Robert Koch - A life in the kingdom of microbes

Hunter of pathogens, master of bacteria:Robert Koch has a number of attributes. The winner of the Nobel Prize in Medicine had to accept failures again and again. But he revolutionized medicine in many areas.

by Dirk Köhne

Berlin, March 24, 1882:It was dead quiet in the conference room of the Physiological Society. Those present understand what medical sensation they are witnessing. The doctor Robert Koch has just informed you that he has isolated the tubercle bacillus. At this time, about every seventh German dies from the lung disease. "Consumption" is considered incurable or, in milder cases, results in lifelong hospitalization. The detection of the tuberculosis bacterium paves the way for the development of a vaccine. Koch determined that the air he breathed was the carrier of the disease:he found tubercle bacilli in the mucus of the sick. This proves that patients with open pulmonary tuberculosis in particular pose a risk. World Tuberculosis Day, celebrated annually on March 24, is based on Koch's discovery.

Koch revolutionizes medicine

When Robert Koch was born in Clausthal at the end of 1843, scientists still believed that plagues and epidemics were triggered by so-called miasms - toxic vapors rising from the ground. Years later, Koch revolutionized medicine with the discovery that diseases such as the plague, tuberculosis and cholera were caused by tiny microorganisms. It proves how important hygiene is in everyday life. During the cholera epidemic in Hamburg in 1892, he implemented measures to combat the disease. He discovers the causative agent of anthrax and tuberculosis and improves the cultivation of bacterial cultures. His research makes a significant contribution to containing epidemics and fighting centuries-old diseases. In 1905, Robert Koch was awarded the Nobel Prize in Medicine and Physiology for his services.

Tracking down the anthrax pathogen

Even as a young hospital doctor, Koch showed great interest in research. During the Franco-Prussian War he learns that soldiers often die of anthrax, although the injuries are not serious. This prompts him to investigate the cause of the anthrax diseases. He invents the hanging drop technique. The microbes are cultured in a drop on the underside of a slide. Koch can now observe and detect bacteria in the blood of infected animals under the microscope. With his observations and findings, he can prove why cattle on certain pastures are repeatedly infected with anthrax:the farmers do not bury the carcasses of the dead animals deep enough in the ground. He also finds out that dried blood from infectious sheep is still contagious after four years.

Sepsis research in mice

After the publication on the anthrax pathogen in 1876, Koch dealt with the problem of wound infections (sepsis). He sets up an animal model for sepsis and finds that different animal species react differently to the different types of bacteria. For example, he identified six different forms of sepsis in mice, which are triggered by six different types of bacteria. Koch published his "Investigations into the Aetiology of Wound Infectious Diseases" in 1878.

Robert Koch:Driven by technical progress

Koch constantly tries to stay at the forefront of technical developments. He optimizes microscopy and takes the first photos of microorganisms.

• Robert Koch Institute
• Robert Koch Foundation
• Nobelprize.org

At the Imperial Health Office in Berlin he developed the so-called culture plate technique. So far, bacteria have been cultured in meat broth or on potato slices. However, meat broth cannot be fixed under the microscope and many pathogenic bacteria do not grow on potato slices. Koch then stabilizes the meat broth with gelatine and pours this culture medium into rectangular "plate dishes". Since then, the method of solid, transparent culture media has been part of every bacteriological research.

Detection of cholera bacteria during an expedition

As a young boy, Robert Koch dreamed of becoming a traveling naturalist - like his role model Alexander von Humboldt. Some of his ten siblings emigrated to Uruguay, Mexico and the United States. When he was offered the leadership of the German Cholera Expedition in 1883, he packed his bags and arrived in Alexandria in August. In Egypt, however, the epidemic is already subsiding and the expedition is therefore moving on to India in November. Two months later, Koch succeeded in detecting cholera bacteria. He also finds out that the pathogen is transmitted through the water. The return to Germany in May 1884 is like a triumphal procession. Kaiser Wilhelm I receives Koch and rewards him with 100,000 marks.

