Challenges Of Multi-Drug Resistant Tuberculosis

Tuberculosis (TB) is a contagious infection disease that primarily affects the lung. It can also spread to other parts of the body like brain and spine principally through hematogenous route and is called Extrapulmonary TB. Sometimes infection directly extends from an adjacent organ. A patient when diagnosed with TB are kept on ani-tubercular drugs for different duration of time for different TB conditions. The commonly used first line drugs for TB are Isoniazid, Rifampicin, Ethambutol, Pyrazinamide and Streptomycin.

Multi-drug resistant TB (MDR-TB) is caused by an organism that is resistant to at least Isoniazid and Rifampicin, the two must potent TB drugs. Resistance occurs when these drugs are misused or mismanaged through provider or from the seeker perspective. Examples of such misuse includes patient unable to complete full course of treatment, when health-care providers prescribe the wrong treatment, the wrong dose or length of time for taking the drugs, when the supply of drugs in not always available or when drugs are of poor quality. 

Crowded setting

Furthermore, drug resistance is more common in people who do not take their TB medicine regularly, ignore the suggestions given by doctors and nurses, develop TB disease again after having taken TB medicine in past, come from area where drug resistance TB is common, have spent time with somebody known to have drug-resistant TB. These transmissions are superimposed especially in the crowded setting such as in the prison and in the hospitals. Additionally, MDR-TB patients transmitting the bacteria through person-to-person route may also be the potential source of infection.

Globally, there were an estimated 45,0000 new cases of MDR-TB in 2021 up from 3.1 percent from 437000 in 2020. The main reason for increase is estimated to have occurred as a result of the impact of COVID-19 pandemic on TB detection. An estimated 191,000 death occur due to MDR-TB in 2021. In SAARC region in the year 2022, there were 57,106 MDR-TB laboratory confirmed cases. However, 54,075 MDR-TB patients were started on treatment. There exists a gap of 3031 MDR-TB patients who were devoid of treatment, leading to further spread of disease. Hence, identifying the cause of the missing cases and designing the programme addressing the cause is critical to put patient on treatment and stop further transmission of the disease in the community.

In some nations management of MDR-TB has been extremely challenging. Recommended medicine is always not available. Furthermore, patient experience many adverse effects from the drugs. In some of the cases severe drug resistant TB may develop. Extensively drug resistant TB (XDR, TB) is a form of MDR-TB with additional resistance to more anti-TB drug responding to fewer available medicine. Different tests have been developed to test the bacteria for sensitivity or resistance to drugs. 

These tests can be molecular that uses a sample of tissue, blood or other body fluids to check for certain genes, proteins, or other molecules that may be a sign of a disease or condition or are culture based that help find bacteria in your body that may be making you sick. Molecular test can provide result in a very short period of time and has been commonly used in different set-ups including low middle income setup like Nepal. WHO has speed up the detection of MDR-TB through use of these noble rapid diagnostic test. Furthermore, shorter treatment regimens have been developed to counter the long drug treatment for MDR-TB, leading to better adherence and reduced loss to follow-up and preventing death.

MDR-TB can be prevented. However, medication should be taken exactly as prescribed by the health care provider following the recommended guidelines. Regularity of doses should be maintained and treatment should not be discontinued. For travel plan or travelling from long distance they should talk with their healthcare provider to ensure they have enough medicine to last while they are away. On the health care provider perspective, they can help prevent MDR- TB by diagnosing the case early following recommended treatment guidelines, monitor patient response to treatment and ensuring that therapy is completed on time.

Contextual intervention

Another way of preventing getting MDR-TB is to avoid exposure to known MDR-TB patients in closed or crowded places such as hospitals, prisons or homeless shelters. Furthermore, respiratory protective devices can be used to prevent the spread of infections along with strict infection and control measures. Ensuring the appropriate use of second line antitubercular drug is critical for further development of resistance.

Challenges of managing MDR-TB are numerous. However, constant advocacy, social mobilisation, partnership, update of the latest guideline, adoption of innovation and intersectoral efforts should be prioritised to prevent further escalation of the disease. Furthermore, investment and innovative operational research in the local context is critical to design contextual intervention. Yes, we can end MDR-TB should be the motto of every professional working for MDR-TB control in the world.

(Dr. Rawal is the Director and Dr. Pykurel is the Research Officer at the SAARC TB and HIV/AIDS Centre, Thimi, Bhaktapur)