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Generation Next

By Michael Purdy

The tools may change—adding machines give way to high-speed computers, microscopes to mass spectrometry—but at its essence public health remains the story of people. Researchers acquire knowledge and use it to save the lives of other people, across town or around the world. The School’s original visionaries, Welch, Howell, McCollum, and company, made their discoveries and passed insights on to the following generation, and so on.

On the following pages, we bring you six young faculty—public health’s next generation. Among a host of young, promising researchers at the School, they are confronting some of today’s most critical public health issues. They study the air we breathe, the water we drink, the health care we receive, the genes we share, the children we love, and the disease we hope to eradicate.

Kellogg Schwab

An ebullient conversationalist, Kellogg Schwab has a talent for colorful, rapid-fire storytelling. His penchant for sending his conversations off in a dozen different directions is echoed in the many projects under way at his lab, most of which are centered on water.

“Most Americans take it for granted that when they take a drink from the water fountain, they’re probably not going to get sick,” Schwab says. But in regions around the world, this essential resource can be the source of deadly illness.  

Schwab, a second-generation microbiologist, is looking at many different ways to detect and eliminate water-borne pathogens. “The old engineering solutions for water purity have worked well for 150 years, but Kellogg is leading the way to new paradigms based in molecular biology,” says John Groopman, PhD, chair of Environmental Health Sciences.

One pathogen under study in Schwab’s lab, the Norwalk virus, made headlines last year for causing outbreaks aboard cruise ships, and has closed down hospitals in England. Just a single viral particle can make people ill. Schwab has been working to adapt mass spectrometry, a technique normally used for trace analysis of chemical elements, to detect the virus in human feces and environmental samples. This should give clinicians and epidemiologists a quicker and more precise method for diagnosing the virus, an essential step for treating it and controlling its spread.

Perhaps just as important to Schwab are his lab’s efforts to develop techniques for cleaning water that are affordable enough for less developed nations. He’s currently helping Procter and Gamble test an inexpensive packet that can rapidly sterilize water with a disinfectant and a coagulating material that traps and removes microorganisms as it settles through the water. The water can then be poured through a cloth to remove the coagulant.

Says Schwab, “We’re all in this boat together.”

Dani Fallin

A quiet but potent revolution has recently swept through efforts to link genes to diseases, and Dani Fallin finds herself in the enviable position of specializing in the new analytic technique responsible for the revolution.

Traditional genetic analysis looks for single points of change in genes associated with disease, but haplotype analysis, one of Fallin’s specialties, compares several points within sections of genes known as haplotypes, which are inherited unaltered from one parent.

“Haplotype analysis gives us a much richer representation of that whole stream of genetic information that’s going down through families,” Fallin explains. “It’s much more information to deal with, but it’s a better way to look for the variations linked to disease.”

Says Jonathan Samet, chair of Epidemiology: “Studies based on haplotype analysis are proving powerful in finding genes associated with disease. This concept has become quite popular, as evidenced by the recent Haplotype Mapping Project initiated by the National Human Genome Research Institute.”

Fallin’s research includes efforts to develop new techniques for both haplotype analysis and genetic epidemiology studies, an approach that broadens the focus of genetic disease studies beyond family groups and into larger, unrelated populations. Switching to a broader, nonfamily-based focus, Fallin explains, lets researchers take advantage of larger pools of genetic data already available from various sources. A cost is paid in terms of loss of the guidance normally provided by family inheritance patterns, but Fallin and others are developing ways to cope with this loss. 

This fall Fallin is embarking on a major new applied study that examines the genetic components of Alzheimer’s disease in 1,100 African Americans. She and her collaborators will search for genes unique to African Americans that could increase their risk of Alzheimer’s.

Michele Cooley

Looking at violence in urban communities through a child’s eyes may help break the cycle of poverty, crime, and violence that has plagued inner cities for so long, believes Michele Cooley.

Looking at violence in urban communities through a child’s eyes may help break the cycle of poverty, crime, and violence that has plagued inner cities for so long, believes Michele Cooley.

Like adults, kids exposed to death and violence experience considerable anxiety and stress—emotions that they often keep bottled up, she says. The result: an impaired ability to concentrate in school that can put them far behind in their studies and at greater risk of entering the culture of drugs and crime. “A lot of times children don’t want to add to the distress of their already burdened parents, so they try to handle it themselves, but they’re ill-equipped—they’re children!” she says.

To help locate the kids most at risk, Cooley developed a school-based screening tool. The Children’s Report of Exposure to Violence assesses a child’s exposure to violence in the media, violence that they have directly witnessed, and incidents when they have been victims. Cooley works with children ages 8 to 12 identified through the survey, helping them develop effective coping strategies.

