Establishment and cryptic transmission of Zika virus in Brazil and the Americas

Abstract

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil1. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 20162) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 20162). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease3. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

Proteoliposome Engineering with Cell‐Free Membrane Protein Synthesis: Control of Membrane Protein Sorting into Liposomes by Chaperoning Systems

“…In addition, IMP dysfunctions were closely related to onset of certain diseases 2. Therefore, elucidating structure and function of IMPs should accelerate understanding of biological phenomena, construction of advanced nanodevices,3 drug discovery,4 and artificial cells 5. However, isolation of IMPs with active conformations remains challenging because hydrophobic IMPs form irreversible aggregates in water.…”

Molecular mapping of Zika spread

“…Previously thought of as mild, Zika has revealed a potent capa city to damage developing neurological tissues, with devastating consequences for the children of infected mothers 1 . Three related papers [2][3][4] in this issue provide much-needed insight into when, where and how the current Zika outbreak emerged and spread. This understanding was gained thanks to a mixture of high-tech molecular-biology and evolutionary techniques, and low-tech sample-collection efforts.…”

“…The focus of two of the studies, by Faria et al 2 The groups used these genomes, along with some existing ones, to construct phylogenetic (evolutionary) trees of Zika in the Americas. In this way, they could reconstruct Zika's spread by following a trail of mutations -accumulated by virus strains that the authors sampled at different times and places -back to the outbreak's most recent common ancestor.…”

From isolate to answer: how whole genome sequencing is helping us rapidly characterise nosocomial bacterial outbreaks

“…Its portability and capacity to perform real-time analysis during sequencing has made it an attractive companion for outbreak investigations in remote regions, as was the case with the ZIBRA project 29 . Clinically, MinION sequencing has been used to retrospectively analyse S. enterica isolates in relation to a European-wide outbreak 30 , which showed that the outbreak strain could be identified from less than 2 hours of sequencing, despite not having the resolution to elucidate transmission pathways.…”