“Within a matter of weeks or months, the virus reaches the brain, where it can cause agitation, confusion, and hydrophobia — a fear of water that results from an inability to swallow. (This, in turn, leads the saliva to become frothy, a hallmark of infection in mammals.) Rabies kills more than fifty thousand people each year; if left untreated, it has a mortality rate approaching a hundred per cent.” But let’s not focus on the negative. The New Yorker’s Patrick House on the brighter side of rabies.