infectious diseases
Zika Virus (ZV) Infections
Transmission of Zika Virus
During the first week of infection, the Zika virus is present in blood. Mosquitoes can acquire the virus when they bite infected people; the mosquitoes can then transmit the virus to other people through bites. Travelers from areas of ongoing Zika virus transmission may have Zika virus in their blood when they return home, and if mosquito vectors are present locally, transmission of Zika virus is possible there. However, because contact betweenAedesmosquitoes and people is infrequent in most of the continental United States and Hawaii (because of mosquito control and people living and working in screened and in air-conditioned environments), local transmission of Zika virus is expected to be rare and limited. Although the Zika virus is transmitted primarily by mosquitoes, other modes of transmission are possible. They include Sexual transmission (including vaginal, anal, and oral sex) Intrauterine transmission from mother to fetus, resulting in congenital infection Blood transfusion Organ or tissue transplantation (theoretically) The Zika virus, like the viruses that cause Dengue , Zika virus is present in semen and can be transmitted by men to their sex partners through sexual intercourse, including vaginal and anal sex and probably oral sex (fellatio), even when the men do not have symptoms. Zika virus persists in semen much longer than in blood, vaginal fluids, and other body fluids. Both male-to-female and male-to-male transmission during unprotected sexual activity (no condoms) has occurred (see also theCDC: Clinical Guidance for Healthcare Providers for Prevention of Sexual Transmission of Zika Virus). Zika virus may also be transmitted by men or women to their sex partners when sex toys are shared, even when infected people have no symptoms. Zika virus also persists in vaginal secretions after it disappears from blood and urine; female-to-male sexual transmission of Zika virus infection has been reported ( Transmission references ). A study in Guatemala reported viral RNA shedding in vaginal secretions intermittently for up to 6 months. However, detection of viral RNA does not prove presence of infectious virus, because polymerase chain reaction may detect one or more gene fragments, not necessarily infectious virus. Transmission by blood transfusion has been reported in Brazil; however, at present, no cases of transmission by blood transfusion have been confirmed in the United States (see also theZika and Blood & Tissue Safety). 1.Colt S, Garcia-Casal MN, Peña-Rosas JP, et al: Transmission of Zika virus through breast milk and other breastfeeding-related bodily-fluids: A systematic review.PLoS Negl Trop Dis11(4):e0005528. 2017. Published 2017 Apr 10. doi:10.1371/journal.pntd.0005528 2.CDC media statement: First female-to-male sexual transmission of Zika virus infection reported in New York City. July 2016. 