The research demonstrated that the coronavirus infected the prostate, penis, testicles and surrounding blood vessels in three male rhesus macaques. The monkeys were examined with whole body scans specially designed to detect sites of infection.

Scientists — who expected to find the coronavirus in spots like the lungs but did not know where else they would find it — were somewhat surprised by the discovery.

“The signal that jumped out at us was the complete spread through the male genital tract,” said Thomas Hope, the paper’s senior author and a professor of cell and developmental biology at Northwestern University Feinberg School of Medicine in Chicago. “We had no idea we would find it there.”