MDR TB
If you are suffering from tuberculosis and are not following the usual course of treatment (as prescribed by your doctor), you are more likely to suffer from multi-drug resistant tuberculosis (MDR-TB). A more severe form of tuberculosis, it is caused by the bacterium, Mycobacterium tuberculosis, which becomes resistant to the drugs used to treat tuberculosis. This is one of the reasons why you might not respond well to the treatment and thus, suffer from MDR-TB.
According to the world health organization (WHO), 5% of the total TB cases all over the world were estimated to be of MDR-TB (multi-drug resistant tuberculosis). And around 3% of all newly diagnosed patients are suffering from MDR-TB. In 2010, India had an estimated 63,000 notified cases, the highest in the South East Asia region. Here are 10 facts about TB you should know.
In MDR-TB, the bacterium becomes resistant to two or more medications (namely isoniazied and rifampicin) that are primarily used to treat the disease. Our expert Dr Jai B Mullerpattan, Associate Consultant, Department of Pulmonology, P.D. Hinduja National Hospital and MRC explains in detail about the causes, symptoms, treatment and prevention of MDR-TB.
Symptoms
It is spread in the same manner as tuberculosis. Symptoms are same as regular TB and include –
Other symptoms may be related to the particular organ involved. Dr Mullerpattan says, 'MDR and drug susceptible TB cannot be distinguished based on signs and symptoms alone. And hence, MDR-TB is confirmed only in the microbiology laboratory.’ However, in these cases, the symptoms progressively get worse and may cause complications and death since the patient does not respond to most anti-TB drugs.
Here is detailed information on drug resistant TB.
Causes
It is often caused when people do not take the full course of TB medicines as per the physician’s prescription. The bacterium spreads through air i.e. when a person suffering from tuberculosis sneezes, coughs, sings or speaks, bacteria present in the saliva gets into the air. And when a normal person breathes in that air, the chances are high that you might suffer from MDR-TB. Also read about how TB is affecting India’s health.
The factors that increase your risk of suffering from MDR-TB are –
- Have a history of TB
- Irregular or non-compliance to treatment
- Contact with a patient of MDR-TB
Read about 5 things you didn’t know about MDR TB.
Diagnosis
Diagnosis of MDR-TB is carried out in the lab. The common tests used to determine MDR-TB strain include --
Microbiological diagnosis (MTB/RIF XPERT tests): MDR-TB is diagnosed by performing laboratory tests to determine resistance to isoniazid and rifampicin in culture isolates.
Genetic tests: In some cases, Alternatively MDR-TB may also be diagnosed by genetic tests such as line probe assays (LPA) showing genetic mutations that match to isoniazid and rifampicin resistance.
*Often rifampicin resistance on MTB/RIF XPERT tests is taken to be a surrogate marker of MDR-TB as almost 90-95% of isolates with rifampicin resistance have concomitant isoniazid resistance.
Read in detail about common diagnostic tests for tuberculosis.
Treatment
As people suffering from MDR-TB are resistant to the first-line of drugs (isoniazid and rifampicin), its treatment involves the use of second-line drugs that are given for 18-24 months. The treatment usually involves an intensive phase of 6-9 months with second-line drugs such as amikacin, kanamycin or capreomycin. Read about DOTS and its 5 basic measures to deal with tuberculosis
The remaining continuation phase is continued for 12-18 months. The total number of drugs used is usually 4-5 drugs to which the TB bacillus is known to be susceptible to, or to which the patient has not been exposed to and likely to be susceptible if a full DST (drug susceptibility testing) is not available. Also read about how stem cell therapy can help patients with deadly MDR-TB.
In general, the treatment of MDR-TB involves –
- Many first line drugs
- One second-line injectable
- One respiratory drug (usually quinolone)
- Many group four drugs such as ethionamide, PAS, cycloserine, etc
- If required, salvage drugs (linezolid, clofazimine, clarithromycin, meropenem-clavulanate, bedaquiline, delaminid, etc) are also prescribed
In the public sector, treatment is provided through the DOTS PLUS or PMDT programme, whereas, in case of the private sector, treatment is either in the supervised or self-administered manner.
You may also like to read revolutionary medicine — doctor treats MDR-TB patients with leprosy drugs.
Prognosis
The treatment of MDR-TB is more toxic and expensive as compared to drug susceptible TB. Hence, it requires intensive follow-up by the patient for response to treatment and side-effects of the medications (if any, experienced by the patient). In some cases, the patient may show sudden flare-up of symptoms during the treatment phase. This is because, you may be infected with a mixed population of TB bacteria, and the resistant bacilli may flare up later in the treatment (after the initial response).
Hence, proper diagnosis of MDR-TB and early treatment is known to be the best way to decrease transmission of tuberculosis.
Here are 6 strategies to overcome challenges in TB treatment.
Prevention
The only way to prevent MDR-TB is to ensure adequate and swift treatment of drug-susceptible TB. And complete your course of medications as recommended by your doctor as it may lead to MDR-TB.
Here are 11 ways you can prevent tuberculosis!
The content has been verified by
Dr Jai B Mullerpattan
, Associate Consultant, Department of Pulmonology, P.D. Hinduja National Hospital and MRC.
91 – 22 – 2490 0302.