The fight against head lice in elementary and preschool schools in the City of Paris is the focus of a unique and specialized screening and treatment program. This program has been entrusted by the Department of Social Services for Children and Health (School Medical and Social Services Division) to the Health Protection Laboratory of the Paris Police Prefecture. Screening is conducted in all elementary and preschool schools in the City of Paris by 11 public health officers. Each public health officer covers a specific geographic area, and each school is visited at least twice a year.