By Julie Steenhuysen
CHICAGO, Oct 17 (Reuters) - An antibiotic used to treat severe bacterial infections showed promise at treating a highly dr ug-resistant and deadly form of tuberculosis, U.S. government and South Korean researchers said on Wednesday.
The study, published in the New England Journal of Medicine, is the first scientifically rigorous clinical trial of Pfizer's antibiotic linezolid, or Zyvox, in patients with extensively drug-resistant TB (XDR-TB), which is resistant to at least four of the drugs most often used to treat the lung infection.
Led by Clifton Barry of the National Institute of Allergy and Infectious Diseases and Sang-Nae Cho, professor of infectious diseases at Yonsei University, South Korea, the study showed the drug was effective when added to patients' current treatments.
"The data that were reported are rather impressive," Dr. Anthony Fauci, director of the institute, a part of the National Institutes of Health, said in a telephone interview.
However, most of the patients - 82 percent - experienced side effects while on the treatment, which tempered the findings, the team reported.
"That is the bad news," Fauci said. "The somewhat encouraging news is that despite the toxicity, when the drug dose was decreased or was temporarily discontinued, the toxic side effects diminished dramatically."
Researchers are desperately looking for new treatments for drug-resistant forms of TB, which threatens to derail progress in the global fight to eradicate the disease.
"To have a study that has a positive result, despite the fact that there are caveats, is an important advance in the right direction," Fauci said.
Treating typical TB cases is a long process, with patients needing to take a cocktail of powerful antibiotics for six months. Many patients fail to complete their treatment, a factor which has fueled a rise in the drug-resistant forms.
Although rare, 77 countries worldwide reported at least one case of XDR-TB by the end of 2011, according to the World Health Organization.
In the United States, at least 57 cases of XDR-TB were reported between 1993 and 2010. Patients infected with XDR-TB typically have very poor clinical outcomes, and with no effective drugs available, they often die.
The study enrolled 39 patients with XDR-TB at South Korean hospitals who had failed to respond to any treatment during the six months before enrolling in the study. Most of the patients at the time were taking 11 drugs on average.
Patients were divided into two groups. One group was treated with 600 milligrams of linezolid immediately, while the other received the medication two months later.
After patients no longer tested positive for TB, or after four months on treatment, study volunteers were randomly assigned to take either a 600 or 300 milligram dose of the drug for another 18 months.
In the patients who took the drug immediately, the addition of linezolid offered a significant benefit in helping patients clear TB bacteria, compared with the delayed treatment group.
Side effects, which occurred in 82 percent of patients, included a decrease in the ability of the bone marrow to produce blood cells, resulting in low red and white blood cell counts, and damage to the optic and peripheral nerves.
Dr. Mel Spigelman, president and chief executive of the TB Alliance, a nonprofit research group, said the findings highlight the potential of this new class of TB drug candidates, known as oxazolidinones, and the treatment challenges posed by XDR-TB.
"Clinicians are currently forced to combat XDR-TB with an incomplete arsenal of inadequate weapons, and the fact that linezolid may be an addition to that arsenal is good news," said Spigelman, who was not involved in the research.
"On the other hand, like many of the existing drugs used to treat XDR-TB, linezolid presents toxicity concerns that may suggest that other, newer oxazolidinones could be more attractive for TB treatment," he said in an e-mail.
Spigelman said additional drugs from this class are in earlier-stage development, and the hope is that they may be as effective and safer than linezolid.
Also on HuffPost:
Yes, the black plague -- responsible for <a href="http://www.smithsonianmag.com/people-places/mall_aug99.html?c=y&page=2" target="_hplink">killing 56 million people in Europe the 14th century</a> -- is still around, but it isn't as deadly or prevalent as it was in Medieval times. Dr. Robert Gaynes, an infectious disease expert at Emory University and author of the book <a href="http://estore.asm.org/viewItemDetails.asp?ItemID=1036" target="_hplink">Germ Theory: Medical Pioneers in Infectious Diseases</a>, said that people contract the disease when they gain access to previously undistrubed ecosystems, thereby making "these types of diseases become evident as a result of animal contact." These days, the disease is most commonly spread by bites from fleas that are infected with Yersinia pestis. When the bacteria enters into a person's skin, it leads to headache, chills, and <a href="http://www.bt.cdc.gov/agent/plague/factsheet.asp" target="_hplink">swollen lymph glands</a>, according to the CDC. Early <a href="http://www.bt.cdc.gov/agent/plague/factsheet.asp" target="_hplink">treatment with antibiotics</a> is essential for survival, as the disease can cause respiratory failure and shock if left untreated. Every year, about 1,000 to 3,000 <a href="http://healthland.time.com/2011/05/10/first-case-of-bubonic-plague-in-2011-appears-in-new-mexico/" target="_hplink">bubonic plague cases</a> occur around the world, with 10 to 20 of those cases in the United States, <em>TIME</em> reported. The first 2011 case of bubonic plague was confirmed in May in a New Mexico man. The reason is murky for why black plague seems to be less deadly today than in the Medieval times, Weinberg said, but it probably has to do with more rats and unclean living conditions back then, as well as a lack of appropriate medicines. In addition, the bacteria back then may be different from the current form, he added.
