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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 hemolytic anemia, and hemophagocytosis. The full genome of the bacterium was sequenced from a blood isolate. Subsequently, we retrospectively (2011–2017) and prospectively (2018–2019) tested 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 There were 15 patients found to be infected by this hemotropic mycoplasma. Among them, 4 (27%) died following splenectomy performed either for spontaneous spleen rupture or to cure refractory autoimmune hemolytic 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. Of 40 tested Pteropus bats, 40% were positive; 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.

New Caledonia and French Polynesia are areas in which arboviruses circulate extensively. A large serological survey among horses from New Caledonia and French Polynesia was carried out to investigate the seroprevalence of flaviviruses in the horse population. Here, 293 equine sera samples were screened for flaviviruses using a competitive enzyme-linked immunosorbent assay (cELISA). The positive sera were then confirmed using a flavivirus-specific microsphere immunoassay (MIA) and seroneutralization tests. This serosurvey showed that 16.6% (27/163) and 30.8% (40/130) of horses were positive for cELISA tests in New Caledonia and French Polynesia, respectively, but the MIA technique, targeting only flaviviruses causing neuro-invasive infections in humans and horses (i.e. West Nile virus [WNV], Japanese encephalitis virus [JEV] and tick-borne encephalitis virus [TBEV]), showed negative results for more than 85% (57/67) of the cELISA-positive animals. Seroneutralization tests with the main flaviviruses circulating in the South Pacific revealed that 6.1% (10/163; confidence interval [95% CI] 3.0%-11.0%) of sera in New Caledonia and 7.7% (10/130; 95% CI 3.8%-13.7%) in French Polynesia were positive for dengue virus serotype 1 (DENV1) and 4.3% (7/163; 95% CI 1.7%-8.6%) in New Caledonia and 15.4% (20/130, 95% CI 9.7%-22.8%) in French Polynesia were found positive for Zika virus (ZIKV). Seroprevalence of the JEV and WNV flaviviruses on the 293 samples from both island groups were comparatively much lower (less than 2%). This seroprevalence study in the horse population shows that horses can be infected with dengue and Zika viruses and that these infections lead to seroconversions in horses. The consequences of these infections in horses and their role in ZIKV and DENV epidemiological cycles are two issues that deserve further investigation., Author summary New Caledonia and French Polynesia, located in the South Pacific, are facing circulation of dengue virus (DENV) for a long time and emergence of Zika virus (ZIKV) since 2013. A large serosurvey among horses’ population from these two islands was carried out to investigate the seroprevalence of the main flaviviruses circulating in the South Pacific. We find out that 6 to 7% of equine sera tested were positive for DENV serotype 1 in the two islands and 4% and 15% were positive for ZIKV in New Caledonia and French Polynesia respectively. Our study highlighted serological evidence of DENV serotype 1 and ZIKV infections of horses leading to meaningful seroconversion. Seroprevalence of other mosquito-borne flaviviruses (i.e. Japanese encephalitis and West-Nile viruses) were comparatively much lower (less than 2%) in New Caledonia and French Polynesia groups suggesting the absence of past active circulation of these viruses in both islands. This finding emphasized the need to investigate the consequences of such infections in the horse population and to determine the role of domestic animals in ZIKV and DENV epidemiological cycles.

We report the development of real-time PCR assays for genotyping Clostridium botulinum group III targeting the newly defined C. novyi sensu lato group; the nontoxic nonhemagglutinin (NTNH)-encoding gene ntnh ; the botulinum neurotoxin (BoNT)-encoding genes bont/C , bont/C/D , bont/D , and bont/D/C ; and the flagellin ( fliC ) gene. The genetic diversity of fliC among C. botulinum group III strains resulted in the definition of five major subgroups named fliC -I to fliC -V. Investigation of fliC subtypes in 560 samples, with various European origins, showed that fliC -I was predominant and found exclusively in samples contaminated by C. botulinum type C/D, fliC -II was rarely detected, no sample was recorded as fliC -III or fliC -V, and only C. botulinum type D/C samples tested positive for fliC -IV. The lack of genetic diversity of the flagellin gene of C. botulinum type C/D would support a clonal spread of type C/D strains in different geographical areas. fliC -I to fliC -III are genetically related (87% to 92% sequence identity), whereas fliC -IV from C. botulinum type D/C is more genetically distant from the other fliC types (with only 50% sequence identity). These findings suggest fliC -I to fliC -III have evolved in a common environment and support a different genetic evolution for fliC -IV. A combination of the C. novyi sensu lato , ntnh , bont , and fliC PCR assays developed in this study allowed better characterization of C. botulinum group III and showed the group to be less genetically diverse than C. botulinum groups I and II, supporting a slow genetic evolution of the strains belonging to C. botulinum group III.

The spatial pattern in Senegal of Crimean-Congo hemorrhagic fever (CCHF) virus IgG antibody prevalence in human and sheep was determined as was the relative abundance of potential tick vectors. A systematic, country-wide serological survey of sheep demonstrated that 10.4% of sheep exhibited IgG to CCHF virus. Sexes were infected equally. Antibody prevalence increased with age from 2.1% during the first year to 18.2% among sheep greater than or equal to 3 years of age. IgG prevalence was highest in the northern, arid Sahelian zone, averaging 75.7% seropositivity, and decreased to zero in the southern, moister Sudano-Guinean and Guinean zones. Human IgG prevalence ranged from 21% to less than 1% among the 8 sites that were sampled throughout the country, being greatest in the arid north and least in the south. Hyalomma ssp. ticks predominated in those biotopes where antibody prevalence was highest. The abundance of Hyalomma ticks may be the proximal determinant of endemic transmission.