“Children are being exposed to violence at a phase in their development where it may very well be having stronger and longer effects, “ William Eaton, PhD, acting chair of Mental Health, points out. “Michele is doing yeoman’s work, both in her development of tools to identify these children and in her work with the children it identifies.”

Among other topics, Cooley has studied how inner-city culture affects reactions toward and tolerance of violence. And she recently began a major effort to adapt for the inner-city environment an Australian program proven to help kids cope with anxiety. 

“We try to make a difference,” says Cooley, “because even a small difference is better than none at all.”

Kevin Frick

Kevin Frick specializes in looking at the economic costs and benefits of both medical treatments and public health policy: Is acupuncture, for instance, a cost- effective way to treat knee pain? Do programs that screen for visual impairment in nursing home patients pay off?

“When you discuss preventive services in the American political scene, the question always is, how cost-effective are they?” says Donald Steinwachs, PhD, chair of Health Policy and Management. “The kinds of information that Kevin is developing are really crucial as a result.”

Says Frick, “There’s an art and a science in bringing this all together. You have to make sure the science is good, but you also want to think about what policymakers will look for.” In his study of nursing home patients, for instance, which he conducted in collaboration with researchers at the Wilmer Eye Institute, he wanted to determine whether regular screening for eye problems (and follow-up treatment) could significantly improve residents’ lives. So far, the study’s results suggest low costs and major benefits.

“You have to think about how to measure the effectiveness,” Frick explains.  “One way might be, ‘Does it make patients easier to manage or medicate?’ Another measure would be to look at how the program affects their mobility and level of socialization.”

In this era of health care rationing, Frick’s expertise is in high demand.  He notes, though, that he doesn’t ever want his analyses to become the sole basis for decisions.

“Just because something looks highly cost-effective doesn’t mean it’s going to pass other tests of equity or fairness and other social-justice issues across sub-populations,” Frick says.

David Sullivan 

Every year, nearly half a billion people are infected with malaria, and every 30 seconds this ancient parasite kills a child.

David Sullivan hopes to discover the secret of malaria’s weak spot: hemozoin, an iron-containing crystal inside the parasite. Scientists know that two types of widely used drugs—quinolines and the artemisinins—interact with hemozoin to kill the parasite. Better understanding those interactions, Sullivan believes, could be key to developing new and more effective malaria-fighting drugs.

“David brings a unique combination of infectious diseases clinician and molecular parasitologist to the area of malaria research,” says Diane Griffin, MD, PhD, chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology. “His work on the role of metal metabolism in the malaria parasite will inform drug design as well as our understanding of basic biological processes in this important human pathogen.”

For his part, Sullivan says the biggest motivator of his research efforts is making discoveries that can help patients.

With colleagues at the School, its Malaria Research Institute, and Hopkins’ Applied Physics Laboratory (APL), he helped develop a mass-spectrometry-based technique for detecting the malaria parasite that is more sensitive and can deliver results much more quickly than traditional tests. This system received the 2002 Invention of the Year Award from APL (page 8). 

And with researchers in the School of Medicine’s Pharmacology Department, Sullivan is putting together a library of FDA-approved drugs and screening for their ability to inhibit the malaria parasite. “If someone finds a drug that targets an important enzyme in the [malaria] parasite, the drug still has to go through all the research and development, which costs hundreds of millions of dollars,” Sullivan explains. Deploying an existing drug against malaria, he says, would eliminate the need for a slew of expensive studies, saving both time and money.

Francesca Dominici     

Francesca Dominici is a numerical detective. By collecting and integrating disparate bits of data, she identifies key statistical patterns that reveal clues about health. Dominici is an expert at bringing together varied data (airborne particulate levels and hospitalization rates, for example) into a single analysis. She also compensates for differences in the ways data are gathered and for incomplete data.

She is putting her statistical prowess to the test now with a major new five-year project led by Jonathan Samet, MD, chair of Epidemiology. The project analyzes two years of Medicare patient care data, air pollution records, smoking surveys, weather data, and census data, integrating billions of pieces of information in the process. Dominici, who is in charge of the statistical assembly and analysis of the data, must develop newmethods to bring it all together.

“The novel statistical models Francesca develops will allow us to address critical public health questions about air pollution,” explains Scott Zeger, PhD, chair of Biostatistics. “These will include: Does air pollution, at the levels in cities in the developed world, cause heart disease, stroke, and death? What are the health costs associated with elevated air pollution? And who is susceptible—only the most frail?”

Dominici was a prominent contributor to the recently completed National Morbidity, Mortality, and Air Pollution Study (NMMAPS), a major multi-year project on which she collaborated with Zeger, Samet, and others. NMMAPS found strong links between air pollution and mortality. The study made headlines around the world and led Dominici to testify before a committee of the Environmental Protection Agency. 

The biostatistician says she was happy to rise to the challenge of public speaking and debate. “I want to push statistical results into the policy arena to have an impact and make change.”