In most cases, a pubic lice infestation is caused by exposure to another person with pubic lice, usually through sexual activity or other close bodily contact (e.g., sleeping in the same bed). In some cases, it may occur as the result of contact with personal objects (e.g., clothes, bedding, towels) recently used by a person with pubic lice.

Contrary to popular belief, it is not likely that pubic lice are spread via toilet seats, according to the Centers for Disease Control and Prevention. Their clawlike feet do not allow them to walk or grasp onto smooth surfaces such as a toilet seat. In addition, pubic lice are not able to survive very long when away from a human host.

People who may be at an increased risk of contracting a pubic lice infestation include:

• Sexually active people under 40
• Men and women with multiple sex partners
• Men and women whose partners have multiple sex partners
• People in crowded living conditions

Pubic lice infestations are extremely rare in infants and children, as well as in prepubescent children.