Zika virus

El virus del Zika es un arbovirus emergente. Se transmite por medio de los mosquitos del género Aedes. Fue descrito por primera vez en mosquitos y monos del bosque Zika en Uganda, en 1947; posteriormente, en seres humanos en el África sub-sahariana para luego llegar al sureste asiático a mediados del siglo XX. En el presente siglo, se diseminó por las islas del Pacífico y llegó a Suramérica, específicamente, en el 2014. Desde entonces, se ha diseminado rápidamente por todo el continente americano; llegó al sur de los Estados Unidos a principios de este año 2016. Desde el punto de vista clínico, se parece mucho a la enfermedad febril causada por los virus del dengue y chikungunya. Sin embargo, recientemente, y por el gran número de personas infectadas en el continente americano, se le ha asociado con la aparición de infecciones congénitas que causan microcefalia y con síndrome de parálisis tipo GuillainBarré. Costa Rica ya reportó el primer caso importado y es muy probable que el virus esté circulando en los mosquitos vectores. La presente revisión tiene como objetivo brindar información acerca de este arbovirus emergente y discutir su diagnóstico.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET

A Fluorescent Real-Time Plaque Assay Enables Single-Cell Analysis of Virus-Induced Cytopathic Effect by Live-Cell Imaging

Conventional plaque assays rely on the use of overlays to restrict viral infection allowing the formation of distinct foci that grow in time as the replication cycle continues leading to countable plaques that are visualized with standard techniques such as crystal violet, neutral red, or immuno- labeling. This classical approach takes several days until large enough plaques can be visualized and counted with some variation due to subjectivity in plaque recognition. Since plaques are clonal lesions produced by virus-induced cytopathic effect, we applied DNA fluorescent dyes with differen- tial cell permeability to visualize them by live-cell imaging. We could observe different stages of that cytopathic effect corresponding to an early wave of cells with chromatin-condensation followed by a wave of dead cells with membrane permeabilization within plaques generated by different animal viruses. This approach enables an automated plaque identification using image analysis to increase single plaque resolution compared to crystal violet counterstaining and allows its application to plaque tracking and plaque reduction assays to test compounds for both antiviral and cytotoxic activities. This fluorescent real-time plaque assay sums to those next-generation technologies by combining this robust classical method with modern fluorescence microscopy and image analysis approaches for future applications in virologyInternational Centre for Genetic Engineering and Biotechnology Grant CRP/CRI18-02.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

Síndrome Respiratorio de Medio Oriente causado por un coronavirus y el Hajj: ¿potencial para una emergencia internacional?

La epidemiología de enfermedades infecciosas en eventos de concentración masiva requiere de un amplio planeamiento y control por parte de los centros de salud de cada país involucrado. El Síndrome Respiratorio de Medio Oriente causado por un coronavirus es causado por un nuevo virus identificado en Medio Oriente en el 2012. Hasta octubre del 2013 se cuentan con 138 casos confirmados por laboratorio con 60 muertes. Cada año, alrededor de dos millones de peregrinos se dirigen hacia La Meca en Arabia Saudita durante el Hajj, una de las concentraciones religiosas masivas más importantes del mundo. Este año se presenta una alerta particular por el Hajj dado que el coronavirus podría ser potencialmente diseminado hacia otros países debido a la movilización de personas que implica este acontecimiento. América posee 4,6 millones de residentes musulmanes, por lo que un adecuado seguimiento de las personas que viajaron a Medio Oriente es imperativo para evitar la diseminación de este coronavirus hacia el continente. La siguiente revisión tiene como objetivo actualizar al lector sobre el tema, brindando información general de los coronavirus, especialmente sobre el que causa el Síndrome Respiratorio de Medio Oriente, la historia en el surgimiento de la enfermedad y sus manifestaciones clínicas; se propone además una serie de recomendaciones generales para las autoridades de salud de cada país para evitar así una epidemia. (MED. UIS. 2013;27(1):25-33)Infectious diseases epidemiology during a mass gathering requires ample planning and implementation of control measures by health authorities in each country involved. Middle East Respiratory Syndrome caused by a coronavirus is caused by a newly identified virus in the Middle East during 2012. Until October 2013, 138 laboratory confirmed cases with 60 deaths have been reported. Every year, almost two million pilgrims direct themselves towards the Mecca in Saudi Arabia during the Hajj, one of the most important religious massive gatherings worldwide. This year represents a particular alert for this event due to the possibility that Middle East Respiratory Syndrome caused by a coronavirus can thus be disseminated throughout the world because of pilgrims’ mobilization. The American continent possesses 4.6 million Muslim residents that may participate in this event. Therefore, an adequate surveillance of the people who traveled to the Middle East is mandatory in order to avoid virus dissemination to our continent. Here we present an up-to-date topic revision, giving general information about coronaviruses, emphasizing on the coronavirus causing the Middle East Respiratory Syndrome, the history of its emerging and its clinical manifestations. We propose also a series of general recommendations directed to the health authorities of each country for appropriate control of disease to prevent dissemination and a potential epidemic. (MED. UIS. 2013;27(1):25-33

