A brief about Tuberculosis (TB)

• Latent Tuberculosis (LTB) also known as Latent Tuberculosis Infection (LTBI) is when a person is infected by the Mycobacterium tuberculosis and not tuberculosis. An active tuberculosis is an contagious disease while the latent tuberculosis is not. Only a 10% of the latent tuberculosis people are likely to develop an active tuberculosis. Also, the person with the latent tuberculosis will not affect other even though he/she has bacterium.

   

The Report

• Globally, around 10 million people developed TB in 2017 and around 107 billion people or you may say 23% of the total population is having a latent tuberculosis and are at risk of adopting an active tuberculosis,, according  to the World  Halth Organisation's Global Health Report, 2018. The world Tuberculosis day is on 24 March.

• Tuberculosis is one of the top 10 causes for the death. Probably all the age group are affected but the the most affected age group are the adults (age >=15) which accounts for the 90% of the cases.Also, those with active tuberculosis are 64% male and 9% living with the HIV. If we talk about TB disease distribution geographically, two-third of the cases are found in only 8 Countries namely,India (27%), China (9%), Indonesia (8%), Philippines (6%), Pakistan (5%), Nigeria (4%), Bangladesh (4%) and South Africa (3%). And only 6% in the WHO regions of Europe and Americas, with 3% for each country.

 

• There many global agencies which formulates policies and provide aids to the TB affected patients such as Sustainable Development Goals (SDGs) and WHO's End TB Strategy. The SDG has set milestones for the year 2025 to eradicate TB 80%, while at the end of the year they percentage will be 90-95%.

Tests for diagnosis

• There are two prominent types of tests carried out to know whether the person is exposed to Tuberculosis:
1. TB skin test and 
2. TB blood test

• TB skin test: The TB skin test is also known as the Mantoux Tuberculin skin test (TST) .The test is performed through injecting a fluid called tuberculin into the skin of the persons' lower part of the arm. The skin test led to to type of results: 
• Positive skin test: It means that the person is affected by the mycobacterium tuberculosis.
• Negative skin test: This results shows that he/she is not likely to be affected by the active latent tuberculosis.

• TB blood test: In this test the a sample of the blood is taken for the further examination of the blood cells. Just like the skin test, the blood test give two types of outputs: 
• Positive TB blood test: Here the person is infected by the harmful bacteria.
• Negative TB blood test: This means that the person did not react to the test and is safe from adopting the disease.

• Moreover, there is an misconception for the arbitrary estimate that two-third of the latent tuberculosis affected patients are likely to be infected by the active tuberculosis. This misunderstandings was cleared by the WHO's latest report on Tuberculosis, which states that only 5-10% are likely to develop active tuberculosis from a latent TB. This 5-10% people will infected from 2 months to 2 years, depends upon one's immune to bacteria. Only small minority will be infected later than two years. This small minority is highest in the low incidence countries such as Norway, Denmark and Canada. On contrast the minority is lowest in the high transmission countries like India.

Prevention

• The prevention of the Mycobacterium tuberculosis and the prevalence of the active as well latent tuberculosis must not be taken lightly to reduce the burden of disease and death caused by TB and to achieve the End TB strategy by 2025 and 2030. Health-care intervention that could be helpful in lowering the risk of LTBI and active TB, which include curing through drug treatment and vaccination for the adults and children to prevent from reactivation of the LTBI.

• So, currently three major health-care intervention are available for TB prevention:
1. treatment of LTBI:
2. prevention of transmission of Mycobacterium tuberculosis through infection prevention and control:
3. vaccination of children with bacille Calmette-Guerin (BCG) vaccine.

• Being a communicable disease not only common citizen but also the heath-care workers are at greater risk to be infected. The prevention of infection of TB measure should be first of all taken for the workers working at different health centers and clinics.

• According to the WHO's Global Health Report, in 2017 9299 TB cases were registered among workers which reported from 65 countries. China accounts for 35% of the total TB cases, Brazil for 11%. Moreover, a tentative calculation is carried out which include 58 countries out of 65, where cases ranges from 0 to 685 per 1,00,000 co-workers, with the highest in the Mozambique.