Sexually Transmitted Bacterial Diseases
Humans suffer from a large number of sexually transmitted diseases (STDs), which can be viral or bacterial. While great apes carry sexually transmitted viruses, there is an apparent lack of bacterial STDs. None of the four major human bacterial STDs (Gonorhoea, Syphilis, Chancroid or Chlamydia) have been reported as naturally occurring in any of the great apes. Chimpanzees can be experimentally infected with only some of these organisms. Considering the high rate of multi-partner mating in chimpanzees and bonobos, the apparent lack of bacterial STDs is surprising. It is possible that all of these diseases emerged in the hominin lineage after our last common ancestor with the other hominids. It is also interesting to note that monogamy would limit the spread of STDs in humans.