In Vitro Inhibition of Zika Virus Replication with Amantadine and Rimantadine Hydrochlorides

Zika virus (ZIKV) is a mosquito-borne flavivirus in which human infection became relevant during recent outbreaks in Latin America due to its unrecognized association with fetal neurological disorders. Currently, there are no approved effective antivirals or vaccines for the treatment or prevention of ZIKV infections. Amantadine and rimantadine are approved antivirals used against susceptible influenza A virus infections that have been shown to have antiviral activity against other viruses, such as dengue virus (DENV). Here, we report the in vitro effectiveness of both amantadine and rimantadine hydrochlorides against ZIKV replication, resulting in a dose-dependent reduction in viral titers of a ZIKV clinical isolate and two different ZIKV reference strains. Additionally, we demonstrate similar in vitro antiviral activity of these drugs against DENV-1 and yellow fever virus (YFV), although at higher drug concentrations for the latter. ZIKV replication was inhibited at drug concentrations well below cytotoxic levels of both compounds, as denoted by the high selectivity indexes obtained with the tested strains. Further work is absolutely needed to determine the potential clinical use of these antivirals against ZIKV infections, but our results suggest the existence of a highly conserved mechanism across flavivirus, susceptible to be blocked by modified more specific adamantane compounds.Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

Chikungunya: un virus que nos acecha

El virus chikungunya representa una amenaza para Costa Rica. Este arbovirus ha sido introducido al continente americano desde finales de 2013. Debido a sus características epidemiológicas y virológicas, y a la presencia de sus vectores en el país, este virus puede llegar a convertirse en la nueva enfermedad endémica de Costa Rica. Aunque el chikungunya tiene una baja tasa de mortalidad, su alta tasa de ataque podría colapsar el sistema de salud nacional durante una epidemia. En esta revisión se resume aspectos clínicos, virológicos, epidemiológicos y entomológicos relacionados con esta virosis, para identificar, diagnosticar y diferenciar posibles casos de fiebre por chikungunya en el país. Además, se enfatiza en el control epidemiológico y de vectores, para prevenir epidemias de esta enfermedad en Costa Rica.Chikungunya virus represents a threat to Costa Rica. This arbovirus was introduced to the American continent during the last trimester of 2013. Due to its epidemiological and virological characteristics, as well as to the presence of its vectors in the territory, chikungunya could become the next novel endemic disease in Costa Rica. Although chikungunya has a low mortality rate, its high rate of attack could cause a collapse of the national health system during an epidemic. In this review we summarize the clinical, virological, epidemiological and entomological characteristics associated to chikungunya virus for a proper identification, diagnosis and differentiation of chikungunya fever cases in the country. Furthermore, we emphasize the importance of the epidemiological and vector control in order to prevent epidemics of this disease in Costa Rica.UCR::Vicerrectoría de Docencia::Salud::Facultad de MicrobiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET

Middle East Respiratory Syndrome caused by a coronavirus and Hajj: an international health threat?

