TasP offers the chance of significantly reducing HIV transmission and eventually bringing the HIV epidemic to an end. The World Health Organization previously recommended starting ART for all people with CD4+
cell counts below 200 cells/mm3
], but, in 2010, this was raised to 350 cells/mm3
]. The United States Department of Health and Human Services and the International AIDS Society-USA guidelines now recommend consideration of ART even when the CD4+
cell count is greater than 500/mm3
], while in San Francisco the public health system recommends that all HIV-positive people should be offered immediate access to ART . Modelling studies show that each of these increases, 200 cells/mm3
to 350 cells/mm3
to 500 cells/mm3
to immediate treatment, will further reduce the incidence of HIV, as well as of AIDS-related tuberculosis [17
A number of studies to investigate the impact of TasP are being planned or have started, and these will provide important and valuable information for the design of more rigorous trials. They will also inform public health policy regarding the management of HIV, regardless of whether or not they show that TasP could stop transmission. However, an ambitious programme of TasP would, in its initial phases, require significant increases in funding, and it will be important to investigate the financial demands and economic impact of TasP. If ways can be found to ensure that those carrying out these projects remain in close contact and exchange ideas, plans and results, the work will proceed more rapidly and efficiently.
In parallel with feasibility studies, it will be important to develop cost-benefit analyses to compare the current HIV/AIDS strategy with one involving much earlier treatment, and, indeed, to examine the impact of targeting TasP at those in greatest need and at those who, for behavioural or biological reasons, are most likely to infect others. Costs will include direct healthcare investments needed to implement the strategy, including the cost of drugs, infrastructure, logistics and human resources. Benefits will include the reduction in new infections, including opportunistic infections, and deaths, reduced demands placed on the healthcare system, and the benefits to society of keeping young adults alive.
The present situation, in which increasing numbers of HIV-positive people need to be maintained on expensive drugs, which must be taken regularly and for life, is not sustainable. Ways must be found to significantly reduce, and perhaps even eliminate, transmission. Where possible, TasP should be backed up and supported by other methods of prevention, including the promotion of behaviour change, making condoms available and accessible, providing male circumcision services, promoting needle exchange programmes, couples counselling, addressing the needs of pregnant women, providing ART to people suffering from other opportunistic infections, especially tuberculosis, and providing pre-exposure prophylaxis to those at very high risk. However, much still needs to be learned and there will be many obstacles to overcome. But if the work starts now, we might hope to see significant and rapid reductions in transmission within the next decade.