Drug resistance in TB remains a man-made phenomenon. It emerges as a result of spontaneous gene mutations in M. tuberculosis that render the bacteria resistant to the most commonly used anti-TB drugs. Among the reasons for this, the non-compliance with the treatment regimens is signaled as the first cause.
Full Answer
What are the different types of drug resistant tuberculosis?
Types of Drug Resistant TB. Multidrug-Resistant TB (MDR TB) Multidrug-resistant TB (MDR TB) is caused by TB bacteria that is resistant to at least isoniazid and rifampin, the two most potent TB drugs. These drugs are used to treat all persons with TB disease. TB experts should be consulted in the treatment of MDR TB.
What is the treatment for drug-resistant tuberculosis?
Treatment of Drug-Resistant TB. Extensively drug-resistant TB (XDR TB) is a rare type of MDR TB that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin). Treating and curing drug-resistant TB is complicated.
Why is drug resistance detection important in tuberculosis (TB)?
Early detection of all forms of drug resistance in TB is a key factor to reduce and contain the spread of these resistant strains. A better knowledge of the mechanisms of action of anti-TB drugs and the development of drug resistance will allow identifying new drug targets and better ways to detect drug resistance.
Is tuberculosis (TB) treatable?
In most cases, TB is treatable and curable; however, people with TB can die if they do not get proper treatment. Sometimes drug-resistant TB occurs when bacteria become resistant to the drugs used to treat TB. This means that the drug can no longer kill the TB bacteria.
Why do we have drug-resistant TB?
The 2 reasons why multidrug resistance continues to emerge and spread are mismanagement of TB treatment and person-to-person transmission. Most people with TB are cured by a strictly followed, 6-month drug regimen that is provided to patients with support and supervision.
Why is TB so resistant to antibiotics?
Mycobacterium tuberculosis is intrinsically resistant to many antibiotics, limiting the number of compounds available for treatment. This intrinsic resistance is due to a number of mechanisms including a thick, waxy, hydrophobic cell envelope and the presence of drug degrading and modifying enzymes.
When did TB become drug-resistant?
Tuberculosis has existed for many centuries, but it was not until 1944 effective effective antibiotic therapy (streptomycin) became available. In 1950, scientist Renee Dubos predicted that that bacteria would eventually develop resistance to antibiotics through random mutations and natural selection .
Why has it become more difficult to treat TB over time?
Scientists have assumed that mycobacteria are so hard to kill because dormant cells exist even in patients with active disease and these cells are far less susceptible to antibiotics than metabolically active bacteria.
What Is Tuberculosis (TB)?
Tuberculosis (TB)(https://www.cdc.gov/tb/publications/factsheets/general/tb.htm) is a disease caused by bacteria that are spread from person to per...
What Is Multidrug-Resistant Tuberculosis (MDR TB)?
Multidrug-resistant TB (MDR TB) is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs. These...
What Is Extensively Drug Resistant Tuberculosis (XDR TB)?
Extensively drug resistant TB (XDR TB) is a rare type of MDR TB that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least...
How Does Drug Resistance Happen?
Resistance to anti-TB drugs can occur when these drugs are misused or mismanaged. Examples include when patients do not complete their full course...
Who Is at Risk For Getting MDR TB?
Drug resistance is more common in people who: 1. Do not take their TB medicine regularly 2. Do not take all of their TB medicine as told by their d...
How Can MDR TB Be Prevented?
The most important thing a person can do to prevent the spread of MDR TB is to take all of their medications exactly as prescribed by their health...
Is There A Vaccine to Prevent TB?
Yes, there is a vaccine for TB disease called Bacille Calmette-Guérin (BCG)(https://www.cdc.gov/tb/publications/factsheets/prevention/bcg.htm). It...
What Should I Do If I Think I Have been Exposed to Someone With TB Disease?
If you think you have been exposed to someone with TB disease, you should contact your doctor or local health department about getting a TB skin te...
