World Tuberculosis Day 2023: Tuberculosis (TB) is the most common infectious and contagious disease globally, especially in developing countries. TB is associated with a very high burden of morbidity and mortality in developing nations. It is also responsible for the increased financial burden on the government. The disease per se and sequelae (after effects) are both in high prevalence and incidence in our country. The occurrence of illness depends on the immunity status of the individuals. Dr Hari Kishan Gonuguntla, Consultant Interventional Pulmonologist, Yashoda Hospitals, Hyderabad, will further explain the role of the TB vaccine in this article.
Pulmonary And Extrapulmonary TB
TB can be broadly classified into Pulmonary (involving lungs) and extrapulmonary (other organs except for lungs).
Pulmonary tuberculosis is spread through droplet infection. Droplets are usually spread during cough when an active tuberculosis patient coughs or sneezes without shielding measures. This kind of infection usually is seen among close contacts of active Pulmonary TB patients, in Overcrowded areas, in poor hygiene conditions, etc.
Extra pulmonary forms of TB are not contagious (do not spread) to others and are usually caused to the activation of TB bacilli in previously infected individuals. Tuberculosis can involve any organ in the body, for ex: the brain, bone, lymph nodes, eyes, kidneys, etc. Therefore, TB can affect multiple sites at the same time. In addition, people living with HIV (PLHIV) and other immune-suppressing conditions are more prone to develop TB.
They develop TB more frequently compared to normal children. According to WHO figures, an estimated 10.6 million individuals will become infected with tuberculosis (TB) worldwide in 2021. The population comprises six million males, 3.4 million women, and 1.2 million children. In 2021, 1.6 million people died from tuberculosis (including 187 000 people with HIV). TB is the 13th most significant cause of mortality worldwide and the second leading infectious killer after COVID-19 (behind HIV/AIDS).
India is responsible for almost one-quarter of the global TB burden. The projected TB incidence in 2021 is 2,590,000 (188 per 100,000 population). The number of HIV-positive TB cases was 53,000. TB killed an estimated 11,000 HIV-positive persons in 2021, and an estimated 493,000 HIV-negative people died.
Timely Diagnosis And Treatment
Notification to government agencies is a critical factor for controlling TB infection. But as prevention is always better than cure, vaccination of every newborn is the best method to decrease the health care and personal burden due to tuberculosis.
Albert Calmette and Camille Guérin discovered the first successful vaccination for Tuberculosis. The Tuberculosis vaccine is called BCG, named after the people who found it (Bacillus Calmette Guerin). They began researching an antituberculosis vaccine at the Pasteur Institute in Lille in 1900. Finally, in 1921, human trials of the BCG vaccine were started.
BCG vaccine is currently administered to every newborn immediately one day after birth, which is the worldwide recommendation. This vaccine has proven to be very effective in preventing Tuberculosis (significantly extrapulmonary tuberculosis). It also decreases disease severity and prevents disseminated (multi-organ involvement) tuberculosis.
In addition, all pregnant females should be educated regarding the importance of vaccination and their beneficial effects on a child`s health.
The BCG vaccine has been shown to protect against meningitis and disseminated tuberculosis: However, it does not protect against initial infection. More crucially, it does not protect against the reactivation of latent lung infection, which is the primary cause of bacillary dissemination in the community.
BCG vaccines are given in all government institutions free of cost to improve adherence to vaccination: But due to a lack of proper knowledge about the disease and the importance of immunisation, few areas in the country report more cases of TB in children. So there is an urgent need to reinforce BCG vaccination to every child immediately after birth.
Many other vaccine trials are going on to prevent tuberculosis, the results of which may be published shortly. To conclude, vaccines should be the primary care modality for people, and every newborn should receive all the vaccines according to schedule.