Flying fox haemolytic fever, description of a new zoonosis caused by “Candidatus Mycoplasma haemohominis”
Abstract Background Hemotropic mycoplasmas, previously classified in the genus Eperythrozoon, have been reported as causing human infections in Brazil, China, Japan and Spain. Methods In 2017, we detected DNA from “Candidatus Mycoplasma haemohominis” in the blood of a Melanesian patient from New Caledonia presenting with febrile splenomegaly,weight loss, life-threatening autoimmune haemolytic anemia and hemophagocytosis. The full genome of the bacterium was sequenced from a blood isolate. Subsequently, we tested retrospectively (2011-2017) and prospectively (2018-2019) patients who had been hospitalized with a similar clinico-biological picture. In addition, as these patients had been in contact with frugivorous bats (authorized under conditions for hunting and eating in New Caledonia) we investigated the role of these animals and their biting flies by testing them for hemotropic mycoplasmas. Results Fifteen patients were found to be infected by this hemotropic mycoplasma. Among them, four (27%) died following splenectomy performed for spontaneous spleen rupture, or to cure refractory autoimmune haemolytic anemia. The bacterium was cultivated from the patient's blood. The full genome of the Neocaledonian “Candidatus M. haemohominis” strain differed from that of a recently identified Japanese strain. Forty-six percent of 40 tested Pteropus bats and 100% of collected bat flies Cyclopodia horsfieldi (Nycteribiidae, Diptera) were positive. Human,bat and dipteran strains were highly similar. Conclusions The bacterium being widely distributed in bats, “Candidatus M. haemohominis” should be regarded as a potential cause of severe infections in humans.