Drug-resistant tuberculosis is one among several other drug resistant infections posing a challenge to disease management today in the world. Tuberculosis (TB) is the world’s leading infectious cause of death, killing up to 1.6 million people yearly. This infectious disease is caused by mycobacterium tuberculosis that spread from person to person through microscopic droplets released into the air. It can happen when a person with the untreated, active form of tuberculosis coughs, speaks, sneezes, spits, laughs or sings.
Infection with TB can either be latent or active. Latent TB infection (also called inactive TB) is when the bacteria is in your system but does not cause any symptoms. This type of infection is not contagious but can progress into an active infection if treatment is not given. An active TB infection is one that results in symptoms including :
- Cough that lasts three or more weeks.
- Coughing up blood.
- Chest pain.
- Pain with breathing or coughing.
- Weight loss.
- Night sweats.
- Loss of appetite.
If you have any of these symptoms, see your doctor to diagnose whether you have TB or your symptoms are due to another problem. The good news is that TB is can be effectively treated with medications. However, there are strains of TB bacteria that have become resistant to these medications making TB treatment challenging for doctors.
The number of TB cases increased dramatically during the 1980s because of the spread of HIV, the virus that causes AIDS. In recent times however, one of the leading reasons TB remains a major killer is the increase in drug-resistant strains of the bacterium. Since the development of the first antibiotics used to fight tuberculosis more than 60 years ago, some TB germs have developed the ability to survive despite medications, and that ability gets passed on to their descendants. An estimated 500,000 people suffer from drug-resistant strains of the disease.
Drug-resistant strains of tuberculosis emerge when an antibiotic fails to kill all of the bacteria it targets. The surviving bacteria become resistant to that particular drug and frequently other antibiotics as well. Some TB bacteria have developed resistance to the most commonly used treatments, such as isoniazid and rifampin.
Some strains of TB have also developed resistance to drugs less commonly used in TB treatment, such as the antibiotics known as fluoroquinolones, and injectable medications including amikacin and capreomycin (Capastat). These medications are often used to treat infections that are resistant to the more commonly used drugs.
New Drug Offers New Hope For Drug-Resistant TB
Health authorities have warned about the growing danger of drug-resistant infections. The United Nations has projected that such infections could cause 10 million deaths each year by 2050 if nothing is done. Drug companies and researchers have since been looking into the development of newer drugs for many of the drug resistant infections we have today.
Only recently, the Food and Drug Administration in the US approved a new drug for highly drug-resistant tuberculosis. The antibiotic, called pretomanid, was developed by a nonprofit group called TB Alliance. Some researchers hope TB Alliance can serve as a model for antibiotic drug development because many drug companies have largely abandoned development of antibiotics because they can cost upward of 1 billion dollars to bring to market but yield far less revenue than drugs for chronic conditions, such as high blood pressure and high cholesterol, or specialty drugs.
Pretomanid is part of a three-drug regimen against highly resistant forms of TB and is the third FDA-approved anti-TB drug in more than 40 years. TB Alliance said 95 of its first 107 patients in its clinical trial had a successful outcome after six months of treatment with the three-drug regimen. The historical treatment success rate is 34 percent.
TB Alliance said it hopes the FDA’s approval will enable other countries, such as China, India and South Africa, to okay the drug and to make it available to their residents.