Yes dehydrating meat does kill some bacteria and parasites.
When beef jerky is properly dehydrated the parasites or bacteria is killed off and so it cannot make you sick.
However if you make beef jerky or other dehydrated meat and don't dehydrate it enough or cure the meat enough or properly then you may not kill all the parasites.
Some bacteria may also be present still in the meat that is dehydrated.
But all bacteria is killed off including all parasites when the meat or other food is fully cooked.
Store bought beef jerky should be free of parasites or bacteria so it should not make you sick unless you leave it out once opened.
But as long as the beef jerky is sealed it can last for a year or longer.