AN ATTEMPT TO INFECT HUMAN BODY LICE, PEDICULUS HUMANUS VAR CORPORIS ON A MILD CASE OF MURINE TYPHUS*

A patient with a sporadic mild case of ty- phus fever assume on epidemiological and cli- nical grounds to be murine typhus was test.ed for his infectivity for normal adult human body lice, Pediculusi humanus va.r corporis, during a period of 5 days from the 9th through 4he 13;th or last day of the disea.se. One out of 105 mice (0.95'/o) was later found to have developed a small numbeir o,f morphologically and tincto- rially typical ricketts.iae. A guinea pig, which was inoculated in succes.sion with two suspen- sions of ground lice showing and n;olt showing definite rickettsia.e in smears, twice gave ne- gative complement fixation with epidemic anti- gen but positive fixation with murine antigen at a titer of l:40. As far as the authors. are awa.re, this is the first report to show that by feeding on a mild case of murine typhus, lic;e became infected with typhus rickettsiae which proved serologically to be R. mooSieri. It is therefore suggested that under nat.ural condi- tions when lice feed continuously on severe cases of murine typhus throughouit the febrile disease, a sufficiently higher percent of lice may become infected with sufficiently larger numbers of typhus ricketts.iae to give rise to outbreaks of louse-borne typhus in Iouse-infested communi- ties.