Scientific name: Mycobacerium tuberculosis

Genus: Mycobacterium

TB has very ancient origins and there is evidence of the disease in Egyptian mummies that revealed skeletal deformities typical of TB, as well as written documents describing TB that were found in India and China.

What was the suspected infectious agent?

The suspected infectious agent was the bacteria, bacillus. This was confirmed by a German physician and scientist Robert Koch who identified the bacteria in 1882.

What type of disease was it?

Before Robert Koch's identification, it could have been classified as an endemic disease. Endemic diseases are diseases that are regularly present in a particular region or location. After Robert Koch's discovery, it was classified as a chronic infectious disease. Chronic infectious diseases are infections that can remain in the body for extended periods of times, like weeks, months, or years.

• Evidence suggests an early progenitor of TB might have affected early hominids in East Africa and as humans began migrating out of Africa, the disease began to spread.

• After the decline of the Roman Empire, TB was widespread in Europe in the VIII and XIX centuries

• TB is now a widespread global health threat

What was the timeline of the spread?

• 3 million years ago: early progenitor of MT might have infected early hominids in East Africa

• 2400 BC: Egyptian mummies reveal skeletal deformities typical of tuberculosis

• 3300 and 2300 years ago: the first written documents describing TB were found in India and China

• 1854: TB is treated in sanatoria, with a strict regimen of bed rest, fresh air at all times

• 1882: Robert Koch identifies that TB is caused by an organism, Mycobacterium Tuberculosis

• 1920: The first human trials of the vaccine BCG, an attenuated version of Mycobacterium bovis (Bovine TB), are launched.

• 1970: First outbreak of drug-resistant TB in the US.

• 1993: The World Health Organization (WHO) declares TB ‘a global emergency’ with deaths from TB higher than any previous year in history. WHO estimates that one third of the world’s population is latently infected with TB, leading to 7-8 million cases of active TB – and 1.3-1.6 million deaths, annually.

Approximately how many people were affected (illness and/ or death)?

• A total of 1.25 million people died from tuberculosis (TB) in 2023 (including 161 000 people with HIV).

• In 2023, an estimated 10.8 million people fell ill with TB worldwide, including 6.0 million men, 3.6 million women and 1.3 million children.

If available, include a picture or a link to a map in your Padlet post that shows location the disease has been detected.

https://www.cdc.gov/tb-surveillance-report-2023/summary/reporting-area.html

Virulence is the ability of a pathogen to cause disease. To define TB virulence, the following factors that should be considered are the ability of a bacterium to avoid the host’s immune response, its capacity to cause lung damage, and its successful transmission to infect a new host. The virulence factors are based on non-protein molecules and proteins.

TB is considered highly virulent, due to its ability to evade the host immune system, its ability to cause progressive lung damage, as well as it being a persistent and latent infection that can be easily transmitted.

Did the virulence change over time?

Yes, TB has evolved over time with the availability of more genome sequences and the adaptation to humans. The primary symptoms have remained the same; these symptoms include chronic cough, fever, fatigue, chest pain, and weight loss.

In the 1800s, the first successful remedy against TB was the introduction of the sanatorium care with continuous fresh air and good nutrition. This was the first approach that improved outcomes before antibiotics. Now, there are effective treatment regimens for inactive and active TB. The BCG vaccine is typically given to infants and small children, which protects children from getting severe forms of active TB.

What medical advances were used in combatting the disease?

Medical advances that were used in combatting the disease included the development of the BCG vaccine, the creation of effective treatment regiments for both latent and active TB, and improvements in diagnostic tools. The BCG vaccine was developed in 1921 to protect infants and small children from severe forms of TB. Effective treatment regimens for drug-susceptible TB disease takes 4, 6, or 9 months depending on the regimen. and directly observed therapy (DOT) is the standard of care. Lastly, diagnostic tools like TB blood or skin tests and chest x-rays are widely used to identify infection.

Were any new technologies applied to this disease? What were they?

Yes, a new technology that was applied to TB was the Xpert MTB/RIF Assay test. This assay is a test that detects Mycobacterium tuberculosis complex (MTBC) and resistance to rifampin (RIF). Rifampin is one of the most effective drugs to treat TB.

TB was declared a global health emergency by the World Health Organization in 1933. For many years, the U.S. government involvement in global TB efforts was relatively limited until the late 1990s. However, in response to the persistent challenges of TB, the U.N. General Assembly has held two high-level meetings in 2018 and 2023 to discuss these challenges and examine progress toward global goals, which focused on ending the epidemic by 2030.

Were any innovative initiatives used in combatting the disease? What were they?

Yes. Some innovative initiatives that are used, but not limited to are:

AI-assisted diagnostics and TrueNat testing: researchers have been using AI with TrueNat to accelerate TB screening and diagnosis; AI can provide automated chest x-ray readings and TrueNat is a new molecular test that can diagnosis TB disease and rifampin resistance in one hour.

Dual testing strategy: Dual testing has been implemented by many countries; this involves testing a person for both TB and SARS-CoV-2 based on their risk for both diseases.

WHO "End TB Strategy": The World Health Organization is also leading the "End TB Strategy" which aims to end the global TB epidemic. This strategy serves as a blueprint for countries to reduce TB incidence by 80%, TB deaths by 90%, and to eliminate catastrophic costs for TB-affected households by 2030.

What could leadership have done better in response to this disease?

Leadership could have acted more quickly to reduce the global TB challenges. Earlier responses and investments towards diagnostic tools, drug development, and treatment access may have prevented, or at least, reduced the amount of infections and deaths from TB.

A societal effect of tuberculosis is the stigma and discrimination that followed the disease. Tuberculosis was stigmatised by most communities mainly due to the fear of transmission during contact with an infected person, but also its association with other factors like HIV, poverty, low social class, malnutrition, or disreputable behavior.

Did any society behaviors change?

Tuberculosis was often associated with poverty which influenced how patients were treated and isolated. The disease also impacted the workforce which which pushed for better working conditions and early health-screening practices. TB also influenced immigration policies, as many countries began screening for the disease.

Did society “learn” from the physical effect of the disease?

Yes, society learned by recognizing the importance of fresh air, nutrition, hygiene, and ventilation. Society also learned by reinforcing the importance of screening, public health reporting, and preventative care.