ROLE OF T. ORIENTIS AND S. CALCITRANS IN RINDERPEST TRANSMISSION.
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earliest records in this connection are some experiments by Curasson in Poland in
1922. He experimented with the tick, Ixodes ricinus Linn. and a species of Tabanus.
An engorged tick was removed from an animal on the second day of fever and imme¬
diately ground up in salt solution, and this mixture when injected into a healthy
animal produced a normal attack of the disease, but negative results were obtained
when the tick was emulsified an hour after the removal. In his experiments with
Tabanus (sp. ?) the material used for injection was a mash of the proboscides of the
flies in salt solution. The results obtained were the same as in the experiments with
ticks.
De Souza [1924] found that a specimen of the tick, Boophilus annulatus
Say. (Margoropus bovis Riley.), which had been feeding on an animal infected with
rinderpest, maintained the virus in its body at full virulence for a period of seven days.
Sen [1925], in his experiments with Musca domestica Linn., Aedes (Stegomyia) albo¬
picta Skuse and Linognathus vituli (Linnæus) carried out at Muktesar, could not
transmit the disease by means of these insects under natural conditions, but he was
able to record positive results when flies (M. domestica) fed on virulent blood, nasal
discharge and fresh fæces from infected animals were crushed in salt solution and
inserted into pockets prepared beneath the skin of susceptible animals, or when saline
suspensions of crushed infected flies were inoculated intravenously into susceptible
animals. He obtained a positive result also in one out of three experiments with
crushed material of Linognathus vituli. The experiments of the same author with
Boophilus annulatus australis Fuller, which were communicated in the report by
Husain [1926], were all negative. In the course of his experiments with Glossina
morsitans, Hornby [1926] was successful in proving the mechanical transmission of
rinderpest under natural conditions in one out of the two experiments, conducted by
him, with these flies. The susceptible animal to which the disease was transmitted
by these flies died of acute rinderpest. Hornby has not given a clinical chart of
this animal, and the complete details of his experiments were not furnished.
In his report Kearney [1927] mentions that some of the cattle in Northern
Nigeria which had come from a district where tsetse (Glossina) is unknown, were
found infected with rinderpest. As Hippoboscids are very common there at certain
times of the year, it is assumed that these were the probable vectors of the disease.
In reviewing the present position regarding insect vectors of rinderpest Datta
and Rajagopalan [1932] have drawn some conclusions from Hornby's experiments
quoted above, and have stated that " Since this species of fly (Glossina morsitans)
is not existent in India, it is apparent from available evidence that there is no
real danger in India from Insect Vectors." This opinion has been challenged by
Crawford [1933] who, while strongly suspecting Tabanus and Stomoxys as probable
transmitters of the disease, says that " if Glossina can transmit infection, as
Hornby thinks, I should imagine that the much larger and deeper biting Tabanus
and Stomoxys could do so too."
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