*2.7. Histochemical Staining*

Chorionic villi derived from the placentae of control and ZIKV-infected women were fixed in 10% para-formaldehyde, embedded in paraffin, and cut in 8 μm sections. Then sections were stained with hematoxylin and eosin, or with Masson's trichrome stain, following standard protocols [26]. The identification of Hofbauer cells in these slides was done with a rat monoclonal antibody against CD68 (Cat. ab53444, Abcam, San Diego, CA; dilution 1:1,000).
