The existence of a new human immunodeficiency virus (HIV) derived from gorillas is reported in this week's Nature Medicine.

Jean-Christophe Plantier identified a new form of HIV in a patient from Cameroon. The new virus is closely related to the known gorilla simian immunodeficiency virus (SIV). This gorilla strand shows no evidence of recombination with other HIV strains or with chimpanzee SIV. The human prevalence of this new form of HIV remains to be determined.

These findings indicate that gorillas, in addition to chimpanzees, are likely sources of HIV. The discovery of this novel HIV lineage highlights the need to better monitor the emergence of new HIV variants, particularly in western central Africa from where existing HIV groups have originated.