V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
The paper “Health Protection in a Shrinking World” by David J. Sencer, appearing in this issue of the Journal, contains a potentially dangerous assumption.
The statement is made, with reference to yellow fever, “… surveillance should be such that the initial case, or at least the first generation of cases, arising from an importation is recognized and the second prevented.” It is further stated, “The technology to accomplish this in the case of yellow fever is available with rapid, mass vaccination and vector control.” Unfortunately, although not specifically stated, this leaves the reader with the inference that the technology for early recognition of cases is also available.
It is my belief that the early recognition of yellow fever, “the initial case, or at least the first generation of cases,” cannot be assumed. Yellow fever is manifested clinically not necessarily or even usually by the classic symptoms and signs described in textbooks.