Does poultry white meat like chicken contain any parasites/parasitic growth/worms in it?
All meat contains parasites. You must cook poultry to 165 degrees internal temperature to kill any bacteria. The most reputable companies for chicken are those that are labeled pasture raised. They are raised without the use of antibiotics. Any of the large poultry companies like Tyson or Perdue administer these drugs to their chickens and raise them in confined areas in total darkness. As to your fish question, there is a thing called codworm that you will occasionally find in cod, salmon and some other varieties of white fish like halibut. Again if you cook the fish thoroughly (145-150 degrees internal temperature) it will not be an issue.
