A man infected with Zika virus in Puerto Rico has died from complications of the infection, health officials said Friday. The man, in his 70s, died from internal bleeding caused by a rare immune reaction to the virus, the Centers for Disease Control and Prevention said. It’s the first death in the United States from Zika virus.

“This demonstrates that, as with Guillain Barre Syndrome cases, that there can be severe manifestations that result from Zika virus infection,” the CDC’s Tyler Sharp told NBC News. The victim had a condition called thrombocytopenia — low platelet count that can result in bleeding. Sharp said it’s a rare but known complication of Zika and not a sign that the virus is causing worse symptoms than expected. FULL REPORT