I have not traveled to any countries that have parasites, yet I have them in my liver. They are creating holes in the liver and can cause non-alcohol-related cirrhosis. Most doctors are not aware of these parasites because they are difficult to diagnose in the O&P stage. So therefore, if they can't scientifically identify them, they don't exist.
I have been doing natural programs of herbs to expel the liver flukes. I have taken pictures to help with the identification. It is working, but I have no idea how extensive the damage is. (My bilirubin is elevated, which happens when you have a lot of worms.) This could be a result of eating sushi.