Maher BMC Public Health 2010, 10:394 http://www.biomedcentral.com/1471-2458/10/394 tum of recent international health gains but will also pre- pare the ground for even greater health gains when the global economy recovers. The global financial crisis threatens global health, particularly exacerbating diseases of inequality such as HIV/AIDS and diseases of poverty such as tuberculosis. The approaches to HIV and tuber- culosis epidemic control are ripe for a re-think. In this paper we look for a possible silver lining in the global eco- nomic crisis regarding health sector efforts for the con- trol of HIV and tuberculosis, which are both among the leading infectious causes of illness and death worldwide [1]. HIV and tuberculosis share many similarities in epi- demic characteristics and challenges in mounting an effective health sector response [2]. Despite also consid- erable overlap in epidemiology [2], the status quo is that not enough has been made of the opportunities for mutual learning and interaction between the respective control programmes. Re-thinking the status quo can help both programmes in two ways: firstly, to learn from each other's experiences with the aim of expediting implemen- tation of their respective stratagems for epidemic control, and secondly, to improve collaboration and advance progress in areas of mutual concern. As part of efforts to strengthen overall health system performance, maximiz- ing synergies and decreasing inefficiencies in the approaches to HIV and tuberculosis epidemic control can generate substantial health gains. The aim of this paper is to re-think established prac- tices and policies for HIV and tuberculosis epidemic con- trol. First there is a comparison between HIV and tuberculosis, showing the important differences, similari- ties and overlap between these epidemics. This then enables identification of the similarities in the main strat- agems for HIV and tuberculosis epidemic control. Review of the current status of the HIV and tuberculosis epidem- ics and of implementation of control measures leads to the conclusion that these epidemics are far from under control, necessitating a re-think of established practices and policies. Based on the similarities between control stratagems, approaches are proposed for better HIV and tuberculosis epidemic control. The opportunities identi- fied for greater synergies between these programmes and the health system could deliver better results and value for money. Although the main focus is on developing countries, which bear the brunt of both epidemics and have the least resources for the health sector response, lessons may also be applicable to developed countries. Discussion HIV and tuberculosis - differences, similarities and overlap HIV is very new and infection is as yet incurable; tuber- culosis very old and has been curable with drugs for the past 60 years. The HIV epidemic arose in the twentieth Page 2 of 11 century following the cross-species transfer of simian immunodeficiency viruses from primates to humans [3]. HIV currently infects 33 million out of the global popula- tion of 6 billion people, i.e. 0.5% of the world's population [4]. HIV infection is lifelong, and fatal if untreated. The virulence of HIV as a new human pathogen mitigates against its success and its further spread may depend on its evolution with selection of less virulent strains. In con- trast to the modernity of HIV, the Mycobacterium tuber- culosis complex clonal group responsible for causing tuberculosis has co-evolved with humanity over the past three million years - our remote early hominid ancestors may have suffered from tuberculosis [5]. Once infected with M. tuberculosis, a person remains infected for many years, probably for life. The vast majority (90%) of people who are infected with M. tuberculosis do not develop tuberculosis [6]. The risk of tuberculosis following M. tuberculosis infection is determined mainly by the indi- vidual's immune status (and hence HIV infection is a potent risk factor for tuberculosis). Even in the absence of treatment, self-cure occurs in three out of ten patients with tuberculosis (without HIV infection) [7]. The suc- cess of M. tuberculosis as a human pathogen, infecting about one-third of the world's population, reflects the extremely long and close relationship it has enjoyed with humanity [8]. The nature of the interaction between the two human pathogens, with a close relationship between HIV and tuberculosis, is a consequence of the fact that HIV is a very new and M. tuberculosis a very old pathogen. HIV and M. tuberculosis share several similarities in their interaction with the human host. They are both life-long infections, with a long and variable latent period between infection and onset of disease - in the case of HIV, about two years in Africa [9] (longer in developed countries) and in the case of M. tuberculosis, usually less than five years [10]. In both cases, the outlook for the infected indi- vidual is worse the later the detection of disease and the start of treatment [11,12]. The annual global toll of deaths from HIV and from tuberculosis is similar - in 2007 there were 1.5 million deaths from HIV [4] (excluding those with tuberculosis), 1.3 million deaths from tuberculosis (among HIV-negative people) [13], and 0.5 million deaths among people with HIV and tuberculosis [13]. The worldwide epidemics of HIV and tuberculosis are both out of control, with HIV still infecting people faster than the pace of antiretroviral treatment roll-out [4] and the absolute number of annual tuberculosis cases still increasing [13]. There is a considerable overlap between those infected with HIV and those infected with M. tuberculosis, espe- cially in sub-Saharan Africa [14], with tuberculosis a lead- ing cause of death among people with HIV infection [14]. Tuberculosis and HIV control programmes clearly have