[Semmelweis - a contemplating human. Scientific historical lessons].

In this article we examine why Semmelweis's seemingly simple, logical and practical discovery was categorically dismissed by the majority of his contemporaries, and why even many years after his death it was accepted with such reservation. We invoke wherever possible Semmelweis's own words citing from the series of articles appearing in the 'Orvosi Hetilap' [Hungarian Medical Weekly Journal] published in 1858 in Hungary, and also from the German language summary of the Journal published in 1860. We came to the conclusion that although Semmelweis did everything in his power to show the causal relationship between the development of puerperal fever (childbed fever) and some infectious substance on the hands of examining doctors and medical students, this was not convincing enough. The predominant theory at the time held that infection was caused by miasma transmitted in the air and therefore stubbornly precluded any notion of infectious matter physically transmitted on unclean hands. We also concluded that the causal sequence observed by Semmelweis was missing an essential empirical element: visual proof of the infectious agent he correctly postulated as physically transmitted. Visually demonstrating the presence of the infectious agent by means of a microscope would have made his case. This finally did occur but only two years after Semmelweis's death. Had the renowned Hungarian obstetrician realized the significance of taking advantage of the opportunity afforded by Dávid Gruby who was conducting experiments in the same town, a more convincing argument could have been made for his theory. In the 1840s and 1850s, Dávid Gruby was experimenting with various microscopic techniques and their application with success in Vienna before continuing his work in France. Gruby's work, especially that of microscopic observations of tissues, received international acceptance. Therefore, the involvement of Gruby and his work with microscopes to support Semmelweis's observations would most probably have forestalled much of the criticism and rejection his theory was initially awarded (among which perhaps Virchow's rejection proved the most damaging). Had Semmelweis utilized microscopic techniques, he would have been celebrated among the first to discover bacterial pathogens, contributing to the development of the currently predominant germ theory. Failure to utilize the microscope was the root cause leading to the tragedy of Semmelweis's rejection by the medical establishment of the time. Despite the increasing numbers of scientists utilizing the microscope at the University of Pest, offered to corroborate his daims with microscopic observations. Efforts have been made have since been to rehabilitate him as the key figure who not only discovered the method of transmission of infectious disease, but also implemented measures of prevention. Elevating him among the ranks of the ten greatest doctors who ever lived is certainly recognition due, but sadly denied to him in his lifetime. Orv Hetil. 2018; 159(26): 1055-1064.