| Abstract: | In 1957, a new tsutsugamushi disease vector,
Leptotrombidium (L) Gaohuensis SP. Nov. was dis
covered during an investigation of the disease in
Gaohu Village, Zhejiang Province. An overall study
of its epidemiology, ecology and etiology was corb
ducted to determine the insect in function as a tsutsu
gamushi disease vector.
The authors conducted an insect bite test on
themselves, showing that the larvac had the ability
to bite humans and cause the infection. The second
generation larvae were divided int0 5 groups of 5-20
larvae each and allowed to bite healthy mice. Two
groups of the mice contracted the disease and died.
Two strains of Rickettsia tsutsugamushi were isolated
from them, and by electron microscopy, large quan
tities of rickettsia parasites were found in the ovum
with the ability to transmit Rickettsia tsutsugamushi.
Isolation of Rickettsia
Gaohuensis indicated that
under suitable conditions.
tsutsugamushi from L
natural infection occurs
L Gaohuensis is distributed throughout 10
counties in Zhejiang Province. It is a dominant
species in the foci disease areas; its seasonal fluctua
tion conforms to that of the disease and its ecological
distribution also conforms with the disease incidence
in the infectious areas.
The findings indicate that L Gaohuensis fulfils
all the criteria for a vector of tsutsugamushi disease,
so it is concluded that L Gaohuensis SP. Nov. is a
new vector for the disease. |