The following year, the Friedrich-Wilhelms-University in Berlin appointed Koch professor and head of the newly created institute for hygiene. But as a teacher he is untalented. Lectures and exams are a cross for him. His health is failing and he therefore seeks relaxation on several long journeys. There is also a crisis in his marriage. Meanwhile, Louis Pasteur's rival research team in Paris is making great strides in active vaccination. Until 1890 there was no noteworthy report from Koch.

Tuberculin:Koch's vaccine remains ineffective

At the 10th International Medical Congress in Berlin in August 1890, Koch presented a vaccine that was supposed to put an end to the tuberculosis pathogen:tuberculin. Thousands of tuberculosis sufferers hope to be cured by the drug. The enthusiasm is great. But the serum does not keep what Koch promises. Long-term cures are not recorded, many subjects even die. Although tuberculin - a mixture of components of killed tubercle bacilli - did not gain acceptance as a remedy, it was later successfully used to detect tuberculosis. The bankruptcy with the supposed vaccine weighs heavily for Koch. But he remains convinced of the healing power of the drug and seven years later presents a modified tuberculin that is also ineffective as a drug.

Koch becomes head of the Institute for Infectious Diseases

In 1891 Koch gave up his professorship and from July 1st became head of the "Royal Prussian Institute for Infectious Diseases" founded especially for him with an experimental and a clinical section. The "Koch'sche Institut" takes over tasks for cities and national authorities. Nine years later, due to the increased number of employees and research work, the institute is relocated to a new building that Koch helped plan - on the north bank in Berlin-Wedding. This institution, the Robert Koch Institute, still bears the name of the founder today.

When the cholera epidemic broke out in Hamburg in August 1892, Koch's know-how was used to fight the epidemic. In contrast to the Hamburg doctors, Koch is familiar with the bacteriological methods for detecting the cholera pathogen. The people of the Hanseatic city are warned to boil their drinking water, and disinfection crews clean the homes of people infected with cholera. When the disease was fought in October, more than 8,600 people died. After the epidemic, a new waste incineration plant and filtration plants go into operation in Hamburg. Continuing education courses are arranged for physicians. A student of Koch, Bernhard Nocht, is appointed to the position of port doctor.

Koch helps in South Africa and New Guinea

In 1896, the British government asked Koch to help fight a cattle plague in South Africa. He travels to Kimberley with his second wife Hedwig and is able to prove there that the blood of sick animals is extremely infectious. However, he does not find the pathogen because it is a viral disease. Nevertheless, he develops a serum that is apparently effective. In March of the following year, the German government asked the bacteriologist to go to India, where the plague had broken out. The way there is complicated because the ship connections to Bombay are interrupted due to the plague. The plague pathogen is already known, but Koch makes an important observation:A large rat death can initiate a plague outbreak.

Malaria expedition to New Guinea

In July 1897, Robert and Hedwig Koch traveled to Africa again and stopped in German East Africa. They stay for almost a year. Robert continues to research the plague and deals with malaria and a cattle disease. In May 1898 the couple returned to Berlin. Malaria also occurs in Germany.

The biggest problem in the German colonial empire with "intermittent fever" is in Kaiser-Wilhelms-Land in German New Guinea. That's why the Colonial Department of the Foreign Office sends Koch there. The expedition reached the island in the Indian Ocean at the end of 1900. During serial examinations of the natives of New Guinea, Koch observed that the natives developed malaria either only slightly or not at all, although he detected the pathogen in their blood. German settlers or Chinese temporary workers fall ill immediately. Apparently, the longer they are in the region, the more resistant they become to the parasite. For the first time, Koch can prove the phenomenon of acquired malaria immunity.

