Re: New to this and worried about being conned (long)
Very good statistics here! Very helpful and enlightening. It shows the great extend of parasitic infestation worldwide. It also confirms that the great majority of these issues are focused on developing countries, as opposed to industrialized nations. The CDC estimate of "10% of Americans infected with worms, mainly children" still applies.
The "visual detection tests aren't always accurate" comments one often hears are certainly true, although the better labs such as Great Plains, Doctors Data, and Great Smokies have good track records on stool analysis. (I'm not familiar with non-U.S. labs, but clearly there's plenty of highly competent labs throughout the world.) Other local and regional labs worldwide have more mixed success, especially if they don't specialize in stool samples. Most folks who make such comments appear unaware of blood serum antibody tests, which are relatively accurate (link below). Eyes can be tricked during visual examination, and sometimes worms/eggs/larva/cysts aren't discharged for a given stool sample, leading to false negatives. But in general, if blood antibodies for a given pathogen show up in the blood, that's a fairly accurate indicator of current or past infection.