<a href="http://www.medicinenet.com/scarlet_fever/article.htm#history" target="_hplink">Scarlet fever</a> was among the rash of diseases that commonly afflicted people in the 19th century (alongside yellow fever, rubella and measles), according to MedicineNet. Scarlet fever most often afflicts children, causing rash and fever. Fortunately, scarlet fever is a lot less common today than it was centuries ago, but it still can be deadly. Today, we now know that scarlet fever is just a form of group A streptococcus (strep), Weinberg said. But instead of just turning into a regular case of strep throat, scarlet fever manifests as a red skin rash. With antibiotics, the disease is easily treated, though complications can occur that <a href="http://www.medicinenet.com/scarlet_fever/article.htm#history" target="_hplink">can lead to sepsis</a> (bacteria in the blood, tissue or bone), according to MedicineNet. Just this summer, Reuters reported that a Hong Kong kindergarten was closed after tests revealed that a child there may have <a href="http://www.reuters.com/article/2011/06/21/us-scarletfever-china-idUSTRE75K14Q20110621" target="_hplink">died from scarlet fever</a>. Scarlet fever is relatively common in that part of the world, but this year a Hong Kong health department spokesman told Reuters that there seem to be more cases of it this year than in past years.
<a href="http://articles.sfgate.com/2011-09-20/bay-area/30178479_1_whooping-cough-booster-shots-childhood-vaccine" target="_hplink">Whooping cough</a>, caused by the Bordetella pertussis bacteria, was a common illness among children in the early 1900s, according to HealthCentral. However, when the vaccine for whooping cough was introduced in the 1940s, cases dropped. But while whooping cough cases are still dramatically lower than 50 years ago, there are still cases that persist today possibly because the vaccine against the disease doesn't provide lasting protection later in life, Weinberg said. Another reason is that older people seem to be able to carry whooping cough in their throats without actually getting sick (due to being vaccinated at a younger age), but that whooping cough is then passed on to infants who haven't yet been vaccinated against the disease, Gaynes said. "This problem has led to a recent recommendation by [the] CDC to have adults get TDAP once as adults (it contains pertussis in the vaccine) and not just a tetanus booster, which is needed every ten years," Gaynes told HuffPost. Recent research presented just last month shows that the <a href="http://articles.sfgate.com/2011-09-20/bay-area/30178479_1_whooping-cough-booster-shots-childhood-vaccine" target="_hplink">protection from the whooping cough vaccine</a> is decreased dramatically once a child reaches age 8 or 9, the <em>San Francisco Chronicle</em> reported. <a href="http://www.cdc.gov/features/pertussis/" target="_hplink">Whooping cough is very contagious</a> -- spread by cough and sneezing -- and is so named because of the sound people who have it make when they cough. Last year, 27,550 people had whooping cough in the United States, according to the CDC. The disease is the deadliest for babies, as it can lead to pneumonia, convulsions and even death.
Polio, the paralysis-causing disease that afflicted former president Franklin D. Roosevelt, isn't completely gone from the world today. However, it has been eliminated from the western world, Weinberg said. The Mayo Clinic reports that the last known <a href="http://www.mayoclinic.com/health/polio/DS00572" target="_hplink">case of polio in the U.S.</a> was in 1979. Polio is still present in <a href="http://www.who.int/mediacentre/factsheets/fs114/en/" target="_hplink">Afghanistan, Pakistan, India and Nigeria</a>, where unrest and dangerous conditions can make it more difficult to get everyone vaccinated against the disease, according to the World Health Organization. Recently, the WHO reported that a dangerous strain of polio -- called wild poliovirus type 1 -- had <a href="http://www.huffingtonpost.com/2011/09/20/polio-china-pakistan_n_971787.html" target="_hplink">made its way from Pakistan to China</a>. Polio<a href="http://www.mayoclinic.com/health/polio/DS00572" target="_hplink"> causes paralysis</a> and can make it hard to breathe, the Mayo Clinic reported. It can even lead to death.
Gout has been known throughout history as the "<a href="http://www.bl.uk/learning/langlit/booksforcooks/1700s/1700sfood.html" target="_hplink">disease of kings</a>" and the "rich man's disease," as it was most commonly seem among the gluttonous rich in the 1700 and 1800s, according to the British Library. Gout is considered an ancient form of <a href="http://www.cdc.gov/arthritis/basics/gout.htm" target="_hplink">inflammatory arthritis</a>, and is caused by metabolic disorder that has not been properly controlled. It occurs when uric acid crystals build up in tissues and fluids, thereby leading to a red, swollen joint that is very painful, according to the Centers for Disease Control and Prevention. The condition is most common in overweight men and women who have gone through menopause. Gout rates have <a href="http://arthritis.webmd.com/news/20101110/gout-cases-on-the-rise-in-u-s" target="_hplink">been on the rise</a> since the 1960s, with cases doubling between 1960 and 1990 and then continuing to rise through 2008, according to WebMD. More than 8 million Americans currently have gout. WebMD reported that the <a href="http://arthritis.webmd.com/news/20101110/gout-cases-on-the-rise-in-u-s" target="_hplink">rise in gout cases</a> may be due to people living longer, as the condition is seen in women only after they have passed menopause. In addition, "you can go years with hyperuricemia and no symptoms. But at some point, enough uric acid accumulates to have a flare-up of gout, so if you're living longer you are more likely to reach that threshold," gout expert Dr. John S. Sundy told WebMD. In addition, Gaynes speculated that it may not even be that gout rates are actually rising -- rather, detection and diagnosis may have improved throughout the years.