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

Video China Investigates Powerful Former Security Chief

Analysts say move by President Xi is an effort to win more party support, take step toward economic reforms, removing those who would stand in way of change More

South Africa Land Reforms Still Contentious 20 Years Later

Activists argue that the pace of land reform is slow and biased; legal experts question how some proposed reforms would be implemented More

In Vietnam, Religious Freedoms Violated, UN Finds

Beliefs reportedly prompt heavy surveillance, intimidation and travel restrictions More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Information War Rages Alongside Real One in Ukrainei
X
Al Pessin
July 31, 2014 8:13 PM
The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video Information War Rages Alongside Real One in Ukraine

The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict in Gaza, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities. Probably the most important destination is the local bakery. VOA’s Scott Bobb reports from Gaza City.
Video

Video US-Funded Program Offers Honduran Children Alternative to Illegal Immigration

President Obama and Central American leaders recently agreed to come up with a plan to address poverty and crime in the region that is fueling the surge of young migrants trying to illegally enter the United States. VOA’s Brian Padden looks at one such program in Honduras - funded in part by the United States - which gives street kids not only food and safety but a chance for a better life without, crossing the border.
Video

Video 'Fab Lab' Igniting Revolution in Kenya

The University of Nairobi’s Science and Technology Park is banking on 3-D prototyping to spark a manufacturing revolution in the country. Lenny Ruvaga has more for from Nairobi's so-called “FabLab” for VOA.
Video

Video Gazans in Shelled School Sought Shelter

Israel's air and ground assault against Hamas-led fighters in Gaza has forced many Palestinians to flee their homes, seeking safety. But safe places are hard to find, as VOA’s Scott Bobb reports from Jabaliya.
Video

Video Rapid Spread of Ebola in West Africa Prompts Global Alert

Across West Africa, health officials are struggling to keep up with what the World Health Organization describes as the worst ebola outbreak on record. The virus has killed hundreds of people this year. U.S. President Barack Obama and other world leaders are watching the developments closely as they weigh what actions, if any, are needed to help contain the disease.
Video

Video Michelle Obama: Young Africans Need to Embrace Women's Rights

U.S. first lady Michelle Obama urged some of Africa's best and brightest to advocate for women's rights in their home countries. As VOA's Pam Dockins explains, Obama spoke to some 500 participants of the Young African Leaders Initiative, a six-week U.S.-based training and development program.
Video

Video Immigrant Influx on Texas Border Heats Up Political Debate

Immigrants from Central America continue to cross the U.S.-Mexico border in south Texas, seeking asylum in the United States, as officials grapple with ways to deal with the problem and provide shelter for thousands of minors among the illegal border crossers. As VOA's Greg Flakus reports from Houston, the issue is complicated by internal U.S. politics and U.S. relations with the troubled nations that immigrants are fleeing.
Video

Video Study: Latino Students Most Segregated in California

Even though legal school segregation ended in the United States 60 years ago, one study finds segregation still occurs in the U.S. based on income and race. The University of California Los Angeles Civil Rights Project finds that students in California are more segregated by race than ever before, especially Latinos. Elizabeth Lee reports for VOA from Los Angeles.

AppleAndroid