La epidemiología de enfermedades infecciosas en eventos de concentración masiva requiere de un amplio planeamiento y control por parte de los centros de salud de cada país involucrado. El Síndrome Respiratorio de Medio Oriente causado por un coronavirus es causado por un nuevo virus identificado en Medio Oriente en el 2012. Hasta octubre del 2013 se cuentan con 138 casos confirmados por laboratorio con 60 muertes. Cada año, alrededor de dos millones de peregrinos se dirigen hacia La Meca en Arabia Saudita durante el Hajj, una de las concentraciones religiosas masivas más importantes del mundo. Este año se presenta una alerta particular por el Hajj dado que el coronavirus podría ser potencialmente diseminado hacia otros países debido a la movilización de personas que implica este acontecimiento. América posee 4,6 millones de residentes musulmanes, por lo que un adecuado seguimiento de las personas que viajaron a Medio Oriente es imperativo para evitar la diseminación de este coronavirus hacia el continente. La siguiente revisión tiene como objetivo actualizar al lector sobre el tema, brindando información general de los coronavirus, especialmente sobre el que causa el Síndrome Respiratorio de Medio Oriente, la historia en el surgimiento de la enfermedad y sus manifestaciones clínicas; se propone además una serie de recomendaciones generales para las autoridades de salud de cada país para evitar así una epidemia.Infectious diseases epidemiology during a mass gathering requires ample planning and implementation of control measures by health authorities in each country involved. Middle East Respiratory Syndrome caused by a coronavirus is caused by a newly identified virus in the Middle East during 2012. Until October 2013, 138 laboratory confirmed cases with 60 deaths have been reported. Every year, almost two million pilgrims direct themselves towards the Mecca in Saudi Arabia during the Hajj, one of the most important religious massive gatherings worldwide. This year represents a particular alert for this event due to the possibility that Middle East Respiratory Syndrome caused by a coronavirus can thus be disseminated throughout the world because of pilgrims’ mobilization. The American continent possesses 4.6 million Muslim residents that may participate in this event. Therefore, an adequate surveillance of the people who traveled to the Middle East is mandatory in order to avoid virus dissemination to our continent. Here we present an up-to-date topic revision, giving general information about coronaviruses, emphasizing on the coronavirus causing the Middle East Respiratory Syndrome, the history of its emerging and its clinical manifestations. We propose also a series of general recommendations directed to the health authorities of each country for appropriate control of disease to prevent dissemination and a potential epidemic.UCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Salud::Maestría Académica en MicrobiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET

Highly individual patterns of virus‑immune IgG effector responses in humans

t IgG responses are fundamental to adaptive immunity and document immunological memory of previous pathogen encounter. While specific antigen recognition is mediated by the variable F(ab′)2 domain of IgG, various effector functions become activated via the constant Fcγ part bridging IgG-opsonized targets to FcγR-expressing immune effector cells. Traditionally, neutralizing IgG is considered the most appropriate correlate of protective humoral immunity to viruses. However, evidence is increasing that antiviral IgG mediates protection to viruses via activation of FcγRs. Using a test system allowing quantitative detection of virus-immune IgG able to activate FcγRs, sera of healthy individuals and vaccinees were assessed with regard to two prototypical human pathogenic viruses: measles and human cytomegalovirus. Marked differences in the capacity of individuals to generate FcγRI-, FcγRIIand FcγRIII-activating responses were noted. Comparison of FcγR-activating IgG with neutralizing and ELISA IgG concentrations did not correlate for HCMV and only very poorly for MV. Since neither neutralizing IgG nor overall IgG responses faithfully predict the activation of FcγRs, only the simultaneous quantification of IgGs activating defined FcγRs will aid to delineate individual “immunograms” of virus IgG immunity. Such new multiparametric assessment of antiviral IgG qualities could be instrumental in defining correlates of protection and disease progression.Deutsche Forschungsgemeinschaft/[He 2526/6-2, GK1045]//AlemaniaHelmholtz Association/[VISTRIE VH-VI-242]//European Commission/[QLRT-2001-01112]//European Commission/[MRTN-CT-2005-019248]//UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET

Sloths host Anhanga virus‐related phleboviruses across large distances in time and space

Sloths are genetically and physiologically divergent mammals. Phleboviruses are major arthropod-borne viruses (arboviruses) causing disease in humans and other animals globally. Sloths host arboviruses, but virus detections are scarce. A phlebovirus termed Anhanga virus (ANHV) was isolated from a Brazilian Linnaeus's two-toed sloth (Choloepus didactylus) in 1962. Here, we investigated the presence of phleboviruses in sera sampled in 2014 from 74 Hoffmann's two-toed (Choloepus hoffmanni, n = 65) and three-toed (Bradypus variegatus, n = 9) sloths in Costa Rica by broadly reactive RT-PCR. A clinically healthy adult Hoffmann's two-toed sloth was infected with a phlebovirus. Viral load in this animal was high at 8.5 × 107 RNA copies/ml. The full coding sequence of the virus was determined by deep sequencing. Phylogenetic analyses and sequence distance comparisons revealed that the new sloth virus, likely representing a new phlebovirus species, provisionally named Penshurt virus (PEHV), was most closely related to ANHV, with amino acid identities of 93.1%, 84.6%, 94.7% and 89.0% in the translated L, M, N and NSs genes, respectively. Significantly more non-synonymous mutations relative to ANHV occurred in the M gene encoding the viral glycoproteins and in the NSs gene encoding a putative interferon antagonist compared to L and N genes. This was compatible with viral adaptation to different sloth species and with micro-evolutionary processes associated with immune evasion during the genealogy of sloth-associated phleboviruses. However, gene-wide mean dN/dS ratios were low at 0.02–0.15 and no sites showed significant evidence for positive selection, pointing to comparable selection pressures within sloth-associated viruses and genetically related phleboviruses infecting hosts other than sloths. The detection of a new phlebovirus closely-related to ANHV, in sloths from Costa Rica fifty years after and more than 3,000 km away from the isolation of ANHV confirmed the host associations of ANHV-related phleboviruses with the two extant species of two-toed sloths

