Mosquitos, Ticks...and Fish! (cont.)

Fish began his Lyme research while working on another North American mosquito-borne disease, lacrosse encephalitis. "While I was at Fordham, there was some discussion of Lyme disease being tick borne, and discussion of it being a bacteria. I went into my backyard and got a bunch of ticks and found half of them infected. They had identified the disease but weren’t sure where it came from. I discovered a corkscrew-shaped spirochete, pretty distinctive, and I knew it came from ticks." He followed this with a field study and a paper that showed most people get Lyme in their backyards.

Fish’s Lyme research is multifaceted. Using NASA satellite maps, researchers are working to develop methods to determine risk by creating geographical risk maps.

Public health agencies will use the maps to make vaccine recommendations and target funding for high risk areas.

Yale is also developing programs to control ticks, including a five-year project to kill the ticks that reproduce on deer. Deer who come to feed at special corn feeders rub against a topical tick-killing substance that remains on their fur. "This is the only hope as far as I can see," says Fish.

In addition, he and his research team are searching for other pathogens that ticks transmit by isolating organisms, culturing them, and introducing them into tick species to see if they transmit them.

"We’re now trying to find agents that can make people sick before they get sick. Ticks have lots of organisms that just stay in ticks. Sometimes they infect vertebrates, then subsequent ticks that feed upon them. We catch ticks and grind them up and do molecular work on them. We recently found a new organism, new to North America, a relapsing fever spirochete [a corkscrew-shaped bacterium] in the same tick that causes Lyme disease. We know it is in ticks and that it infects mice. We know it is not Lyme disease but we don’t know how it affects people."

Fish pays a tribute to his Albright biology professor (now emeritus) John Hall, who "taught me how to trap mice." Since mice are the reservoir of infection for Lyme disease, "We trapped 1,000 mice and vaccinated them all, then went out to see if there were fewer ticks with the spirochete. There were fewer, but not as many fewer as we hoped. So we're working on an oral vaccine to put in mouse food."