Experimental Transmission of Yellow Fever to Laboratory Animals

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  • Lagos, Nigeria


  1. 1.Yellow fever was successfully transmitted to Macacus rhesus.
  2. 2.It was easily transmitted from man to monkey, as well as from monkey to monkey, by the injection of citrated blood taken early in the course of the disease. It was also transmitted from monkey to monkey by Aëdes (Stegomyia) aegypti.
  3. 3.Mosquitoes, when once infected, were found to remain infective for the entire period of their lives, which in our experience exceeded three months in some instances, and the bite of a single infected mosquito was sufficient to produce a fatal infection in a monkey.
  4. 4.The virus was not transmitted from one generation of mosquitoes to another through the eggs.
  5. 5.When in the circulating blood of monkeys, the virus passed through Berkefeld filters of V and N grades, and also through Seitz asbestos filters, but it was not filtrable through Berkefeld W filters.
  6. 6.The virus was not filtrable when in the mosquitoes.
  7. 7.The clinical course of the disease and the lesions produced by the virus in Macacus rhesus were similar to those found in human yellow fever.
  8. 8.Attempts to cultivate the virus either from infectious blood or from filtered mosquito emulsions were negative.
  9. 9.No spirochetes, leptospiras, or other forms of microörganism were found in tissues of infected animals stained by Giemsa and Levaditi methods.
  10. 10.Indian crown monkeys (Macacus sinicus) were susceptible to yellow fever only to a moderate degree.
  11. 11.Chimpanzees, local African monkeys, and guinea pigs were totally refractory.