Tuberculosis
Image: Patient with advanced active tuberculosis
Tuberculosis is an infectious disease that primarily affects the lungs. Tuberculosis, or TB, is caused by the bacteria mycobacterium tuberculosis. Although TB usually affects the lungs, it can also affect the organs in the circulatory, lymphatic, and nervous systems.
When a person is infected with mycobaterium tuberculosis, the bacteria enter the lungs and begin to multiply uncontrollably. This causes pneumonia, which is essentially an inflammatory lung infection that affects the lungs' air sacs, or alveoli. Pneumonia can cause chest pain, uncontrollable coughing, and fever among other symptoms. Lymph nodes, which are one of the body's white blood cell-making factories, become swollen and potentially painful. As the TB bacteria attempt to spread all over the body, the body's immune system tries to defend the attack by forming scar tissue (also known as fibrosis) around the bacteria. However, if the body's immune system is unable to fight the TB bacteria, or if the bacteria manages to break through the scar tissue, the disease returns to what is called the active stage. This could cause damage to the kidneys, bones, and the lining of the spinal cord and brain (meninges).
According to the World Health Organization (WHO), tuberculosis is the second largest single infectious agent killer worldwide, after HIV/AIDS. In 2011, of those 8.7 million people who were diagnosed with tuberculosis, 1.4 million died.
There are two types of TB:
When a person is infected with mycobaterium tuberculosis, the bacteria enter the lungs and begin to multiply uncontrollably. This causes pneumonia, which is essentially an inflammatory lung infection that affects the lungs' air sacs, or alveoli. Pneumonia can cause chest pain, uncontrollable coughing, and fever among other symptoms. Lymph nodes, which are one of the body's white blood cell-making factories, become swollen and potentially painful. As the TB bacteria attempt to spread all over the body, the body's immune system tries to defend the attack by forming scar tissue (also known as fibrosis) around the bacteria. However, if the body's immune system is unable to fight the TB bacteria, or if the bacteria manages to break through the scar tissue, the disease returns to what is called the active stage. This could cause damage to the kidneys, bones, and the lining of the spinal cord and brain (meninges).
According to the World Health Organization (WHO), tuberculosis is the second largest single infectious agent killer worldwide, after HIV/AIDS. In 2011, of those 8.7 million people who were diagnosed with tuberculosis, 1.4 million died.
There are two types of TB:
- Latent TB: when the patient has been infected by the TB bacteria, but the bacteria are inactive and show no symptoms; not contagious
- Active TB: when the patient has been infected by the TB bacteria, the bacteria are active, and show symptoms; highly contagious (MayoClinic)
Who is at Risk of Contracting Tuberculosis?
Image: Malnourished child with tuberculosis
There are several groups of people that are at higher risk of contracting tuberculosis. They are:
- young children
- family members of those who have TB
- alcoholics and substance abusers
- malnourished people
- HIV/AIDS patients
Why is Tuberculosis Prevalent in Developing Countries?
Image: Estimated Tuberculosis Incidence Rates 2011
According to the World Health Organization, over 95% of tuberculosis-related deaths occur in mostly Less Economically Developed Countries (LEDCs).This is due to a variety of reasons, the main one being that more people in developing countries have less developed or functioning immune systems. A poverty-stricken person is less likely to have a strong immune system when compared to a person living in a developed country, simply because they do not necessarily have access to proper medical attention and a healthy diet.
Furthermore, most people with active tuberculosis in developing countries die due to tuberculosis because they do not have access to the antiretroviral drugs that need to be taken in order to fight the infection. These drugs are, in most cases, too expensive to afford for the poverty-stricken patients who struggle to meet daily living expenses. Also, drugs that are used to fight tuberculosis often have to be taken over the long term, making them an economic burden on the patients.
Furthermore, most people with active tuberculosis in developing countries die due to tuberculosis because they do not have access to the antiretroviral drugs that need to be taken in order to fight the infection. These drugs are, in most cases, too expensive to afford for the poverty-stricken patients who struggle to meet daily living expenses. Also, drugs that are used to fight tuberculosis often have to be taken over the long term, making them an economic burden on the patients.
As can be seen in the map to the left, and the one found above, there are similarities in the sense that the highest incident rates of tuberculosis can be found where there are high rates of HIV cases. The diagram on the left accurately shows this, and illustrates how those with HIV are at higher risk of contracting tuberculosis. As mentioned in the HIV/AIDS page, when someone has been affected by the HIV virus, their body's immune system in rendered incapable of fighting off infections and bacteria, causing them to be more susceptible to diseases like tuberculosis.
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How can Tuberculosis be Prevented?
Image: A Woman in India Getting Ready to be Vaccinated
Tuberculosis can be prevented by administrating vaccinations during childhood. According to the World Health Organization, the Bacille Calmette-Guerim (BCG) vaccination is the only vaccination currently available today against tuberculosis. It is very effective when administered during childhood. However, the vaccine is not effective in adults who receive it. A person can lower their chances of inhaling the tuberculosis bacteria and consequently contracting latent tuberculosis (the non-active form) by avoiding close proximity with those who have active TB, and by staying in cell-ventilated area. Using face-masks is highly recommended. In order for a person to lower the risks of latent TB turning into active TB, it is highly recommended that the person take a 4 month long course of isoniazid or a 9 month course of rifampin, which are both antibiotics that work by killing the bacteria mycobacterium tuberculosis.
It is important to have a strong, healthy, and functioning immune system in the fight against tuberculosis. Having a fully functional immune system ensures that in the case that a person is indeed exposed to tuberculosis-causing bacteria, the immune system is able to fight it and to keep it in its latent (non-active) stage.
It is important to have a strong, healthy, and functioning immune system in the fight against tuberculosis. Having a fully functional immune system ensures that in the case that a person is indeed exposed to tuberculosis-causing bacteria, the immune system is able to fight it and to keep it in its latent (non-active) stage.
Photo Credits
Diagram of Tuberculosis Bacteria in Lungs. Digital image. Web. <http://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/articles/health_and_medical_reference/infectious_disease/understanding_tuberculosis_basics.jpg>. Diagram Showing Spread of Tuberculosis. Digital image. Web. <http://sau53.org/dcs/classes/8grade/cemetery/hill/diagram.jpg>. "Estimated HIV Prevalence in New TB Cases 2011." Map. Web. <http://gamapserver.who.int/mapLibrary/Files/Maps/Global_HIVprevalence_TBcases_2011.png>. Girl with Tuberculosis. Digital image. Web. <http://blog.psiimpact.com/wp-content/uploads/2012/08/2.jpg>. "Global TB Incidence 2011." Map. Web. <http://gamapserver.who.int/mapLibrary/Files/Maps/Global_TB_incidence_2011.png>. Malnourished Child with Tuberculosis. Digital image. Web. <http://1.bp.blogspot.com/-mYk3FSKScZc/Tn7jcJaz8bI/AAAAAAAABLs/7fxgpjBLqwk/s1600/Tuberculosis+patients.gif>. Man with Advanced Latent Tuberculosis. Digital image. Web. <http://cache.boston.com/universal/site_graphics/blogs/bigpicture/2008_pt3/35_nachtwey.jpg>. Woman Getting Ready to be Vaccinated. Digital image. Web. <http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2011/4/20/1303330018375/TB-vaccinations-India-007.jpg>. |