# Syndemic Factors Associated with Zika Virus Infection Prevalence and Risk Factors in a Cohort of Women Living in Endemic Areas for Arboviruses in Northeast Brazil

## TL;DR

This study explores how social, environmental, and health factors together influence Zika virus infection rates in women in Brazil.

## Contribution

The study introduces a syndemic approach to understanding Zika virus prevalence linked to socioeconomic and environmental factors.

## Key findings

- Zika virus baseline prevalence was 43%, increasing to 44.7% after follow-up.
- Women with more syndemic factors had higher odds of Zika virus infection.
- Tailored interventions targeting syndemic conditions are needed to reduce Zika's impact.

## Abstract

Background: We sought to explain the seroprevalence of Zika Virus (ZIKV) as a syndemic of socioeconomic, environmental, and health factors in a cohort of women living in Brazil. Methods: This is a cohort study comprising 1498 women between 15 and 39 years of age followed up in two waves between February 2018 and August 2019. Two questionnaires addressed the arbovirus’s socioeconomic, demographic, and behavioral aspects and participants’ arbovirus infection history. Blood samples were collected to detect IgM and IgG for ZIKV, chikungunya virus (CHIKV), and dengue virus (DENV), and RT-PCR for ZIKV. Results: The baseline prevalence for ZIKV was 43% (95%CI: 40.5, 45.6), increasing to 44.7% in the following period (95%CI: 42, 47.1). We found a prevalence of 44.1% among women having one syndemic factor, 49.9% for those having two, and 58% for women having three or more factors. Women reporting a single syndemic factor resulted in higher odds of acquiring ZIKV (OR = 1.6, 95%CI: 1.2–2.4). There were increased adjusted odds among women having two or three or more factors (OR = 2.1, 95%CI: 1.6–3.1; OR = 2.9, 95%CI: 2.0–4.3, respectively). Conclusions: Tailored interventions targeting syndemic conditions, such as the co-circulation of urban arboviruses and poor living conditions, are crucial to improving the burden produced by ZIKV.