Echinococcus multilocularis in red foxes in North Belgium: Prevalence and trends in distribution

A cross-sectional systematic sampling was carried out during three consecutive winters from 2012 to 2015, to update the knowledge on the fox tapeworm (Echinococcus multilocularis) distribution in the red fox (Vulpes vulpes) in Flanders. Earlier studies reported the low endemicity status of this tapeworm in the northern region of Belgium, in contrast to the south of the country and neighbouring countries. Using a modified Segmental Sedimentation and Counting Technique, followed by PCR-RFLP and sequencing, 923 foxes' intestines were examined for the presence of E. multilocularis. Based on microscopic examination, 38 out of 923 foxes were suspected to be infected with either E. multilocularis or Amoebotaenia spp., of which 19 were molecularly confirmed to be E. multilocularis, 18 were found positive for Amoebotaenia spp. and one was negative. The overall prevalence for E. multilocularis of 2.1% confirms the low endemicity of the fox tapeworm in Flanders. However, in one area in the most eastern part of Flanders (Voeren), neighbouring the Netherlands and Wallonia, a prevalence of 57% (12/21) was observed. Continuous monitoring of the fox tapeworm remains needed to assess spatio-temporal trends in distribution and to assess the risk of this zoonotic infection in Europe. The challenging differential diagnosis of E. multilocularis and Amoebotaenia spp. based on microscopic examination calls for attention.