Stop Tuberculosis: World Tuberculosis Day
24th March 2012
Each year, March 24th marks World Tuberculosis Day to build awareness and promote the issue of TB still being an epidemic in many parts of the world, causing the deaths of millions of people world-wide. World Tuberculosis Day commemorates the day that Dr. Robert Koch, a German physician, isolated the Tuberculosis bacillus in 1882 at a time when TB was raging across all continents killing 1 out of 7 persons.
Tuberculosis or TB is an infectious, airborne disease caused by the TB bacillus most frequently attacking the lungs. Most TB infections come in the form of an asymptomatic/latent infection (LTBI) which is not transmittable, while about 1 in 10 persons sees the infection turn to active TB. Tuberculosis symptoms and signs are quite harsh and if not treated, TB can lead to death. The infection is transmitted through saliva, coughing and sneezing and in addition to requiring long courses of antibiotics in consequence of the disease's infectious nature and severity of symptoms, TB patients need to be quarantined and their social activities screened to prevent further spreading of the disease. Also, TB is considered to be a disease of poverty as 95% of TB deaths are accounted for in the developing world. However, TB occurs frequently in Western countries as well.
Recently, we had the chance to talk to a 29 year old female TB patient. Asked about her condition, she described her symptoms as strong heat waves, fever and coughing, as well as feeling constantly exhausted. She was diagnosed right after visiting her GP where a blood screen test was carried out to confirm the diagnosis. In her case, treatment required a 3-month hospital stay quarantined from other non-infectious patients, and daily shots of antibiotics. Once released from the hospital, she was still required to wear a surgical-like mask when in public places.
According to the World Health Organisation's research in 2010 there were 8.8 million new TB cases world-wide; in 2010, 1.4 million people died from TB and 5.7 million were actively being treated for TB. Moreover:
- In 2009, there were 9.7 million orphan children in consequence of TB deaths
- TB is one of the three greatest causes of death for women aged 15-44
- In 2010, there were 650,000 cases of multi drug-resistant TB
To understand better Tuberculosis symptoms and signs, treatments and preventive care, we talked to Dr Pere-Joan Cardona, Doctor of Medicine from the Autonomous University of Barcelona, Clinical Microbiologist, Associate Professor, Department of Genetics and Microbiology, Autonomous University of Barcelona and Head of Experimental Tuberculosis Unit of the Institut Germans Trias i Pujol. Here is what Dr Cardona had to say:
Mycobacterium tuberculosis is transmitted by aerosol, like influenza. Fortunately, because the bacilli must reach the alveolar space and infect Alveolar Macrophages, the rate of infection is less efficacious than in influenza, in a ration of 1:3. About symptomatology, this is a major TB issue. Because the bacilli are very slow, the progression is usually asymptomatic. As it usually affects the lungs, the principal symptom is coughing. WHO states that a cough of more than 2 weeks in duration must raise the suspicion of TB. There are other symptoms, like losing weight or chronic febricula. That's why the most important thing is the visibility issue! If people, especially health professionals, know that TB exists, they will look for it and will find it . This is crucial because the quicker a TB case is found, the less people will become infected.
Good news is that only 10% of infected people will progress to active TB. Half of this 10% can be explained by a rapid progression of the disease in people that have an immunosupression (like Aids, or in children). The other half is more difficult to predict, but smoking and alcoholism are a major factor; other diseases like diabetes tend to facilitate the progression of TB; but, for a high percentage of this half of infected persons we cannot identify the causes. It appears that a genetic factor could be related to an exaggerated response to the bacilli inducing a destruction of an infected person's own tissues, leading to active TB.
When asked in what cases Tuberculosis leads to death, Dr Cardona underlines,
TB can be cured with some combination of drugs. Why, nowadays, there are still about 2 million deaths? Mainly because some patients are not properly diagnosed, or do not have access to treatments. Also, there is a growing issue: the increase of the multiresistant strains. Furthermore, the problem of TB is the stigma that comes with it. It has been associated with poverty for such a long time that nobody wants to disclose that they have TB. It is incredible! People openly declare that they have cancer, but everybody hide the contraction of TB, when having TB is actually good news as it can be cured!
Another relevant question Dr Cardona answered addresses courses of treatment for both TB and drug-resistant TB, a dangerous form of the disease that has a mortality rate of 80%.
The standard treatment of LTBI involves a 6 to 9-month administration of isoniazid, although new treatments are assayed, such as a 3-month treatement with rifapentine plus moxifloxacin. Active TB treatment has two phases: the intensive one, that requires the administration of four drugs (usually isoniazid, rifampicin, ethambutol and pyrazinamide); and a continuation phase that requires the administration of isoniazid and rifampicine for four months. Regarding drug-resistant TB, there is no specific answer. The option is to prescribe the second line drugs, which are less effective, more expensive and havr a higher toxicity rate.
Finally, talking about preventive care, Dr Cardona suggests the following,
Everybody can get infected. Once LTBI is contracted, the best is to live a balanced life as much as possible in terms of not abusing drugs, maintaining a balanced diet, doing exercise, donating blood if possible (this also reduces induction of inflammatory based diseases, like diabetes, atherosclerosis and cancer)... However, if you have a genetic predisposition, unfortunately you will develop TB.
In conclusion, there is the other side of the coin related to the fight against TB. Since 1995, 46 million people have been successfully treated and up to 6.8 million lives saved through DOTS, a rigorous approach to treatment endorsed by the World Health Organization. In addition to that, the number of people who contracted TB has been falling since 2005; the global incidence rate fell to 128 cases per 100,000 population in 2010, after it peaked in 2002 at 141 cases per 100,000, and most importantly, since 1990, the TB death rate has fallen by 40%.
For further information about TB or how to get involved in rasing awareness during World Tuberculosis Day, please refer to the following web-sites:
Also, to browse through, read, share and download for free IntechOpen's publications on the subject of Tuberculosis, choose from the list below or visit our Infectious Diseases page.
"Understanding Tuberculosis - Deciphering the Secret Life of Bacilli", edited by Pere-Joan Cardona, IntechOpen, Feb. 2012
"Understanding Tuberculosis - New Approaches to Fighting Against Drug Resistance", edited by Pere-Joan Cardona, IntechOpen, Feb. 2012
"Understanding Tuberculosis - Analyzing the Origin of Mycobacterium Tuberculosis Pathogenicity", edited by Pere-Joan Cardona, IntechOpen, Feb. 2012
"Understanding Tuberculosis - Global Experiences and Innovative Approaches to the Diagnosis", edited by Pere-Joan Cardona, IntechOpen, Feb. 2012
"Pulmonary Infection", edited by Amer Amal, IntechOpen, March 2012
About Dr. Pere-Joan Cardona: After obtaining his MD at the Universitat Autònoma de Barcelona, Pere-Joan Cardona started an internship in Clinical Microbiology in 1994, in the Hospital Germans Trias i Pujol, where he was familiarized with the problem of TB in its clinical and diagnostic challenges. Invited by Ian Orme at CSU, he was trained on the development of TB experimental models. PhD was obtained in 1999. He became Head of the Experimental Tuberculosis Unit at the Institut Germans Trias i Pujol of Badalona and Assistant Professor of Microbiology at UAB. He has been involved for the last 15 years in the study of the pathophysiology of TB infection. Additionally, he has authored 70 peer-reviewed publications in the field and is responsible for the development of different experimental models in mice, guinea pigs, goats and mini-pigs, and in the development of new drug regimens and vaccines against TB; he has also edited up to 60 peer review papers. His "h" index" is 21.