Up until January 2012, Giving What We Can recommended the Stop TB Partnership as a top charity. This recommendation was withdrawn due to concerns about their capacity to use additional funds to effectively deliver cheap and effective antibiotic treatments - though this does not mean that they are not doing fantastic work.
This blog post provides a summary of our report (forthcoming), which gives an update on whether cost-effective interventions for TB still exist.
Tuberculosis (TB) is a disease caused by bacteria of the Mycobacterium Tuberculosis complex . It is airborne and primarily spread by inhaling microscopic droplets through another person’s coughing or sneezing .
In approximately a third of the world’s population TB is latent (i.e. not yet manifesting symptoms or causing harm to the patient, and not contagious). In 2013 there were approximately 11 million cases of active (i.e. harmful, symptomatic and contagious) TB. 
The estimated effects of TB are:
There are several factors that increase the incidence of TB. These include:
Factors that increase the likelihood of death from the active stage are often of a social nature. They include a lack of healthcare resources  unreliable diagnosis techniques , and disbelief in the population in the benefits of TB medical treatment .
Interventions for TB need to either directly treat the disease, or indirectly target prevalence through addressing risk factors.
The most cost-effective direct intervention appears to be treatment of drug-susceptible TB through short-course chemotherapy, a standard treatment regimen that forms part of the WHO's Directly Observed Treatment, Short-Course (DOTS) strategy. In DCP2, the authors estimate that it costs $5-50 per DALY (2001 USD) to treat non-drug-resistant TB, where the patient is HIV-negative. 
We also recommend that charities focus direct interventions in areas where there is a high concentration of TB sufferers and high-risk groups, in order to minimise extra costs, such as transportation.
There are other interventions besides direct medical treatment that may help combat TB and be cost effective. Worthy of note is that the World Bank rates the intervention of improved biomass stoves as having a cost of $50-100 per DALY  suggesting that there are interventions that reduce indoor air pollution that may be highly cost-effective.
Excitingly, there are several charities working in these areas that appear to be highly cost-effective. Although exact figures are not currently available, Target TB appears to be averting DALYs at a cost of less than $50 per DALY. A calculation of this figure, along with discussion of other promising organisations, is included in the report, but it is important to note that our analysis of these organisations is very preliminary and so this estimate may be subject to substantial revision as we learn more about Target TB.
Much more research is needed in this area. However, some TB interventions appear very promising, and we look forward to seeing further exploration of these.