September 17, Dr. Guy Palmer, Washington State University College of Veterinary Medicine, spoke to a standing-room only audience of veterinary faculty and students about "Emerging Infectious Diseases: Why the Tropics Matter," as the Oscar W. Schalm lecturer for 2007.
Palmer outlined his research on how anaplasma parasites and other pathogens ensure their survival by changing over time, infecting and re-infecting hosts that can transmit disease even when they are not clinically ill.
"Some viruses can mutate a lot, but protozoal bacteria can put a ‘silent’ piece of the genome into a different location" in a process known as gene conversion, said Palmer. This process, which takes place on the surface coat of an organism, enables pathogens to make changes in their genetics without rapid mutation. As long as its host lives, such organisms can avoid being cleared from the immune system, Palmer explained. "The persistent phase provides a long opportunity to transmit, even at lower levels than in an acute illness." The tropics provide ample opportunity for populations to become infected quickly, transmit disease rapidly, and carry more than one infection at a time. Tropical regions also contain a great diversity of species, which provide opportunities for pathogens to jump the species barrier, Palmer said.
Palmer’s research concerns understanding antigenic variation of vector-borne pathogens at the in-host and population levels. His genome sequencing approaches have progressed from completion of individual strains of the rickettsial Anaplasma marginale to examination of large numbers of strains to better understand flow of strains under conditions of high transmission. His research is supported by the NIH, USDA, and the Welcome Trust and has resulted in more than 170 refereed publications.
Other diseases of interest to Palmer, are trypanosomiasis, or sleeping sickness, and HIV, which he called "the greatest disease of our time." He also cited measles, a pathogen that emerged in the wild, was transmitted to cattle as rinderpest, and ultimately jumped into the human species. Palmer said that measles remains "one of the top ten killers of children worldwide."
Palmer earned a BS in Biology (summa cum laude) followed by a DVM from Kansas State University. He completed a residency in comparative pathology in 1983 and is board-certified in anatomic pathology by the American College of Veterinary Pathologists. With support from a NIH Fellowship, he completed a PhD in microbiology in 1984 with a dissertation about research in rickettsial immunity. After an additional post-doctoral fellowship, Palmer joined the faculty in the Departments of Comparative/Experimental Pathology and Infectious Diseases at the University of Florida. Since 1988, with the exception of two years as a Senior Research Fellow in Switzerland and Spain, Palmer has been at Washington State University. He is one of the 19 Regents Professors within the university system. Palmer was elected to membership in the National Academies Institute of Medicine in 2006 and is a member of the Global Health Group within the institute.
The Oscar W. Schalm Lectureship promotes a tradition of scholarship, service and commitment to veterinary medicine and recognizes the lecturer’s distinguished contributions to the profession.
A founding faculty member of the School of Veterinary Medicine, Oscar W. Schalm was an eminent teacher and research scientist. Schalm played a leading role in the school's development, serving as first chair of the department of Clinical Pathology. He also served in the role of assistant and associate deans from 1952 to 1962. Notable accomplishments include development of the California Mastitis Test, a standard test for diagnosis and evaluation of milk quality used throughout the world, and the establishment of veterinary hematology as a distinct discipline of veterinary medicine.
The Schalm Lectureship comprises two talks held each year, one lecture for veterinarians attending the school’s annual continuing education conference and a second presentation for students and faculty members.