NEW TUBERCULOSIS STUDY MIGHT ANSWER QUESTIONS ABOUT DISEASE DISTRIBUTION

Seals might be responsible for the spread of tuberculosis.A new study published in the journal Nature suggests that seals may be responsible for spreading tuberculosis across the Atlantic Ocean. In the past, the distribution of tuberculosis has befuddled scientists, as evidence of the disease has contradictory genetic and archeological links. Genetic evidence hints that the disease was prevalent in Europe and settlers brought the disease to the Americas. However, archeological evidence shows that tuberculosis was present in North and South America thousands of years before those settlers arrived. The new study has the potential to be a landmark paper, first documenting how tuberculosis spread from Africa and Europe to other parts of the world. However, there are scientists twho disagree with some of the study’s findings, particularly dating the disease at no more than 6,000 years old. Meanwhile, tuberculosis is posing a public health risk due to drug-resistant strains. It is extremely contagious and can be spread by no more than a cough or sneeze. While the disease can usually be cured with a cocktail of drugs over several months, drug-resistant strains take double the amount of time to cure and could eventually render drugs unsuccessful. The field of pharmacy technology will be tasked with developing stronger drugs to fend off tuberculosis.

What is tuberculosis?

Tuberculosis, often shortened to TB, is a disease caused by bacteria that is spread through the air via coughing, sneezing or speaking.The bacteria often attacks the lungs, but tuberculosis can spread to any part of the body.However, not everyone infected with TB bacteria becomes sick. There are two conditions related to the bacteria: latent TB infection and TB disease.Many people infected with TB won’t exhibit symptoms, as the body will fight the bacteria and prevent it from growing. This is known as latent TB infection, a condition in which the person will not feel sick and cannot spread the infection to others. Latent TB infection can develop into TB disease if the bacteria multiply and become active in the body.

TB disease can develop at any time for those infected with the bacteria, and those with weak immune systems are at higher risk. Tuberculosis is especially dangerous for individuals infected with HIV. Those with TB disease will develop potentially life-threatening symptoms and have the ability to spread the bacteria. Symptoms of TB include chronic cough, fatigue, chest pain, coughing up blood, loss of appetite, chills and fever.

If you are concerned that you have been exposed to or infected with TB, contact your local health care provider to schedule an appointment to get tested.

The new theory on how tuberculosis spreads

Scientists analyzed the DNA of three 1,000-year-old Peruvian mummies and found a TB bacteria strain that was most closely related to one currently seen in seals and sea lions.Along with other circumstantial evidence, this brought the team to the possible conclusion that seals infected in Africa likely transmitted the disease across the Atlantic. Seals have been previously linked to other pathogens that infected South American hunters, and TB-infected seals have been found to spread the bacteria to beach-grazing cows.Perhaps the most controversial point of the study is that the team dated TB as being no more than 6,000 years old. Past archeological research found TB bacteria in a human specimen 3,000 years older than this and in bison bones that are 17,000 years old.For the moment, the research can’t determine if seals directly infected the mummies, but the team’s theory could be a crucial piece of the puzzling history of tuberculosis.

Drug-resistant strains

As TB bacteria becomes more resistant to drugs, the highly contagious infection poses a public health threat. TB is typically cured by an amalgamation of drugs taken over a period of six to nine months. Drug-resistant TB becomes more challenging and expensive to treat, and patients then have to take medication for as long as 24 months.Tuberculosis infects millions of people worldwide every year, causing 1.3 million deaths in 2012 alone, according to the World Health Organization.10

The public dangers of tuberculosis also increase as some patients choose to neglect treatment. Not finishing the full prescription can cause the disease to come back stronger than before. In some cases, patients face arrest warrants because they pose a public health risk. A recent case of drug-resistant TB escalated into a man hunt in Southern California after a 24-year-old man who stopped treatment fled from officials.11 The patient is considered highly contagious, causing much concern among law enforcement and public health officials. This is not the first case in which a patient has hid from medical professionals.

Health care professionals will be challenged to find more efficient cures for TB,  reduce patient anxiety about the long-term nature of treatment and contain the bacteria from endangering the public.

1“Basic TB Facts” U.S Centers for Disease Control and Prevention. March 13, 2012. http://www.cdc.gov/tb/topic/basics/default.htm#spreads

2“Basic TB Facts” U.S Centers for Disease Control and Prevention. March 13, 2012. http://www.cdc.gov/tb/topic/basics/default.htm#spreads

3“Basic TB Facts” U.S Centers for Disease Control and Prevention. March 13, 2012. http://www.cdc.gov/tb/topic/basics/default.htm#spreads

4“Basic TB Facts” U.S Centers for Disease Control and Prevention. March 13, 2012. http://www.cdc.gov/tb/topic/basics/default.htm#spreads

5“Basic TB Facts” U.S Centers for Disease Control and Prevention. March 13, 2012. http://www.cdc.gov/tb/topic/basics/default.htm#spreads

6“Pre-Columbian mycobacterial genomes reveal seals as a source of New World human tuberculosis” by Kirsten I. Bos, Kelly M. Harkins, Alexander Herbig, Mireia Coscolla, Nico Weber, Iñaki Comas, Stephen A. Forrest, Josephine M. Bryant, Simon R. Harris, Verena J. Schuenemann, Tessa J. Campbell, Kerrtu Majander, Alicia K. Wilbur, Ricardo A. Guichon, Dawnie L. Wolfe Steadman, Della Collins Cook, Stefan Niemann, Marcel A. Behr, Martin Zumarraga, Ricardo Bastida, Daniel Huson, Kay Nieselt, Douglas Young, Julian Parkhill, Jane E. Buikstra. Nature. August 20, 2014. http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13591.html

7“Tuberculosis Is Newer Than Thought, Study Says” by Carl Zimmer. The New York Times. August 20, 2014. http://www.nytimes.com/2014/08/21/science/tuberculosis-is-newer-than-what-was-thought-study-says.html?_r=0

8“Tuberculosis Is Newer Than Thought, Study Says” by Carl Zimmer. The New York Times. August 20, 2014. http://www.nytimes.com/2014/08/21/science/tuberculosis-is-newer-than-what-was-thought-study-says.html?_r=0

9“Where is Agustin Zeferino? Arrest warrant issued for contagious, drug-resistant TB patient” by Linda Nguyen. Tech Times. August 24, 2014.  http://www.techtimes.com/articles/13896/20140824/where-is-agustin-zeferino-arrest-warrant-issued-for-contagious-drug-resistant-tb-patient.htm

10“Tuberculosis (TB)” Global Health Observatory. World Health Organization. http://www.who.int/gho/tb/en/

11“Where is Agustin Zeferino? Arrest warrant issued for contagious, drug-resistant TB patient” by Linda Nguyen. Tech Times. August 24, 2014.  http://www.techtimes.com/articles/13896/20140824/where-is-agustin-zeferino-arrest-warrant-issued-for-contagious-drug-resistant-tb-patient.htm

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