MDR-XDR Tuberculosis causes, impacts, control and measures

Tuberculosis is chronic infection caused by mycobacterium tuberculosis bacteria which attacks lungs. It is spread by air when infected person coughs, sneezes, or talks. According to World Health Organization (WHO) 10 million people affected and around 1.6 million died due to tuberculosis in 2017. One million people children became ill and 230,000 have died due to this global public health problem. India is leading nation in the whole world when it comes to number of deaths. In 2017 only, around 433000(4.33lakh) people died due to tuberculosis in India.

What is the nature of tuberculosis? It is one of the chronic communicable or contagious diseases. It is spread by bacteria contained in the very small droplets coming out from an infected person when he or she coughs, sneezes, speaks, spits, laughs or sings. It develops when someone comes in contact with sputum of the sick person. The bacterium is released in the air and infects the nearby people. Tuberculosis is not spread by handshake, touching and sharing foods. Even if someone comes in contact with bacterium, the sickness depends on the immunity power of that person. If immunity system is strong enough against that bacterium the person will not catch the tuberculosis. People with strong immunity generally don’t develop the disease but if it does, it takes around 2-3 months or more than that.

 

Who are generally affected by this infection? The nearby or close people are more likely to be infected by the tuberculosis bacterium. Public places or crowded areas are more prone to this disease. The persons who are in constantly interacting with sick person like family members, co workers, and medical staff are generally more prone. It takes good amount of contact time between sick person and other person. The HIV infected persons are more prone because of very less immune power and can be fatal. The HIV infected persons are at high risk of Tuberculosis related deaths. The HIV combined with tuberculosis is major public health issue in African continent. The rate of increase of global cases related to TB is 1% every year.    

                                                           

Which nations or countries are currently most affected? The communicable diseases like tuberculosis is more prevalent in the nations where the public health system is not robust and preventive measures are lacking. The status of economy also impacts the control and spread of the diseases. It is said that tuberculosis is the disease of poverty. Tuberculosis impacts poor and malnourished people.  In the last century the tuberculosis was a grave public health issue in the United States. Although currently the US is not affected like other developing and least developed countries but due to globalization, trade, travel and movement of human force no country can be 100 percentages safe from communicable diseases. Tuberculosis is leading cause of deaths in African nations, India, China, Bangladesh, Indonesia, Pakistan and Philippines. The global warming and climate change is also setting new trends and patterns of diseases across the globe.

What are visible symptoms? The infected person develops signs like cough, fever, sweating in nights and weight loss. But these symptoms may be mild for long time and it would be difficult to diagnose tuberculosis based on these symptoms. In this time of delay the disease can spread to other peoples too. The ill person can affect 10-15 people in one year if the cure and treatment is not started. It is reported that 2/3rd people may die due to improper or lack of treatment.

      

How diagnosis is being done? The tests used to diagnose TB are skin, imaging, sputum and blood test. Generally skin test is most commonly used but it can show different results in situations like when person is already vaccinated by BCG. The blood tests are now actively adopted for proper diagnosis.  

Is Tuberculosis curable? Yes it is curable if diagnosed timely and proper medication is taken. The tuberculosis which has not yet reached stages of MDR and XDR can be treated with the standard course of 6 months. When mycobacterium become active within the body and immune system is not able to stop bacteria’s growth the TB disease develops. The patients who are new and never had TB before are treated with the four antimicrobial drugs. These drugs are called the first line of defense. Again the use of these drugs depends on the condition of the patient and infection level. The first four drugs against tuberculosis are:-

-isoniazid(INH)

-rifampin(RIF)

-ethambutol(EMB)

-pyrazinamide(PZA)   

What is second line of defense against Tuberculosis? The second line of defense drugs is only used to treat bacteria that have become resistant to first line of defense. There are three possible reasons when a drug is termed as second line drug.

- When the drug is less effective than first line of defense drugs. Ex aminoglycosides drugs

- The drug can have side effect after use. Ex cycloserine

- It is effective but unavailable due to various socio economic factors Ex fluoroquinolones drugs

What is difference between MDR and XDR TB? When TB bacteria become resistant to at least isoniazid and rifampin, it is called Multidrug Resistant TB. Extensively drug resistant TB is rare type of MDR TB when bacteria develops resistance to fluoroquinolone and at least against one of three inject able second line of defense drugs like amikacin,kanamycin  

What are causes of MDR TB? When tuberculosis bacteria become develops resistant against first line of defense TB drugs then that bacteria cannot be killed easily and becomes resistant to those drugs. Generally the bacteria become resistant when the drugs are mismanaged or misused. The careless attitude towards taking drugs on schedule may make bacteria resistant. Since bacteria become resistant very fast that’s why WHO introduced the DOTS program for the nations which needs to be followed very strictly under the supervision of skilled medical worker.

Below are main reasons of developing MDR TB.

-The drugs are not taken properly according to DOTS.

-The full course is not taken.

-Single dose of drugs should not be missed.

-The drugs are not available in the region.

-The drugs are not of good standards.

-When people spend significant time with persons or regions having MDR -TB

     

Is MDR TB curable? The second line of defense drugs is used to treat MDR TB for two years. The drugs are toxic, treatment is rough, expensive  and the success rate has been 50%.The developing and underdeveloped nations has less success rate in comparison to developed world. The HIV infected persons are more prone to develop MDR TB because of their weak immune power and these people also have high risk of death due to tuberculosis.   

What are the side effects of tuberculosis drugs? The side effects can vary from mild to severe based on the type of drugs and duration of the treatment. For normal tuberculosis the treatment duration is 6-9 months while for MDR TB it is at least 20 months. The normal tuberculosis drugs may have side effects like rashes on skin, nausea and liver failure, while drugs of MDR TB may have effects like permanent hearing loss and dizziness, kidney and liver damage too.

Being communicable disease and highly resistance nature of the tuberculosis bacteria the disease need extraordinary care and control system in place. The communities should be made aware how drug resistant bacteria can develop. According to WHO in 2017, MDR remains to be public health issue and 558000 new cases of drug resistant were reported. India, China and Russia comprise half of the global cases. It is reported that around 8.5% of MDR TB cases had XDR TB in 2017.

Ending tuberculosis from the world by 2030 is one of the sustainable goals of the United Nations. To achieve this goal individual, community, governments should work together in coordinated manner. The nongovernmental organizations have important role to play in making people aware and providing support. The nations should formulate efficient polices and should follow in letter and spirit. The adequate medical infrastructure should be in place. The focus should be on continuous investment in research and development. Recently drugs are being developed to reduce the time gap to identify the infections. These new development and best management practices should be made available to highly affected and poor areas of the world.