University of California Seal

Hans Riemman


Hans P. Riemann

Professor Emeritus of Food Safety and Epidemiology

UC Davis

1920 – 2007


Hans Riemann passed away on March 6, 2007, just days before his 87th birthday, in the home of his oldest daughter in Hoersholm, Denmark. He leaves behind two daughters, four grandchildren, and one great grandchild, all living in Denmark. A Professor Emeritus of the Department of Population Health and Reproduction of the UC Davis School of Veterinary Medicine, Hans was recognized throughout the world as a pioneering leader in teaching, research and service in the fields of microbiology, food safety, and veterinary epidemiology.


The youngest of six children, Hans was born in 1920 on a 65-acre farm with cows, pigs, chickens, and horses just outside Ejstrup, a small town in the southern part of Jutland, Denmark. Following graduation from high school, he was accepted into the Royal Veterinary and Agricultural University in Copenhagen, Denmark, (the school his brother attended) and graduated with a DVM degree in 1943, during the German occupation of Denmark in World War II.


Hans entered food animal practice in 1943, during a difficult time because of the war. They had no medicines and finally, because of no gasoline, he made calls on horseback. He left practice, married Yrsa Thorgils in 1944, and served as a Public Health Officer for the City of Copenhagen, Denmark until 1945. For the next decade (1945–54), he served as section head of the Food Preservation Institute, Technical University of Denmark and microbiologist in the Technical Laboratory of the Ministry of Fisheries; it was during this period that Hans’ and Yrsa’s two daughters were born. It was also here that he initiated a prolific and steady stream of over 200 publications and seven books spanning a period of 60 years (1948–2007). From 1954 to 1959, he served as Chief Veterinarian and Microbiologist of the Danish Meat Research Institute, and in 1959 he was invited to join the Department of Food Science, University of Illinois, Urbana, Illinois, as a research associate in microbiology. Hans and his family spent a year and a half in Illinois, where he conducted research on germination of bacterial spores, and subsequently returned to Denmark, where he served as Director of Research of the Danish Meat Research Institute from 1960–64. His research in Illinois served as the basis of his PhD degree in microbiology, received from the University of Copenhagen, Denmark in 1963. Hans and Yrsa were divorced the same year.


Hans became acquainted with Professor Emil Mrak, Chancellor of UC Davis, and Professor George Stewart, Department of Food Science and Technology, UC Davis; in 1963 received a letter from Chancellor Mrak inviting him to the UC Davis campus. Hans arrived on the campus in 1964, with joint appointments in the Department of Public Health, School of Veterinary Medicine, and the Department of Food Science and Technology, College of Agriculture. In 1966, he became a full-time member of the new Department of Epidemiology and Preventive Medicine (EPM) in the veterinary school, at the time it was the first department of veterinary epidemiology in the world. He became a full professor in 1970 and served as Chair of the department from 1977 to 1988. Hans retired in 1990 at age 70, the mandatory retirement age at that time. He was an exceptionally effective administrator and very successful in generating research funds throughout his career. Hans maintained an active research and publication program until his death.


His teaching, research, publications, and presentations at scientific meetings and academic institutions around the world, as well as, consultations to governments, academia, and industry in Denmark, Norway, Sweden, Brazil, Mexico, and Japan, encompassed the areas of microbiology, food safety, foodborne diseases, food processing, epidemiology, livestock health, and disease control and eradication. He fostered and participated in academic programs in Brazil, providing food safety instruction for students from Latin American countries, was instrumental in the establishment of veterinary epidemiology in Denmark, and providing veterinary epidemiology instruction for students from Nordic countries.


He initiated the first course on the UC Davis campus dedicated to foodborne diseases (EPM 150, Food-Borne Infections and Intoxications). To meet the needs of the course, he assembled and edited an appropriate book, Food-Borne Infections and Intoxications (Academic Press, 1969), which he considered his signature publication. It is now in its 3rd edition (Foodborne Infections and Intoxications, Academic Press/Elsevier, 2006) co-edited by Professor Dean Cliver, and had become the definitive textbook on the subject. He and Dean Cliver also co-edited Foodborne Diseases, 2nd edition (Academic Press, 2002).


Hans enthusiastically embraced the opportunities for veterinary medicine provided by the creation of the new EPM department. In essence, he broadened his career focus and became one of the few progenitors of the emerging discipline of veterinary epidemiology in the 20th century. It would be hard to identify any veterinary epidemiologist today who has not been touched by his work or his teaching, directly or through his many disciples. He helped to found the pioneering Master of Preventive Veterinary Medicine (MPVM) degree program at UC Davis, the second of two professional degrees (DVM and MPVM) given by the School of Veterinary Medicine and the only such program of its kind in the world at the time. With Professor Calvin Schwabe, he was instrumental in founding the UC Davis Graduate Group in Epidemiology. Together with colleagues Calvin Schwabe and Charles Franti, Hans co-wrote Epidemiology in Veterinary Practice, the first textbook ever published in veterinary epidemiology (Lea & Frebiger, 1977). His students include hundreds of graduates from the MPVM program, numerous Ph.D. and M.S. students, as well as post doctorates and visiting professors, many of whom occupy positions of teaching, research, and leadership in universities and public agencies throughout the world. He was a brilliant man, and no matter what the teaching assignment was, within a short period of time he was ready to teach highly diversified subjects.


Hans received many honors during his lifetime, including serving as the founding editor of Preventive Veterinary Medicine, the standard-bearer among journals for manuscripts in veterinary epidemiology through today; election to membership in the Danish Academy of Technical Sciences in 1962; an honorary Dr. Medicineae Veterinariae degree at the Royal Veterinary and Agricultural University in Copenhagen, Denmark in 1990; and election to the Norwegian Academy of Science and Letters in 1991.


Finally, Hans was chosen by Queen Margrethe II of Denmark to be the recipient of the Order of the Knight of Dannebrog in 1999 for his great influence in preventive medicine, exchange of students and researchers between Davis and Denmark, and the establishment of an international research environment in Denmark. The knighthood, seldom given to people who work outside the Kingdom of Denmark, was presented to Hans by the Danish Consul General on behalf of the Queen at a ceremony held at the UC Davis University Club.


Following the death of his second wife, Wilhelmina, in 2005, Hans returned to Denmark in 2006 to be with his family. Shortly before he left, colleagues and friends gathered for a farewell dinner and conveyed to him a framed State of California Legislature Assembly Resolution that thanked him for his dedicated and exemplary service to the people of California and beyond.


His daughter Nana wrote, “If I should characterize him shortly, I would say he was rather quiet, reserved, modest, and thoughtful (as professors are!), but very hard working, helpful, willing to listen to others, and with his own sense of quiet humor.” Friends, colleagues, and admirers throughout the world will nod in agreement when reading this beautifully crafted remembrance of a very special person, Sir Hans Riemann.


Dean O. Cliver

Constantin Genigeorgis

Richard H. McCapes, Chair