discuss strategies that emphasize the need for simple, yet strong patient tracking systems at HIV care and treatment sites, routine reporting to national monitoring and evaluation systems, and laboratory-based monitoring systems. The need for conducting community based surveys (i.e. among persons inside and outside HIV care and treatment programs) to evaluate impact and assess program coverage and assess barriers to HIV diagnosis and care in the general population is also discussed. An understanding of the impact of HIV care and treatment programs and factors associated with access to them is critical for the sustainability of the world's cities.