Robert Koch Tuberculosis Quotes

Theobald Smith, yet another of those forgotten heroes of medical history. Smith, born in 1859, was the son of German immigrants (the family name was Schmitt) in upstate New York and grew up speaking German, so was able to follow and appreciate the experiments of Robert Koch more quickly than most of his American contemporaries. He taught himself Koch’s methods for culturing bacteria and was thus able to isolate salmonella in 1885, long before any other American could do so. Daniel Salmon was head of the Bureau of Animal Husbandry at the U.S. Department of Agriculture and was primarily an administrator, but the convention of the day was to list the bureau head as lead author on the department’s papers, and that was the name that got attached to the microbe. Smith was also robbed of credit for the discovery of the infectious protozoa Babesia, which is wrongly named for a Romanian bacteriologist, Victor Babeş. In a long and distinguished career, Smith also did important work on yellow fever, diphtheria, African sleeping sickness, and fecal contamination of drinking water, and showed that tuberculosis in humans and in livestock was caused by different microorganisms, proving Koch wrong on two vital points. Koch also believed that TB could not jump from animals to humans, and Smith showed that that was wrong, too. It was thanks to this discovery that pasteurization of milk became a standard practice. Smith was, in short, the most important American bacteriologist during what was the golden age of bacteriology and yet is almost completely forgotten now.

This was one instance in which the medical profession totally rejected something that they were not ready to accept because, in part, there was no framework for understanding the new concept. It was only later, when the causative agents were clearly identified through the work of Robert Koch, Louis Pasteur, and Joseph Lister, that it became accepted that germs cause disease. Koch discovered that a microscopic agent was the cause of tuberculosis and showed this with total certainty, leading to a revolution in medicine. All of a sudden, science and technology seemed to hold tremendous power, once it was understood that so many diseases were caused by infectious agents, and powerful new technologies could be developed to treat them with great specificity. This naturally gave rise to a “find it and fix it” culture. Over the last one hundred years, medical science has given rise to many wonderful things. However, it is now very heavily focused on disease. We spend almost no time on health. We make an assumption that for every disease, there is a defect that we need to find and fix. We don’t deal with people throughout their lives, but only when they’re sick. In the United States, we have become accustomed to assuming that one’s health is managed by one’s doctor, and that individuals have little responsibility or control over their health. Where does this leave us? On the one hand, life expectancy in 1900 was forty years. Today it’s eighty years. We have doubled life expectancy in a hundred years. That’s almost miraculous. On the other hand, in 1900 the most likely cause of death for a young man between the ages of fifteen and twenty-five would have been infection. Today, it’s murder, suicide, drug abuse, or violent accidents. We have made tremendous progress, but some of the consequences of our progress are absolutely terrifying. In addition, we have a tremendous accumulation of chronic diseases, many of which are fostered by people’s own behavior. One of the problems with Western medicine is that it tends to make a reductionist assumption that for every disease, there is a single causative factor that we need to find and fix. We now are learning that there are often multiple factors, rather than a single reductionist cause of disease. People are born with a baseline risk, and then environmental factors impinge on that risk over time. There is a tremendous difference in susceptibility to different diseases, yet we often have a lot of control over environmental factors that contribute to disease progression.

Robert Koch, a pioneering figure of the modern germ theory of disease (Chapter 12). In 1882 he identified Mycobacterium tuberculosis, and he established rigorous proof—in compliance with his own famous postulates—of its causative role in the disease.

Pasteur equally as mischief-makers. As late as 1883, Michel Peter, a Parisian physician held in high esteem by his colleagues, went so far as to denounce Pasteur’s work to his face, at an address at the National Academy of Medicine. “What do I care about your microbes? . . . I have said, and I repeat, that all this research on microbes are not worth the time spent on them or the fuss made about them, and that after all the work nothing would be changed in medicine, there would only be a few extra microbes. Medicine . . . is threatened by the invasion of incompetent, and rash persons given to dreaming.” But as the discoveries mounted, these holdouts were increasingly marginalized.

There are two eras in the modern history of tuberculosis—before and after Robert Koch’s 1882 discovery of Mycobacterium tuberculosis, which successfully established the germ theory of disease and demonstrated that tuberculosis is contagious.

Mycobacterium tuberculosis was discovered by Robert Koch in 1882, and for that reason it is also known as “Koch’s bacillus” or the “tubercle bacillus.

Mycobacterium tuberculosis was discovered by Robert Koch in 1882, and for that reason it is also known as “Koch’s bacillus” or the “tubercle bacillus.” Humans contract it through four disparate and highly unequal modes of transmission. Of these, three are relatively infrequent and have played only an auxiliary role in the modern epidemic: (1) transplacental transmission from mother to fetus, (2) inoculation of bacteria through an abrasion or shared needles, and (3) ingestion of bacilli through infected milk or meat. The fourth mode of transmission stands apart as overwhelmingly important—the inhalation of M. tuberculosis in contaminated airborne droplets expelled by sufferers as they cough, sneeze, or talk.