ABSTRACT
Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). 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 disease. 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.
Subject(s)
Zika Virus Infection/transmission , Zika Virus Infection/virology , Zika Virus/isolation & purification , Americas/epidemiology , Basic Reproduction Number , Brazil/epidemiology , Genetic Variation , Genome, Viral/genetics , Humans , Microcephaly/epidemiology , Microcephaly/virology , Molecular Epidemiology , Phylogeography , Spatio-Temporal Analysis , Zika Virus/genetics , Zika Virus Infection/epidemiologyABSTRACT
The present study evaluated the effect of storage conditions on the LDL efficacy for cryopreserving ovine sperm. In this way, we compared egg yolk extender with three different forms for LDL storing, LDL diluted in Tris-glucose extender and stored in frozen (i) and freeze-dried (ii) states and LDL stored pure and added into the extender prior to use (iii). We also tested the effect of two storage temperatures (-20 and -80 °C) and three storage times (30, 60, 120 d). Frozen and freeze-dried extenders containing LDL, as well as LDL stored pure, improved post-thaw sperm quality. Storage temperatures did not influence negatively the cryoprotectiveness of LDL extenders. Furthermore, lyophilised LDL extenders stored at -20 °C were more effective in preserving sperm longevity than the other extenders stored at -20 °C. Finally, LDL extenders stored for 30 and 120 d were more efficient than 60 d in preserving ram sperm freezability.
Subject(s)
Cryopreservation/methods , Cryoprotective Agents/pharmacology , Lipoproteins, LDL/pharmacology , Semen Preservation/methods , Animals , Freeze Drying , Freezing , Male , Sheep , Sperm Motility/drug effects , Spermatozoa/drug effects , TemperatureABSTRACT
This paper is an historical review of the health policy in Brazil. Ranged since the arrival of the real portuguese family to Brazil until nowadays. The review intent to contextualize present facts based on historical, social and political facts for the needed foundation to give best comprehension of the ways in which is organizing the health policy in Brazil.
