The Sergyaran worm plague was an ailment caused by some type of burrowing creature found on Sergyar. The presence of these "worms" under a person's skin caused severe bloating. In the initial years of the outbreak, the planet was closed to new colonists. At first, victims were treated surgically, which could leave extensive scars. Later, however, an effective oral vermicide was developed, allowing the planet to be re-opened to colonization.