Zika Virus in Semen: What We Know and What We Need to Know

The emergence of the Zika virus (ZIKV) epidemic in South and Central America has ascended to the forefront of international attention. While research regarding the effects and details surrounding ZIKV in pregnancy is well underway, especially related to blood-borne transmission, less attention has been devoted to ZIKV infection in semen and questions concerning implications of ZIKV infection in men. In this review, we present what is known and unknown, and the implications for localization of ZIKV to the male urogenital system. We examine the duration and viral load of ZIKV in semen, male and female transmission of ZIKV, the asymptomatic male carrier, and the consequences for assisted reproductive technology and sperm banking facilities. Furthermore, we discuss the potential for active ZIKV transmission in the United States as world travel continues to rise and the evolution and case history of ZIKV sexual transmission. We also review the current government-sponsored and reproductive society recommendations for managing sexual transmission of ZIKV and elucidate future research needs.