Tackling Tuberculosis Head on Through Screening, Further Preventative Measures

Tuberculosis (TB) remains a global health crisis as the leading infectious cause of death in many regions of the world.

Experts, Amee Patrawalla, MD, MPH, program director and associate professor at Rutgers New Jersey Medical School, and Jerry Simbarashe. Zifodya, MD, MPH, assistant professor at Tulane University School of Medicine, shed light on the challenges and advancements in tackling the disease during the American Thoracic Society (ATS) conference in May, giving insight into the prevention, screening and management of TB, more specifically in latent TB.

Globally, TB is affecting regions like Africa, Southeast Asia and Eastern Europe, according to Zifodya. It is transmitted through the air by coughing, sneezing or spitting, and targets the lungs, but can also affect various organs throughout the body.

In 2022 alone, an estimated 10.6 million new TB cases were reported, mainly in low-income regions, highlighting the urgent need for further efforts in TB prevention and control, Zifodya added.

He also discussed TB's changing landscape, noting climate change effects such as wildfires are increasing TB cases.

Additionally, he touched on the growing threat of multidrug-resistant TB (MDR-TB), caused by TB bacteria that are resistant to at isoniazid and rifampin, the most effective first-line TB treatment drugs, especially in countries like India, the Philippines and Russia.

Timely diagnosis, proper treatment and enhanced environmental efforts are crucial to curb TB and MDR-TB spread, he added.

At the ATS meeting, Zifodya and Patrawalla addressed both latent and active TB and their differences when focusing on TB prevention and attacking the disease early on.

According to Zifodya, latent TB is known as an infection while active TB reaches the progressed disease state.

Latent TB infection (LTBI) is characterized by the absence of symptoms, non-infectiousness and can transition to active TB if left untreated. Active TB occurs when the body's immune system can't stop TB germs from multiplying and growing.

Identifying patients at risk and implementing the best screening measures are crucial in TB control efforts, Patrawalla expressed.

"Current evidence really points to TB progression from infection to disease really being more of a spectrum or a continuum, and not really a dichotomy,” she said. “But much of our testing, workup, evaluation and treatment is really based on whether TB is active or latent. And hopefully in the future, we will have better tests so that we can refine this a little bit.”

Key indications for LTBI screening include patients with a history of living in or traveling to high TB burden countries, folks who are immunosuppressed (including those with HIV or organ transplants) and close contacts of infectious TB cases.

Patrawalla compared available testing options for LTBI, favoring Interferon-Gamma Release Assays (IGRAs) over Tuberculin Skin Tests (TSTs) due to their convenience and accuracy, mainly in bacille Calmette-Guerin-vaccinated (BCG) folks.

BCG is a vaccine that prevents TB and other mycobacterial infections, according to the CDC.

Treatment strategies for LTBI typically involve shorter, rifamycin-based regimens, such as four months of rifampin or three months of isoniazid and rifapentine, to improve adherence and minimize hepatotoxicity.

Alternative treatments could be considered based on the patient’s symptoms and drug interactions.

Effective TB prevention and control requires early detection, targeted screening and treatment plans suited for patients, stressed Patrawalla and Zifodya.