Tuberculosis (TB) continues to plague mankind despite being both curable and preventable. Although clear advances have been made, a stagnated 1.65 percent annual decline in rates, the growing prevalence of multidrug resistance and the lack of an effective vaccine demonstrate how far we are from the elimination goal of one case per million by 2050. The fact remains that TB is the leading infectious disease killer worldwide—estimated to infect 25 percent of the world’s population and take the lives of four thousand people each day.
Although the burden of disease is not as high in developed countries, it remains a threat because of globalization and migration. The vast silent reservoir of TB infection assures future outbreaks of contagious TB, in both high and low risk settings. Making a sustainable difference in the fight against TB will require taking proactive disease control measures that find active TB when it is less infectious and easier to cure. We must also effectively cripple the sleeping giant of latent infection with preventive treatment.
We are not there yet. Current global efforts are dependent on the passive detection of the disease in people who are sick enough to seek out a doctor. This results in delayed diagnosis, spread of disease and, ultimately, higher morbidity and death rates. It also inadvertently replenishes the reservoir of TB infection, guaranteeing TB’s persistence while encouraging drug resistance. Further, this passive approach puts the financial burden on the very people seeking care for TB, raising human rights questions about the lack of proactive screening in populations known to have high rates of TB.
The good news is that in addition to new tools, drugs and shorter prevention regimens, there is global change afoot on two fronts. In 2014, the WHO announced an End TB Strategy that emphasizes early diagnosis and prevention. The Zero TB Initiative, launched in 2016 by the Stop TB Partnership, the Department of Global Health and Social Medicine at Harvard Medical School, Advance Access & Delivery, and Interactive Research and Development, takes a paradigm-shifting comprehensive “search, treat, and prevent” approach, focusing on creating islands of elimination within high burden areas. While mathematical modeling studies underpin the WHO’s strategy, the Zero TB initiative is based on proven disease interventions and represents the implementation needed to accelerate and win the war against TB.
The bad news is that the scale-up of the Zero TB effort is too slow and limited to reach global targets. The major road block is a global infrastructure of TB care and control that is woefully ill equipped in resources and capacity to implement comprehensive disease control and prevention. Most local public health programs in high burden settings merely serve as treatment and data collection centers without capacity to actively protect and promote public health.
Full-scale program strengthening is needed now to modernize and effectively adopt the new technical advances offered by rapid molecular tests, shorter prevention regimens and new drugs. With interferon gamma release assays (IGRAs), we now have an accurate and efficient replacement for the 100-year-old traditional skin test for detecting the latent disease before it progresses to active. Sustainable change will require moving from a cost-driven approach to a realistic one that truly gives the TB army the infrastructure and tools it needs to win the war.
We urgently need to build, equip and modernize the ground troops of TB control and prevention around the world. Combining the advances in treatment and diagnosis with new strategic purpose, manpower and knowledge is essential if we are to move from today’s passive stagnant position to actively take the road to victory.