I remember a swiss article about 30 years ago where Rubus caesius fruits were contaminated with fox faeces containing Echinococcus eggs(?).

Thank you András for the lead. However, I can not find this reference either. Perhaps someone else can help with more leads to references.

http://www.hygiene.uni-wuerzburg.de/forschung/ag_brehm/fox_tapeworm_basics/

Perhaps Prof Brehm can help you. He was cited some years ago in a German newpaper...

Dear Brian,

Here you are some resources:

http://www.ncbi.nlm.nih.gov/pubmed/17553227

http://www.swild.ch/publi/Takumi_EpiInf2012.pdf

http://www.research-projects.uzh.ch/p10436.htm

https://www.researchgate.net/publication/18412150_Human_echinococcosis_in_Switzerland_during_the_years_1956-1969

Article [Human echinococcosis in Switzerland during the years 1956-1969]

Dear Brian,

Last week I attended a congress on alveolar echinococcosis in France.

There a researcher from Poland showed some results of air/soil/water/plant contamination.

Maybe you should contact her, here is the link to her article (only on soil):

http://www.sciencedirect.com/science/article/pii/S0304401714001010

Dear Sébastien Comte, the Polish paper is now out (Lass et al.): 

http://link.springer.com/article/10.1007%2Fs00436-015-4630-9

There has also been a challenge by Robertson et al. to the Polish study due to the finding of Echinococcus DNA on raspberries, which is by some considered unlikely contamination. 

http://link.springer.com/article/10.1007%2Fs00436-016-5015-4