sentences:  The patient's sickness was first attributed to "Bartonella bacilliformis", a known related species with a similar appearance under a microscope that is spread by sand flies and infects 10% of the human population in some regions of Peru with Oroya fever.Antibiotic treatment based on this diagnosis rapidly cured her infection, but further investigation proved the bacteria were of a formerly unknown species.It is possible that other cases diagnosed as Oroya fever result from this species.