Louse-borne diseases are infections transmitted by lice, small parasitic insects that live on the skin and feed on human blood. The most common louse-borne diseases include typhus, caused by bacteria, and trench fever, which is linked to the body louse. These diseases often spread in crowded conditions where hygiene is poor. Lice can carry pathogens that enter the human body through bites or scratches. Symptoms of louse-borne diseases may include fever, headache, and body aches. Effective prevention includes maintaining good hygiene, avoiding close contact with infested individuals, and treating lice infestations promptly.