Among 546 live births, placental tissues from 60 (11%) were RT-PCR positive for Zika virus, including 38/363 (10%) from pregnancies with recent unspecified maternal flavivirus infection and 9/86 (10%) with negative maternal Zika virus IgM, where possible maternal exposure occurred >12 weeks before serum collection (after which time maternal Zika virus IgM antibodies might have waned) (5) (Table 2). Here, CD40LG is linked to Flavivirus Infections.