Tuberculosis is a bacterial disease which causes nodular lesions in the body’s tissues (tubercles). Pulmonary tuberculosis occurs in the lungs. The World Health organisation claims that tuberculosis killed 1.7 million people globally in 2009, so it is still very much present today. Tuberculosis is most prominent in developing countries due to the lack of available treatment to save lives.

Tuberculosis was one of the most common causes of disease in the 18th and 19th Centuries. The last stage of tuberculosis was also known as consumption in Victorian times, and was nearly always fatal. It is considered to be the leading cause of death by any microbial pathogen in the World’s history, claiming an estimated 1 billion lives. This disease can be dated back to 2400 BC as tests on Egyptian Mummies have shown tubercular decay in their spines.

Tuberculosis became an epidemic in the 18th and 19th Centuries mostly in Europe and North America. In 1870 it claimed 1 in 5 lives of the entire population in the US; this was very similar to the figures in Great Britain. For most of the 19th century it is stated that 70%-90% of the US and European urban populations were infected with tuberculosis with 80% of those individuals who then developed active tuberculosis bacteria (TB) dying of the bacterial infection. Population density had a major impact on TB transmission as 40% of all deaths in cities were from TB.

The first breakthrough came at the beginning of the 18th century when Theophile Laennec(1781-1826) invented the stethoscope in 1816. Laennec was a French physicist whose mother died of TB when he was only five years old. A stethoscope is used on the chest to detect rhythmic heart and lung sounds and could help identify any problems in the chest region. Laennec started his work on pathogenesis (study of cells) and this was further advanced by Jean-Antoine Villemin in 1865.

Jean Antoine Villemin(1827-1892) was a French physicist who proved that TB is an infectious disease; previously TB was thought to be hereditary. In 1853 he qualified as an army officer and it wasn’t until 1865 that he made his scientific discovery. Villemin used injections and showed that the blood from one tubercular patient can spread the disease to animals, thereby proving that TB is an infectious disease.

Robert Koch (1843-1910), a German physicist, was one of the very first microbiologists. In 1882 he identified the tubercule bacillus and proved that it was a rod shaped bacterium, as well as identifying the causes/transmission of TB, cholera and anthrax. Koch also promoted the understanding of microbiology in the human body by developing technological advancements in laboratories.

On the evening of 24 March 1882, Koch gave a lecture that is considered by many to be the most important in medical history. Koch demonstrated how he had invented a new staining method, using all of his laboratory equipment in the lecture room and allowing the audience to see the findings for themselves. Koch showed tissue dissections from the lungs of infected patients, guinea pigs and apes. He proved to his audience that the cause of this disease was infection by a specific micro-organism which Koch had isolated. Koch proved that without the tubercule bacillus there was no chance of disease. He told the audience to look in the microscopes for themselves, leaving them stunned. In 1905 he received a Nobel Prize for his findings in the field of tuberculosis.

In 1890, Koch described what became known as the Tuberculin Reaction. This discovery helped the physicians Felix Mendel and Charles Mantoux develop what is now known as the ‘Mantoux (or Mendel-Mantoux) Test’. This was a skin test involving an injection just below the skin which would detect whether any bacterial proteins are present; a positive result would indicate a person has previously been exposed to TB. Unfortunately, due to false results, this test was not actually used in practice until almost a century later (2005).

Wilhelm Conrad Rontgen (1845 – 1923) was born in Germany and studied at Zurich University, graduating in 1869. Rontgen is known for inventing the X-Ray in 1895 and taking the famous first X-Ray on his wife’s hand (see picture). His discovery that objects of different thickness would fluoresce differently is still regarded as one of the greatest discoveries in scientific history. Rontgen won the Nobel Prize in 1901. X-Rays detect the electromagnetic radiation by measuring different wavelengths to obtain an image. It wasn’t until World War Two that it was used globally to diagnose patients with tuberculosis. Before 1912 X-rays were only used in medicine and dentistry because they didn’t have a high enough voltage and therefore the source of the X-Rays would break down. It took a further 19 years for the General Electric Company to develop the 1,000,000 volt X-ray generator. X-Rays could then be used to treat tuberculosis throughout the 20th Century. In 2004, the International Union of Pure and Applied Chemistry (IUPAC) named element 111 ‘roentgenium’ in honour of Rontgen’s accomplishments in the fields of mechanical engineering and physics.

All the discoveries mentioned above advanced the treatment of this bacterial infection in the late 19th Century and the 20th Century. However, the next breakthrough wasn’t until 1944 when streptomycin was developed – this was an antibiotic used in a number of bacterial infections. Eight years later another antibiotic called Isoniazid was developed to help treat the disease.

