Dr Ignaz Semmelweis: the ‘Forgotten Father’ of infection control

By Ollie Symes
16th March 2022

Medical theories, much like all other scientific theories, are under constant scrutiny and can undergo revisions, updates, or even complete dismissal as the field advances. However, history has demonstrated time and again the reluctance of experts to consider a new theory, especially if it contradicts the established doctrine. 

One such example is the story of Dr Ignaz Semmelweis, a 19^th century Hungarian obstetrician who pioneered handwashing in hospitals to reduce infection rate. Unfortunately, Semmelweis’ theory was rejected and mocked by the medical community and his ideas largely ignored and forgotten until decades after his death, by which time they became a cornerstone to Joseph Lister’s antiseptic research. 

The late 18^th and early 19^th century saw huge advancements in surgical techniques and anesthetics, giving overzealous surgeons more reason to operate when they may not have before. However, with the concept of bacterial infection yet to be developed or discovered, little consideration was given to the hygiene of hospital staff or facilities. This combination of inspired surgeons and poor hygiene resulted in soaring rates of post-operation infections and related deaths.

In 1847, Semmelweis was appointed with a 2-year assistant professorship post in the maternity ward of the Vienna General Hospital. Whilst working on the ward, Semmelweis was alarmed by the high post-delivery mortality rate of the mothers (a condition termed ‘puerperal’ or ‘childbed fever’). After closely monitoring the mortality rate in relation to who was present at the deliveries, Semmelweis found that women whose deliveries were performed by medical students and physicians were at a much higher risk in comparison to those delivered by midwives or nurses. 

Semmelweis concluded that the higher rates of mortality in women were due to the physicians and medical students handling cadavers during autopsies prior to performing the deliveries, something the midwives and nurses did not do. Without necessarily understanding the bacterial underpinning to his argument, Semmelweis associated exposure to cadaverous material with an increased risk of infection and death. 

Using a chlorine of lime solution (to us known as calcium hypochlorite, or bleaching powder), Semmelweis introduced a mandatory handwashing policy for medical students and physicians before performing deliveries. Interestingly, chlorine was chosen more so because it removed the foul smell of the cadavers – its excellent disinfectant properties were unbeknown to Semmelweis.

In a controlled trial, the mortality rate fell from 18% to 2% after the introduction of mandatory handwashing. This 2% mortality rate for the medical students and physician-performed deliveries was now as low as that observed with the midwives and nurses, demonstrating the link between exposure to cadaverous material and increased infection rates. Elated and encouraged with the results, Semmelweis also began washing the medical instruments in the ward, lowering the morality rate yet again to only 1%.

Despite this demonstrable success, Semmelweis failed to convince his superiors. Old guard academics at the hospital rejected his conclusions, instead believing the lower mortality to be a result of the hospital’s new ventilation system. This ventilation argument was supported by the prevailing theory of the time: that ‘bad air’ was the origin of all disease and infection. Termed miasma theory, it was widely accepted with many advocates and very few dissenters. As we now know, miasma theory is a flawed model and thus failed to account for the high rates of post-operation infections in the mid-19^th century.

Semmelweis was unwavering with his belief in handwashing, a stance which labeled him a nonconformist to the popular miasma theory. As a result, senior staff of the hospital refused renewal of his assistant professorship. Feeling betrayed, Semmelweis left Vienna and returned to Hungary where his ideas were accepted and widely implemented across the country – saving countless lives. Sadly, the influence stopped with Hungary; the wider medical community of Europe and beyond rejected his ideas. 

Considering the medical establishment of the mid-19^th century believed that some disease and infections were simply ‘unpreventable’, Semmelweis’ proposal was always going to face opposition. Moreover, the very suggestion that doctors were the cause of infection appeared as an attack on the profession. As an individual with Hungarian and Jewish origins, historians have also suggested that Semmelweis experienced discrimination from the medical community. 

The continued antagonism between the establishment and Semmelweis reached a crescendo in 1865 when he was admitted to an ‘insane asylum’. He was beaten, developed an infection and died, losing his life to the very phenomenon he fought to prevent. Over the next 20 years, inspired by Semmelweis’ work, Joseph Lister continued to investigate and develop the field of antiseptics, revolutionising modern medicine in the process. 

So, next time you find yourself washing your hands, singing happy birthday for 20 seconds as you thoroughly spread the soap, consider Semmelweis’ story, and how he developed what continues to be a simple yet effective form of infection control.

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Ollie Symes is a Chemistry PhD student, researching new synthetic methods to install bioisoteres in drug-like molecules. He has recently developed a keen interest in writing and science communication, and loves to incorporate a historical angle whenever possible.