“ Symptoms of Oropouche infection are typical of many viruses and usually last a week: fever, rash, muscle aches, headache. But some cases can be more severe, causing encephalitis and meningitis —inflammation of the brain and its surrounding membrane that can cause it to swell. And as with Zika, a mother can transmit the virus to the fetus during pregnancy — which can lead to birth defects and even fetal death.