What Are The Symptoms of TB Disease?
The general symptoms of TB disease include feelings of sickness or weakness, weight loss, fever, and night sweats. The symptoms of TB disease of th...
What Is Extensively Drug-Resistant Tuberculosis (XDR TB)?
Extensively drug-resistant TB (XDR TB) is a rare type of multidrug-resistant tuberculosis (MDR TB) that is resistant to isoniazid and rifampin, plu...
Why Is XDR TB So Serious?
Because XDR TB is resistant to the most potent TB drugs, the remaining treatment options are less effective, have more side effects, and are more e...
Who Is at Risk For Getting XDR TB?
Drug-resistant TB (MDR or XDR) is more common in people who: 1. Do not take their TB medicine regularly 2. Do not take all of their TB medicines as...
How Can I Prevent Myself from Getting TB?
Avoid close contact for a prolonged period of time with known TB patients in crowded, enclosed environments like clinics, hospitals, prisons, or ho...
Can The TB Vaccine (BCG) Help Prevent XDR TB?
The TB vaccine is called Bacille Calmette-Guérin (BCG)(https://www.cdc.gov/tb/publications/factsheets/prevention/bcg.htm), and it is used in many c...
If I Have Drug-Susceptible Tb, How Can I Prevent Getting Drug-Resistant TB?
The most important thing is for you to continue taking all your TB medicines exactly as prescribed. No doses should be missed and treatment should...
Can XDR TB Be Treated and Cured?
Yes, in some cases. Some TB control programs have shown that cure is possible for an estimated 30% to 50% of affected people. Successful outcomes d...
What Are The Symptoms of XDR TB?
The general symptoms of TB disease include feelings of sickness or weakness, weight loss, fever, and night sweats. The symptoms of TB disease of th...
What Should I Do If I Have been Around Someone Who Has XDR TB?
If you think you have been exposed to someone with XDR TB disease, you should contact your doctor or local health department about getting a TB ski...
How Long Does It Take to Find Out If You Have XDR TB?
If TB bacteria are found in the sputum (phlegm), the diagnosis of TB can be made in a day or two, but this finding will not be able to distinguish...
Why is XDR TB so resistant to TB drugs?
Because XDR TB is resistant to the most potent TB drugs, patients are left with treatment options that are much less effective. XDR TB is of special concern for persons with HIV infection or other conditions that can weaken the immune system.
How to prevent MDR TB?
Another way to prevent getting MDR TB is to avoid exposure to known MDR TB patients in closed or crowded places such as hospitals, prisons, or homeless shelters. If you work in hospitals or health-care settings where TB patients are likely to be seen, you should consult infection control or occupational health experts.
What is MDR TB?
What is multidrug-resistant tuberculosis (MDR TB)? Multidrug-resistant TB (MDR TB) is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs. These drugs are used to treat all persons with TB disease.
What are the symptoms of TB in the lungs?
The symptoms of TB disease of the lungs may also include coughing, chest pain, and coughing up blood. Symptoms of TB disease in other parts of the body depend on the area affected. If you have these symptoms, you should contact your doctor or local health department.
What to do if you think you have been exposed to someone with TB?
If you think you have been exposed to someone with TB disease, you should contact your doctor or local health department about getting a TB skin test or TB blood test. And tell the doctor or nurse when you spent time with this person.
How long does TB float in the air?
These bacteria can float in the air for several hours, depending on the environment. Persons who breathe in the air containing these TB bacteria can become infected. TB is not spread by. Shaking someone’s hand. Sharing food or drink. Touching bed linens or toilet seats. Sharing toothbrushes.
Can TB be curable?
TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. In most cases, TB is treatable and curable; however, persons with TB can die if they do not get proper treatment.
What is a drug resistant TB?
Drug-resistant tuberculosis (TB) is TB disease caused by M. tuberculosis organisms that are resistant to at least one first-line anti-TB drug. Multidrug-resistant TB (MDR TB) is resistant to more than one anti-TB drug and at least isoniazid (INH) and rifampin (RIF). Treating and curing drug-resistant TB is complicated.
