Karl Friedrich Meyer

He was one of the most prodigious scientists in many areas of infectious diseases in man and animals, the ecology of pathogens, epidemiology and public health.

The Transvaal Department of Agriculture in the (then) Union of South Africa had just established a large, special Institute devoted to research in public health and farm animal diseases, the latter being important for the economy of the country.

[1] In addition, Meyer had to develop vaccines, one against rabies, another to protect cattle against pleuro-pneumonia, a disease with devastating economic consequences for the farmers.

Shortly after returning to Switzerland, Meyer was offered a position as an assistant professor at the Veterinary School of the University of Pennsylvania in Philadelphia.

Meyer was promoted to professor, and was put in charge of the diagnostic section of the Laboratory and Experimental Farm of the Pennsylvania Livestock Sanitary Board.

[1] Meyer’s personality, his enormous knowledge combined with his energy and extraordinary drive were just what was needed to tackle the many pioneering tasks.

He was a generalist, meaning that he always concurrently concentrated on the interactions and interdependence of the factors involved, as they are: (i) the disease agents (biology, habitat, hosts, transmission to man, infectiousness, etc.

); (ii) disease in man and animals (diagnosis, therapies, pathology, epidemiology); (iii) public health; and (iv) education.

[6] A selection of concise overviews of Meyer’s impacts on the understanding of the diseases he worked on, their diagnoses and treatments, and their prevention are presented below.

He suggested classing the various species of bacteria into one family (genus), formally named Brucella, to honor the discoverer, Sir David Bruce (microbiologist and pathologist; 1855–1931).

Meyer started his work on botulism after 1913, when home canning became popular during the war, and sterilization techniques were not sufficient.

Around 1920, the entire canning industry in California (whose business in canned food then amounted to almost a billion dollars) was in jeopardy because many deaths occurred throughout the country due to lack of proper sterilization in the canneries.

Thus, he deserves the credit for developing safe canning procedures, for realizing effective control over industrial hygiene, and for the prevention of botulism.

In the early 1930s, thousands of horses in California suffered and died from a paralytic disease, later called western equine encephalitis.

– Meyer and his colleagues at the Hooper later demonstrated that mosquitoes pick up the virus from chicken and (migratory) birds and transfer it to man and to horses.

And it turned out that the isolation of the virus by Meyer led to the discovery of similar kinds causing other types of encephalitis in man.

During the years of World War II a vaccine against yellow fever was used in the Armed Forces that produced (unexpectedly) adverse reactions such as jaundice.

It was actually manufactured at the Hooper when the Army needed vaccines to protect the troops in Vietnam (one endemic area where many plague cases were seen among soldiers).

Towards this goal, the Hooper became a center for testing thousands of birds and selecting the ones free of the bacteria, with the result that germs and disease largely disappeared from local commerce.

And the California State Department of Health decided (in 1929) to monitor the mussels closely, and to publicize a ban on harvesting of shellfish, when the annual appearance of the poison is detected.

Meyer worked, in addition to the many fields mentioned, also on the effects of air pollution and lead on farm animals, as well as on typhoid fever (– after a spaghetti casserole served at a church dinner poisoned about 100 people).

He also explored influenza and its epidemiology, looked into malaria, tetanus, viral hepatitis, anthrax, poliomyelitis, dysentery, pseudotuberculosis, common cold, and dental bacteriology.

Meyer’s extraordinary series of publications and papers presented at conferences (including talks on the radio) were important parts in promoting the state of the art.

[5] Friends and colleagues concluded after his death that Meyer had more influence on microbiology and epidemiology than any other scientist of his time: he was driven by a deep-seated concern for the public health He always went beyond research to implement practical measures of preventing and fighting the diseases.

A former student and friend once wrote: "Meyer would have won a Nobel Prize if he hadn't worked on so many areas of discovery that nobody could keep track of all that he was doing".