How did Joseph Lister's antiseptic surgery improve public health?

Joseph Lister revolutionized public health by establishing the principles of antiseptic surgery, which drastically reduced mortality rates associated with surgical procedures.12

Before his innovations, surgical patients frequently succumbed to "hospital disease," or operative sepsis, caused by bacterial infection. By applying Louis Pasteur’s germ theory, Lister recognized that bacteria must be prevented from entering surgical wounds. He introduced carbolic acid as a chemical barrier to disinfect surgical instruments, clean wounds, and sanitize the operating environment.13

The impact of these techniques was profound: in his own wards, surgical mortality fell from 45 percent to 15 percent between 1865 and 1869. By proving that operations could be performed safely, Lister’s work transformed surgery from a high-risk, last-resort measure into a reliable medical intervention. His fundamental principle—that preventing bacterial entry is essential to patient safety—remains the cornerstone of modern surgical practice today.123