How can you believe in creationism with these horrific human parasites?

With all these parasites and horific tropical diseases, how can you believe a God designed them. I'm not even talking about the pictures of the diseases. It is more the ingenious and frightening mechanisms that the parasites use to feed off their human hosts. If you believe in creationism. You must believe in a God who created these horrors with the express purpose of human suffering. Let's hear the creationist explanation????