1.2 Discoveries in modern medicine
A lot has changed since the 1800s: our understanding of the causes, treatment and prevention of infectious diseases has considerably improved. In this section you will learn how our knowledge developed, who contributed to developing new insights and why this new approach was so revolutionary at the time.
Activity 3: Development of hygiene theory
Watch Video 2 on the discoveries of Ignaz Semmelweis, a physician working in Vienna in the mid-19th century, and answer the question that follows.
Transcript: Video 2
Years before the germ theory of disease was developed, the Viennese physician Ignaz Semmelweis came to the startling discovery that doctors could save the lives of patients simply by washing their hands. Although he couldn’t explain why hand disinfection was so effective, his research in 1847 would go on to transform the way surgery is carried out and infectious diseases are controlled today.
Known locally as the saviour of women, Semmelweis initiated handwashing policies which helped to drastically reduce the mortality rate from childbed fever in Viennese obstetrics clinics where he worked.
Childbed fever, or puerperal fever, is the infection of the female reproductive organs following childbirth and was a common cause of death at the time. Semmelweis’ attention was first drawn to the mortality rates at the clinics he worked at, because women would beg to be admitted to the clinics run by midwives rather than those staffed by students. The women were so desperate to avoid the student clinics that they would rather give birth in the street. After looking into the mortality rates of the two clinics, he found that the student run clinic did indeed have a much higher mortality rate for puerperal fever – sometimes three times higher. After eliminating various factors, Semmelweis came to the conclusion that the students carried something from the dissection rooms where they performed autopsies, to the patients they examined during labor. He ordered the students to wash their hands in a solution of chlorinated lime before each examination. The mortality rate fell from 18 per cent to 1 per cent.
Despite the success of this policy, Semmelweis faced the wrath of the medical community. He could offer no acceptable explanation for his findings as the notion that there were germs causing disease was unaccepted, and various doctors were offended by the insinuation that their hands were dirty. He was ostracised and ridiculed by the leading medical figures of his time, and eventually driven out of Vienna.
After struggling for years to promote his hand disinfection policies, Semmelweis was admitted to an insane asylum at the age of 47. He died 14 days later.
What did Ignaz Semmelweis discover?
Answer
He discovered that doctors could save lives by simply washing their hands.
Semmelweis was not the first person to see the connection between hygiene and the spread of puerperal fever (childbirth fever); Alexander Gordon had made a similar observation about 50 years earlier. He discovered that puerperal fever was spread from patient to patient by the attending midwife or doctor. To limit the spread of the disease, he recommended fumigating clothing and burning bedlinen used by women with puerperal fever. He also recommended the cleanliness of the attending doctors and midwives.
At the time that Gordon and later Semmelweis made their discoveries on the importance of hygiene in the spread of disease, they did not know what actually caused infections. That discovery was made a few years later by the collective efforts of Louis Pasteur and Robert Koch, whose discovered that diseases were caused by microscopic organisms – which they called ‘germs’.
Activity 4: Definitions of microbes
a.
True
b.
False
The correct answer is a.
Discussion
When
a.
True
b.
False
The correct answer is b.
Discussion
Microbes are microscopic organisms that exist as a single cell or as a colony of cells. Some microbes cause diseases; these microbes are called pathogens (they are
a.
True
b.
False
The correct answer is a.
Discussion
Microbes are microscopic organisms that exist as a single cell or as a colony of cells. Bacteria are cellular micro-organisms. Some bacteria cause diseases and are referred to as pathogenic bacteria. Most species of bacteria, however, are not harmful to us. You will learn more about bacteria in Section 2.1.
a.
True
b.
False
The correct answer is b.
Discussion
Yeasts, and single-celled animals such as amoebae, are also classed as microbes. They may or may not be pathogenic.
Discovery of antibiotics
After germ theory was established, people knew what caused infectious diseases. The search for a cure for these diseases had begun.
In 1928, Alexander Fleming discovered which
Transcript: Video 3
In Section 2.2 you will learn more about what antibiotics are, and in Section 2.3 you will learn more about what antibiotics do.
Timeline
The following timeline summarises important moments in history that shaped our understanding of the prevention, causes and treatment of infectious diseases:
Before 1800: The general understanding was that diseases were caused by bad gases, which were called miasmas, or by an imbalance of fluids in the body. The treatment for diseases at that time included blood-letting and treatments that are now regarded as quackery.
1795: Alexander Gordon observed that puerperal fever was spread between patients by attending midwives and doctors. He recommended cleanliness of the attending medical staff as a measure to prevent disease from spreading, but his recommendations were largely ignored.
1847: Ignaz Semmelweis discovered hygiene theory – that is, the importance of handwashing in preventing puerperal fever. He was also largely ignored.
1854: John Snow traced an outbreak of cholera to a single contaminated water pump in London, and thus discovered the link between contaminated water and this disease. He is considered to be one of the founding fathers of the discipline of
1850–1880: Collective efforts by Louis Pasteur and Robert Koch led to the discovery that diseases are caused by micro-organisms (germ theory).
1928: Alexander Fleming discovered that a substance produced by a mould – which he called penicillin – could kill bacteria. Florey and Chain later played an important role in making the antibiotic penicillin widely available. Fleming, Florey and Chain were awarded the 1945 Nobel Prize for Medicine for their achievements.
1.1 Medicine in the 1800s
