Do you Think Koch's Postulates Need to Be Updated?

Question

Koch's postulates are:

1. The microorganism must be found in abundance in all organisms suffering from the disease, but not in healthy organisms.
2. The microorganism must be isolated from a diseased organism and grown in pure culture.
3. The cultured microorganism should cause disease when introduced into a healthy organism.
4. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

Now this is the Thing, Let's Say a Certain Disease is Cleared By Some Anti-X (e. g. Acyclovir Clearing HSV, a Beta-Lactam [Penicillin or Cephalosporin] and Some Infection). Are Not these Just as Strong a Evidence for the Presence of an microorganism as Koch's Postulates?

Furthermore, Prophylaxis, an Organism Administered Anti-X, Don't Get the Disease (e. g. HIV Post- Exposure Prophylaxis [Perhaps this Will Work In Pre-Exposure too]).

Furthermore Again, the Transmission of a Disease is Greatly Reduced From Infected Organism to Uninfected Organism By Anti-X (e.g. Vertical Transmission of HIV With AZT).

Thanks Prof Kevin, WRT HSV I'm Referring to the Clearance of the Viral Particles not the Provirus. WRT your Other Point, I Would Expect Acyclovir to Clear VZV Viral Particles too.

Thanks Spreed, I don't Think Wikipedia is Always Correct.

Spreed, I Have Been Repeatedly Amonished to Not Say "Possible" in My Assessments as a MSIII, MSIV, Intern, By Other Real Doctors, they Wanted me to Act as if I Were Perfect.

Sorry, Admonished, I Wish Yahoo Would Allow Corrections.

Answer 1

Great question as usual.
I wonder what you think of this clip from Wikipedia ?

"Koch abandoned the second part of the first postulate altogether when he discovered asymptomatic carriers of cholera and, later, typhoid. Asymptomatic carriers are now known to be a common feature of many infectious diseases, especially viruses such as polio, herpes simplex, HIV and hepatitis C. As a specific example, all doctors and virologists agree that polio virus causes paralysis in just a few infected subjects, and the success of the polio vaccine in preventing disease supports the conviction that the polio virus is the causative agent.

The third postulate specifies "should", not "must", because as Koch himself proved in regard to both tuberculosis and cholera, not all organisms exposed to an infectious agent will acquire the infection. This may be due to chance, to acquired immunity, or to genetic immunity. An example of genetic immunity: human immunodeficiency virus (HIV) seems to be normally unable to infect persons who carry the deletion CCR5 Δ32."

It seems by this that Koch was still updating his own 1884 and 1890 postulates in follow-up articles from 1893 [Koch R. (1893) J. Hyg. Inf. 14, 319-333].
I'm sure he would agree that further refining was necessary as more information came in.

So, the answer is YES - - and Koch would help you with the updates if he were still alive. His postulates were still a wonderfully astute advance for scientific medicine in 1884.
Bacteria had been seen under the microscope more than 200 years earlier. What took thinking people SO LONG to figure out the relationship to disease? ? ?

Added Note - The Wikipedia is much maligned in academia - at least in the academic history world of the university where I still take grad courses in history. Yet, some Wiki articles are not bad at all. I think it's a matter of using more than one source. That's what tell my college world history students - though it is just my opinion.

Added note - Of course Wikipedia is not always correct.
I doubt that any of us are always correct - - although we doctors are supposed to be - or face potential law suits.
My comment is simply that some answers in Wiki are
not that bad.

Answer 2

Some good answers....I just have a matter of clarity to add regarding some of your responses:

Circular logic is basically: A is true because B is true and B is true because A is true. IF you were using circular logic and IF you were talking about symptoms (which you did not mention, at all), you'd be saying, according to Prof Kevin that: symptoms (A) were relieved by anti-x (B), anti-x is effective (B) because symptoms were relieved (A).

A key characteristic of circular logic is an assumption of the very proposition to be proved: anti-x is effective. You did not do that. Your conclusion is not identical to the premise. You seem to simply be saying that anti-x clearing the organism is evidence that an organism exists.

Furthermore, saying that your (what has been termed) "circular reasoning" is based on the fact that many different types of organisms cause similar symptoms doesn't address the premises in your inquiry, makes no sense in terms of "circular logic", but doesn't lead to the conclusion, Prof Kevin has made, that if anti-x clears an illness it doesn't tell you what was causing it. I mean, there are only so many organisms say, acyclovir treats, right? So, one can ONLY assume (in the absence of psychosomatic illness) that disease clearance IS attributable to anti-x no matter what the mechanism (<--this from W W D's response).

Answer 3

The equivocal ''healthy'' criterion is a little suspect, e.g. malnutrition could reduce immunity to opportunistic microorganisms and 'seasonal' infections (flu), a condition much like the AIDS example, but opposite in that the malnourished are presenting symptom whereas healthy infectees do not present symptom for infection of same X. The postulates simply need annotation as update.

Answer 4

Not so simple.

First, if the HSV has had an opportunity to go latent (which all Herpesviruses can) than it CANNOT be cleared with any current technology.

Secondly, it looks like you are assuming that clearance of a symptom with a particular anti-X means that a specific microorganism was present to cause the symptom. This "circular logic" might work if only one microbe can cause a particular symptom, but in fact, many different types of organisms can cause similar symptoms. Indeed, many different types of microbes can also be cleared by various "broad spectrum" antibiotics, such as the ones you've mentioned - so if you can remove an illness, that does not necessarily tell you what was causing the illness in the first place.

Sorry.

Answer 5

While I am no microbiologist, from what smattering of cursory glancing into fundamental microbiology textbooks has taught me: asymptomatic carriers do exist for many micro-organisms including bacteria and more for viruses. Now that whole genomes of viruses are being isolated from other animals/plants (I am unable to give you the specific examples......), so Koch's postulates have to be rewritten.
Also the question of viruses and even bacteria lying dormant in many systems to surface decades later.......I wonder whether we are all some huge commensal or something.

Answer 6

It sounds to me as though Koch's postulates ought to be removed. But of course, I have a rather ruthless approach to things that trouble me. Happy hunting.

Answer 7

Close, but no cigar. Anti-X may work through an unknown and unrelated mechanism, so there's still a hole in the concept. It offers some evidence, but not to the degree that you can take it to the bank.

Answer 8

You Go
Man!!!!!!!!!

V=peace

Once you get a conclusion to your analyses.
Bless