The civil administration in Mumbai firmly believes that ‘prevention is better than cure’ and is working on a plan to begin scouting for persons with latent tuberculosis infection (LTBI). These are people who harbour the TB-causing bacteria within, where it can lie dormant. While most never get sick, it can, without warning, manifest as disease in others.
Mumbai, which is known to be an epicentre of the deadly disease, is already overburdened with active TB cases (as many as 130,000 cases according to latest estimates). It also sees many cases of the worst drug-resistant forms of the disease. Therefore, tackling LTBI may appear premature. However, some experts feel that it is never too early to attack the bacteria from all fronts.
The strategy
“We have a high burden of active TB cases. But there are wider discussions going on at the Central government-level about LTBI. For Mumbai too, we are discussing the possibility of a pilot project that could help us target the bacteria in advance [of active infection],” says Dr. Daksha Shah, Mumbai TB officer. The authorities are holding consultations with the World Health Organisation (WHO) to take the project further. The civic body follows social contacts of active TB patients and screens them for signs of infection. If there are symptoms, doctors offer them preventive treatment, and if need be, schedule detailed follow-ups to detect signs of an LTBI.
“In most countries, contacts with a latent infection are put on Isoniazid, a preventive. But can you imagine putting every patient’s contacts on preventives when each such patient may be sharing a room or rooms with 10 to 20 people?” asks Mumbai-based chest physician, Dr. Zarir Udwadia. He recommends sustained follow-ups: “I advise chest x-rays every six months for a patient’s family even if they claim to be feeling well. That way you are likely to detect the disease at an early stage and not when it’s too late.”
He recollects the case of a young girl who recently went to the U.S. after completing her TB treatment. When her college heard that she had TB, they screened everyone there as a precautionary measure. “It is routine in the West. That’s how they have controlled the infection. But for us, LTBI treatment is not a priority given that we are unable to cope with the burden of drug-resistant TB,” says Dr. Udwadia.
TB is caused by Mycobacterium tuberculosis , a species of pathogenic bacteria, that is spread through air. The bacteria most often attacks the lungs. When an infected patient sneezes or coughs, the droplets carrying the bacteria spread in the air and any person who inhales them may get infected.
The WHO too lays emphasis on a specific strategy to tackle latent TB but only in high- and upper middle-income countries with a low incidence of the disease. According to a WHO report, approximately 10% of people with LTBI will develop TB, with the majority of them getting it within the first five years of infection. It says: “Systematic testing and treatment of LTBI in at-risk populations is a critical component of the WHO’s eight-point framework adapted from the ‘End TB Strategy’ to target pre-elimination and, ultimately, elimination in low incidence countries.”
Other than the mode of air, the latent infection can also be contracted from an improper skin or blood test. Some experts aver that LTBI can often be tackled by maintaining good health and observing coughing and sneezing etiquette. “TB bacilli are extremely intelligent. They can gauge the body’s immunity without moving or multiplying. They lurk within the body for five to eight years and as soon as the body’s immunity weakens, they start multiplying and eating the lungs,” says Dr. Lalitkumar Anande, chief medical officer at the Sewri TB Hospital in Mumbai, and also Asia’s largest.
‘Prep up immunity’
“Therefore, to win the war against the bacilli, one must keep the immune system upbeat. Additionally, people should not spread the droplets in the air by coughing and sneezing openly. The basic etiquette of using a handkerchief or at least the hand to cover the face should be followed,” says Dr. Anande, who believes that antioxidants and micronutrients are good immunity boosters. He says that the government’s call to end TB by 2025 can be achieved if the public focusses on these basic measures while the health administration aggressively targets active TB cases.
jyoti.s@thehindu.co.in
Published - April 08, 2018 12:02 am IST
