Head lice are not as common in adults as they are in children, but they are still susceptible to infection. Adults are most susceptible to catching a case through close contact with another person’s head. This contact is crucial in spreading lice from one head to another. The best way to prevent head lice is to avoid contact with children.
Head lice can infest any head with hair. Adults who are rarely in contact with children are less likely to have head lice than those who regularly play with children. Those who do have lice may have recently traveled to an area where lice are more common. For example, parents in the Netherlands tend to be less strict in their efforts to remove lice, and as a result, a larger proportion of adults have the disease than those in the US.
However, African-Americans are less likely to develop head lice than other races. This is partly due to the shape of their hair shafts. Because head louse claws are designed to grab uncoiled hair, they are less likely to get infected. People with two parents are especially protected from lice from African-Americans.
According to the World Health Organization, head lice are a zoonosis and a disease. During epidemics, adults often get infected with head lice. The infection may occur in schools, daycares, nurseries, and the home of a child. But if you have close contact with an infected child, you may also get infected. However, adult head lice are rarer in African-Americans than in whites and Asians, probably because the louse prefer white hair and Asian hair.