Given the high DENV seroprevalence observed in the area from which the ZIKV-IgM-positive group (mean age = 40 years) originated (93.5% of the Caribbean island population (mean age = 38 years), [26]) it is likely that they were infected with DENV prior to ZIKV infection, although we have no way of knowing whether the antibodies that recognized ZEDIII were actually induced by DENV. The gene discussed is CD40LG; the disease is Zika virus infectious disease.