This problem is prevalent all over the world. Within the U.S., the problem is increasing at an epidemic rate. The reason is that most people don't even consider that parasites could be a problem. Nearly everyone has parasites of one kind or another. We get them from uncooked fruit, vegetables, meat, etc., and also from pets.
Most parasites are microscopic and very difficult to detect.
Parasites can sap your strength and energy, live off the nutrients from your food and even the very tissues of your body, and poison your body with the toxins they secrete. Parasites drain the immune system and can be the cause of many physical problems that the doctors cannot identify. When a person tells me about a general run-down feeling, lack of energy, and mysterious symptoms that the doctors can't identify, I immediately think of parasites. It would be a mistake to believe that any of us have somehow managed to avoid getting parasites. Some parasites can survive extremely high temperatures.