Pubic lice, commonly known as "crabs" due to their crustacean-like appearance, are parasitic insects which inhabit human pubic hair. However, they can also be found in eyebrows, underarms, and abdomen. Unlike fleas, lice cannot jump. Instead, they crawl very quickly, with legs designed specifically for grasping widely spaced pubic hairs.
Pubic lice are most often transmitted during sexual contact but can also survive on linens and other materials for up to two days. Their only food source is human blood, which they acquire by biting the skin surrounding hair follicles. Their saliva contains an anti-coagulant which prevents blood in bite wound from clotting.
This enzyme, along with other components of louse saliva, causes an allergic reaction in the human host, resulting in the inflammation and itching characteristic to pubic lice infestation.
Did Humans Get Pubic Lice From Gorillas?
New research suggests humans may have first contracted pubic lice from gorillas. DNA shows that the current gorilla and pubic louses - now two different species of louse - evolved from a common ancestor approximately 3 to 4 million years ago. But because the human and gorilla lineage diverged several million years before this, humans must have been infected by coming into contact with gorillas instead of the gorilla louse evolving with the gorilla. Although intimate contact is usually responsible for transmitting pubic lice, bestiality between gorillas and humans is not suspected. Instead, scientists hypothesize that the lice infected humans who ate infested gorillas or slept in their nests.
Lice Found in South American Mummies
In 2002, pubic louse eggs were found attached to the pubic hairs of a 2000-year old Chilean mummy. Adult lice were also found in the sediment on clothing on a 1000-year old Peruvian mummy. Because Columbus first reached the Americas less than 600 years ago, it is thought that the pubic lice found on these South American mummies must have been introduced when early humans migrated to the New World.
Ancient Times & 18th Century Europe
Lice have been a problem in Europe at least since biblical times. Many remedies, including viper broth, oil from hyssop, and tobacco juice were said to kill lice. Women were said to create ointments from ashes and bacon grease which were then applied to infected areas. Lice are mentioned several times in the Bible, most often referring to the third plague sent on Egypt. In 1786, Scottish poet Robert Burns published "To a Louse", which uses the louse crawling in a woman's hair as a metaphor for seeing the faults in others.
Free Love of the 1960s
Pubic lice have been considered an epidemic in the United States in all socioeconomic levels since the 1960s. It is likely that the "free love" movement, characterized by sexual promiscuity, did much to increase pubic lice transmission.
The Future of Pubic Lice
Recent advances in biology and epidemiology have helped us to understand the transmission and pathology of pubic lice. Although pubic lice may be cleared with careful cleaning of linens along with a chemical treatment of infested hair, it is unlikely that pubic lice will ever be eradicated. With the louse's mode of transmission coinciding with the most essential human interaction - sexual reproduction - we have little hope of ridding the world of the pubic louse.