In addition to ongoing joint surveillance activities, researchers should collaborate in applied public health studies. For example, physician and veterinarian teams could conduct serosurveys of humans who live and work near high-risk animal populations to assess their risk of acquiring zoonoses. Long-term surveillance studies could be conducted on humans who are exposed to deer and elk, which are at risk of acquiring chronic wasting disease in disease-endemic regions of Colorado, Wyoming, and Nebraska (23). Surveillance studies on the role of vaccinat- ed and unvaccinated horses in the amplification of WNV to humans would help improve our understanding of the epidemiology of virus activity (24). Comparative Medicine Research Collaborations The need for physicians and veterinarians to work together to control zoonoses extends beyond the individual and population health settings and should include collabo- rations in comparative medicine research. Comparative medicine is the study of the anatomic, physiologic, and pathophysiologic processes across species, including humans. Considerable attention is paid to infectious dis- eases, specifically the study of host-agent interactions. As an academic discipline, comparative medicine is not new; the first chair in it was established in 1862 in France (25). The field has an illustrious history. In 1893, Theobald Smith, a physician, and F.L. Kilbourne, a veterinarian, published a paper establishing that an infectious agent, Babesia bigemina, the cause of cattle fever, was transmit- ted by an arthropod vector (25). Their seminal work helped set the stage for Walter Reed’s discovery of yellow fever transmission (25). Another physician-veterinarian team, Drs. Rolf Zinkernagel and Peter C. Doherty, won the 1996 Nobel Prize in physiology or medicine for their discovery of how the immune system distinguishes normal cells from virus-infected cells (26). Zoonoses, Links between Human and Veterinary Medicine These 2 examples illustrate that medicine and veteri- nary medicine are complementary; they are synergistic in generating new scientific insights across species. In essence, the 2 disciplines epitomize the philosophy of comparative medicine. And yet, as societies’ needs grow to have scientists work together to understand and control emerging zoonoses, evidence suggests that the next gener- ation of medical and veterinary medical scientists are not collaborating with each other. Biomedical and comparative medicine research is losing its appeal as a career among physicians and veterinarians. On the physician side, the decline in physician-scien- tists is evidenced by several trends. First, from 1970 to 1997, the number of physician-scientists obtaining National Institutes of Health (NIH) support has been essentially flat and shrinking in proportion to doctoral recipients who seek and obtain funding (27). Second, from 1994 to 1997, the number of first-time physician-scientists seeking NIH funds dropped by 31%, and the percentage of medical school graduates interested in research careers fell from 14% in 1989 to 10% in 1996 (27). Medical school faculties now comprise 25% fewer physician-scientists than 20 years ago (28). For veterinarian-scientists, the situation is considered dire. A 2004 National Academy of Sciences (NAS) report found that of American Veterinary Medical Association members, <1% were board certified in laboratory animal medicine and <2% were board certified in pathology (29). In addition, the total number of veterinarians who receive NIH grant funding is small. In 2001, only 4.7% of all NIH grants funded for animal research were awarded to veteri- narian principal investigators (29). Reasons for the lack of interest in research are similar for both medical and veterinary students: an emphasis on clinical care, educational debt, and a lack of mentors and research opportunities (30,31). Medical schools now Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 12, No. 4, April 2006 559