Tuberculosis (TB) is a contagious disease usually caused by bacteria (Mycobacterium tuberculosis). It infects the lungs of human beings and can spread to other organs of the body like bone, brain, spine, etc. TB was the leading cause of death all over the world in the 20th century. This deadly disease was incurable. Therefore TB was considered a terminal illness.
Studies of human skeletons reveal that it has affected humans for thousands of years – but its cause remained unknown until March 24, 1882, when Dr. Robert Koch made a significant breakthrough and announced the much-needed discovery of the bacillus subsequently named Mycobacterium tuberculosis. The new finding has made TB a curable disease. But it takes a lot of time in curing the patients. They need to take medicines for six to nine months.
Tuberculosis is a communicable disease that spreads from one person to another through the air. People who are sick with TB expel bacteria into the air through coughing, sneezing, or speaking. It usually affects the lungs (pulmonary TB) but can also affect other sites (extrapulmonary TB).
When a person develops active TB disease, the symptoms (such as cough, fever, night sweats, or weight loss) may be mild for many months. It can lead to a delay in seeking care and results in the transmission of the bacteria to others. People with active TB can infect 5–15 other people through close contact.
The most common tests that are usually taking place to find out TB bacteria in the body are the TB skin test and blood test. But the TB skin test is not 100% perfect.
Diagnostic tests for TB disease include sputum smear microscopy (developed more than 100 years ago), rapid molecular tests (first endorsed by WHO in 2010), and culture-based methods; the latter take up to 12 weeks to provide results but remain the reference standard. TB that is resistant to first-line and second-line anti-TB drugs can be detected using rapid tests, culture methods, and sequencing technologies. Without treatment, the mortality rate from TB is high.
The effective drugs of TB, first discovered in the 1940s and 50s, could kill TB bacteria. Currently, a TB patient has to take timely medicines at least 6 to 9 months for complete recovery. Apart from several other drugs, four major drugs have approval for the treatment of TB: isoniazid, rifampicin, ethambutol, and pyrazinamide. The only licensed vaccine for the prevention of TB disease is the Bacille Calmette-Guérin (BCG) vaccine. The BCG vaccine was developed almost 100 years ago, which prevents severe forms of TB in children. Currently, widely used all over the world.
In 2018, an estimated 1.5 million people died due to TB, while 10 million people fell ill with the disease worldwide. Overall 5.7 million men, 3.2 million women, and 1.1 million children were infected by tuberculosis. TB incidence is falling globally at about 2% per year (WHO report).
As per WHO data, in 2000, there were 172 incidences of tuberculosis per 100,000 people across the world. But by 2018, this figure had decreased to 132 per 100,000 people.
Lesotho reported the highest incidence of the disease in the world. In 2000, the nation reported 992 incidences of tuberculosis per 100,000 people. But by 2018, this figure had decreased to 611. The Philippines occupied second place with 554 incidences reported in 2018. Mozambique and the Central African Republic are the two other nations that had more than 500 incidences per 100,000 people. In both countries, the figures stood at 551 and 540 respectively.
Among regions, the Sub-Saharan African region, according to the 2018 data, was the worst affected by the disease where the incidence of tuberculosis per 100,000 people stood at 231. But this was a climbdown from the 344 figure that was reported in 2000. South Asia held second place reporting 206 incidences of tuberculosis per 100,000 people. Among the South Asian nations, Pakistan had the highest incidences of tuberculosis at 100,000 with the number standing at 265. Bangladesh and India reported figures of 221 and 199 respectively. The Maldives had the lowest figure in South Asia, with 33 incidences of tuberculosis per 100,000 people.
In Europe, tuberculosis was at one time the most dreaded disease but has been contained over the years. Still, Moldova and Ukraine had reported a little higher incidence of the disease at 86 and 80, respectively. On the other hand, a majority of the nations had reported figures of 10 and less. The two major nations of North America, the United States, and Canada – had even done better with just 3 and 5.6 incidences of tuberculosis per 100,000 people. In Australia and New Zealand, the figure stood at 6.6 and 7.3, respectively.
As per the WHO’s Global TB Report 2019, India had 2.69 million patients in 2018. In 2017, the number was 2.74 million. It means a 1.8% decline. In 2018, the 30 high TB burden countries accounted for 87% of new TB cases. India is the only country where TB cases are in a double-digit percentage of 27% of the total TB cases in the world. Eight countries account for two-thirds of the TB burden globally. India is on the number one spot, followed by China, Indonesia, Philippines, Pakistan, Bangladesh, South Africa, and the Democratic Republic of the Congo, Myanmar, Ethiopia, Russia, Nigeria, Vietnam, Kenya, North Korea, Mozambique, Brazil, Thailand, Tanzania, and Angola.
In 2018, the largest number of new TB cases took place in the South-East Asian region, with 44% of new cases followed by the African region, with 24%, and the Western Pacific with 18%.
Incidence of Tuberculosis (per 100,000 people) as per the Year 2018:
|S. No.||Countries||Incidence of Tuberculosis (per 100,000 people), 2018|
|4||Central African Republic||540|
|11||Papua New Guinea||432|
|13||Republic of the Congo||375|
|20||Democratic Republic of the Congo||321|
|55||Sao Tome and Principe||124|
|62||Federated States of Micronesia||108|
|65||Northern Mariana Islands||95|
|125||Bosnia and Herzegovina||25|
|131||Trinidad and Tobago||21|
|173||Saint Vincent and the Grenadines||6.3|
|174||Turks and Caicos Islands||6.1|
|191||British Virgin Islands||3.9|
|195||United States of America||3|
|199||United Arab Emirates||1|