RESUMEN
Tick-borne encephalitis virus' (TBEV) geographic range and the human incidence are increasing throughout Europe, putting a number of non-endemic regions and countries at risk of outbreaks. In spring 2020, there was an outbreak of tick-born encephalitis (TBE) in Ain, Eastern France, where the virus had never been detected before. All patients but one had consumed traditional unpasteurised raw goat cheese from a local producer. We conducted an investigation in the suspected farm using an integrative One Health approach. Our methodology included (i) the detection of virus in cheese and milk products, (ii) serological testing of all animals in the suspected farm and surrounding farms, (iii) an analysis of the landscape and localisation of wooded area, (iv) the capture of questing ticks and small mammals for virus detection and estimating enzootic hazard, and (v) virus isolation and genome sequencing. This approach allowed us to confirm the alimentary origin of the TBE outbreak and witness in real-time the seroconversion of recently exposed individuals and excretion of virus in goat milk. In addition, we identified a wooded focus area where and around which there is a risk of TBEV exposure. We provide the first TBEV isolate responsible for the first alimentary-transmitted TBE in France, obtained its full-length genome sequence, and found that it belongs to the European subtype of TBEV. TBEV is now a notifiable human disease in France, which should facilitate surveillance of its incidence and distribution throughout France.
RESUMEN
Experimental studies have demonstrated that cats can be infected by Echinococcus multilocularis, although few data are available concerning their natural infection. This study was designed to compare experimental findings with information on the prevalence of natural E. multilocularis infections of cats in a rural high endemic area. Of 19 intestines of domestic cats (Felis s. catus) and five of European wildcats (Felis s. silvestris) analyzed by segmental sedimentation and counting technique (SSCT), infection by E. multilocularis was observed for one individual of each species, resulting in a prevalence estimated at 5%, (CI95%: 1-26) in domestic cats and at 20% (CI95%: 1-72) in wildcats. High worm burdens (680 and 7040) were noted, but comprised only immature worms. The same EmsB microsatellite profile obtained from the worms' DNA was observed in the two cats as in foxes from the same area and from other European countries. The presence of E. multilocularis DNA was diagnosed in 3.1% (10/321) of the domestic cat feces collected on the field in two villages. However, no E. multilocularis eggs were found after flotation with zinc chloride of the positive feces. The detection of DNA from E. multilocularis was thought to be due to the presence of cells from worms untied from the intestine and corresponding to prepatent infection or due to the digested metacestode. These results from E. multilocularis presence in wild and domestic cat populations agree with those previously obtained by experimental infections. These findings support that these cats play an insignificant role in E. multilocularis transmission, even in a "highly endemic" region. Nevertheless, since the presence of thick-shelled E. multilocularis eggs from cats has already been reported, the associated zoonotic risk cannot be totally ruled out, even if it is very low.