Background
Ever year on the 24th of March the world commemorates World Tuberculosis (TB) day. This is the day in 1882 when Dr Robert Koch announced to the Berlin Physiological Society the discovery of the Mycobacterium tuberculosis (MTB) as the bacillus that causes TB.1This is a day the whole world has an opportunity to raise public awareness that TB is still an epidemic in most parts of the world and it results in the loss of many lives especially in developing countries.

Importance of tuberculosis
According to the 2015 World Health Organization (WHO) global TB report, an estimated 9.6 million people were infected with TB and 1.5 million people lost their lives due to TB.2 South Africa is burdened by the worst TB epidemic in the world, with 450 000 [400 000 – 510 000] South Africans acquiring TB in 2014 alone.2

What is tuberculosis? 
Tuberculosis (TB) is a disease caused by a bacterium called Mycobacterium tuberculosis. The bacterium often affects the lungs, but can affect most parts of the body, such as the brain, the spine, kidney etc.

How TB spreads 
TB is spread from one person to another through the air.  The bacterium is spread when a person with TB of the lung or throat coughs, sneezes, talks, sings or spits. TB bacterium survives longer in a dark enclosed place and remains suspended in the air for several hours. This bacterium can be inhaled by anyone who shares the same air and cause infection. The spread of TB usually occurs indoors and in areas where there is poor ventilation. You will not get TB disease when you shake hands, kissing, sharing food, touching clothes or blankets and when using the same toothbrush.3

Latent TB infection
Latent TB infection is when the TB bacteria live in your body (inactive) without making you sick. Not everyone who has the TB bacterium becomes sick because there are those whom their bodies are able to fight the bacterium from multiplying. People with latent TB do not have TB symptoms and they cannot spread the bacterium to others.

TB Disease
When the TB bacterium becomes active because of a weak immune system, it will start multiplying in your body and it is called TB disease. People who are diagnosed by a health professional as having TB disease are sick and may spread the bacteria to people who are around them. In some cases people develop the TB disease immediately after becoming infected with the TB bacterium and even before the body defense mechanism can start fighting the bacterium. Other people may get sick some years after they have been infected. People who are HIV positive are also at a risk of developing TB disease as a result of a weakened immune system.
Symptoms of TB disease include the following;

  • Coughing for two weeks or more
  • Night sweats
  • Unexplained loss of weight
  • Fever

Risk factors for TB
Everyone is at risk of TB because it is spread through the air, but there are certain people who are at higher risk of developing TB disease, such as:

  • People Living with HIV
  • Those who were diagnosed with TB in the last two years
  • People who smoke
  • Alcohol abusers
  • People with other medical conditions such as silicosis, diabetes
  • Poor living and working conditions
  • Young and elderly persons

TB diagnosis
A person with any of the TB symptoms should consult their health provider or the occupational health doctor or nurse at work. The health provider or occupational health doctor or nurse will ask you to cough into a bottle and your sputum specimen will be sent to the laboratory for examination. If you have TB, you will be given medicine right away.

Can TB be cured?
Yes, TB disease can be cured if treated early. You should take the medicine for at least six months. It is very important to take the medicines as prescribed and finish all of them.

TB treatment 

  • Latent TB infection – If you have latent TB infection but not TB disease, your occupational health doctor or nurse may want you to be treated to keep you from developing TB disease. Treatment of latent TB infection reduces the risk that TB infection will progress to TB disease. Treatment of latent TB infection is essential to controlling and eliminating TB. The decision about taking treatment for latent TB infection will be based on your chances of developing TB disease.

 

  • TB disease – TB treatment is usually in the form of tablets and should be taken at least six months and sometimes up to 9 months. This is because the TB bacterium is difficult to kill. A combination of four different medicines are used to treat TB disease to make sure that all the bacteria hiding in the different parts of the body are killed. Even though you will start feeling better and your symptoms will go away after two weeks of taking treatment, do not stop taking the medicines. If you stop taking anti TB medicines too soon, you could get sick again. You could also get a kind of TB that will not respond to the common medicines used to treat it (Drug-Resistant TB).

