One phase of the lifecycle only happens in humans and dogs. Once no one (or their dog) has it, then the cycle is done. The out-of-human part is three phases of

One phase of the lifecycle only happens in humans and dogs. Once no one (or their dog) has it, then the cycle is done. The out-of-human part is three phases of larva which take a few weeks, although I didn’t see how long the phase 3 larva could persist without a human or dog host to proceed to adulthood. https://www.cdc.gov/parasites/guineaworm/biology.html https://www.cdc.gov/parasites/guineaworm/biology.html