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Entries in drug resistant TB (2)

Sunday
Mar242013

It’s World Tuberculosis Day: 5 Things You Didn't Know About TB

Duncan Smith/Thinkstock(NEW YORK) -- The lung disease Tuberculosis kills nearly 1.5 million people each year, mostly in developing countries. World Tuberculosis Day is observed on March 24 to "raise awareness about the burden of tuberculosis (TB) worldwide and the status of TB prevention and control efforts," according to the World Health Organization. With that in mind, here are five things you might not have known about this deadly disease.

1.    Tuberculosis Is Caused by Bacteria and Spread Through the Air

According to the World Health Organization, "when people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected."

The symptoms include fever, bloody cough and fatigue.

2.    Tuberculosis Is Growing More Resistant to Treatment Worldwide

Although TB is curable, the treatment regimen requires patients dutifully to take multiple antibiotics daily for several months, and if there are any deviations from protocol or incomplete courses, the bacteria can easily develop a resistance to the drugs.

The WHO estimates that about 5 percent of the cases of this disease are multidrug-resistant tuberculosis. Known as MDR-TB, these bacteria have developed resistance to two of the first-line tuberculosis drugs, isoniazid and rifampicin. An even more resistant strain of TB exists.  XDR-TB was first reported in 2006 and are resistant to several types of drugs. While MDR-TB is difficult and costly to treat, XDR-TB is even harder.

3.    Tuberculosis Is Global Threat

Tuberculosis kills at least 1.34 million people each year worldwide. And now the disease, once curable with antibiotics, is becoming resistant to multiple drugs.

Although most cases of TB and multidrug-resistant TB are found in developing countries, the disease, which kills at least 1.34 million people worldwide each year has been found in developed country as well. According to WHO data, 92 cases of multidrug-resistant TB were reported in the United States in 2011.

4.    People With Weak Immune Systems Are More Susceptible to Getting TB

People with weak immune systems or those who have HIV are at greater risk in contracting TB. It is the leading killer of people with HIV, according to WHO. Additionally, according to the WHO, smoking and tobacco use make people more susceptible to TB, and their data says that more than 20 percent of TB cases globally are attributable to smoking.

5.    Drug-Resistant TB Could Bring Back Sanatoria, Secluded Hospitals

Before the advent of antibiotics, people with infectious diseases like tuberculosis were sent to sanatoria, secluded hospitals that healed through good food, fresh air and sunlight. The isolated buildings also quarantined infected patients, thwarting the spread of contagious and dangerous diseases. Before the advent of the drug rifampicin in the 1960’s, some sanatoria housed several thousand patients at once.

Now, in regions of the world increasingly burdened by drug-resistant TB, sanatoria might be coming back. But the recent emergence of new, antibiotic-resistant strains of the disease-causing bacteria in South Africa has prompted a call for the return of sanitoria.

Copyright 2013 ABC News Radio

Thursday
Aug302012

Tuberculosis Becoming More Drug-Resistant Worldwide

John Foxx/Stockbyte/Thinkstock(NEW YORK) -- Tuberculosis is growing more resistant to treatment worldwide, according to a study released Wednesday in the journal The Lancet -- a finding that suggests the potentially fatal disease is becoming more difficult and costly to treat.

Currently, 8.8 million patients worldwide are infected with tuberculosis, according to the World Health Organization (WHO). Although it is curable, the treatment regimen requires patients dutifully to take multiple antibiotics daily for several months -- and if there are any deviations from protocol or incomplete courses, drug resistance develops easily.

The WHO estimates that about 5 percent of the cases of this disease are multidrug-resistant tuberculosis, or MDR-TB -- in other words, caused by bacteria that have developed resistance to two of the first-line tuberculosis drugs, isoniazid and rifampicin.

Worse, as additional antibiotics are being thrown at the disease, forms that are even more resistant have begun to emerge. First reported in 2006, cases of extensively drug-resistant tuberculosis (XDR-TB) are resistant to drugs called fluoroquinolones, as well as to one of the three available intravenous drugs. While MDR-TB is difficult and costly to treat, XDR-TB is even harder.

The Lancet study looked at 1,278 MDR-TB patients from eight countries. The researchers found that nearly 44 percent had already developed resistance not only to the two first-line drugs, but to at least one second-line drug as well. Additionally, the researchers found that 6.7 percent of the patients had developed resistance to at least two second-line drugs -- thus classifying them as having XDR-TB.

In this study, the strongest risk factors for drug resistance were previous treatment with second-line drugs -- indicating that prior treatments were ineffectual and exacerbated the resistance of the tuberculosis. Other factors associated with resistance to second-line injectable drugs were unemployment, a history of imprisonment, alcohol abuse and smoking.

The study, known as the Preserving Effective TB Treatment Study (PETTS), was launched by the International Working Group on MDR tuberculosis and coordinated through the health departments in Estonia, Latvia, Peru, Philippines, Russia, South Africa, South Korea and Thailand. Drug-susceptibility testing was performed at the U.S. Centers for Disease Control and Prevention.

The figures offered by the new study, though alarming, appear to be close to what international health officials expected. While the new number is higher than a figure in a 2010 WHO report, which indicated that only 5.4 percent of MDR-TB patients had XDR-TB in the same time period, an even more recent update by the WHO estimates a prevalence of 9.4 percent of MDR-TB patients with the XDR-TB mutations.

"The global emergency of extensively drug-resistant tuberculosis heralds the advent of widespread, virtually untreatable tuberculosis," lead author Tracy Dalton of the Centers for Disease Control writes in the report.

Because tuberculosis can easily be transmitted through droplets in the air -- as occurs when someone with the disease coughs -- the disease is a menace to public health. In 2010, 1.1 million people worldwide died from tuberculosis.

"These results show that XDR tuberculosis is increasingly a cause for concern, especially in areas where prevalence of MDR tuberculosis is high," Sven Hoffner of the department of preparedness at the Swedish Institute for Communicable Disease Control in Sweden writes in a commentary to accompany the new study.

"The true scale of the burden of MDR and XDR tuberculosis might be underestimated and seem to be rapidly increasing."

While experts grow increasingly concerned about the growing resistance of antibiotics to tuberculosis, some advocate a different approach -- prevention.

"The genome of tuberculosis is highly plastic, so we will always be 'chasing our tail' in terms of antibiotic-driven approaches," says Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and president of the Sabin Vaccine Institute. "This study points to the urgency for accelerating the development of a [tuberculosis] vaccine."

Copyright 2012 ABC News Radio







ABC News Radio