By Fran Simon
They are disease detectives, not content to diagnose each patient and determine the most effective treatment regimen. They sometimes track hundreds of thousands of patients, reviewing hundreds of thousands of numbers, statistics and charts, possibly over decades, to determine the risk factors of disease. Epidemiologists strive to identify the causes of diseases in relation to other diseases, environmental exposures, lifestyle conditions and genetic factors.
Few in the field of public health would disagree. The creation of a strong, independent department of epidemiology has been one of Whelton's highest priorities since coming to Tulane at the beginning of 1997 from his positions as director of the Welch Center for Prevention, Epidemiology and Clinical Research, the Outpatient General Clinical Research Center, and the community- based PRO-Health Research Center at the Johns Hopkins Medical Institutions in Baltimore.
Earlier this year, Roger Sherwin, MD, was named interim chair of a new Department of Epidemiology at Tulane's School of Public Health and Tropical Medicine. Previously, epidemiology was part of a combined Department of Biostatistics and Epidemiology, under the leadership of Larry Webber, PhD, who now chairs a separate Department of Biostatistics.
"Recognizing the central importance of both epidemiology and biostatistics to public health and the growth of our school, we had reached a stage when it was necessary to establish departments for both disciplines," said Whelton.
An expert in preventive cardiology and cardiovascular disease intervention strategies, Sherwin's main research interest is in studying risk factors and lifestyle modification aimed at the prevention of coronary heart disease. Formerly, Sherwin was professor in the Department of Epidemiology and Preventive Medicine at the University of Maryland School of Medicine in Baltimore. From 1972 to 1983, Sherwin was principal investigator of the Baltimore Center of the MRFIT (Multiple Risk Factor Intervention Trial), a landmark study of interventions to prevent cardiovascular disease that was conducted at 22 centers around the United States.
"Roger is one of the leading investigators and educators in the field of cardiovascular epidemiology. I am delighted that he has agreed to help build the Department of Epidemiology at Tulane into one of the pre-eminent epidemiology departments in the world," says Whelton.
Sherwin received his medical degree from Cambridge University, followed by residency training in internal medicine in London, a fellowship at the Johns Hopkins University School of Medicine, and graduate studies in biostatistics at the Johns Hopkins University School of Hygiene and Public Health. He is a member of the American Epidemiological Society and a fellow of the American College of Epidemiology.
Research projects within the department include investigations focused on the epi-demiology and prevention of cardiovascular disease, infectious diseases, cancer and kidney diseases. "We plan to begin by enhancing the greatest strength we have, which is in the area of cardiovascular disease epidemiology," Sherwin says. "I'm in favor of building on strengths, rather than trying to cover the waterfront."
Researchers in cardiovascular disease epidemiology at Tulane include Sherwin; Whelton; Chancellor John C. LaRosa; Gerald Berenson, MD (principal investigator of the world renowned Bogalusa Heart Study, the longest running study of cardiovascular risk factors in children, adolescents and young adults); Sathanur Srinivasan, PhD; Jiang He, MD, PhD (see profile); and Gail Louis, RN.
Whelton, an authority on the epidemiology,
prevention and treatment of cardiovascular and
renal disease, has authored several books and
hundreds of articles on these topics. He has conducted
a series of ground-breaking studies on
hypertension for the National Heart, Lung and
Blood Institute, the National Institute of Diabetes
and Digestive and Kidney Diseases, and
the National Institute on Aging. These have
included leadership of the two largest investigations
designed to study the effects of lifestyle
interventions in the prevention and treatment
of hypertension (TOHP and TONE) and of
the National Heart, Lung and Blood Institute
Working Group, which was charged with the
creation of a national policy for prevention of
hypertension.
Both the TOHP (Trials of Hypertension Prevention) study, which was conducted in two phases in more than 4,000 participants, aged 30-54 years, and the TONE (Trial of Non-pharmacologic Interventions in the Elderly) study, which was conducted in 975 patients, aged 60 to 80 years, demonstrated the value of weight loss and sodium reduction in prevention and treatment of hypertension.
Whelton also led the recruitment drive for the ongoing Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) which, with more than 42,500 participants, is the largest cardiovascular disease clinical trial conducted to date. He and Louis direct one of nine regional coordinating centers for this trial from Tulane.
