News / Health

Tuberculosis Evades Detection by Hiding in Bone Marrow

A man (L) is x-rayed to detect tuberculosis during a medical examination, Jan. 29, 2013.
A man (L) is x-rayed to detect tuberculosis during a medical examination, Jan. 29, 2013.
Jessica Berman
It's been a long-standing medical mystery: how tuberculosis (TB), a potentially fatal respiratory infection, can spring to life in a patient after lying dormant for many years.  Scientists have discovered that the bacterium which causes TB hides in cells in the bone marrow, making it hard to treat with antibiotics. 

Unlike other bacterial infections, tuberculosis is notoriously difficult to treat.  Despite the availability of antibiotics for 50 years, treatment for TB involves a rigorous multi-drug regimen of up to six months' duration.  

That’s led researchers to conclude that Mycobacterium tuberculosis, the pathogen that causes the deadly lung ailment, is lurking in tissue, where neither antibiotics nor the body’s protective immune system can kill it.

One potential hiding place is bone marrow, a spongy tissue inside bones containing stem cells responsible for manufacturing a variety of blood cells.  Marrow has mechanisms for keeping out foreign substances, including antibiotics.

Researcher Antonio Campos-Neto, director of the Forsyth Center for Global Infectious Diseases in Cambridge, Massachusetts, and his colleagues at Stanford University School of Medicine in California conducted test tube, or in vitro, experiments to see what happened when bone marrow cells and the TB bacterium were mixed together.

“And sure enough, you know, in vitro experiments show the microorganism could be internalized very easily inside the stem cells,” said Campos-Neto.

That finding, according to Campos-Neto, may explain why the lung disease exists in two forms -- a latent phase in which individuals can be infected for decades without symptoms, and an active phase, characterized by extreme illness and, without treatment, death.

And it may have implications for the treatment of TB, explaining why antibiotics do not always rid patients of the disease.

“Many, many [TB] patients who have been successfully treated, later on in their life they can come back with tuberculosis again.  And nobody ever understood why this was so difficult, and now we start to have this firsthand [knowledge] that it’s because the TB is hiding itself in some protective niche that drugs cannot reach,” explained Campos-Neto.

An estimated 2.2 billion people around the world live symptom-free with latent tuberculosis.  Once active, the illness kills upwards of 1.7 million people every year.  

Campos-Neto says researchers need to learn more about this complex disease so new diagnostic tests and effective treatments can be developed.

An article by Antonio Campos-Neto and colleagues on latent tuberculosis is published in the journal Science Translational Medicine.

You May Like

Americans Celebrate Thanksgiving

Feasts centering on turkeys with an array of traditional sides and desserts are part of the holiday's traditions, which falls on the fourth Thursday in November More

Video For Obama, Ferguson Violence is a Personal Issue

With two years left in term, analysts say, president has less to lose by taking conversation on race further More

Video Italian Espresso Expands Into Space

When Italian astronaut Samantha Cristoforetti headed for the ISS, her countrymen worried how she would survive six months drinking only instant coffee More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Community Kicks Off Thanksgiving With Paradei
X
Anush Avetisyan
November 26, 2014 10:57 PM
Thursday is Thanksgiving in the United States, a holiday whose roots go back to the country's earliest days as a British colony. One way Americans celebrate the occasion is with parades. Anush Avetisyan takes us to one such event on the day before Thanksgiving near Washington, where a community's diversity is on display. Joy Wagner narrates
Video

Video US Community Kicks Off Thanksgiving With Parade

Thursday is Thanksgiving in the United States, a holiday whose roots go back to the country's earliest days as a British colony. One way Americans celebrate the occasion is with parades. Anush Avetisyan takes us to one such event on the day before Thanksgiving near Washington, where a community's diversity is on display. Joy Wagner narrates
Video

Video For Obama, Ferguson Violence is a Personal Issue

Throughout the crisis in Ferguson, Missouri, President Barack Obama has urged calm, restraint and respect for the rule of law. But the events in Ferguson have prompted him to call — more openly than he has before — for profound changes to end the racism and distrust that he believes still exists between whites and blacks in the United States. VOA White House correspondent Luis Ramirez reports.
Video

