What is it ?

  Pathology-the science of TB

Tuberculosis (TB) is due infection with a bacterium called Mycobacterium Tuberculosis. This bacteria needs oxygen to survive hence commonly it is found in infected individuals lungs. This bacteria has special proteins in its cell wall which allows it to survive in our body's white blood cells where it can further divide. TB is seen all over the world, but in India it remains the leading infectious cause of death killing around 500,000 people pre year with 2 million new cases each year. In India it is estimated that 60-80% of children below the age of 14 are infected. TB is more prevalent in areas associated with overcrowding, poor nutrition and inadequate social conditions. It is spread predominantly by droplet infection.

     

When TB first enters the body as droplets it usually settles in the lungs. However it can spread elsewhere for instance a particular section of our intestine. Once in these sites it produces a characteristic lesion called a granuloma - an area where the TB bacteria is found surrounded by our body's' white blood cells and resulting pus from the interaction. In the large majority of people these heal leaving some bacteria that for some reason hibernate. These surviving bacterium only reactivate at certain times – when patients are elderly, alcoholics or have some other condition meaning they are immunosuppressed. This reactivation leads to the formation of cavities in lungs. In severe cases the bacterium can spread into the blood and affect the brain.

     

     

It was found in 1992 that in India only around 50% of patients with TB received an accurate diagnosis and less than half were treated correctly. As a result the World Health Organization ( WHO ) highlighted the role of directly observed treatment ( DOTS ). Consequently patients are diagnosed on the basis of sputum containing the microbes, followed by direct observation of treatment. This has been implemented since 1993.

Treatment involves the prescription of antibiotics for two weeks. If after this symptoms remain patients are asked to go to larger hospitals to have a chest X-ray after which different antibiotics are started. However these antibiotics are given for longer periods – around 6 months. Crucially the intensive phase of therapy, which is within the first two months, is the period when patients are directly observed by a health care worker or by a community member who is a non family member. Over the next four months only the first of the three weekly doses are observed.

     

The general health service is not available to many especially those in rural areas.
A large amount of people when unwell use the unregulated private sector which results in poor long term follow up – patients are treated and feel better initially but then carry on as normal. However the nature of TB means it persists and reactivates. Areas with no electricity, drought and famine means poor access as well as treatment completion rates are very low.

Qualities of drugs – some of the antibiotics used are affected by water. In particular due to poor packaging medicines degrade due to high humidity before they can reach affected areas.
Long standing patterns in India including the loss of wages, the need to pay for transportation which are all barriers to patients from receiving care.

£150 would buy and maintain a bicycle for an outreach worker.
£800 would pay for food needed to supplement the diets of 100 poor patients.
£1000 would pay for TB medicines needed for children (not provided by the government) for one hospital for a year.
£1000 would buy lab equipment including a microscope.
£2,000 would pay the cost of a village awareness raising day.
£8,500 would buy a jeep for a TB service.
£40,000 would buy a new X-ray machine.