Posted on World TB Day, by:
Madhukar Pai, MD, PhD
Director, McGill Global Health Programs, Montreal, Canada
TB is an ancient disease that has plagued humans for centuries. Today, India alone accounts for a quarter of all TB cases in the world. Over 2.2 million new TB cases occur every year and TB kills nearly 900 people every day in India. The emergence of severe forms of drug resistant TB has worsened the situation, especially in cities like Mumbai.
TB is caused by bacteria that are spread from person to person through the air. Long-term cough and fever are the most important symptoms of TB. When a person with TB coughs, TB bacteria get expelled into the air. The bacteria can then get inhaled by another person who can become newly infected. TB usually affects the lungs,but it can also affect other parts of the body. TB can affect adults and children, and can affect people from all walks of life. Persons with HIV infection and AIDS are particularly prone to getting TB.
The positive news is that TB is treatable and curable. However, unlike most common infectious diseases (e.g. malaria or pneumonia) that require a few days of antibiotic treatment, TB requires several antibiotics and 6 months of treatment. Otherwise, TB bacteria will become resistant to antibiotics. Multidrug-resistant (MDR-TB) refers to TB that is resistant to rifampicin and isoniazid, two of the most critical first-line antibiotics used to treat TB.
Accurate diagnosis: the first key step
Because TB is a curable disease, it is very important to accurately diagnose the disease and to do it early, before severe lung damage occurs, and before other people in the community are infected.
All individuals with cough for more than 2 weeks must seek care early and get their sputum tested for TB. Sadly, many persons with chronic cough do not seek medical care,and this results in long delays before a diagnosis is made. Sputum testing can involve microscopic examination for the TB bacteria, culture to grow the bacteria in a tube, or newer molecular tests that multiply and detect TB DNA.
GeneXpertis the biggest new advance in TB detection. It is a highly accurate, molecular test that has been endorsed by the World Health Organization (WHO). This technology is completely automated and can rapidly detect TB as well as drug-resistant TB within 2 hours (photograph). Over 16 million GeneXpert tests have been done globally.
Thanks to the Initiative for Promoting Affordable and Quality TB tests (www.ipaqt.org), led by the Clinton Foundation, it is now widely available in over 100 labs across India at prices that are 50% less than the market price. Through the IPAQT initiative other WHO-approved TB tests such as liquid culture are also available at subsidised rates.
Correct and regular treatment can save lives
If TB is diagnosed, the most important thing a patient can do to is to take all of their medications exactly as prescribed by their doctor. No doses should be missed and treatment should not be stopped early, even if the patients feel better. Patients who cannot afford to buy drugs in the private sector must seek treatment in the public sector where drugs are available free of cost.
Doctors have an important role to play in ensuring that their TB patients are treated correctly. Doctors must follow recommended treatment guidelines, monitor patients’ response to treatment, and make sure therapy is completed. Doctors should also avoid starting anti-TB drug treatment without doing any laboratory testing to confirm the disease. If TB is confirmed, they should start treatment promptly and follow Standards for TB Care in India.
For regular, drug-sensitive TB, a standard 4-drug treatment must be started, and the total duration of treatment must not be less than 6 months. Drug-resistance usually happens when patients do not complete their full course of treatment; when doctors prescribe the wrong treatment, the wrong dose, or length of time for taking the drugs.
If drug-resistance is suspected, it should be confirmed using laboratory tests such as GeneXpert and liquid culture. For drug-resistant TB, second-line drug treatment must be started, and the total duration of treatment must be at least 2 years. Treatment for MDR-TB can be very expensive in the private sector, and such patients can access free treatment in specialized public hospitals that can treat MDR-TB patients.
With correct diagnosis and complete treatment, TB can be cured and loss of life averted.Importantly, this will also help control the spread of this deadly infection.