doxycycline, but if left untreated, the fatality rate is 30%. Relapsing fever can be treated with tetracycline and depending on the severity of the disease, if left untreated it has a fatality rate between 10 and 40%. Trench fever can be treated with either doxycycline or gentamicin, if left untreated the fatality rate is less than 1%. See also List of parasites of humans References External links Body and head lice on the UF/IFAS Featured Creatures Web Site Ectoparasites Insects described in 1758 Lice Parasitic arthropods of humans Taxa named by Carl Linnaeus