We curse with pus (etter), tbc (tering), cholera (kolere), plague (pest) and more recently cancer (kanker). Although that often hits a bit too close home for some people. There's more that I'm forgetting right now. I have heard people describe something bad as being AIDS. So new ones are actually being added.

One of the theories is that it came from Yiddish where diseases are also used as curses. Another popular theory is that because the Dutch population isn't very religious we switched to diseases because that's whst we feared in stead of God. The truth lays probably somewhere in the middle.