Amplified fragment length polymorphism (AFLP) fingerprinting of the pandemic isolates of Vibrio cholerae has revealed variation in the genetic structure. Two clusters have been identified: Cluster I and Cluster II. Cluster I consists mainly of strains from the 1960s and 1970s, while cluster II contains mainly strains from the 1980s and 1990s, based on a the change in the clone structure. This grouping of strains is best seen in the strains from the African Continent.[52]
