Female-to-male sexual transmssion of Zika virus infection.

Dear Editor,

We read the publication on ‘The challenge given by Zika virus’ with a great interest.1 Rodriguez and Sebastian mentioned that ‘No sexual transmission of Zika virus from infected women to their partners and from infected people without symptoms has been reported’.1 Indeed, sexual transmission is a possible mode of Zika virus transmission.2 Either homosexual or heterosexual contact might be the starting point of pathogenic virus transmission.3 Regarding female-to-male sexual transmission of Zika virus, there are some reports on this problem. Davidson et al first reported a suspected female-to-male sexual transmission of Zika Virus from New York city in 2016.4 This case report had several laboratory evidences showing the possibility of disease transmission.4 After that, there are many reports on this issue.5 As noted by Sherley and Ong, ‘Unusually for a mosquito-borne virus, sexual spread has also been reported; with cases of male-to-female, female-to-male and male-to-male sexual transmission all now published in the scientific literature’.5 According to the summative analysis by Moreira et al on sexual transmission of Zika virus, female-to-male transmission is detected in 3.7%.6 Nevertheless, the common difficulty for diagnosis of a male-to-female or female-to-male sexual transmission of Zika virus is the ruling out of the chance of mosquito transmission, mosquito bite, of the two partners.7 The diagnosis requires both clinical epidemiological molecular laboratory investigations for final confirmation.7