As most of you know, one of the duties of the President of the American Society of Tropical Medicine and Hygiene specified by the by-laws is the presentation of an address at the annual meet ing. I do not know what type of address those responsible for this provision had in mind, but a review of previous presidential addresses reveals a wide variety both of philosophical and scientific topics. Since I do not feel competent to address you on a philosophical subject, I have chosen to review a scientific topic which has been of interest to me during the past few years. In making this choice, I know that the subject matter will be of relatively little interest to those of you in other fields and for this I apologize. I shall illustrate later, however, that the topic I have chosen is especially appropriate for the site of our gathering this year and for the bicentennial which our joint meeting commemorates. Those of you unfamiliar with recent work and discussions on dengue may be puzzled by the first part of the title of this address. I should like to explain that it was chosen to call attention to what I believe is the transparency of arguments used in support of a widely disseminated hypoth esis on the pathogenesis of dengue hemorrhagic fever— but that it was not intended that the analogy be carried so far as to imply that those who have proposed this hypothesis are the counter parts of the two rogues in Hans Christian Ander sen's story.'

There has been considerable speculation as to why dengue, long considered an annoying but benign disease, has in the last 20 years become a leading cause of hospitalization and death among children in a number of Southeast Asian countries. 2 The life-threatening forms of dengue usually are associated with hemorrhage, hypovolemic shock,