Is jerky safe concerning parasites?
In the US, commercial jerky is inspected by the Food Safety and Inspection Service help ensure safety.  See the FSIS Compliance Guideline for Meat 
and Poultry Jerky Produced by Small 
and Very Small Establishments  for detailed information on commercial jerky preparation methods, which must include a "lethality" step based on heat, acidity, or other means to ensure pathogens are killed.  They may also use more sophisticated methods to ensure proper drying. 



Googling "jerky safety" will yield a wealth of University Extension results based on FDA research, providing specific recipes for safely creating jerky at home.

Traditional methods (soaking in brine, then drying) are not sufficient to kill all pathogens (not just parasites).  The FDA now recommends the the "hot pickle cure" method as the most effective way of creating safe jerky.

See for example the recipe published via Cornell.  In summary:


Treat the meat carefully prior to jerking, using proper refrigeration and so on.
Prepare a brine of the proper strength, and bring it to a boil.
Dip the jerky pieces into the boiling brine long enough for them to turn grey.
Dry in a temperature controlled dehydrator, checking for sufficient drying (the meat should crack when bent).