As we reflect on the progress made in the fight against tuberculosis (TB), the Centers for Disease Control and Prevention stress that without actions to accelerate progress, the goal of eliminating TB in the United States by the end of the century will not be met.
Today, March 24, is World TB Day, a day dedicated to promoting awareness on tuberculosis (TB), reflecting on the progress that has already been made, and the steps that still need to be taken to win the fight against the disease.
In light of this day, the Centers for Disease Control and Prevention (CDC) has released preliminary 2016 TB surveillance data highlighting a decline in the number of cases and incidence of the disease. However, despite these declines, their findings suggest that unless actions are taken to accelerate progress in fighting the disease, the goal of eliminating TB in the United States by the end of the century will not be met.
According to the preliminary surveillance data, in 2016, a total of 9287 new cases of tuberculosis within the United States were reported, which is a 2.7% drop compared with 2015. In fact, the CDC’s most recent Morbidity and Mortality Weekly Report notes that this case count “represents the lowest number of TB cases recorded since reporting began in 1953.”
Similarly, TB incidence in 2016 also appears to have decreased by 3.4% in case rate per 100,000 people. Despite this decline, the incidence rate of TB infections reported in twelve states was higher than the national incidence. The states in question? Alaska, Arkansas, California, Florida, Georgia, Hawaii, Maryland, Minnesota, New Jersey, New York, North Dakota, and Texas. Out of all the states, Hawaii had the highest TB incidence rate, with 8.3 per 100,000 persons; Wyoming had the lowest incidence rate, with 0.2 cases per 100,000 persons. Unfortunately, overall, “the TB incidence rate remains at levels 29 times higher than the TB-elimination target rate.”
Caused by a bacterium called Mycobacterium tuberculosis, tuberculosis is a chronic disease that usually attacks the lungs, but can also affect other parts of the body such as the brain, intestines, kidneys, or even the spine. Since its discovery in 1882, tuberculosis has caused many illnesses and taken countless lives on a global scale; in fact, it was the first infectious disease to be declared by the World Health Organization as a global health emergency back in 1993. Today, tuberculosis remains a threat, as new cases continue to be reported throughout the United States and around the world.
“The disease can strike a heavy physical, emotional, and financial blow to people and families affected,” Philip LoBue, MD, director of the Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC, said in a statement on 2017 World TB Day.
Because of these devastating effects, researchers have come up with an approach to accelerate progress towards TB elimination. Dr. LoBue explained, “Analyses suggest that eliminating TB will require a dual approach: strengthening existing TB programs/systems to diagnose and treat active TB disease, and intensifying efforts to identify and treat latent TB infections among those who are infected with TB bacteria but are not yet sick.”
When it comes to current efforts for infection control, the big focus has been on the quick identification and treatment of those with active TB disease, to prevent further transmission from person-to-person. In addition, researchers have focused on identifying anyone who may have been exposed to infected individuals in order to prevent “a resurgence of TB.” These efforts are not for naught; according to Dr. LoBue, “Over the last 20 years alone, health departments and the CDC TB control efforts have prevented as many as 300,000 people from developing TB disease, saving more than $6 billion in costs.”
However, Dr. LoBue stressed, these efforts are not enough to get to the end goal. With 85% of TB cases within the United States associated with reactivated latent TB infection—which could have been acquired years earlier—and 13 million individuals unknowingly infected by latent TB in the United States, new efforts need to be made to address these infections. The fact that those who are infected with latent TB are asymptomatic until reactivation means that these individuals could go years without falling ill, and thus never seek treatment, which is why 5-10% of them will end up developing the disease.
There is hope when it comes to addressing the issue, though. “The good news is that we have more tools than ever to rapidly diagnose and treat latent TB infection and prevent the development of TB disease. With better diagnostic tests, shorter treatments, and new guidelines to assist physicians in testing, the United States has a greater opportunity than ever before to eliminate TB in this country.” according to Dr. LoBue.
This approach could not only assist in preventing several individuals from unnecessary suffering that comes with falling ill, but it could also cut costs in a big way. Dr. LoBue explained, “Treating a single person for drug-susceptible TB disease costs about $18,000—some 36 times more than the $500 it costs to proactively treat a person for latent TB infection. The cost for treating drug-resistant TB is even higher, ranging from $154,000 to $494,000—which is 300 to nearly 1,000 times the cost of treatment for latent TB infection.”
In fact, in a statement for World TB Day, the National Institute of Allergy and Infectious Diseases (NIAID) noted that there has been a rise in incidence of these multidrug-resistant (MDR) and extensively drug-resistant strains (XDR) of TB. Treatement for MDR-TB could last for two years and individuals are known to experience severe side effects. Even harder to treat is XDR-TB, and NIAID notes that “for some patients, no effective drugs are available.”
In an effort to address these issues, NIAID is actively contributing to the National Action Plan for Combating MDR-TB which is dedicated to the development of new diagnostic tools, antibiotics, and therapies to assist in the treatment of these difficult infections. For example, the drug bedaquiline will be tested for effectiveness against MDR-TB by NIAID’s HIV/AIDS Clinical Trials Networks and the goal of another trial is to see if a combination therapy consisting of bedaquiline and delmanid is effective against MDR-TB.
Currently, the only TB vaccine available is bacilli Calmette-Guerin, which was developed back in 1921. Although the vaccine does offer protection “against disseminated disease and death in children,” NIAID says that it’s “much less effective against the transmissible pulmonary form of the disease in adults.” For this reason, a new drug, that is both safe and effective against the disease, is imperative for infection control.
The only way to achieve the goal of eliminating TB is through collaborative efforts; both public health systems and private providers need to participate and drive home the World TB Day theme, “Unite to End TB.” It is important that healthcare providers pay close attention to the care of more susceptible populations, such as, those who are immunocompromised, those with increased exposure to TB who had been born in or traveling to countries with higher prevalence, those who smoke/are exposed to those who do, and those living in homeless shelters, correctional facilities, or long-term care facilities.
“TB is a preventable and curable disease. We’ve come a long way in fighting the disease in the past century but in order to reach TB elimination, we must intensify our efforts and implement a dual approach to put an end to a disease that has plagued mankind for thousands of years,” Dr. LoBue concluded.