Physician-Scientist Babak Javid Takes the Pulse of TB Treatment
Tuberculosis (TB) is an infectious disease that is currently one of the top 10 causes of death worldwide, and one of the major priorities at the Center for Infectious Disease Research (CIDR) and our collaborators. One investigator on the front lines combating this disease is Dr. Babak Javid , a physician-scientist who regularly treats TB patients in clinic and researches strategies to improve TB therapy in the lab. He is currently a professor at Tsinghua University in Beijing, China, studying the bacteria responsible for TB, Mycobacterium tuberculosis (Mtb).
Figure 1: Top 10 Causes of Death in 2015 . The numbers represent millions of people who died from each cause. Blue color denotes non-contagious diseases. Red denotes infectious diseases. Green denotes injuries.
“It is a tragedy that TB is the only curable top ten cause of death worldwide,” Dr. Javid said, explaining why he chose to work on TB. “It still kills more than 1.5 million people in the world. This is because they are the poorest people in the world. There are no poster children for TB.”
Figure 2. 1.7 million people died of TB during 2016 . This is equivalent to someone dying every 20 seconds.
More alarmingly, the World Health Organization (WHO) has estimated that about one-quarter of the world’s population is latently infected with TB without having symptoms . Why is the infection so widespread? This is in part because TB passes between individuals through the air by breathing in tiny droplets containing Mtb. According to the WHO and Centers for Disease Control and Prevention (CDC), these droplets can be suspended in the air for several hours and are commonly generated by TB patients through coughing, sneezing, speaking, or singing [2, 4]. People exposed to these droplets can be infected with Mtb, which either makes them sick right away, or can persist latently without causing symptoms for up to decades. People latently infected with TB have a 5-15% chance of developing disease symptoms, thus serving as a large source of future infection.
Although a TB cure exists, the treatment is difficult. Therapy requires the patient to take four different drugs every day for six months . The side effects are nasty. Diagnosing TB adds to the challenge as symptoms are often mistaken for other diseases, which means that many sufferers unknowingly transmit the disease to others.
Difficulties in Treating TB
The length of treatment coupled with the side effects causes many patients to stop taking the drugs before they are cured. This leads to a vicious cycle of people getting sick again, sometimes with bacteria that have become resistant to several of the standard TB drugs—this drug-resistant form of the disease is called MDR-TB. In 2016, the WHO recorded an estimated half a million cases of MDR-TB . Of these individuals, only 2 in 10 were successfully diagnosed and began therapy. Treating MDR-TB is even more difficult—requiring up to 2 years of drugs, which include daily injections and over 14,000 pills in total. Even with this arsenal, MDR-TB is a lot harder to cure. Only half of MDR-TB patients who begin taking drugs are successfully treated .
Figure 3: Treatment for MDR-TB. Only 1 in 10 MDR-TB patients are successfully cured.
Dr. Javid believes that research is necessary to improve treatment strategies for TB. Most of the existing drugs for TB were developed in the 1950s and 1960s —70 years ago. Resistance to every one of these drugs has emerged. “As a physician, more resources and implementation will help,” he said. “There are specific knowledge gaps in TB diagnosis and treatment in resource-poor settings. That’s why I’m in research.”
Scientists are researching to find new strategies to diagnose and treat TB. Efforts at CIDR include looking for a blood diagnostic for TB , looking for new TB drug targets by disrupting the way that the bacteria sense and respond to their environment, stimulating the immune system to help fight infection, and developing more effective ways to combine individual drugs into treatment regimens.
Future of TB Treatment
“[As a phycisian-scientist], there is a potential to translate new discoveries quite quickly,” Dr. Javid said. Recent advances have made him optimistic about the future of TB treatment. “Something that has been satisfying is to take early stage clinical discovery and applying that early to patients, and this has really helped … There are two new TB drugs [developed within the last five years]. We have repurposed drugs for treating TB. For [patients with TB resistant to most standard drugs], these might be game changing. It would have been inconceivable five years ago. We will figure out how to shorten TB treatment to two months. Shortening TB treatment will happen in the next decade.”
Statements from Dr. Babak Javid have been edited for clarity and conciseness. If you would like to stay updated on the tuberculosis research being done at CIDR, here are our TB laboratories:
- Babak Javid Webpage: https://openwetware.org/wiki/Javidlab:labmembers
- World Health Organization. “The top 10 causes of death fact sheet.”
- World Health Organization. “Tuberculosis fact sheet.”
- Centers for Disease Control and Prevention. “How TB spreads.”
- Centers for Disease Control and Prevention. “Treatment for TB disease.” https://www.cdc.gov/tb/topic/treatment/tbdisease.h...
- Ma et al., “Global tuberculosis drug development pipeline: the need and the reality.” Lancet 2010: 375(9731), pp2100-2109. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(10)60395-9/ppt