Typhoid campaign and forced isolation

Because Koch's measures to combat malaria in New Guinea were too expensive for the colonial administration, the physician dealt with the wartime epidemic typhus, which broke out locally in Germany in 1901. Koch enlists the Prussian military in a typhoid campaign that starts near Trier. In order to track down people infected with typhoid, teachers and clergy are interviewed and lists of absenteeism from schools and data from local health insurance companies are evaluated. The suspects are examined bacteriologically. Sick and healthy infected people are isolated. From 1903, the campaign was expanded to southwest Germany. A total of eleven test stations will be set up. The medical staff examines hundreds of thousands of people and isolates - sometimes under duress - thousands of suspects.

Nobel prize for the discovery of the tuberculosis pathogen

In 1904, Koch resigned as head of his institute at his own request. The following year his path leads again to German East Africa, where sleeping sickness broke out.

On the Sese Islands in Lake Victoria, 20,000 people - around two-thirds of the population - have died from it. Koch injects the patient with the arsenic drug Atoxyl. They then complain of pain, dizziness, nausea and colic. Some even go blind. Many patients flee treatment. Koch suggests carrying out serial examinations in contaminated regions and housing the sick in "concentration camps". As a result, more than 1,200 sleep sickness stations are set up. However, there were no healing successes.

When Koch got the news of his Nobel Prize nomination, he interrupted his stay and went to Sweden. He accepts the award in Stockholm at the end of 1905.

Robert Koch Foundation to fight tuberculosis

In 1906, Koch traveled to Lake Victoria again with an expedition. A year later, the "Robert Koch Foundation to Combat Tuberculosis" was established.

A private journey took him via the USA to Japan in 1908, where he visited his former colleague Shibasaburo Kitasato. In April 1910, Koch suffered a heart attack in Berlin. On May 23 he arrives in Baden-Baden for a cure. Four days later, a doctor finds the dead Nobel Prize winner in front of his open balcony door. Koch is cremated at his own request. The urn is taken to his institute in Berlin and buried in the mausoleum built in his honor.

Robert Koch:CV of a top researcher

1843 :Robert Koch is born on December 11th as the son of the head of the mining authority Hermann Koch and his wife Mathilde in Clausthal (district of Goslar). He grew up with ten siblings.
1848 :The boy gets private lessons - already at the age of four he had taught himself to read and write.
1851 :Attended the humanistic grammar school in Clausthal until graduation in 1862
1862 :Koch is studying philology in Göttingen, but switches to medicine in the first semester.
1866 :Completion of medical studies with state examination and doctorate
1867 :He marries the pastor's daughter Emmy Fratz in May. A year later, the marriage produces a daughter, Gertrud.
1868 :Medical work in Hamburg, Langenhagen near Hanover, Niemegk near Potsdam and Rakwitz in the province of Posen.
1871 :Koch volunteers in the Franco-Prussian War and works in the field hospital. He mainly cares for typhoid and dysentery patients.
1872 :He takes the physics exam and becomes a district doctor in Wollstein (province of Posen).
1876 :When examining the animal disease anthrax, Koch identified specific pathogens for the first time. "The Etiology of Anthrax Disease Based on the Developmental History of Bacillus Anthracis" is published.
1880 :Koch is appointed to the Imperial Health Office in Berlin.
1882 :He proves the tuberculosis bacterium and presents his discovery in his famous lecture on the "Etiology of Tuberculosis" before the Berlin Physiological Society.
1885 :The Berlin University appointed him professor and head of the Institute for Infectious Diseases.
1890 :At the International Medical Congress in Berlin, Koch presented the drug "Tuberkulin 1890", which he hoped would be successful in curing tuberculosis.
1891 :He gives up his professorship and becomes head of the Prussian Institute for Infectious Diseases - today's Robert Koch Institute in Berlin.
1893 :His wife divorced and Koch married 17-year-old Hedwig Freiberg in the same year.
1896 -1906 :Several trips, especially to tropical countries - he researches the origin and transmission of the plague, malaria, sleeping sickness and rinderpest.
1905 :Koch interrupts his stay on the Sese Islands in Lake Victoria to accept the Nobel Prize.
1907 :The Robert Koch Foundation is founded.
1910 :The Nobel Prize winner dies on May 27th in Baden-Baden.