Editing Ignaz Semmelweis (section)

== Work on cause of child bed fever mortality ==
=== Position at Vienna General Hospital ===
Semmelweis was appointed assistant to Professor [[Johann Klein]] in the First Obstetrical Clinic of the [[Vienna General Hospital]] on 1 July 1846.{{sfn|Benedek|1983|p=72}}{{sfnm|1a1=Semmelweis|1y=1983|1p=34|2a1=Schmidt|2y=1850|2p=501}}{{efn-ua|Details: On 1 July 1844 Semmelweis became a trainee physician's assistant at the Vienna maternity clinic (in German, ''Aspirant Assistentarztes an der Wiener Geburtshilflichen Klinik'') and on 1 July 1846 he was appointed an ordinary physician's assistant (in German, ''ordentlicher Assistentarzt''). On 20 October 1846, his predecessor [[Franz Breit (obstetrician)|Franz Breit]] (an obstetrician) returned and Semmelweis was demoted. By 20 March 20 1847, Breit was appointed professor in [[Tübingen]] and Semmelweis resumed the ''Assistentarzt'' position.{{sfn|Benedek|1983|p=72}}}}

Two maternity clinics were at the Viennese hospital. The First Clinic had an average [[Maternal bond|maternal]] [[mortality rate]] of about 10% due to puerperal fever. The Second Clinic's rate averaged less than 4%. Women begged to be admitted to the Second Clinic, due to the reputation of the First Clinic.{{sfn|Semmelweis|1983|p=69}} Semmelweis described desperate women begging on their knees not to be admitted to the First Clinic.{{sfn|Semmelweis|1983|p=70}}

Women began purposefully giving birth in the streets, pretending to have given birth ''en route'' to the hospital so they could avoid being admitted to the clinic where the risk of infection, birth complications and death were substantially higher. 

Semmelweis was puzzled that puerperal fever was rare among women giving street births, prompting his curiosity as to what protected those who delivered outside the clinic.{{sfn|Semmelweis|1983|p=81}}

=== Analysis of child bed fever mortality ===

Troubled by the mortality discrepancy between the two clinics, Semmelweis searched for differences. He excluded overcrowding as a cause since the Second Clinic was always more crowded.{{sfn|Semmelweis|1983|p=86}} He eliminated climate because the two clinics were in close geographical proximity to each other. He altered the position in which mothers gave birth and proposed that priests giving last rites in the clinic was terrifying women after birth causing them to develop the fever.{{sfn|Semmelweis|1983|p=46}}

[[File:Yearly mortality rates 1841-1846 two clinics.png|thumb|right|500px|[[Puerperal fever]] mortality rates for the First and Second Clinics at the Vienna General Hospital 1841–1846.]]
{|class="wikitable"<!--generated with [[:de:Wikipedia:Helferlein/VBA-Macro for EXCEL tableconversion]] V1.7-->
|+ [[Puerperal fever]] mortality rates for the First and Second Clinic at the Vienna General Hospital 1841–1846.
|- style="vertical-align:bottom;"
|style="height:13px; width:63px; |&nbsp;
|colspan="3" style="width:55px; text-align:center; |First clinic
|style="width:26px; |&nbsp;
|colspan="3" style="width:55px; text-align:center; |Second clinic
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|Year
|Births
|Deaths
|Rate (%)
|&nbsp;
|Births
|Deaths
|Rate (%)
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1841
|3,036
|237
|7.8
|&nbsp;
|2,442
|86
|3.5
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1842
|3,287
|518
|15.8
|&nbsp;
|2,659
|202
|7.6
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1843
|3,060
|274
|9.0
|&nbsp;
|2,739
|164
|6.0
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1844
|3,157
|260
|8.2
|&nbsp;
|2,956
|68
|2.3
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1845
|3,492
|241
|6.9
|&nbsp;
|3,241
|66
|2.0
|- style="text-align:right; vertical-align:bottom;"
|style="height:13px;|1846
|4,010
|459
|11.4
|&nbsp;
|3,754
|105
|2.8
|}

===Theory of cadaverous poisoning===

Semmelweis' breakthrough occurred in 1847, following the death of his good friend [[Jakob Kolletschka]], who had been accidentally poked with a student's scalpel while performing a [[Autopsy|''post mortem'' examination]]. Kolletschka's autopsy showed a [[pathology]] similar to that of the women who were dying from puerperal fever. Semmelweis immediately proposed a connection between [[cadaver]]ic contamination and puerperal fever.{{sfn|Lane|Blum|Fee|2010|pp=}}

He proposed that he and the medical students carried "cadaverous particles" on their hands{{efn-ua|Semmelweis's reference to "cadaverous particles" were (in German) "''an der Hand klebende Cadavertheile''"{{sfn|Benedek|1983|page=95}}}} from the autopsy room to the patients they examined in the First Obstetrical Clinic. This explained why the student [[Midwife|midwives]] in the Second Clinic, who were not engaged in autopsies and had no contact with corpses, saw a much lower mortality rate.

The [[germ theory of disease]] had not yet been accepted in Vienna. Thus, Semmelweis concluded some unknown "cadaverous material" caused childbed fever. He instituted a policy of using a solution of chlorinated lime ([[calcium hypochlorite]]) for washing hands between autopsy work and the examination of patients. He did this because he found that this chlorinated solution worked best to remove the putrid smell of infected autopsy tissue, and thus perhaps destroyed the causal "poisonous" or contaminating "cadaveric" agent hypothetically being transmitted by this material.  The result was the mortality rate in the First Clinic declined 90% and was then comparable to that in the Second Clinic. The mortality rate in April 1847, before the new [[hand washing]] procedures were instituted, was 18.3%. The new procedures started in mid-May leading to lower rates:  June 2.2%, July 1.2%, and August 1.9%.  In two months in the year following this discovery, for the first time since the introduction of anatomical orientation, the death rate was zero.{{sfn|Ataman|Vatanoğlu-Lutz|Yıldırım|2013|pp=35–39}}