With a glint in his Irish eyes, Whelton has referred to himself and Jiang He as the "banana kings," of epidemiological research because of their work in potassium consumption and its relationship to hypertension. Whelton was first author of a seminal meta-analysis, published in the Journal of the American Medical Association (May 28, 1997), which concluded that potassium supplementation may play an important role in the prevention and management of high blood pressure. Their work in this area continues with an ongoing trial of potassium and protein supplementation in China.
While pursuing her doctoral degree, Hassig worked at the Louisiana Office of Public Health in the early days of HIV surveillance. Then, she worked for Project SIDA in Zaire for two years, helping to establish a public health school in Zaire and teaching there. Hassig spun off several projects of her own, including studies of the economic impact of HIV on patients, screening for HIV and its impact on perinatal transmission. She also took advantage of a high rate of multiple births in Zaire to study twins, acquisition of HIV and progression of AIDS. She discovered that HIV infection and progression is not parallel, even in identical twins.
Now, Hassig is co-principal investigator of a study funded by the National Institutes of Health to monitor adherence to protease inhibitors among HIV outpatients at Charity Hospital. In addition, she participates in Tulane's subcontract with the University of North Carolina for research support on the USAID-funded HIV Operations Research (HORIZONS) Project, to develop and identify best practices for the prevention of HIV/AIDS and other sexually transmitted diseases.
Adjunct assistant professor Patty Kissinger, RN, (MPH '87, PhD '92) also specializes in epidemiology of HIV/AIDS and other sexually transmitted diseases, as well as women's reproductive health.
Kissinger, who coordinates the HIV/STD track within the Department of Epidemiology, is currently involved in three Centers for Disease Control and Prevention (CDC) funded research studies: a multi-center infertility prevention program focusing on chlamydia; an HIV clinical trial in rural areas of Louisiana (areas surrounding Lafayette, Lake Charles, Alexandria, Monroe and Shreveport); and an HIV partner notification study, to determine the effectiveness of this standard of care in reducing HIV transmission.
Based at the HIV outpatient clinic at Charity Hospital of Louisiana at New Orleans, Kissinger also works extensively with state family planning clinics, Planned Parenthood, city health department clinics and the Tulane-LSU pediatric AIDS program. She is participating in "10 or so" smaller studies of various aspects of the AIDS crisis, including HIV testing patterns and condom behavior.
According to Whelton, the AIDS epidemic provides the most recent example of the need for global public health research and intervention to prevent and control diseases. "Epidemiology is at the heart of public health strategies for disease prevention and health promotion. At its best, it involves being engaged before a crisis, and promoting good health," Whelton says.
Environmental epidemiologist Felicia Rabito (MPH '89, PhD '98) is conducting a randomized intervention study undertaken by the CDC-funded Tulane Prevention Research Center. The project will identify and validate intervention methods for lowering lead levels in inner city New Orleans through environmental and nutritional intervention strategies that involve the community.
Nationally, blood lead levels in children have declined dramatically over the past 15 years but about 8.9 percent of children still have levels that are abnormally high. In New Orleans the situation is much worse. More than one out of every three children (38%) screened during 1993-1995 in New Orleans City Health Department clinics had an elevated blood lead level, according to research conducted by Rabito and LuAnn White, PhD, co-director of the Tulane Prevention Research Center.
The Prevention Research Center will coordinate closely with another major grant to combat childhood lead toxicity. The Louisiana Office of Public Health has received $1.5 million over three years from the CDC to develop a statewide lead toxicity surveillance and prevention program for children. White and Rabito of the SPHTM's Center for Applied Environmental Public Health will manage the program, in close cooperation with the Louisiana Office of Public Health and the City of New Orleans Health Department.
An innovative component of the lead intervention project is Lead Busters, a group of five residents hired from the C.J. Peete public housing development. The Lead Busters are being trained as health workers to implement strategies that were custom-designed to reduce exposure to lead in their own community.
"This is a different approach, because the Lead Busters will be involved in recruiting study participants, implementing the intervention strategies, taking environmental samples and measuring outcomes," Rabito says. "We don't know if this will work, but I'm passionate about what we're doing."
Curiosity. Passion. Prevention. Action. It's these characteristics and more that attract researchers and health care practitioners alike to the field of epidemiology.
Whelton recalls his first day as a student in an epidemiology lecture, as he began his epidemiology training in London with a mid-career award from the Millbank Foundation. "I thought, 'This is exciting! This will allow me to have such an impact - much more than as a clinician.' It was one of those moments - a real turning point - that might happen only once or twice in a career."