We need people – people like those in TB Alert, who are focused and ambitious and care for people at grass roots in the UK, India and Africa. Dr Lucica Ditiu, Executive Secretary of the Stop TB Partnership
BCG (Bacille Calmette-Guérin) is a live vaccine against tuberculosis. The vaccine is prepared from a strain of the weakened bovine tuberculosis bacillus, Mycobacterium bovis. BCG is currently the only licensed vaccine against TB, and has been in use since 1921. It is one of the most widely used vaccines worldwide, yet we still see around 9 million new cases of TB annually – a testament to the BCG’s limited effectiveness.
- 80% effective in preventing TB for 15 years from date of vaccination
- More effective against complex forms of TB in children
- Of limited effectiveness in people over the age of 35
- Less effective when administered in equatorial regions (due to high levels of naturally occurring environmental mycobacteria).
- Visit The Truth About TB, to find out about BCG in the UK.
Early diagnosis and treatment is the most effective way to prevent the spread of tuberculosis.
A person with untreated smear positive pulmonary tuberculosis – the only form of TB that carries an infection risk – can infect up to 10–15 other people per year. Once diagnosed with TB, and started on treatment, the majority of patients cease to be infectious after two weeks of taking the medication.
If someone has a drug-resistant form of the illness, however, they will be infectious for a longer time.
Tuberculosis control depends on successful finding and treatment of infected individuals, to prevent people with infectious TB passing it on to others. This may take three forms:
- Passive case finding: where individuals present to health services with symptoms. This requires individuals to be aware of TB symptoms, and to engage with healthcare
- Active case finding: outreach schemes, targeting high-burden communities
- Contact tracing: close contacts of people diagnosed with infectious TB are screened for the illness
TB is an airborne infection. TB bacteria are released into the air when someone with active TB coughs or sneezes. Infection risk can be reduced with a few simple precautions:
- Good ventilation: TB can remain suspended in the air for several hours with no ventilation
- Natural light: UV light kills off TB bacteria
- Good hygiene: someone with infectious TB can limit the number of particles released into the air by covering the mouth and nose when coughing or sneezing.
A healthy immune system is the best form of defence against TB: 60% of adults with a healthy immune system can completely kill TB bacteria, 30% of infected adults can hold it dormant and only 10% develop active TB.