Zika Virus and Sexual Transmission: A New Route of Transmission for Mosquito-borne Flaviviruses


Beginning in 2015, concern over a new global epidemic has spread in the media, governmental agencies, legislative bodies and the public at large. This newly emerging threat has been reported to cause symptoms ranging from mild fever, rash, and body aches, to severe birth defects and acute onset paralysis. The causative agent of this disease, Zika virus, is closely related to two other important human pathogens, dengue and West Nile Virus (WNV), but has some distinguishing features that has raised alarms from the scientific community. Like its two close relatives, this virus is a member of the Flaviviridae family, a class of single stranded RNA viruses with a positive sense genome and is spread primarily via the bite of an infected mosquito. However, this virus has demonstrated another route of transmission that is particularly concerning for people outside of the regions where the main mosquito vector for this virus is present. Sexual transmission of Zika virus has been increasingly reported, from both infected males and females to their partner, which has resulted in the World Health Organization (WHO) and the Center for Disease Control (CDC) issuing warnings to those living in or travelling to areas of Zika transmission to practice abstinence and/or avoid unprotected sexual contact for up to six months after infection with this virus. This perspective will outline the evidence for sexual transmission and persistence of viral infection in semen and vaginal secretions as well as review the animal models for sexual transmission of Zika virus.