Compared with bacterial food spoilers such as Salmonella, Escherichia coli, or Campylobacter, which each cause many more cases annually, Cyclospora, a protozoan parasite, hasn’t been “on the radar” as much, says Kellogg Schwab, a public health scientist at Johns Hopkins University. PulseNet, a national network that uses DNA data from pathogens to connect cases across states, only tracks bacteria-related foodborne illnesses.