The number one rule when dealing with any food that might have come into contact with animals or animal feces is to **wash it**. I could not find any other numbers than those from a [study conducted in Ethiopia][1] which notes that

> It was also observed that decreased parasitic contamination was
> significantly associated with washing the products before displaying
> it for selling (P < 0.001).

Although the numbers in the associated [table][2] from the study are not as convincing at the first glance. This has to, however, take into account that almost half of the water used for washing the fruits came from the river and even the pipe water in Ethiopia may not always be 100% parasite-free.

Apart from that, there is little actual evidence in the form of hard numbers to be found, but washing is recommended as a great way of protecting yourself from parasites. If you want, you can [wash your vegetables in a water-vinegar(5%) or water-salt(10%) solution][3] as this help with removing pesticides anyway and might be helpful with parasites as well (vinegar for example is the ultimate go-to killer for almost anything as far as I know).  

There is a good chance that you will at some point in your life be a host to a parasite. Prevention, like washing your fruit and cautiousness about symptoms associated with parasitic infection are the best tools you have to manage that successfully. As I am living with pets, I've fallen into the habit of taking [Mebendazole][4] sporadically to make sure I am not being parasited on. You should discuss this with your doctor though.


  [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5340032/
  [2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5340032/table/Tab3/
  [3]: https://nutritionfacts.org/2017/04/20/the-best-way-to-wash-fruit-and-vegetables/
  [4]: https://en.wikipedia.org/wiki/Mebendazole