Are we forgetting that TB prevention is better than cure?

    29-Oct-2019
-Shobha Shukla
Without infection there is no disease: Nip the TB infection Prevention of new infections of TB bacteria (Mycobacterium tuberculosis) and their progression to active TB disease is critical to reduce the burden of TB disease and to achieve the goal of ending TB by 2030. Around 587 million (35%) of the total estimated 1.7 billion people infected with latent TB infection (LTBI) globally live in the South East Asia region. About 7% (43.3 million) of these are children under 15 years of age. A person with latent TB infection (LTBI) does not have symptoms and cannot spread TB bacteria to others. But in some of them the latent TB infection will progress to active TB disease in their life. All cases of active TB come from this pool of people with LTBI. The political declaration at the first ever UN high-level meeting on TB in September 2018 included a target to provide TB preventive treatment to at least 30 million people during 2018–2022: 6 million people living with HIV, 4 million children below 5 years of age who are household contacts of people with active TB, and 20 million other household contacts, with a view to empty this pool of latent TB.
The World Health Organization (WHO) recommends TB preventive treatment for people living with HIV, household contacts of bacteriologically-confirmed pulmonary TB cases and clinical risk groups in all countries.
LATENT TB MANAGEMENT
India has the highest TB burden: 27% of the global TB burden. 40% of its population (400 million people) is infected with LTBI. 10% of them (40 million) are likely to develop active TB disease in their lifetime.
Dr Rohit Sarin, Director of the National Institute of Tuberculosis and Respiratory Diseases, India, and member of Technical Working Group of government of India on LTBI, agrees that to prevent incidence of active TB disease, we have to cut down TB transmission to reduce the latent TB pool. Probably the best way to do this is to diagnose a TB patient early on and to put the patient on effective treatment so that the patient is no longer infectious and will no longer transmit, he told CNS (Citizen News Service).
But managing latent TB infection in such a large population (400 million) is no easy task. So perhaps it becomes more pertinent to identify the groups which have a greater chance of breaking into active disease and then give them preventive treatment. But before we treat for LTBI we have to rule out active TB in these persons.
TEST AND TREAT
Dr Sarin shared that “The latest RNTCP guidelines for latent TB management have the test and treat strategy. But the recommendation is to treat without testing in certain groups. These are children below 5 years of age who are contacts of a TB patient and people who are living with HIV. In other groups, which include inmates of jails, people in congregate settings and in old age homes, healthcare workers, people on chronic immunosuppressive therapy, we need to first test for LTBI and in case the person is infected we start that person on treatment”.
The tests available in India are the tuberculin skin test or the Interferon Gamma Release Assay (IGRA), which is a blood test. The current treatment in the public health programme for LTBI management is daily dose of isoniazid for six months. However the country is also considering newer TB preventive treatment options, such as, a once weekly, 12 week regimen of Isoniazid and Refapentine. As a clinician one can give any of these therapies but from programmatic point of view it has to be operationally feasible for a large population, said Dr Sarin.
BOOST OUR IMMUNITY
Dr Surya Kant, Professor and Head of the Department of Respiratory Medicine, King George's Medical University, makes a strong case of beating LTBI through improving the body’s immune system. Dr Surya Kant has been the President of three important lung health professionals' associations in India: Indian Chest Society, National College of Chest Physicians, and Indian College of Allergy, Asthma and Applied Immunology.
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