 

Drug resistant TB (MDR-TB and XDR-TB)

Drug-resistant TB can occur when the drugs used to treat TB are misused or mismanaged. Examples include:

  • When people do not complete the full course of treatment;
  • When health providers or your occupational health doctor or nurse prescribe the wrong treatment, the wrong dose, or wrong length of time for taking the drugs;
  • When the supply of drugs is not always available; or
  • When the drugs are of poor quality.

Drug-resistant TB is more common in people who:

  • Do not take their TB drugs regularly;
  • Do not take all of their TB drugs;
  • Develop TB disease again, after being treated for TB disease in the past;
  • Come from areas of the world where drug-resistant TB is common;
  • Have spent time with someone known to have drug-resistant TB disease

Drug-resistant TB is spread the same way that drug susceptible TB is spread. Drug-resistant TB is more difficult to treat, is more expensive to manage and may require hospital stay.
The relationship between TB and HIV

People who are living with HIV are more at risk of getting TB infection and disease. If you are HIV positive you must report symptoms of TB and request to be tested by your health provider or occupational health doctor or nurse. If you have TB, and are HIV positive you can be started on antiretroviral treatment early to improve your response to TB medicines and prevent death. If you do not have TB you can be started on TB preventive treatment, this treatment will help prevent you from getting TB disease. Therefore, you must get tested for HIV and know your status. Not all people with TB are HIV positive and not all HIV positive people have TB.

Workplaces with TB as an occupational hazard 
People who are working in the mines, construction work, stone crushing and in other similar occupations are vulnerable to TB. Construction workers and mine workers especially gold miners are repeatedly exposed to respirable silica dust as they work for long hours in dusty environments.  Exposure to silica dust increases the risk of silicosis which in turn is a risk factor for TB.  Other risk factors for TB in the mining and construction industries include HIV, increasing age, drilling occupation, poor working and living conditions, smoking and alcohol abuse. Health workers are the other group of workers with TB as a long known and recognized as an occupational hazard. Studies have shown that the risk of active TB is two to three times higher among healthcare workers than in the general population. This is because health workers are themselves exposed to high levels of HIV infection, high TB exposure at work and the poor levels of TB infection and prevention control in many health facilities

Workplaces with TB as workplace issue 
TB is a workplace issue because health is very important not only for the well being of the worker but that of the enterprise.
In high TB prevalent settings, TB is imposing huge costs on enterprises through declining productivity and earnings, absenteeism, increasing labour costs, loss of skills and experience, health care benefits and funeral costs. Thus, employers and employees should work together in promoting and performing TB control activities in the workplace.

Elements of a workplace TB programme
There should always be a commitment by the management to provide explit commitment to cooperate action including making resources available for TB infection control in the workplace.  Clear management policies should be developed and implemented. The policy should cover issues about confidentiality, discrimination, time allowed for medical treatment and job modification where there is a need. TB awareness and educational campaigns should also addressed issues about stigma and discrimination, ongoing education about the importance of early diagnosis and treatment, risk factors related to TB and management of side effects of TB treatment.

References:
1.       MMWR. Historical Perspectives Centennial: Koch’s Discovery of the Tubercle Bacillus. [Updated 2016]; [Cited 2016 March 22]. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/00000222.htm
2.      World Health Organisation. Global Tuberculosis report. 2015. Available from: http://www.who.int/tb/publications/global_report/en/
3.      Center for Diseases Control and Prevention. Tuberculosis. Available from: http://www.cdc.gov/niosh/topics/tb/
4.      Menzies D, Joshi R, Pai M. Risk of tuberculosis infection and disease associated with work in health care setting. Int J Tuberc Dis.2007;11(6): 593-605
5.      Baussano I, Nunn P, Williams B, Pivetta E, Bugiani M, Scano F: Tuberculosis among health care workers. Emerg Infect Dis 2011, 17(3):488–494.
6.      UNAIDS, International Labour Organisation, World Health Organisation. Working together with businesses: Guidance on TB and TB/HIV prevention, diagnosis, treatment and care in the workplace http://apps.who.int/iris/bitstream/10665/44833/1/9789241503228_eng.pdf