Specific Mutations in the PB2 Protein of Influenza A Virus Compensate for the Lack of Efficient Interferon Antagonism of the NS1 Protein of Bat Influenza A-Like Viruses

Recently, two new influenza A-like viruses have been discovered in bats, A/little yellow-shouldered bat/Guatemala/060/2010 (HL17NL10) and A/flat-faced bat/Peru/033/2010 (HL18NL11). The hemagglutinin (HA)-like (HL) and neuraminidase (NA)-like (NL) proteins of these viruses lack hemagglutination and neuraminidase activities, despite their sequence and structural homologies with the HA and NA proteins of conventional influenza A viruses. We have now investigated whether the NS1 proteins of the HL17NL10 and HL18NL11 viruses can functionally replace the NS1 protein of a conventional influenza A virus. For this purpose, we generated recombinant influenza A/Puerto Rico/8/1934 (PR8) H1N1 viruses containing the NS1 protein of the PR8 wild-type, HL17NL10, and HL18NL11 viruses. These viruses (r/NS1PR8, r/NS1HL17, and r/NS1HL18, respectively) were tested for replication in bat and nonbat mammalian cells and in mice. Our results demonstrate that the r/NS1HL17 and r/NS1HL18 viruses are attenuated in vitro and in vivo. However, the bat NS1 recombinant viruses showed a phenotype similar to that of the r/NS1PR8 virus in STAT1/ human A549 cells and mice, both in vitro and in vivo systems being unable to respond to interferon (IFN). Interestingly, multiple mouse passages of the r/NS1HL17 and r/NS1HL18 viruses resulted in selection of mutant viruses containing single amino acid mutations in the viral PB2 protein. In contrast to the parental viruses, virulence and IFN antagonism were restored in the selected PB2 mutants. Our results indicate that the NS1 protein of bat influenza A-like viruses is less efficient than the NS1 protein of its conventional influenza A virus NS1 counterpart in antagonizing the IFN response and that this deficiency can be overcome by the influenza virus PB2 protein.Universidad de Costa Rica/[803-B4-656]/UCR/Costa RicaCenter for Research on Influenza Pathogenesis (CRIP)NIAID-funded Center of Excellence for Influenza Research and Surveillance (CEIRS)Deutsche Forschungsgemeinschaft (SCHW632/15-1)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

Heterologous hyperimmune polyclonal antibodies against SARS-COV-2: A broad coverage, affordable, and scalable potential immunotherapy for Covid-19

The emergence and dissemination of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resulting COVID-19 pandemic triggered a global public health crisis. Although several SARS-CoV-2 vaccines have been developed, demand far exceeds supply, access to them is inequitable, and thus, populations in low- and middle-income countries are unlikely to be protected soon (1). Furthermore, there are no specific therapies available, which is a challenge for COVID-19 patient care (2). Thus, the appearance of SARS-CoV-2 variants and reports of reinfections associated with immune escape (3, 4) highlight the urgent need for effective and broad coverage COVID-19 therapeutics. Intravenous administration of human or heterologous antibodies is a therapy successfully used in patients with viral respiratory diseases (5). Accordingly, formulations containing SARS-CoV-2 specific antibodies are an attractive therapeutic option for COVID-19 patients (6). SARS-CoV-2 specific antibodies could limit infection by direct virion neutralization and/or by targeting infected cells for elimination via complement or antibody-mediated cytotoxicity (6). Specific SARS-CoV-2 antibody-based therapeutics include convalescent plasma (CP), monoclonal antibodies (mAbs), human polyclonal IgG formulations purified from CP or transgenic animals, and heterologous hyperimmune polyclonal antibodies (pAbs) (6). Although the window for using antibody-based therapeutics varies, clinical data show that they are mainly effective if administered early after symptoms onset (6).Universidad de Costa Rica/[741-C0-198]/UCR/Costa RicaCaja Costarricense del Seguro Social/[]/CCSS/Costa RicaBanco Centroamericano de Integración Económica/[]/BCIE/Costa RicaGerman academic exchange services/[57592642]/DAAD/AlemaniaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET