Germ versus Fertile Field Theories

Jacob Schor

February 17, 2007


This past week at the House Health and Human Services hearing on HB 1192 to regulate the practice of naturopathic medicine here in Colorado, I listened to the testimony of Mark Johnson, MD. Dr. Johnson testified against our bill on behalf of the Colorado Medical Society. In his testimony, among other interesting perspectives, Dr. Johnson claimed that there are no scientific studies supporting anything that naturopathic doctors do.


This comes as a great relief to me. From hence forward, I no longer feel obligated to footnote articles that I write. A timely decision because what I am going to write about today is an old debate in medicine, one that we hardly hear about in these modern times, and one which Dr. Johnson might pooh-pooh as unscientific. I will mention only one study. Published in the Journal of the American Medical Association (JAMA) in 1919, the study will be too old to satisfy the esteemed Dr. Johnson.



Once upon a time, the big debate in medicine was whether the germ theory was valid. Louis Pasteur had discovered germs but there were many people who, even decades later, felt it wasn't so much germs that caused illness but what they called the “fertile field.” The idea being that germs will only grow in a body that offers a ‘fertile field,' best described as a welcoming environment that tolerates and encourages their growth. The story goes that Pasteur argued in favor of his germ theory for most of his life but recanted in favor of the ‘fertile field' on his deathbed. Though mostly forgotten in modern medicine, this was still a central question debated during our education as naturopaths. The germ theory is so fixed in our modern thinking that it is easy to forget the older fertile field theory and slip into believing that disease is all about germs.


I was reminded of this a few weeks ago. I came across and then forwarded out an email link to an entertaining short video on “How to cough and sneeze.” The premise of the video is that many people cough and sneeze into their hands. They then spread germs as they touch doorknobs, telephones and other shared objects. Doing so is how we spread the germs that cause colds and other illnesses. The better and safer method of coughing and sneezing is to do so into cloth, say your shirt sleeve. The woven fabric traps the germs and they die without spreading infection. It is an attractive idea and makes sense. That is if the Germ Theory is true.

Watch the video:


A few days after emailing this video link out, I read a fascinating excerpt from a study on flu transmission. Here is my one reference for this letter.


Rosenau, MJ. Experiments to determine mode of spread of influenza . JAMA. 1919;73:311-313.


Somewhere back in 1918, the year of the big flu epidemic that claimed 50 million lives. Rosenau and six colleagues took 100 volunteers, "all of the most susceptible age," none of whom had ever had influenza. That is, "from the most careful histories that we could elicit, they gave no account of a febrile attack of any kind," during the previous year, and thus no evidence they would have had immunity to the 1918 virus.


The purpose of the study was to gain knowledge on how flu spread. The authors selected influenza donors from patients in a "distinct focus or outbreak of influenza, sometimes an epidemic in a school with 100 cases, from which we would select typical cases, in order to prevent mistakes in diagnosis of influenza." Rosenau went on to say,


"A few of the donors were in the first day of the disease. Others were in the second or third day of the disease……."


"Then we proceeded to transfer the virus obtained from cases of the disease; that is, we collected the material and mucous secretions of the mouth and nose and bronchi from cases of the disease and transferred this to our volunteers. We always obtained the material in the following way: The patients with fever, in bed, have a large, shallow, tray like arrangement before him or her, and we washed out one nostril with some sterile salt solution, using perhaps 5 c.c., which is allowed to run into this tray; and that nostril is blown vigorously into the tray. That is repeated with the other nostril. The patient then gargles the solution. Next we obtain some bronchial mucous through coughing, and then we swab the mucous surface of each nares and also the mucous membranes of the throat." Then they mixed all this collected material together and squirted it into the noses of the volunteers.


Remarkably, Rosenau reported that,

"None of them took sick in any way."

Frustrated with lack of disease transmission, they continued his experiments on 10 additional subjects.


"The volunteer was led up to the bedside of the patient; he was introduced. He sat down alongside the bed of the patients. They shook hands, and by instructions, he got as close as he conveniently could, and they talked for several minutes. At the end of five minutes, the patient breathed out as hard as he could, while the volunteer, muzzle to muzzle, received this expired breath, and at the same time was breathing in as the patient breathed out. This they repeated five times, and they did it fairly faithfully in almost all instances. After they had done this five times, the patient coughed directly into the face of the volunteer, face to face, five different times. I may say that the volunteers were perfectly splendid about carrying out the technic of these experiments. They did it with a high idealism. They were inspired with the thought that they might help others. They went through the program in a splendid spirit. After our volunteer had had this sort of contact with the patients, talking and chatting and shaking hands with him for five minutes, and receiving his breath five times, and then his cough directly in his face, he moved to the next patient whom we had selected, and repeated this, and so on, until this volunteer had had that sort of contact with ten different cases of influenza, in different stages of the disease, mostly fresh cases, none of them more than three days old. We will remember that each one of the ten volunteers had that sort of intimate contact with each one of the ten different influenza patients. They were watched carefully for seven days - and none of them took sick in any way."

