Lice are very small, wingless parasitic insects that feed on human blood. The three distinct types of lice that can live on humans are head lice, body lice and pubic lice. Body lice are the only type that spread disease, according to the Centers for Disease Control and Prevention. An infestation of body lice is known as pediculosis. It is spread through direct contact with an infested person or their articles of clothing and bedding.
EpidemicTyphus
Epidemic typhus, or louse-borne typhus, is a potentially serious disease caused by a bacteria called Rickettsia prowazekii. Typhus caused by rickettsia organisms occurs worldwide with outbreaks linked to natural disasters, war and poverty. Disease transmission occurs when louse feces get into a wound, cut or scrape in the skin.
Symptoms begin seven to 14 days after transmission with extreme fatigue, severe headache and high fever. A pink rash develops on the trunk within four to six days. Some people get an enlarged spleen. Gangrene, pneumonia, and brain or kidney involvement are serious complications and increase the risk of death. The elderly are at increased risk of developing fatal illness if left untreated. Epidemic typhus is usually not fatal in children.
Trench Fever
Another pathogen spread by body lice is Bartonella quintana. As with typhus, the disease is spread through the feces of body lice. It has emerged as a feature of the homeless population in the United States and is prevalent in Mexico and parts of Europe, states The Merck Manuals Online Medical Library.
Symptoms of the disease appear 14 to 30 days after transmission, producing sudden weakness, dizziness, headache, high fever, back and leg pain, and a rash. Sometimes the fever comes and goes over a period of weeks. Trench fever may cause an enlarged spleen and liver. Most people recover within one to two months but can have relapses even years later.
Relapsing Fever
Borrelia recurrentis is the louse-spread bacteria responsible for relapsing fever. The illness is primarily found in parts of South America and Africa and is rare in the United States, notes The Merck Manuals Online Medical Library. An infected louse can transmit the disease to someone after being crushed on the skin, at which time the freed bacteria may enter the body through an abrasion.
After becoming infected, it takes from three to 11 days for symptoms to appear. The illness begins with chills, high fever, severe headache, rapid heartbeat, joint and muscle aches, nausea and vomiting, and mental confusion. Symptoms are often accompanied by a rash. The fever goes away in three to five days but then returns several days to two weeks later, according to MedlinePlus. Fever and other symptoms come and go multiple times before full recovery. Complications of heart inflammation, hepatitis, pneumonia, seizures and coma can occur.
