Germ Theory and Public Health

By Dr. Kelli Criss

Last week, we considered how germ theory advanced the discovery of vaccines.  As the world continues its struggle to contain the spread of COVID-19, our blog, Germ Theory and Public Health, emphasizes the impact germ theory had in the last quarter of the nineteenth century upon health institutions, medical practitioners, and the public.  

Germ Theory’s Revolution 

From 1875-1900, scientists like Louis Pasteur in France and Robert Koch in Germany helped develop germ theory that remains the standard in medicine over a century later.  Their discoveries helped science understand the microbiology behind diseases that gripped the population.  Typhoid, cholera, tuberculosis, diphtheria, and tetanus were demystified, preventable, containable, and curable thanks to scientific advances.   

Targeted Prevention 

During the late nineteenth century when scientists could specifically identify the pathogen causing an illness, they could also improve prevention.  Efforts to improve public health were possible through helping the population avoid environmental conditions that accelerated disease.  At this time in America, major cities experienced tuberculosis as the leading cause of death.  Identification of the pathogens causing tuberculosis enabled test development which revealed high levels of infection in individuals that existed only as a dormant form of tuberculosis in the 1890s.  To curb the advancing of the disease to an active state, cities worked to correct housing and working conditions which accelerated the stimulation of active tuberculosis.  Likewise, officials worked to cleanse water supplies that could carry cholera and efforts were made to pasteurize milk in order to avoid fever linked to unpasteurized milk.   

Sterilization Techniques  

As germs made more sense to scientists, techniques for preventing infection through sterilization created advances in surgery.  Operating rooms could be cleansed to eradicate bacteria and a process of sterile procedures were instituted in operations to keep germs out.  As surgery became safer and the discovery of X rays enabled better diagnosis for problems requiring surgery, the use of surgery expanded.   

Practice of Medicine Expands 

During the late nineteenth century, population shifts, transportation expansion and communication technology advances led to an influx of medical professionals in cities where doctors were easily accessible to their patients and fellow physicians.  The population was leaving the rural areas for urban ones.  Railroads connected cities and created hubs just as streetcar lines enabled intra-city movement.  As people moved and railroads expanded, doctors relocated to cities, often establishing their offices by streetcar lines and near hospitals.  The telephone enabled patients to rapidly reach physicians and enabled doctors to contact other physicians, hospitals, and pharmacies.   

As doctors became more accessible, then competition took over leading to decreased costs for patients.  Medical insurance did not emerge until the end of the nineteenth century; however, some protection was available through union and immigration society’s providing benefits for membership.  As more people moved to cities, hospitals emerged to help care for patients who had no relatives to help them when they were sick.   

Improved Medical Education & Regulation 

Likewise, as more doctors practiced and more hospitals emerged, regulation of medical education increased when previously in the first half of the nineteenth century medical education was not standardized, and doctors were not licensed.  A landmark decision in 1888 by the U.S. Supreme Court, Dent v. West Virginia established the states’ right to license physicians.  This decision initiated the formation of state board of medical examiners and medical education improvements.  The length of medical education extended from only two to three years at medical schools like Harvard while some schools began insisting on a four-year medical training program and required a four-year undergraduate degree as a condition of admission to medical school.   

Gratitude “In the Day of Trouble” 

As we have the benefit of looking back upon the end of the nineteenth century, there’s no difficulty in seeing the amazing discoveries and improvement God accomplished through man.  Being in the midst of a pandemic leaves little room for focusing on any advances being made because it’s warfare.  The Florida Faith and Freedom Coalition believes that God is at work even as our world struggles.  We are reminded of David’s words in Psalm 27:5 (New American Standard),  

“For in the day of trouble He will conceal me in His tabernacle; In the secret place of His tent He will hide me; He will lift me up on a rock.”  

 Even though the stress is real, we remember all God has done in the past to help the world and to help us in our individual lives.  Recounting all God has done helps with feeling gratitude and hope “in the day of trouble.” 

We’ll see you again next week.  Until then, you can sign-up for our newsletter and get further information about Florida Faith and Freedom Coalition on our homepage.   

Timeline of Events 

1856 – Joseph Lister develops an antiseptic method used to disinfect operating rooms to eradicate microorganisms.   

1883 – Johns Hopkins Medical School requires four years of training and requires a four-year undergraduate degree for admission into the school.   

1895 – X rays are discovered and improve diagnostic capabilities of doctors.    

1889 -1891 – 40 % of world’s population infected with influenza during epidemic. 


Hooper, J. (1999, February).  A New germ theory.  The Atlantic.  Retrieved from  

Tompkins, V. (1997).  American eras: Development of the Industrial United States, 1878-1899.  New York, NY: Gale 


Lecture 14: The Germ Theory of Disease from History 234: Epidemics in Western Society since 1600, an Open Yale Course

Leave a Reply

Your email address will not be published. Required fields are marked *