Video Online Magazine Gets Kids Discussing Big Questions

Teen culture in America is often criticized for being superficial. But an online magazine has been encouraging some teenagers to explore deeper issues, and rewarding their efforts. VOA religion reporter Jerome Socolovsky went to this year’s Kidspirit awards ceremony in New York.
Video

Video Aung San Suu Kyi: Myanmar Opposition to Keep Pushing for Constitutional Change

Myanmar opposition leader Aung San Suu Kyi says she and her supporters will continue pushing to amend a constitutional clause that bars her from running for president next year. VOA's Than Lwin Htun reports from the capital Naypyitaw in this report narrated by Colin Lovett.
Video

Video Mali Attempts to Shut Down Ebola Transmission Chain

Senegal and Nigeria were able to stop small Ebola outbreaks by closely monitoring those who had contact with the sick person and quickly isolating anyone with symptoms. Mali is now scrambling to do the same. VOA’s Anne Look reports from Mali on what the country is doing to shut down the chain of transmission.
Video

Video Ukraine Marks Anniversary of Deadly 1930s Famine

During a commemoration for millions who died of starvation in Ukraine in the early 1930s, President Petro Poroshenko lashed out at Soviet-era totalitarianism for causing the deaths and accused today’s Russian-backed rebels in the east of using similar tactics. VOA’s Daniel Shearf reports from Kyiv.
Video

Video Hong Kong Protests at a Crossroads

New public opinion polls in Hong Kong indicate declining support for pro-democracy demonstrations after weeks of street protests. VOA’s Bill Ide in Guangzhou and Pros Laput in Hong Kong spoke with protesters and observers about whether demonstrators have been too aggressive in pushing for change.
Video

Video US Immigration Relief Imminent for Mixed-Status Families

Tens of thousands of undocumented immigrants in the Washington, D.C., area may benefit from a controversial presidential order announced this week. It's not a path to citizenship, as some activists hoped. But it will allow more immigrants who arrived as children or who have citizen children, to avoid deportation and work legally. VOA's Victoria Macchi talks with one young man who benefited from an earlier presidential order, and whose parents may now benefit after years of living in fear.
Video

Video New Skateboard Defies Gravity

A futuristic dream only a couple of decades ago, the hoverboard – a skateboard that floats above the ground - has finally been made possible. While still not ready for mass production, it promises to become a cool mode of transport... at least over some surfaces. VOA’s George Putic reports.
Video

Video Falling Gas Prices Impact US Oil Extraction

With the price of oil now less than $80 a barrel, motorists throughout the United States are benefiting from gas prices below $3 a gallon. But as VOA’s Kane Farabaugh reports, the decreasing price of petroleum has a downside for the hydraulic fracturing industry in the United States.
Video

Video Tensions Build on Korean Peninsula Amid Military Drills

It has been another tense week on the Korean peninsula as Pyongyang threatened to again test nuclear weapons while the U.S. and South Korean forces held joint military exercises in a show of force. VOA’s Brian Padden reports from the Kunsan Air Base in South Korea.
Video

Video Mama Sarah Obama Honored at UN Women’s Entrepreneurship Day

President Barack Obama's step-grandmother is in the United States to raise money to build a $12 million school and hospital center in Kogelo, Kenya, the birthplace of the president's father, Barack Obama, Sr. She was honored for her decades of work to aid poor Kenyans at a Women's Entrepreneurship Day at the United Nations.
Video

Video Ebola Economic Toll Stirs W. Africa Food Security Concerns

The World Bank said Wednesday that it expects the economic impact of the Ebola outbreak on the sub-Saharan economy to cost somewhere betweenf $3 billion to $4 billion - well below a previously-outlined worst-case scenario of $32 billion. Some economists, however, paint a gloomier picture - warning that the disruption to regional markets and trading is considerable. Henry Ridgwell reports from London.
Video

Video Chaos, Abuse Defy Solution in Libya

The political and security crisis in Libya is deepening, with competing governments and, according to Amnesty International, widespread human rights violations committed with impunity. VOA’s Al Pessin reports from London.
Video

Video US Hosts Record 866,000 Foreign Students

Close to 900,000 international students are studying at American universities and colleges, more than ever before. About half of them come from Asia, mostly China. The United States hosts more foreign students than any other country in the world, and its foreign student population is steadily growing. Zlatica Hoke reports.

All About America

AppleAndroid