How long can TB be treated without treatment?
A potential regimen should include a daily fluoroquinolone. Contacts who are not immunosuppressed may be treated for 6 months or observed without treatment.
How long does it take to test for drug resistance?
Drug resistance is proven by drug-susceptibility testing. However, since this testing can take weeks , treatment should be started with an empirical treatment regimen based on expert advice as soon as drug-resistant TB disease is suspected. When the testing results are known, the treatment regimen should be adjusted according to the results.
What is DOT in TB?
Patients should be monitored closely throughout treatment. Directly observed therapy (DOT) always should be used in the treatment of drug-resistant TB to ensure adherence.
Can rifabutin be used in place of RIF?
Rifabutin, which has fewer problematic drug interactions, may be used in place of RIF. As new antiretroviral agents and pharmacokinetic data become available, these recommendations are likely to be modified. Visit Managing Drug Interactions in the Treatment of HIV-Related Tuberculosis for the most recent recommendations.
How does the CDC help with TB?
CDC is collaborating with other federal agencies and international partners to raise awareness and enhance strategies for TB prevention worldwide by: 1 Strengthening TB services for people living with HIV/AIDS; 2 Guiding preparedness and outbreak investigation responses; 3 Improving access to TB drugs; 4 Conducting routine surveillance (including drug susceptibility) and periodic surveys; 5 Implementing new, rapid diagnostic tests; 6 Developing and promoting, national and international TB testing standards; 7 Conducting program evaluation (e.g., National TB Indicators Project [NTIP]); 8 Building capacity of health care providers to diagnose and treat TB; 9 Reinvigorating the Federal TB Task Force; 10 Providing assistance to improve TB program capacity in the U.S. and abroad; and 11 Developing education, risk, and media communications (Web- and print-based) to aid in preparedness and public awareness of TB prevention and control issues.
How many people can cure TB?
Some TB control programs have shown that cure is possible for an estimated 30% to 50% of affected people. Successful outcomes depend greatly on the extent of the drug resistance, the severity of the disease, whether the patient’s immune system is weakened, and adherence to treatment.
What is XDR TB?
Extensively drug-resistant TB (XDR TB) is a rare type of multidrug-resistant tuberculosis (M DR TB) that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin). MDR TB is caused by an organism that is resistant to at least isoniazid ...
What to do if you think you have been exposed to someone with XDR TB?
If you think you have been exposed to someone with XDR TB disease, you should contact your doctor or local health department about getting a TB skin test or blood test for TB infection. You should tell the doctor or nurse when you spent time with this person.
How long does it take to test for TB?
Final diagnosis for TB, and especially for XDR TB, may take from 6 to 16 weeks.
How is TB spread?
TB bacteria are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, shouts, or sings. These bacteria can float in the air for several hours, depending on the environment. Persons who breathe in the air containing these TB bacteria can become infected.
What are the symptoms of TB?
The general symptoms of TB disease include feelings of sickness or weakness, weight loss, fever, and night sweats. The symptoms of TB disease of the lungs may also include coughing, chest pain, and coughing up blood. Symptoms of TB disease in other parts of the body depend on the area affected.
How long does it take to cure MDR TB?
Treatment can take up to two years, cure rates are lower and fatalities are higher. In poorer countries, it can be very difficult to treat MDR-TB. Treatment options are limited and expensive, the best medicines may not be available, and patients can experience many bad side effects from the drugs.
How many people developed MDR-TB in 2015?
Multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) are major global health threats. WHO estimates that 480,000 people developed MDR-TB in 2015, but only 52% of cases were identified and treated appropriately.
How long does it take for TB to develop?
Drug-resistant forms of TB can develop if treatment is incorrect or incomplete. This can happen for several reasons. Because treatment for TB takes six months and can have difficult side effects, people may be tempted to stop taking their medication before they have completed treatment, particularly if they are starting to feel better. ...