Arthur Hill Hassal was a doctor of medicine, biological sciences and a pioneer of public health regulations and legislation. In 1866 he survived the disease and became highly motivated to help patients who had also suffered tuberculosis. Hassal established a hospital on the Isle of Wight because he believed that the quality of the natural environment would lead to better treatment. The hospital was located near the town of Ventnor and was primarily designed to treat diseases of the chest including tuberculosis. In 1815 it was recorded that one in four patients in England acquired TB and of those, 50% died. If there was no treatment available there was little chance of survival.

The number of infected people increased during the First World War. This is because tuberculosis is an air born bacterium and could spread in the trenches. Before antibiotics were found to treat this disease the only option available was to quarantine the patient, rest in bed and abstain from all forms of physical activity.

At the end of World War One (1918) the army wasn’t prepared to treat the large numbers of infected tuberculosis patients. It is estimated that 50,000 men were rejected from enrolling in the military due their previous medical history or following a physical examination. It is estimated that a further 10,000 men who were accepted would have been rejected if chest X-Rays had been used. Of these 10,000 men, 5,000 were later diagnosed with having the disease while serving in the Great War. The chest X-Rays were later used in World War Two and were used as assessments in over half of those drafted for the Second World War.

There are two forms of TB infection; primary and secondary. The patient’s condition following a primary infection usually improves over time and is asymptomatic. However over months or years the primary infection can develop into a secondary infection. In the First World War there was no way of determining whether someone had a primary infection. The symptoms of secondary tuberculosis are: weight loss, night sweats, a high temperature (fever) and extreme tiredness. Pulmonary (lungs) tuberculosis symptoms are a persistent cough that lasts more than three weeks and breathlessness that gets progressively worse over time. TB can also develop in other areas of the body. These include persistently swollen glands, abdominal pain, pain and loss of movement in affected bone or joints, confusion, a persistent headache or seizures. All of these symptoms would have been used in the First World War to diagnose whether someone had secondary tuberculosis.

The mortality rate increased after the 1st World War (8 per 100,000 in between 1914 and 1918). This was mainly due to the poor hygiene and trench conditions which enabled airborne bacteria to infect more people. Overcrowding in the trenches was another factor which led to quicker transmission of the bacteria. There were other diseases that spread during World War 1 including Trench Fever – this was caused by the body’s lice and was spread from soldier to soldier. The horrific conditions promoted the uncontrollable spread of several infectious diseases.

Mark Daniels, member of the scientific staff at the Medical Research Council, delivered a Milroy Lecture at the Royal College of Physicians entitled: ‘Tuberculosis in Europe During and After the Second World War.’ Early in the War, German tuberculosis patients were forced to work in Germany and this led to a massive spread in the rate of infection. There was overcrowding due to limited housing and people gathering in bomb shelters where more people became infected. Malnutrition was also another factor that led to an increase in the number of infected individuals during and after the Second World War. In many areas of Europe the population lived in near starvation.

In Scandinavian countries there was no definitive increase in the number of people infected with tuberculosis. Norway was one of the few countries to use the BCG vaccination (a live strain of mycobacterium bovis used to treat tuberculosis) during the war. The BCG vaccine was first used on humans in 1921 and became the best form of treating the population, before they could get infected. There is now herd immunity as most of the population has been immunised, thereby diminishing the spread of TB.

Today in England, tuberculosis is still very present; in 2009 there were 5,758 cases of which 73% were non-UK born people. This implies that herd immunity has not yet been achieved in the countries from which non-UK born people have emigrated from. 39% of the TB cases are from London as highly populated, urban, overcrowded environments allow for an increased spread of the bacterial pathogen. This is because everyone is closer together and the pathogen can pass from one individual to another. London is also an international city. People in deprived areas of the country are seven times more likely to get tuberculosis than those in less deprived areas. 35% of the cases are found in individuals who are unemployed or no longer in education. Only 12% of the population have a social factor that causes tuberculosis e.g. drug abuse, alcohol abuse, homelessness and imprisonment.

Tuberculosis bacteria (TB) are very unique at infecting individuals. Bacteria in the body is usually ingested by white blood cells, however this differs with TB. TB allows itself to be ingested by specific white blood cells called macrophages. The TB stays active and recruits a whole host of other blood cells and forms a granuloma (a mass of granulation tissue formed in response to inflammation, infection or the mere presence of a foreign substance). They remain in the granulation tissue and become dormant. If they escape they can set up many infection sites throughout the body. To create a granuloma the bacteria must break out of the vacuole (jelly like fluid within the cytoplasm of the cell enclosed by a membrane). The TB can then apoptose (kill) the host cell once within the cytoplasm leading to subsequent widespread tissue fibrosis and possibly death.

Matthew Draper