Invited commentary: Dengue lessons from Cuba

An 18-year interval between a dengue virus type 1 outbreak in 1977-1979 and a dengue virus type 2 outbreak in 1997 in Santiago de Cuba, Cuba, provided a unique opportunity to evaluate risk factors for dengue disease. All pati ents with symptomatic dengue, including 205 cases of dengue hemorrhagic fev er and 12 deaths, were adults born before the dengue virus type 1 epidemic, and nearly all (98%) experienced secondary dengue virus infections. In con trast, almost all of those who seroconverted without illness (97%) experien ced primary dengue virus infection. This provides epidemiologic support for the immune enhancement theory of dengue pathogenesis. The Cuban experience suggests that immune enhancement can be seen even 20 years after the prima ry dengue virus infection. It also supports the contention that primary inf ections with dengue virus type 2 (and dengue virus type 4) are largely subc linical. These observations have implications for dengue vaccine developmen t based on live-attenuated viruses.