Many people have contracted tape worm, my brother when he was real little contrated it by eating some sand. Wouldn't you know it, there is where he got it, in a sandbox. Many people allow their dogs to use the sandbox at playgrounds for them to go, and this is how it is often transmitted. There used to be a public service announcement, I wish they would run it again, warning of this, but the good old public services just assumme that everyone stoops and scoops, which of course is not the case. The public needs to be reminded of such dangers. Itchy anus is one of the primary indicators and if left untreated, it is horrible the consequences. Therefore, if you should suspect of a person having this, get them to a doctor asap
