According to the Centers for Disease Control, “Head lice should not be considered as a medical or public health hazard. Head lice are not known to spread disease. Head lice can be an annoyance because their presence may cause itching and loss of sleep. Sometimes the itching can lead to excessive scratching that can sometimes increase the chance of a secondary skin infection.” For more information on head lice, see the following links.
Illinois Department of Public Health
Centers for Disease Control
Frequently Asked Questions (Link)