The World Health Organization (WHO) has updated its fact sheet on Tuberculosis (TB). The revision coincided with the World TB Day- 24 March 2016.
TB is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs, but may also affect other parts of the body.
TB is both curable and preventable.
Most often, TB is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected.
About one-third of the world’s population has latent TB, which means people have been infected by TB bacteria but are not (yet) ill with the disease and cannot transmit the disease.
Ending the TB epidemic by 2030 is among the health targets of the newly adopted Sustainable Development Goals.
- In 2014, 9.6 million people fell ill with TB and 1.5 million died from the disease.
- Over 95% of TB deaths occur in low- and middle-income countries, and it is among the top 5 causes of death for women aged 15 to 44.
- In 2014, an estimated 1 million children became ill with TB and 140 000 children died of TB.
- TB is a leading killer of HIV-positive people: in 2015, 1 in 3 HIV deaths was due to TB.
Natural course (without proper treatment)
People with active TB can infect 10-15 other people through close contact over the course of a year.
Without proper treatment, 45% of HIV-negative people with TB on average and nearly all HIV-positive people with TB will die.
All age groups are at risk, but most cases are adults in their productive years.
Over 95% of cases and deaths are in developing countries.
People infected with HIV are 20 to 30 times more likely to develop active TB.
The risk of active TB is also greater in persons suffering from other conditions that impair the immune system.
Tobacco use greatly increases the risk of TB disease and death. More than 20% of TB cases worldwide are attributable to smoking.
Global impact of TB
- 58% of all new cases occurred in the South-East Asia and Western Pacific Regions of WHO.
- However, Africa carried the most severe burden, with 281 cases per 100 000 population (compared to a global average of 133).
- About 80% of reported TB cases occurred in 22 countries.
- The 6 countries having the largest number of incident cases were India, Indonesia, Nigeria, Pakistan, People’s Republic of China and South Africa.
Symptoms and Diagnosis
Pulmonary TB (PTB)
- Cough (more than 2 weeks) with sputum
- Fever (usually low grade, increases in the evening)
- Night sweats
- Weight loss and weakness
- Coughing blood/ Blood in sputum (Haemoptysis), etc.
Diagnosis usually involves testing sputum for the presence of tuberculosis bacteria.
In children the above may be absent, making it very difficult to diagnose TB in them
The diagnosis of Drug-Resistant TB is complex.
Active, drug-susceptible TB disease is treated with a standard 6 month course of 4 antimicrobial drugs.
The vast majority of TB cases can be cured when medicines are provided and taken properly.
TB and HIV
HIV and TB form a lethal combination, each speeding the other’s progress.
People living with HIV are 20 to 30 times more likely to develop active TB disease than people without HIV.
- About 0.4 million people died of HIV-associated TB.
- Approximately one third of deaths among HIV-positive people were due to TB
- There were an estimated 1.2 million new cases of TB amongst people who were HIV-positive, 74% of whom were living in Africa.
Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to, at least, isoniazid and rifampicin, the 2 most powerful, first-line (or standard) anti-TB drugs.
A primary cause of MDR-TB is inappropriate treatment. Inappropriate or incorrect use of anti-TB drugs, or use of poor quality medicines, can cause drug resistance.
In some cases, more severe drug resistance can develop. Extensively drug-resistant TB, XDR-TB, is a form of multi-drug resistant tuberculosis that responds to even fewer available medicines, including the most effective second-line anti-TB drugs.
About 480 000 people developed MDR-TB in the world in 2014. More than half of these cases were in India, the People’s Republic of China and the Russian Federation.
Link to the updated fact sheet:
Link to Data and statistics on TB:
Link to Global Tuberculosis Report 2015: