Lying in wait: the resurgence of dengue virus after the Zika epidemic in Brazil

Anderson Brito ,Benedito Antônio Lopes Da Fonseca,Quan Minh Tran,Elaine Cristina Manini Minto,Rafael Freitas Oliveira Franca,Márcio Junio Lima Siconelli,Luzia Márcia Romanholi Passos,Mylena Ribeiro Pereira,Gabriel Luz Wallau,Luíza Antunes De Castro-Jorge ,Derek A T Cummings,Angkana T Huang,Guy Baele,Filipe Zimmer Dezordi,Joseph R Fauver,Rodrigo Dias De Oliveira Carvalho,Mary E Petrone,Rachel J Oidtman,T Alex Perkins,Chaney C Kalinich,E Kaitlynn Allen ,Guido España ,Laís Ceschini Machado ,Nathan D Grubaugh

doi:10.1038/s41467-021-22921-7

Abstract

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017–2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. In this study we use epidemiological, climatological and genomic data to investigate dengue dynamics in recent years in Brazil. First, we estimate dengue virus force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s. Our estimates reveal that DENV transmission was low in 2017–2018, despite conditions being suitable for viral spread. Our study also shows a marked decline in dengue susceptibility between 2002 and 2019, which could explain the synchronous decline of dengue in the country, partially as a result of protective immunity from prior ZIKV and/or DENV infections. Furthermore, we performed phylogeographic analyses using 69 newly sequenced genomes of dengue virus serotype 1 and 2 from Brazil, and found that the outbreaks in 2018–2019 were caused by local DENV lineages that persisted for 5–10 years, circulating cryptically before and after the Zika epidemic. We hypothesize that DENV lineages may circulate at low transmission levels for many years, until local conditions are suitable for higher transmission, when they cause major outbreaks.

Highlights

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017–2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases
We found that the recent dengue outbreaks were caused by Dengue virus (DENV) lineages circulating in Brazil before the Zika epidemic, representing lineages that endured the period of low transmission
Our results indicate that DENV established cryptic transmission for more than 5 years before causing outbreaks in 2019, perhaps due to the dynamics of population immunity or broad public health measures in the aftermath of the Zika epidemic[21,32], scenarios that may have occurred across the Americas

Summary

Introduction

After the Zika virus (ZIKV) epidemic in the Americas in 2016, both Zika and dengue incidence declined to record lows in many countries in 2017–2018, but in 2019 dengue resurged in Brazil, causing ~2.1 million cases. Human interventions, such as enhanced mosquito control, or changes in human behavior in response to the Zika epidemic could explain the decline in reported dengue cases[14,15] Ecological factors, such as local humidity and temperature, may impact the transmission dynamics of arboviral diseases[16]. Since about one-fifth of DENV infections result in clinically apparent symptoms[2,23], high levels of crossprotection could lead to lower number of severe infections, and even higher underreporting This last scenario could explain the declines in dengue cases observed in countries hard hit by DENV and ZIKV prior to dengue resurgence in 2019, like in Brazil[24], Bolivia[7], Suriname[6], and Nicaragua[5]

Methods

Results

Conclusion