a1 From the Virus Research Institute, Entebbe
To show that blood-sucking insects can transmit viruses which cause human diseases, human beings themselves must be used for experiments, or, as this is rarely possible, their place must be taken by suitable laboratory animals. For this purpose an animal species must be available with the following attributes: it must regularly circulate much virus in its blood after infection, and it must be susceptible to infection by the intracutaneous inoculation of a small dose of virus. None of the animal species available possess these attributes during experimentation with many human viruses. Insect transmission can often then be demonstrated by using the indirect method described in this paper.
* Now of the Department of Pathology, University of Cambridge.