Drug Resistant Tuberculosis What Should You Know
Dr.Sonia Lal Gupta and Dr.Sameer Gupta
Tuberculosis is one of the top 10 causes of death worldwide and India has the maximum number of cases of this deadly but curable and treatable disease. The World Health Organization’s Global Tuberculosis Report in 2016 estimates that there are 79,000 cases of MDR-TB or Multi-Drug Resistance Tuberculosis. This is becoming a serious problem and a big public health issue.
What is Tuberculosis?
Tuberculosis is a disease caused by the bacteria Mycobacterium Tuberculosis. It is spread from person to person through the air. When people with tuberculosis sneeze, spit or cough, the bacteria goes into the air and if someone inhales these germs, they can become affected.
It usually affects the lungs but can also spread to all other organs of the body. Symptoms of tuberculosis include a cough, low-grade fever, night sweats or unexplained weight loss.
When a person develops tuberculosis, they can have mild symptoms for many months before being detected with the infection. People affected with HIV are 20 to 30 more times likely to develop active tuberculosis.
An active case of tuberculosis usually can be treated with a standard 6 month course of 4 anti-Tb drugs. Since these medications have been used for many years, new forms of Tb that are resistant to the standard Tb drugs are being seen. There are multiple forms of Drug Resistant Tuberculosis that include:
- Multi drug resistant TB or MDR-TB shows resistance to the most effective anti-TB drugs – Isoniazid and Rifampicin.
- Extensively-drug resistant TB or XDR-TB is a more severe form of MDR-TB which is additionally resistant to the 2nd line drugs that include at least one of the 3 injectable anti-TB drugs.
- Extremely drug resistant TB or XXDR-TB shows resistance to all the 12 drugs making it virtually untreatable.
How TB becomes Drug – Resistant
Various reasons have lead to drug resistant form of tuberculosis:
- Delays in detection and referral: In most instances, detection of drug resistant TB is delayed due to the limited availability of good diagnostic services. This perpetuates a cycle of TB transmission. By the time an infected patient is diagnosed, one might have visited several doctors and in the process may have infected many others with drug resistant strains of TB.
- Adherence to treatment regimens: To prevent drug resistance, it is vital to ensure treatment adherence and access to quality medication. Many patients do not adhere to the prescribed TB drug regimens, which in turn promotes resistance.
- Expensive drug regimens: While a course of standard TB drugs costs approximately Rs. 1000, MDR-TB drugs can cost more than Rs.1-1.5 lakh, and the cost of XDR-TB treatment is even higher. This has a significant impact on the livelihoods of drug resistant patients and prevents many from completing treatment.
According to the WHO, 480,000 people were affected with MDR-TB in 2015 worldwide. In India, it is estimated that 2.5% of all new TB cases are MDR-TB.
Treatment of Drug-Resistant Tuberculosis – The DOTS-Plus Protocol
The DOTS or the Directly Observed Treatment, Short-Course is the standard treatment course used for the treatment of tuberculosis. The DOTS-Plus the protocol for diagnosis and treatment of MDR-TB. While MDR-TB can be treated and cured using second line drugs, the treatment is extremely complex, expensive and can have severe side effects. The duration for the treatment of this program is two years.
Drug sensitivity tests are specialized laboratory tests used to diagnose MDR-TB. These tests are usually done after patients fail the standard 6 month treatment course. At times, after failing the 6 month treatment course, a 8 month treatment is initiated. If the second treatment fails, then the patient is tested for drug-resistant TB and put on treatment accordingly.
Unfortunately during this time, due to inappropriate treatment regimes, the disease strain may mutate into a highly drug resistant strain which is much difficult to treat in terms of the cost, the longer duration of treatment and the severe side effects. Experts from the TB field are of the opinion that the number may be grossly underestimated and testing for drug resistance at the outset is the way forward.
The WHO has developed newly adopted sustainable goals for ending the TB epidemic by 2030 and is also making new guidelines to help curb new forms of drug-resistant tuberculosis.
To know more about the experience of a person who suffered and fought the battle with Drug Resistant TB, watch this episode of NDTV “Doctors on Call”.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for qualified medical opinion. Always consult a specialist or your own doctor for more information.