Around the turn of the 20th century, tuberculosis (also referred to as consumption during the era), was a leading cause of death in the United States.
Medical advances have largely eradicated TB from being a threat to our health. However, the deadly, infectious disease is still around. This brochure will help you understand some vital information about TB, including its signs and symptoms, risk factors, treatments, and prognoses.
Please contact your physician immediately if you suspect that you have TB
Spread by germs that travel through the air, TB can be a deadly disease, if not treated in time. Besides the lungs, it can affect the brain, spine, or kidneys. TB is caused by a bacterium called Mycobacterium tuberculosis.
TB is communicable via the air. When a person coughs, speaks, sneezes, or even sings, tiny bacteria-containing droplets are released into the air, spreading the illness.
It is important to remember that TB is NOT spread by:
- sharing food or drink
- shaking hands
- touching toilet seats or bed linens
- sharing toothbrushes
- kissing
Tuberculosis
Signs & Symptoms
- a bad cough that lasts three weeks or longer
- chest pain
- coughing up sputum or blood
- fatigue or weakness
- weight loss
- lack of appetite
- chills
- fever
- night sweats
Two Kinds of TB
Two kinds of TB exist in people: latent TB infection, and TB disease. In latent TB infection, people may have the bacteria in their bodies without getting ill. In fact, most people who become infected are able to fight the disease. People with latent TB are not considered infectious and cannot transmit the disease to others. In some cases, the latent TB may become active, thus becoming infectious (TB Disease) (www.cdc.gov).
However, if the immune system cannot stop the TB bacteria from multiplying, and they become active, the person becomes sick and can transmit the disease to others. Some people may have latent TB for years before getting active TB, while others may become sick in a matter of weeks shortly after becoming infected (www.cdc.gov).
Surprisingly, one-third of the world's population is infected with TB. In 2012, there were about 9 million known cases of TB, and 1.3 million people died from the illness. In immunocompromised people such as those with HIV infection, TB is a leading killer. (cdc.gov). The incidence of known TB cases, as well as the case rate, in the US has dropped significantly.
Diagnosis and Treatment
The TB Skin Test (also called the Mantoux tuberculin skin test) is done by injecting a very small amount of fluid into the skin and lower part of the arm (cdc.gov). Within 48 to 72 hours, the health care worker returns to examine the site for a reaction. A raised, hard area, or swelling, if present, is measured with a ruler. If the area is large enough, it means that the person tested is infected with TB. Blood tests called interferon gamma-release assays (IGRAs) are also used to detect TB infection. The blood tests -- the QFT-GIT or the T-Spot -- more specifically test for latent TB infection or TB disease. Usually, people who have received the BCG vaccine for TB disease will get their blood tested for the presence of TB antibodies. Repeated IGRAs do not pose a problem (cdc.gov).
Treatments vary for those with LTBI and those with TB disease. For LTBI, there are four approved treatment regimens. Commonly-used drugs are isoniazid, rifampin, and rifapentine. Ten drugs are currently approved for the treatment of TB disease. The treatment of TB disease can last up to nine months, with an initial treatment phase lasting two months. For those who begin the treatment regimen for TB disease or LTBI, it is important that they complete the entire regimen, as some bacteria may become treatment-resistant if they are not all killed (cdc.gov).
Prevention of TB is being examined at a number of levels. Researchers are trying to figure out how TB can lay dormant for many years, and then become actively infectious in both children and adults. Such research offers a glimpse into how Mycobacterium tuberculosis might interact with its host organism.
Much of today's focus on prevention hinges on the discovery and utilization of a TB vaccine. A vaccine could both protect the immune system of those who are not infected, as well as boost the immune system of those who have dormant TB that progresses into active TB (niaid.gov, internet).
The National Institute of Allergies and Infectious Diseases (NIAID) is looking into synthetic vaccines as well as vaccine adjuvants that boost the immune system's ability to fend off TB. Already, some preclinical studies have yielded promising results for potential vaccines. Some of these animal models have been approved for clinical trials of TB vaccines.
The Future of TB: A Cure?
Current and future treatment trends include more advanced antibiotics, as well as the addition of antibiotics known to affect TB to an accepted treatment protocol.
With the advent of molecular genetics and genomic phenotyping, scientists have learned much more about different lineages and strains of TB. Researchers are looking forward to next-generation DNA sequencing in order to further unravel the mysteries of TB (Comas & Gagneaux, 2009).
A cure for TB is a long ways off, but research on prevention and treatment has accelerated, with the possibilities of more specific DNA sequencing leading the way. Because of the HIV epidemic, scientists have achieved a greater understanding of the complexities of the body's immune system.
However, due to TB's long incubation time and its designation as a Biosafety Level 3 pathogen, it is a painstaking process to culture the microbe to culture in a laboratory (Comas & Gagneaux, 2009).
Conclusion
TB continues to challenge researchers, as the global epidemic grows. While a potential vaccine and more advanced antibiotics hold great promise and are currently being evaluated, a cure for the dreaded disease is not yet within the sights of medical researchers. In fact, much basic research must still be done in order to understand exactly how TB infects its hosts. More novel approaches and a new open-mindedness towards prevention and treatment will continue to move research of TB in the right direction.
References
Tuberculosis. Retrieved on 25 Oct 2014 from http://www.niaid.nih.gov/topics/tube rculosis/research/treatment/Pages/def ault.aspx
Comas I, Gagneux S (2009) The Past and Future of Tuberculosis Research. PLoS Pathog 5(10): e1000600. doi:10.1371/journal.ppat.1000600
