Spillover: Animal Infections and the Next Human Pandemic

by David Quammen

So forget about deer abundance. White-tailed deer are involved in the Lyme disease system, yes, but involved like a trace element, a catalyst. Their presence is important but their numerousness is not. The littler mammals are far more critical in determining the scale of disease risk to people. Adventitious years of big acorn crops, yielding population explosions of mice and chipmunks, are more likely to influence the number of Lyme disease cases among Connecticut children than anything that deer hunters may do. Beyond helping the blacklegged tick (infected or uninfected) to survive, white-tailed deer are almost irrelevant to Lyme disease epidemiology. They don’t magnify the prevalence of infection in the forest. They don’t pass the spirochete to humans or to newly hatched ticks. They’re dead-end hosts, Ostfeld told me.