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Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC).Evidence favoring a causative role for ZIKV in microcephaly has emerged and was the object of several publications. For instance, ZIKV was detected in the amniotic fluids of two fetuses that presented microcephaly, which strongly suggests intrauterine transmission 7 . In addition, detection of the virus together with numerous alterations in the brain of an aborted fetus, while the virus was not detected in any other fetal tissue, also suggested a neurotropism 8 . Epidemiological data showed varied percentage of risk of microcephaly when infection occurs in the first trimester in different geographical locations, suggesting that other factors such as virus strain and co-infections may also contribute to the development of congenital defects 9 . Therefore, the understanding of the mechanisms involved in the neurotoxicity caused by ZIKV is of great relevance.Studies in animal models have also reinforced the link between ZIKV infection and congenital malformations 10-12 . These, however, do not reproduce properly the human infection, since mice are resistant to ZIKV

Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration.

Zika virus (ZIKV), a flavivirus, and chikungunya virus (CHIKV), an alphavirus, are infectious RNA arboviruses transmitted to humans by the bite of Aedes species mosquitoes. Both viruses have only recently emerged in the Western Hemisphere (1, 2), and along with dengue virus (DENV), another flavivirus, now circulate widely in Brazil. The acute illness caused by these viruses, characterized by fever, rash, myalgia, arthralgia, and conjunctivitis, is nonspecific, and differential diagnosis on the basis of clinical findings alone is challenging. Later infectious sequelae include chronic arthritis for CHIKV (2) and encephalitis, immune-mediated syndromes, and stroke for DENV (3). Recently, the association between ZIKV infection and severe fetal complications such as microcephaly in pregnant women has been established (4), and the virus has also been linked to neurological complications such as Guillain-Barré syndrome (5). Thus, broadbased assays are needed for differential diagnosis of vectorborne febrile illnesses and to identify potential coinfections. Here we report the utility of metagenomic next-generation sequencing (mNGS) as a screening tool to identify coinfections and the use of genome recovery and phylogenetic analyses directly from patient serum samples in the context of the ongoing ZIKV outbreak. We also show that the clinical presentation of arboviral coinfections seems to favor the virus present at a higher titer in acutely infected individuals. MATERIALS AND METHODSZIKV serum sample collection, ZIKV RT-PCR, and DENV antibody testing. Written consent from patients was obtained under a study protocol approved by the Brazil Ministry of Health (Certificado de Apresentação para Apreciação Ética 45483115.0.0000.0046, no. 1159.184, Brazil). Serum samples were obtained from 15 patients seen at Aliança Hospital in Salvador, Bahia, Brazil, from April 2015 to January 2016 who were given a presumptive diagnosis of an acute viral illness by emergency department physicians and were found to be positive by qualitative reverse transcription-PCR (RT-PCR) testing for ZIKV. Serum samples Bahia01 to Bahia15 were subjected to RNA extraction using the QIAamp viral RNA minikit (Qiagen), and RNA was reverse transcribed using the Superscript II reverse transcriptase kit (Invitrogen), followed by qualitative RT-PCR testing for ZIKV using primers targeting the NS5 gene (6). Serum samples were also tested for DENV infection using an enzyme-linked immunosorbent assay (ELISA) specific for the NS1 antigen and anti-DENV IgG/IgM according to the manufacturer's instructions (Dengue Duo Test; Bioeasy Diagnostica, Brazil).Metagenomic next-generation sequencing. A separate serum aliquot was extracted for total nucleic acid using the Qiagen viral RNA minikit (Qiagen), followed by DNase treatment using a cocktail of Turbo DNase (Thermo Fisher Scientific) and Baseline-Zero DNase (Epicentre Biotechnologies), followed by NGS library construction using the NexteraXT kit (Illumina) as previously described (7,8). Runs of single-end, 160-base pair...

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AbsractWe report the presence of Chikungunya (CHIKV) RNA in the blood, urine and semen during the acute phase of the disease in an adult with a dual infection with Dengue virus type 3. The patient, a 25 yr-old man from Salvador, Brazil, reported a 6-day duration of high fever, arthralgia, myalgia, headache and photophobia.Blood and semen specimens were positive for CHIKV in the first collected samples; semen and urine specimens were positive for CHIKV after 30 days of symptoms onset. DENV-3 RNA was positive in blood specimen when first collected 6 days after the initiation of symptoms.We describe for the first time the presence of CHIKV RNA in urine and semen for an extended period of time and we address the possible implications of these findings for diagnosis and transmission dynamics.