Three decades ago, it seemed that modern medicine had virtually eliminated many infectious diseases. Armed with antibiotics, vaccines and a sense of victory in the war against microbes, medical schools began to look at the discipline of microbiology in a different light, and in 1972 Yale joined others in disbanding its department.

By the 1980s, however, such deadly microbes as HIV, Ebola, Marburg, and Legionnaires’ disease surfaced to remind physicians that infectious diseases were still alive and represented very real public health threats. Moreover, some of the older pathogens had developed resistance to drugs that had once been effective.

With this in mind, faculty at the School of Medicine began work several years ago to reestablish a formal program in the microbiology of infectious disease. In July, those plans came to fruition with the appointment of Jorge E. Galan, D.V.M., Ph.D., as the first chair of a new Section of Microbial Pathogenesis. Support for the program came from The Esther A. and Joseph Klingenstein Fund Inc. and the Lucille P. Markey Charitable Trust.

“Times change,” Dr. Galan said in an interview. “With the new emerging infections, and with others making a comeback as you would expect in any kind of biological cycle, there is a new interest in infectious disease. I hope that interest is here to stay.”

Microbial Pathogenesis is the fifth autonomous section at the medical school and the first created since 1988, when the Section of Immunobiology was founded. Dr. Galan and his colleagues will focus their research on the interactions that occur between pathogens and their hosts, an increasingly rich and fruitful area of research. The section also will become the academic and administrative home to a four-year-old graduate track in microbiology now administered as part of the Biomedical and Biological Sciences Program. The microbiology track, which has 25 students this year, was created in anticipation of the new section’s founding.

Dr. Galan and his two colleagues in the section, Craig R. Roy, Ph.D., and Norma W. Andrews, Ph.D., will carry out research on bacteria and parasites and teach first- and second-year medical students. In addition, the new chair plans to apply for a training grant to further strengthen the microbiology track. Over the next few years, the section is expected to grow to a total of six faculty members.

Caroline W. Slayman, Ph.D., deputy dean for academic and scientific affairs and chair of the task force that recommended the section, said Dr. Galan was selected as chair because he is one of the world’s leading researchers in the area of bacterial pathogens. “His selection,” she said, “reflects the feeling of the search committee that the real challenge is to work with pathogens and study their interactions with their host cells.”

Keith A. Joiner, M.D., professor of medicine and epidemiology, and a member of the search committee, said Dr. Galan was recruited not only for his work in bacterial pathogenesis, but also for his broad scientific perspective, which will facilitate interactions with colleagues in related fields such as cell biology, immunology, epidemiology, infectious diseases and structural biology.

Dr. Andrews, a faculty member in cell biology for the past four years, is an authority on parasite-host interactions. Dr. Roy worked in the same department as Dr. Galan at the State University of New York at Stony Brook and was recruited to Yale to continue his research on bacterial pathogenesis. Using Legionella pneumophila as a medium, Dr. Roy studies mechanisms by which bacteria subvert the normal functioning of human cells.

Dr. Galan believes the idea that infectious diseases will one day be completely eradicated is mistaken. “We will never, ever be able to conquer infectious diseases,” he said. “We may learn how to deal with a given pathogen but eventually other pathogens will emerge. This is going to be a battle forever, there is no question about it.”