Experimental studies on Epidemic Hemorrhagic Fever: Pediculus Vestimenti and Xenopsyllac Cheopis as Suspected Vectors of the Disease

Abstract

As mentioned in previous reports, it was clear that the epidemic hemorrhagic fever (EHG) could be induced to quite healthy persons by inoculation of the blood specimens collected from the patients with genuine EHF. Therefore, the agents of EHF were certainly considered to exist in the blood of patients in acute stage of EHF.
Dr. Masaji KITANO found a specific species of tick, ‘Togedani’, attaching to rat and playing an important role as a carrier of the disease, and so he insisted that the togedani inhabiting the areas where, EHF was prevelent, might be a natural possessor of the agents. In addition, it was supposed that in such circumstances, other insects such as vermin, fleas, bed-bugs, flies, or mosquitoes might be also reservor of the agents at least transiently. However, because no soarlling blood-sucking insects could remain being active in serious cold of winter in the noreheastern part of China where EHF had been prevalent still in this season, these kinds of insects could be excluded from the object of investigation. The author examined the infectivity of fleas and lice isolated from patients, and acquisition of infectivity on the artificially incubated unstained louse line by stinging the patients with EHF. Thus, it was confirmed that the healthy persons would develop the disease by stinging of poisoning louse.
It is not clear whether lice in the epidemic area naturally possess the agents of EHF, but it is doubtless that the poisoning lice which have sucked the blood from a healthy person, may cause him an infection of EHF. Therefore, it is concluded that a louse must be looked upon as a carrier of EHF.
On the other hand, as to the flea, the author failed to confirm whether flea had infectivity of EHF to man, in consequence of several biological experiments.