Trichinosis happens when raw meat infested with the cysts is eaten. The infested animal develops the cysts after eating raw meat infested with the cysts. These days pigs aren't fed raw meat, they are fed commercial diets that are mostly grain. That particular cyst like most worm cysts, are killed by freezing. Most meat is frozen before it is delivered to the market and mostly we store meat in the freezer as well. If you come across a local guy butchering a pig fed slop and the slop isn't cooked then there could be a problem. I suspect if you come across pastured pigs that might be catching some animals on their own there might be a problem. Unlikely but possible. And you just need to give the meat a good long freezing to kill the cysts.