Maher BMC Public Health 2010, 10:394 http://www.biomedcentral.com/1471-2458/10/394 mutual concerns: the prevention of HIV infection and the treatment of HIV/AIDS should be components of tuber- culosis control, and tuberculosis care and prevention should be priorities in the management of HIV/AIDS [15,16]. Despite recognition of the potential benefits of collaboration between tuberculosis programmes and HIV/AIDS programmes they have often continued to pursue separate courses [17]. They can no longer afford to do so in an era of global economic crisis which demands maximum cost efficiencies. The exigencies of the global economic crisis provide an impetus for HIV programmes and tuberculosis programmes together to take stock of their activities and progress in epidemic control. They need to consider not only how to improve collaboration aimed at advancing progress in the areas of mutual concern, but also how to learn from each other's experiences with the aim of advancing progress in imple- menting their respective main stratagems for epidemic control. Stratagems for HIV and tuberculosis epidemic control The principle of infectious disease epidemic control is to reduce the average number of people infected by each infectious case so that the case reproduction number is less than one. This results in declining incidence of infec- tion. The main stratagems for HIV and tuberculosis epi- demic control include: prevention of primary infection, modification of risk factors for infection, drug prophy- laxis, decreased transmission by treatment of infected individuals (treatment as prevention), and vaccination to prevent progression from infection to disease. The emphasis has been on different stratagems for HIV and for tuberculosis epidemic control, with decreased trans- mission by treatment of infected individuals (treatment as prevention) gaining attention recently for HIV, whereas this has been the mainstay of tuberculosis con- trol for the past 60 years. The emphasis in HIV control has until recently mainly been on promoting behavioural modifications aimed at decreasing the risk of primary infection [18]. In revolutio- nising the care of people with HIV, antiretroviral therapy (ART) has opened the door to treatment as prevention. The benefits of early ART initiation are not only improved individual patient outcomes but also reduced infectiousness and therefore decreased HIV transmission [19]. How best to use ART for prevention has emerged as the most pressing question that faces HIV/AIDS science [20]. Could universal voluntary testing with immediate ART be a strategy for elimination of HIV transmission? A mathematical model shows that this strategy could greatly accelerate the transition from the present endemic phase, in which most adults with HIV infection are not on ART, to an elimination phase, in which most are on ART, within 5 years [21]. There is an urgent need for Page 3 of 11 research to establish the feasibility of this approach and validate the modeling results. Removal of tuberculosis patients from their homes for isolation in sanatoria may have played a role in decreasing M. tuberculosis transmission in the pre-chemotherapy era. However the development of specific anti-tuberculo- sis chemotherapy 60 years ago raised the prospect of reducing transmission risk through decreased infectious- ness of the index cases [22]. This can be achieved by prompt diagnosis and effective treatment, which lie at the heart of modern approaches to tuberculosis control [23]. With proper treatment, a person with infectious tubercu- losis very quickly becomes non-infectious - probably most often in less than two weeks - and so can no longer transmit infection to others [24]. Shortening the period of infectivity can maximize the impact of ART and of antituberculosis chemotherapy on transmission of HIV and M. tuberculosis respectively. In the case of HIV, substantial transmission occurs while the infected person is asymptomatic, so shortening the period of infectivity may well require regular testing of asymptomatic people for HIV infection, and testing of people after an at-risk exposure, as well as prompt diag- nosis and effective treatment of people when they present with symptoms of HIV-related disease. In the case of tuberculosis, transmission occurs from patients with pul- monary tuberculosis when they are symptomatic with cough, so early diagnosis requires patient access to qual- ity health services providing rapid and reliable diagnosis. In both cases, promotion of community awareness is nec- essary for effective health-seeking behaviour, so that peo- ple understand and accept the need for testing as early as possible to maximize the possibility of effective action to decrease transmission. The specific interventions to address HIV and tubercu- losis can be grouped under the main stratagems for epi- demic control (prevention of primary infection, modification of risk factors for infection, drug prophy- laxis, decreased transmission by treatment of infected individuals, and vaccination to prevent progression from infection to disease) (Table 1) [25-45]. Current status of HIV and tuberculosis epidemics and of control measures Assessment of the current status of the HIV and tubercu- losis epidemics indicates that these epidemics are far from under control (Table 2) [2,4,13]. Although there has been considerable progress in global implementation of measures for HIV and tubercu- losis epidemic control, there is still a long way to go before achieving universal access for all to HIV and tuberculosis diagnosis and treatment (Table 3) [13,46-50]. Regarding activities requiring collaboration between HIV and tuberculosis programmes ("collaborative TB/