Dengue Transmission without Involvement of Mosquito Vector

In fact, development of dengue virus infection by intranasal instillation of the virus suspension was demonstrated many years ago in human volunteers [3] and experimental animals (monkeys and marmosets) [4]. Thus, with the number of cases of imported dengue increasing sharply, the report by Chen and Wilson [ 1 ] was a timely reminder-not only to health care workers, but to diagnosticians and laboratory workers dealing with dengue viruses-that such viruses, which are currently classified at a lower biosafety level, can, if concentrated, present a potential for direct transmission. Arbovirus Diseases Branch, Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Ft.