Persistence of Zika Virus in Body Fluids — Final Report

THE AUTHORS REPLY:

In reply to Sánchez-Montalvá and colleagues: in contrast to dengue, which has a well-defined spectrum of severe disease, most cases of noncongenital ZIKV disease are mild, except for rare complications such as Guillain–Barré syndrome.¹ In the participants in our study, the signs and symptoms were consistent with uncomplicated ZIKV disease. Furthermore, with respect to the duration of detectable ZIKV RNA, we saw no difference between the 35% of participants who were enrolled at outpatient clinics and those who were enrolled at emergency departments (P = 0.22). We agree that it is not known whether humans can be reinfected with ZIKV; however, studies in mice have shown protection from reinfection, including an absence of detectable viremia.² In vitro evidence of antibody-dependent enhancement can occur in flaviviruses in the absence of in vivo evidence.³ A study from Colombia showed no evidence of in vivo enhancement of ZIKV in patients with previous dengue virus infection.⁴ Moreover, findings in men from the continental United States, where dengue virus rarely circulates, were similar to those of our study.⁵ Finally, sexual transmission contributes to a small percentage of ZIKV infections and would not affect our findings.