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.

ResumoEste trabalho teve por objetivos delimitar e caracterizar o campo de estudos sobre avaliação das intervenções breves (IB) para o uso abusivo de álcool em atenção primária à saúde. Utilizaram-se estratégias de busca bibliográfica em bases de dados (Medline, PsycInfo, Lilacs), para identificar estudos empíricos -ensaio clínico -de avaliação de resultados comparativos da aplicação de IB na atenção primária, publicados entre janeiro de 1990 e dezembro de 2003. Foram encontrados 26 estudos, a maior parte deles realizada nos Estados Unidos da América, em 1997, que avaliaram a efetividade de intervenções de aconselhamento breve junto a usuários problemáticos de álcool, com aplicação de material didático e reavaliação posterior. Em sua maioria, mostraram que IB reduzem o consumo do álcool. O delineamento usual foi do tipo longitudinal, de ensaio clínico randomizado. A medida de desfecho mais freqüente foi o padrão de consumo de bebidas alcoólicas. Não houve padronização das intervenções, relatadas como eficazes em 25 estudos. Não foram encontrados estudos latino-americanos ou do Caribe no Lilacs.Palavras-chave: abuso de álcool; intervenções breves; cuidados primários de saúde; revisão de literatura. Summary This work aimed to identify, and characterize the field of evaluation studies of brief interventions (BI) for alcohol abuse in primary health care. A bibliographical search was carried out, using databases (Medline Brief Interventions for Alcohol Abuse in Primary Health CareIntervenções breves para o uso abusivo de álcool em atenção primária

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After Zika virus (ZIKV) emerged and caused an epidemic in the Americas in 2016, both Zika and dengue incidence declined in the following years (2017-2018) to a record low in many countries. Following this period of low incidence, dengue resurged in 2019 in Brazil, causing ~2.1 million cases. The reasons for the recent fluctuations in dengue incidence and the maintenance of dengue virus (DENV) through periods of low transmission are unknown. To investigate this, we used a combination of epidemiological and climatological data to estimate dengue force of infection (FOI) and model mosquito-borne transmission suitability since the early 2000s in Brazil. Our estimates of FOI revealed that the rate of DENV transmission in 2018-2019 was exceptionally low, due to a low proportion of susceptible population rather than changes to ecological conditions. This supports the hypothesis that the synchronous decline of dengue in Brazil may be explained by protective immunity from pre-exposure to ZIKV and/or DENV in prior years. Furthermore, we sequenced 69 genomes of dengue virus serotype 1 (DENV-1) and DENV-2 circulating in Northeast and Southeast Brazil, and performed phylogeographic analyses to uncover patterns of viral spread. We found that the outbreaks in Brazil in 2019 were caused by DENV lineages that were circulating locally prior to the Zika epidemic and spread cryptically during the period of low transmission. Despite the period of low transmission, endemic DENV lineages persisted for 5-10 years in Brazil before causing major outbreaks. Our study challenges the paradigm that dengue outbreaks are caused by recently introduced new lineages, but rather they may be driven by established lineages circulating at low levels until the conditions are conducive for outbreaks.