They obtained specimens twice monthly for 6 months. Samples were tested for Zika RNA using real-time reverse transcriptase polymerase chain reaction assay and for infectious Zika virus using Vero cell culture and plaque assay.
Investigators detected Zika virus RNA in the semen of 60 men (33%), including semen samples from 22 of the 36 men (61%) tested within 30 days after illness onset, investigators said in the report.
While Zika virus RNA shedding decreased considerably in the 3 months after illness onset, it did continue for 281 days in one man, they noted.
Men who were older and those who ejaculated less frequently were more likely to have prolonged RNA shedding in semen, results of multivariable analysis showed.