Can TB be passed on to others?
They may be given the incorrect treatment or may fear the stigma of having TB. People with infectious drug-resistant TB can then also pass this drug-resistant strain on to others.
What does it mean when you have drug resistant TB?
A person has drug resistant TB if the TB bacteria that the person is infected with, will not respond to, which means that they are resistant to, at least one of the main TB drugs. Drug susceptible TB is the opposite. If someone is infected with TB bacteria that are fully susceptible, it means that all of the TB drugs will be effective so long as ...
What are the two main types of drug resistant TB?
What are the main types of drug resistant TB? There are two main types, MDR TB and XDR TB. MDR TB is the type of drug resistant TB, when the bacteria are resistant to the TB drugs rifampicin and isoniazid. MDR TB is the name given to TB when the bacteria that are causing it are resistant to at least isoniazid and rifampicin, ...
Why do people get TB?
There are two ways that people get it. Firstly, people get acquired drug resistant TB when their TB treatment is inadequate. This can be for a number of reasons, including the fact that patients fail to keep to proper TB treatment regimens. It can also be that the wrong TB drugs are prescribed, or sub standard TB drugs are used for treatment.
What does it mean when you have TB?
If someone is infected with TB bacteria that are fully susceptible, it means that all of the TB drugs will be effective so long as they are taken properly. It still means that several drugs need to be taken together to provide effective TB treatment.
What is XDR TB?
XDR TB is defined as strains resistant to at least rifampicin and isoniazid. This is in addition to strains being resistant to one of the fluoroquinolones, as well as resistant to at least one of the second line injectable TB drugs amikacin, kanamycin or capreomycin. 2“Extensively drug-resistant tuberculosis ...
What is MDR TB?
MDR-TB is caused by strains of Mycobacterium tuberculosisthat are resistant to at least rifampicin and isoniazid, two key drugs in the treatment of the disease. Since 2006, it has been recognized the presence of even more resistant strains of M. tuberculosislabelled as extensively drug resistant (XDR)-TB [2,3,4].
What is the second line of anti-tuberculosis?
Para-Amino Salicylic Acid. Although it was one of the first anti-tuberculosis drugs used in the treatment of the disease, together with isoniazid and streptomycin, para-amino salicylic acid or PAS is now considered as a second-line drug part of the treatment regimen for MDR-TB.
Where do mutations occur in pyrazinamide resistant strains?
Mutations in the gene pncAremain as the most common finding in pyrazinamide resistant strains. These mutations, however, are scattered throughout the gene but most occur in a 561-bp region in the open reading frame or in an 82-bp region of its putative promoter [60,61].
What is the name of the anti-tuberculosis drug used for MDR?
3.5. Cycloserine. Cycloserine is an oral bacteriostatic second-line anti-tuberculosis drug used in MDR-TB treatment regimens. It is an analog of d-alanine that by blocking the activity of d-alanine: d-alanine ligase inhibits the synthesis of peptidoglycan.
How many deaths from TB in 2012?
Tuberculosis (TB) remains as an important infectious disease and public health concern worldwide. According to the latest World Health Organization (WHO) report, there were an estimated 8.6 million incident cases of TB in 2012 and 1.3 million deaths were attributed to the disease.
Which antibiotics inhibit protein synthesis?
Kanamycin, Capreomycin, Amikacin, Viomycin. These four antibiotics have the same mechanism of action by inhibiting the protein synthesis but, while kanamycin and amikacin are aminoglycosides, capreomycin and viomycin are cyclic peptide antibiotics. All four are second-line drugs used in the management of MDR-TB.
Is tuberculosis a public health problem?
Tuberculosis (TB) is a serious public health problem worldwide. Its situation is worsened by the presence of multidrug resistant (MDR) strains of Mycobacterium tuberculosis, the causative agent of the disease. In recent years, even more serious forms of drug resistance have been reported.
