Prevalence of signs and symptoms among Dengue virus (DENV)-IgM-negative pregnant persons with rash (N = 631) who tested negative for Zika (ZIKV), and Chikungunya (CHIKV) viruses (N = 305), positive for ZIKV mono-infection (N = 213), positive for CHIKV mono-infection (N = 55), and positive for sequential ZIKV/CHIKV infection (N = 58). Here, CD40LG is linked to infection.