The genius plague
(Book)

"What if the pandemic you thought would kill you made you more intelligent instead? In the Amazon jungle, a disease is spreading. To those who survive, it grants enhanced communication, memory, and pattern recognition. But the miracle may be the sinister survival mechanism of a fungal organism, manipulating the infected into serving it. Paul Johns, a mycologist, is convinced the fungal host is the next stage of human evolution, while his brother Neil, an analyst at the NSA, is committed to its destruction. Is the human race the master in this symbiotic relationship, or are we becoming the pawns of a subtly dominating and utterly alien intelligence?"--,Provided by publisher.