Botosso VF, Precioso AR, Wilder-Smith A, de Oliveira DBL, de Oliveira FBL, De Oliveira CM, Soares CP, Oliveira LTL, dos Santo RMV, de Agostini Utescher CL, Coutinho FAB, Massad E. Seroprevalence of Zika in Brazil stratified by age and geographic distribution.
Epidemiol Infect 2023;
151:1-16. [PMID:
37965751 PMCID:
PMC10728971 DOI:
10.1017/s0950268823001814]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 11/16/2023] Open
Abstract
Congenital Zika is a devastating consequence of maternal Zika virus infections. Estimates of age-dependent seroprevalence profiles are central to our understanding of the force of Zika virus infections. We set out to calculate the age-dependent seroprevalence of Zika virus infections in Brazil. We analyzed serum samples stratified by age and geographic location, collected from 2016 to 2019, from about 16,000 volunteers enrolled in a Phase 3 dengue vaccine trial led by the Institute Butantan in Brazil. Our results show that Zika seroprevalence has a remarkable age-dependent and geographical distribution, with an average age of the first infection varying from region to region, ranging from 4.97 (3.03–5.41) to 7.24 (6.98–7.90) years. The calculated basic reproduction number, , varied from region to region, ranging from 1.18 (1.04–1.41) to 2.33 (1.54–3.85). Such data are paramount to determine the optimal age to vaccinate against Zika, if and when such a vaccine becomes available.
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