By forcing people buying bigger turtles, it is not going to stop people from not washing their hands before eating their food. It looks to me the problem is really how to properly taking care of turtles. Correctly/better maintained turtle tanks obviously are cleaner with less undesirable viruses, germs in them. Bigger turtle isn't going to make people take care of it better. Of course there is personal hygiene problem since it is still required to wash your hands afterward even if the turtle tank is extremely clean.
This case also reminds me how poorly the general mass taking care of their fish, or rather how quickly they kill their new fish off. Some fish also have diseases. A few years ago I learned there is a marine fish disease that can be transmitted to humans as well. There are germs, viruses everywhere. We can't just keep coming up with laws trying to protect people from their own fault.
Think about that, some people don't wash their hands after using the restroom. That caused me never try to open a public restroom door from the inside with my hands directly because of that dirty handle. Imagine how many germs and potential viruses from sick people can be on there? After all that unpleasant imagination, I don't believe there should be a law to force people wash their hands after using the restroom.
Not so long ago there was a debate in New York City about passing a law to forbid the sale of large soda in movie theaters? "Because it's unhealthy".
I think I am going off the topic lol, but my point is we don't need laws to protect us from ourselves.
On the other hand we absolutely need better education for pet owners.
After all that unpleasant imagination, I don't believe there should be a law to force people wash their hands after using the restroom. 
