Dr. R. Bradley Sack, a professor at the Johns Hopkins University's Bloomberg School of Public Health who was an internationally known expert in the field of diarrheal diseases, including cholera, died April 24 at his Lutherville home of complications from an aneurysm.
He was 81.
"Brad was one of the unsung heroes of public health," Dr. David Peters, chairman of the department of international health at the Bloomberg School, wrote in a statement. "He was at the forefront of understanding, treating and preventing enteric infectious diseases, making a major impact from his research in India, Bangladesh, Peru and White Mountain Apache Indian Reserve in Arizona."
"He was a careful and creative clinician scientist, renowned for his compassion and his dedication to mentoring students and faculty," according to the statement. "He will be sorely missed."
"I first interacted with Brad when I was in the department of medicine and he was running" the Inernational Travel Medicine Service at Hopkins, Dr. Michael J. Klag, an expert on the epidemiology of major chronic diseases and dean of the Bloomberg School, wrote in a statement to colleagues.
"I was immediately impressed with how committed and passionate he was to the work and to delivering quality care," Dr. Klag said. "As everyone has said, he was humble and kind — as well as smart."
The son of the Rev. Noble Sack, a pastor and seminary professor in the Evangelical United Brethren Church, and Wilma Hyink Sack, a teacher, Richard Bradley Sack was born in Le Sueur, Minn., and was raised in Iowa and Illinois, where he graduated from high school in Peotone, Ill.
Dr. Sack, who never used his first name, graduated summa cum laude from Lewis and Clark College in Portland, Ore., in 1956 and earned his medical degree in 1960 from the University of Oregon.
He completed a residency in internal medicine at the University of Washington in Seattle, and a fellowship in infectious diseases at what is now the Johns Hopkins Bloomberg School of Public Health, and received a doctorate, also from Johns Hopkins.
Dr. Sack was working as an orderly at Good Samaritan Hospital in Portland, Ore., when he met and fell in love with the former Josephine "Jo" Nystom, a student nurse. They married in 1955.
"Only time I ever outranked him," Mrs. Sack said with a laugh.
"Brad decided that he wanted to be a doctor from the time he was a young boy," said a brother, Dr. David A. Sack of Fallston, who, like his brother with whom he worked at Hopkins, is an epidemiologist.
Two other brothers, William Sack and Robert Sack, are also doctors.
"I think we all went into medicine for altruistic reasons," Dr. David A. Sack said.
"It's easier for the brothers to reflect on the roots of their humanitarian service. It was engrained by the father ... and their mother," according to a 2015 profile in a Johns Hopkins Public Health publication.
"Of their father's sense of service, Brad said, 'It was very much in his bones. He was a giver. By what he did and said, he would give himself to students or the congregation, always conscious of relating to people.'"
Dr. Sack's interest in infectious diseases began early in his career when he studied in Guatemala as a medical student under a scholarship.
He joined the Hopkins medical faculty in 1962, where the focus of his medical research was infectious diarrheal diseases, including cholera.
Dr. Sack lived abroad for eight years with his family in India, Peru and Bangladesh to conduct his research, and the results of his work significantly reduced childhood deaths throughout the world, colleagues said.
In the 1960s, he worked with Drs. Charles Carpenter and Nathaniel Pierce in Calcutta, where he developed and refined a treatment for cholera that employed the use of intravenous solutions.
This research also led to the discovery and refinement of oral rehydration solution, a cholera treatment adopted by the World Health Organization that has been credited with saving the lives of more than 50 million children over the last 50 years.
Dr. Sack was an advocate of the use of a salty, starchy chicken-and-rice soup for those suffering from cholera or diarrhea who needed to be rehydrated.
"It's so simple," he told The Baltimore Sun in 1987.
Also while in Calcutta, Dr. Sack and his colleagues discovered in 1968 a bacterium that is known as enterotoxigenic E coli, a pathogen that was a major cause of severe diarrhea in residents of poor countries as well as travelers.
"This was a pivotal discovery," his brother said.
In the late 1970s, the antibiotic doxycycline was found to be effective against the disease, better known as "traveler's diarrhea" or "Montezuma's revenge."
Dr. Sack told The Sun in 1978 that Americans have a "50 percent to 60 percent change of getting the disease if they go to countries where it is prevalent.
"This is the first drug that has really been shown to be highly effective against the disease," he said.
In 1986, his work helped lead to creation of the International Travel Service at Hopkins Hospital. The three threats to Americans who travel abroad, Dr. Sack told The Sun in a 1985 interview, are diarrhea, malaria and hepatitis.
He said the best way to avoid diarrhea, which strikes at least half of all travelers, is to avoid fresh vegetables or fruits that cannot be peeled or cooked. "Also pass up the inviting eclairs in the airport," he advised.
"I worked with Brad at Hopkins, and we did much of the same work. As a fellow, I worked in his laboratory. He was eight years older and my mentor," Dr. David A. Sack said. "He was very methodical, easygoing and led by example."
In addition to his work at Hopkins, Dr. Sack established National Institutes of Health-funded research centers in Lima, Peru, and at the White Mountain Apache Reservation in Whiteriver, Ariz. He helped create the Johns Hopkins Center for American Indian Health.
From 1991 to 1994, he and his wife lived in Bangladesh, where they worked at the International Center for Diarrhea Research, where he was associate director.
He also was a consultant to the World Health Organization and advised governments and health programs in Indonesia, Thailand, Bangladesh, India, Turkey, North Yemen, Nigeria, Brazil, China, Togo, and Trinidad.
Dr. Sack also co-edited two books and wrote or co-wrote more than 350 peer-reviewed publications.
He had only recently retired.
He was an active member of Maryland Presbyterian Church and the Child Health Foundation, which works to help communities solve problems in low-income areas.
Dr. Sack, who played the double bass, directed choirs in Calcutta and Bangladesh. He also enjoyed photography.
It was Dr. Sack's wish that there be no funeral, and his only request was that his church choir perform "Be Thou My Vision," which it did this past Sunday.
In addition to his wife and brother, he is survived by three sons, Daniel Sack of Cockeysville, Jonathan Sack of Timonium and James Sack of Three Rivers, Calif.; a daughter, Collette Kokinos of Timonium; two other brothers, Dr. William Sack and Dr. Robert Sack, both of Portland, Ore.; a sister, Kathy Steinmentz of Portland; and six grandchildren.
NOTE: An earlier version of this article misstated Dr. Sack's role in creation of Hopkins' Center for American Indian Health, and also erred in stating Dr. Klag's relationship with the Bloomberg School - he is the current dean. They have been corrected here. The Sun regrets the errors.