Rosenau concluded, "We entered the outbreak with a notion that we knew the cause of the disease, and were quite sure we knew how it was transmitted from person-to-person. Perhaps, if we have learned anything, it is that we are not quite sure what we know about the disease."


So much for our worrying about where we cough and sneeze. Perhaps those results were just a fluke, though in all the intervening years, no published papers demonstrate experimentally how influenza spreads. Obviously, most people in both the medical field and the lay public as well, assume that influenza is spread in aerosolized droplets when people cough and sneeze, or through oral and nasal secretions spread to the hands and then objects, but this is acknowledged to still be just theory.

( Emerg Infect Dis. 2006 Nov;12(11):1657-62) [i]


[OK, one reference, I confess that I am addicted to PubMed, and despite the Good Dr. Johnson's proclamation otherwise, naturopathic doctors do rely on modern science to inform our practices]


A theory which is still controversial: “ Despite many years of study, from the plains of Salisbury , to the hills of Virginia , to the collegiate environment of Madison , WI , the precise routes rhinovirus takes to inflict the misery of the common cold on a susceptible population remain controversial. ” (Pediatr Infect Dis J. 2000 Oct;19(10 Suppl):S97-102) [ii]


[OK, two references…. I promise to wean myself out of the National Library of Medicine. Otherwise, according to the Colorado Medical Society, I will be a disgrace to my profession, a naturopath paying attention to science!)


How can we better explain this fertile field idea? Instead of thinking that you get sick when you bump into a particular germ in sufficient quantities, think that germs are ubiquitous and you get sick when you can no longer resist their constant attempts to dominate your biology. Successful resistance to disease depends on many factors. Dr. Cannell is of course obsessed about vitamin D, and would probably put vitamin D deficiency as the number one reason that people succumb to the flu. Certainly, other nutrient deficiencies weaken immune defense. Inadequate levels of vitamin C, A, zinc, selenium are just a few, which according to my new policy I will not substantiate with footnotes. Stress and its resultant effects on immune function provide another argument for varying resistance to infection. Not getting enough sleep and mounting sleep debt also provide an explanation. So too are toxin overload and the hindrance of normal immune function.


Perhaps another way to think of this is that your immune system wages a constant struggle within in your body against viruses, only this usually goes unnoticed until a large and distinct immune response is needed to gain the upper hand. When your nose starts to run, a fever spikes, and you feel under the weather and feel sick, these are symptoms of your immune system making a bigger effort to fight infection. Such a reaction is needed, when the body failed to stop an infection early on with more subtle immune “diplomacy.”


With all long lasting debates, there is usually some element of truth on both sides of the argument. It appears to be human nature to want to win arguments rather than to accept and appreciate another's point of view in addition to one's own. For the time being, at least this winter, I for one am going to take my vitamins, especially vitamin D, and get all the sleep I can. Even if it is only an unproven theory, I am still going to wash my hands between patients and hold my breath and duck when people cough in my direction. Maybe the answer is that it takes both; maybe people only get sick when enough germs land on a fertile enough field.


[i] Emerg Infect Dis. 2006 Nov;12(11):1657-62.

Review of aerosol transmission of influenza A virus.

Tellier R.

Division of Microbiology, Hospital for Sick Children, Toronto , Ontario , Canada

In theory, influenza viruses can be transmitted through aerosols, large droplets, or direct contact with secretions (or fomites). These 3 modes are not mutually exclusive. Published findings that support the occurrence of aerosol transmission were reviewed to assess the importance of this mode of transmission. Published evidence indicates that aerosol transmission of influenza can be an important mode of transmission, which has obvious implications for pandemic influenza planning and in particular for recommendations about the use of N95 respirators as part of personal protective equipment.

PMID: 17283614 [PubMed - in process]


[ii] Pediatr Infect Dis J. 2000 Oct;19(10 Suppl):S97-102.

Transmission of viral respiratory infections in the home.Goldmann DA.

Department of Medicine Children's Hospital, Boston , MA 02115 , USA .


Respiratory viruses in the home exploit multiple modes of transmission. RSV is transmitted primarily by contact with ill children and contaminated objects in the environment. Influenza appears to be spread mainly by airborne droplet nuclei. Despite many years of study, from the plains of Salisbury , to the hills of Virginia , to the collegiate environment of Madison , WI , the precise routes rhinovirus takes to inflict the misery of the common cold on a susceptible population remain controversial.


PMID: 11052396 [PubMed - indexed for MEDLINE]