Infectious disease expert John M. Leedom, professor emeritus of the Department of Medicine at the Keck School of Medicine of USC, died unexpectedly of a heart attack on June 27 while visiting Australia. He was 74.

Leedom served for more than 40 years at the LAC+USC Medical Center, fighting to check the spread of antibiotic-resistant bacteria and later devoting much of his efforts to battle the spread of the human immunodeficiency virus (HIV).

During his tenure, he published more than 100 research papers on infectious diseases – including meningitis, polio and AIDS – and trained thousands of young physicians.

Allen Mathies, dean emeritus of the Keck School and a fellow infectious disease expert who worked with Leedom for many years, called his colleague “a remarkably compassionate physician who was also a strong teacher” whose high expectations of students pushed them to excel.

A native of Peoria, Ill., Leedom graduated from the University of Illinois in 1955 and also received his medical degree from the institution in 1958. Following his internship in Washington D.C., and his residency in Illinois, Leedom joined the Keck School of Medicine as an assistant professor in 1962.

Leedom became associate professor of medicine in 1968 and professor of medicine in 1976, a position he held until retiring in 2002.

In addition, he served as attending physician for medicine and communicable diseases at the LAC+USC Medical Center from 1965 to 2002 and as chief of the division of infectious diseases at the medical center from 1975 to 2002.

In that capacity, he witnessed the start of the AIDS epidemic in the early 1980s and strove to treat those infected and block its spread as the first director of the Multidisciplinary AIDS Clinic and the AIDS Service in 1985.

Under his direction through 2002, the AIDS Service tested many of the drugs which have helped to make HIV a survivable infection.

Fred Sattler, chief of infectious diseases at the Keck School, succeeded Leedom as chief and also as principal investigator of the large AIDS Clinical Trial Group grant at USC that Leedom established.

Sattler, who first met Leedom in 1986, said, “I was immediately impressed by his compassion and dedication to providing the highest quality care for all patients, but especially those who were underserved or who had been abandoned for care by others, in particular, those afflicted by AIDS, when the virus had not even been discovered.”

Sattler said his colleague and mentor worked tirelessly with administrators, colleagues and members of the community to establish the Rand Schrader HIV Clinic, “a true national university-based flagship and AIDS ward at LAC+USC Medical Center.”

He described Leedom as “the consummate physician whose knowledge and wisdom in solving infectious diseases problems seemed unequaled. Students, residents, fellows and faculty colleagues came to his office daily and would ask (advice on) challenging cases, as they knew he would be able to help them solve the diagnosis or treatment of these most difficult cases that had evaded their skills.”

Sattler added, “For me, John’s greatest quality was his unparalleled ethical standards and desire to always do the right thing, a characteristic that he instilled in hundreds, if not, thousands of trainees.”

Leedom, who lived in Monterey Park, is survived by his wife, Anita, son John and daughter-in-law Megan, daughter Liane, granddaughters Lauren and Heather and grandsons Ari and Benjamin.

Donations may be made to the John M. Leedom, M.D. Memorial Fund online at http://uscsom.convio.net/JohnLeedom or via mail at Keck School of Medicine of USC, c/o: David Eshaghpour, 1975 Zonal Avenue, Suite 300, Los Angeles, CA 90033-9026.

A memorial service will be held July 16 at the Harlyne J. Norris Cancer Research Tower’s Aresty Conference Center at 3 p.m.

The family has created a Web site in his memory at http://tinyurl.com/6mz7nm