what lice carries disease for typhus
Body lice can spread epidemic typhus, trench fever, and louse-borne relapsing fever. Although louse-borne (epidemic) typhus is no longer widespread, outbreaks of this disease still occur during times of war, civil unrest, natural or man-made disasters, and in prisons where people live together in unsanitary conditions.
In 1909 Ricketts and his assistant, Russel M. Wilder, went to Mexico City to study epidemic typhus. They found that it was transmitted by the body louse (Pediculus humanus) and located the disease-causing organism both in the blood of the victim and in the bodies of the lice.