Superbugs. Bird flu. Whooping cough. West Nile virus. Every day, it seems headlines and news broadcasts sound the alarm about the disease du jour. New, antibiotic-resistant species of bacteria, weakening immunity from vaccines, aggressive viruses, and even the ability of some pathogens to “jump” from animals to humans make today’s world a frightening one. It’s enough to make you want to put on a sterile suit and not set foot outside the house.

Biomedical researchers within the college and across the university, recognizing the critical need to address the problem of continually evolving infectious diseases, are studying the nature of disease from all perspectives—from the molecular level all the way up to how pathogens transmit within populations and across the globe. What they are learning will ultimately lead to advances in preventing the spread of disease.

Microbiologist Eric Harvill is working with two closely related bacteria, Bordetella pertussis and Bordetella parapertussis, which cause whooping cough. Using genetic-modification techniques, he is learning how these bacteria interact with their host and how they spread from host to host. B. pertussis and B. parapertussis are endemic in human populations; they are always around. And while the pertussis vaccine does a fairly good job of preventing the most severe form of whooping cough, it does not prevent transmission. “These bacteria circulate very effectively; they’re among the most infectious agents known,” says Harvill. “So what happens is that people get infected frequently, but they don’t get the full-blown disease. In fact, they may not have any symptoms at all. Virtually every person in any large population will be infected with these bacteria multiple times throughout their lifetime—they just don't get sick because they have immunity through vaccination.”

Before vaccination programs, whooping cough was a childhood disease—not because children were more susceptible, but because the spread of the pathogen was such that nobody made it through childhood without being infected. Because the full-blown disease was evident only the first time a person was infected, whooping cough was observed mainly in children. Now that children are vaccinated at a very young age, the disease is less of a problem in children. Instead, whooping cough is making a comeback in teens, whose vaccine immunity has waned. Because of this trend, a new whooping cough vaccine for adolescents was introduced last summer.