In the 19th Century, Koch put forward what are now known as Koch's Postulates and they are the conditions that must be fulfilled in order to identify an organism as thecausative agent of a disease. These conditions are as follows;
1. The specific organism should be shown to be present in all cases of animals suffering from a specific disease but shold not be found in healthy animals.
2. The specific microorganism should be isolated from the diseased animal and grown in pure culture on artificial laboratory media.
3. This freshly isolated microorganism, when inoculated into a healthy laboratory animal, should cause the same disease seen in the original animal.
4. The microorganism should be reisolated in pure culture from the experimental infection.
I've found a few sites on the internet which deal with HIV and Koch's Postulates and one of the better ones can be found at
The page you’re looking for isn’t available | NIH: National Institute of Allergy and Infectious Diseases
Personally, I'm of the opinion that the link between HIV infection and AIDS is so strong that it's wishful thinking causing some to doubt it.
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