The early experience with rolling out vaccination against COVID-19 has brought one aspect of disease control into sharp relief — the vaccine is only as good as the implementation strategy that utilizes it. This lesson has long been clear in TB control. Right now, we have good diagnostics and effective and inexpensive drugs, even if they can be improved. But they are being implemented inconsistently around the world, resulting in a huge number of preventable deaths. Having a strong TB control program is the best weapon we have both to ensure proper treatment of individuals and also, because treatment is our best form of prevention, protecting public health.
But rapid change is a challenge to even the best TB control programs. After all, one of the reasons that that these programs can be successful is that they are standardized, ensuring the same care to all patients. However, some of the new technologies require much more individualization, particularly when it comes to drug-resistant disease. And changing even standardized approaches can be very difficult in large and bureaucratic organizations. In fact, many of us have heard from programs that would prefer to stick with older paradigms even when new interventions are demonstrably superior.
Because there are so many new aspects of diagnosis and treatment, it is now time to embrace change and make it an integral part of TB control. Measures that might help include:
- Algorithms that account for the varying speed and sensitivity of newer diagnostics. It would be simpler if any given country adopted a new diagnostic modality at all nationwide sites simultaneously. This will not happen. Instead, TB controllers are going to be faced with different types of information on each patient at each site. They will need help in understanding how to interpret these tests and what each finding should trigger for treatment and contact tracing.
- Rapid recognition of drug resistance. Earlier appropriate treatment is associated with decreased transmission but, in many programs, resistance isn’t recognized until clinical failure occurs. Finding patients with drug resistance not only benefits them but has important consequences for public health.
- An ability to rapidly incorporate advances in therapeutics. WHO guidelines are changing rapidly and the pace of change is likely to accelerate. Not all drugs are equally accessible in all parts of the world. But some of these hold the promise of having a significant impact on individuals and populations. TB control programs should be planning for how they will change rather than simply responding to new guidelines when they arise.
- Creating structures for individualized therapy. Identifying and optimally treating drug resistant TB requires a separate pathway within control programs. The best programs not only diagnose drug resistance early but also create individualized treatment regimens based on the specific resistance profiles of isolates. This can be accomplished either through expert guidance for each individual or, perhaps more practically, through predefined algorithms that change as new information becomes available. In fact, most clinical trials have been performed with patients with varying degrees of drug resistance, enabling the creation of appropriate algorithms.
- Integration or, at least, coordination with HIV treatment programs. Patients, particularly those with low CD4 counts, benefit from starting HIV treatment early when TB is diagnosed. And a single program is best suited to monitor drug-drug interactions between antiretrovirals and TB antibiotics.
We live in an exciting time for TB control. After decades of incremental changes we are on the edge of substantive advancements in how we approach the identification, treatment and prevention of TB. But they will only make a difference if we can apply them across the spectrum of translation, all the way from the lab to the public health program.