title: Halley's Comet and others: the bacterial star shells.
mesh_terms: D001424:Bacterial Infections / Q000453:epidemiology* / Q000209:etiology; D004196:Disease Outbreaks / Q000517:prevention & control; D004197:Disease Reservoirs; D005118:Extraterrestrial Environment; D006801:Humans; D010507:Periodicity