Five of the ten children who were diagnosed with microcephaly in the ZIKV-unexposed group were born to mothers who tested IgG-positive for Rubella, Cytomegalovirus, Toxoplasmosis and/or Herpes; notably, none tested IgM-positive for any of these infections, so we cannot discern whether the infections occurred during or prior to pregnancy. This evidence concerns the gene CD40LG and infection.