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Objective To examine the diagnostic performance of real-time reverse transcription (RT)-polymerase chain reaction (PCR) assays for Zika virus detection. Methods We compared seven published real-time RT-PCR assays and two new assays that we have developed. To determine the analytical sensitivity of each assay, we constructed a synthetic universal control ribonucleic acid (uncRNA) containing all of the assays' target regions on one RNA strand and spiked human blood or urine with known quantities of African or Asian Zika virus strains. Viral loads in 33 samples from Zika virus-infected patients were determined by using one of the new assays. Findings Oligonucleotides of the published real-time RT-PCR assays, showed up to 10 potential mismatches with the Asian lineage causing the current outbreak, compared with 0 to 4 mismatches for the new assays. The 95% lower detection limit of the seven most sensitive assays ranged from 2.1 to 12.1 uncRNA copies/reaction. Two assays had lower sensitivities of 17.0 and 1373.3 uncRNA copies/reaction and showed a similar sensitivity when using spiked samples. The mean viral loads in samples from Zika virus-infected patients were 5 x 104 RNA copies/mL of blood and 2 x [10.sup.4] RNA coples/mL of urine. Conclusion We provide reagents and updated protocols for Zika virus detection suitable for the current outbreak strains. Some published assays might be unsuitable for Zika virus detection, due to the limited sensitivity and potential incompatibility with some strains. Viral concentrations in the clinical samples were close to the technical detection limit, suggesting that the use of insensitive assays will cause false-negative results. Objectif Etudier la performance diagnostique des tests bases sur l'amplification en chaine par polymerase (PCR) en temps reel apres transcription inverse (RT) pour detecter le virus Zika. Methodes Nous avons compare sept tests publies utilisant la RT-PCR en temps reel et deux nouveaux tests developpes par nos soins. Afin de determiner la sensibilite analytique de chaque test, nous avons concu un acide ribonucleique synthetique de controle universel (ARNcun) contenant toutes les regions ciblees par les tests sur une helice ARN et enrichi de l'urine ou du sang humain de quantites connues de souches africaines ou asiatiques du virus Zika. Les charges virales dans 33 echantillons provenant de patients infectes par le virus Zika ont ete determinees a l'aide de l'un des nouveaux tests. Resultats Les oligonucleotides des tests publies utilisant la RT-PCR en temps reel ont presente jusqu'a TOmauvais apparlements potentiels avec la lignee asiatique provoquant l'epidemie actuelle, alors qu'on a constate de 0 a 4 mauvais appariements dans le cas des nouveaux tests. La limite de detection inferieure a 95% des sept tests les plus sensibles variait de 2,1 a 12,1 copies dARNcun/reaction. Deux tests presentaient des sensibilites plus basses de 17,0 et 1373,3 copies d'ARNcun/reaction et montraient une sensibilite similaire lorsque des echantillons enrichis etaient utilises. Les charges virales moyennes dans les echantillons provenant de patients infectes par le virus Zika etaient de 5 x 104 copies d'ARN/mL de sang et de 2 x 104 copies dARN/mL d'urine. Conclusion Nous proposons pour detecter le virus Zika des reactifs et des protocoles actualises, adaptes aux souches responsables de la flambee actuelle.Tous les tests publies ne permettent pas de detecter le virus Zika en raison d'une sensibilite limitee et d'une incompatibilite potentielle avec certaines souches. Les concentrations virales dans les echantillons cliniques etaient proches de la limite de detection technique, ce qui laisse penser que l'utilisation de tests insensibles donnera des resultats faussement negatifs. Objetivo Examinar el rendimiento del diagnostico de las pruebas de reaccion en cadena de la polimerasa de transcriptasa inversa (RT-PCR) en tiempo real para la deteccion del virus de Zika. Metodos Se compararon siete pruebas de RT-PCR en tiempo real publicadas y dos pruebas nuevas que se han desarrollado. Con el fin de determinar la sensibilidad analitica de cada prueba, se construyo un acido ribonucleico sintetico de control universal (uncRNA) que contenia todas las regiones objetivo de las pruebas en una hebra de RNA y se anadio a sangre u orina humana con cantidades conocidas de cepas de virus de Zika de Asia o Africa. Se determinaron las cargas viricas en 33 muestras procedentes de pacientes infectados por el virus de Zika a traves de una de las pruebas nuevas. Resultados Los oligonucleotidos de las pruebas de RT-PCR en tiempo real publicadas mostraron hasta 10 posibles discordancias con el linaje de Asia causante de los brotes actuales, en comparacion con 0 de 4 discordancias en el caso de las pruebas nuevas. El limite de deteccion inferior del 95% de las siete pruebas mas sensibles abarco de 2,1 a 12,1 copias/reaccion de uncRNA. Dos pruebas mostraron sensibilidades inferiores de 17,0 y 1373,3 copias/reaccion de uncRNA y presentaron una sensibilidad similar al usar muestras Infectadas. Las cargas viricas medias en las muestras procedentes de pacientes infectados por el virus de Zika fueron de 5 x 104 copias de RNA/mL de sangre y de 2 x [10.sup.4] coplas de RNA/ml de orina. Conclusion Se proporcionan reactivos y protocolos actualizados para la deteccion adecuada del virus de Zika en el caso de las cepas de brotes actuales. Algunas pruebas publicadas pueden no ser adecuadas para la deteccion del virus de Zika, debido a la limitada sensibilidad y a la posible incompatibilidad con algunas cepas. Las concentraciones viricas en las muestras clinicas se acercaron al limite de deteccion tecnico, lo que sugeria que el uso de pruebas Intensivas causaria resultados falsos negativos., Introduction The Zika virus is a mosquito-borne flavivirus with an approximately 11 kilobase ribonucleic acid (RNA) genome. (1) The virus usually causes a mild infection in adults, symptoms include fever, [...]

Hepatitis E virus (HEV) is a major cause of acute hepatitis worldwide (1). Four HEV genotypes belonging to the species Orthohepevirus A are commonly found in humans (HEV-1 through HEV-4). [...]

Preclinical testing of novel therapeutics for chronic hepatitis B (CHB) requires suitable animal models. Equids host homologs of hepatitis C virus (HCV). Because coinfections of hepatitis B virus (HBV) and HCV occur in humans, we screened 2,917 specimens from equids from five continents for HBV. We discovered a distinct HBV species (Equid HBV, EqHBV) in 3.2% of donkeys and zebras by PCR and antibodies against EqHBV in 5.4% of donkeys and zebras. Molecular, histopathological, and biochemical analyses revealed that infection patterns of EqHBV resembled those of HBV in humans, including hepatotropism, moderate liver damage, evolutionary stasis, and potential horizontal virus transmission. Naturally infected donkeys showed chronic infections resembling CHB with high viral loads of up to 2.6 × 109 mean copies per milliliter serum for >6 mo and weak antibody responses. Antibodies against Equid HCV were codetected in 26.5% of donkeys seropositive for EqHBV, corroborating susceptibility to both hepatitis viruses. Deltavirus pseudotypes carrying EqHBV surface proteins were unable to infect human cells via the HBV receptor NTCP (Na+/taurocholate cotransporting polypeptide), suggesting alternative viral entry mechanisms. Both HBV and EqHBV deltavirus pseudotypes infected primary horse hepatocytes in vitro, supporting a broad host range for EqHBV among equids and suggesting that horses might be suitable for EqHBV and HBV infections in vivo. Evolutionary analyses suggested that EqHBV originated in Africa several thousand years ago, commensurate with the domestication of donkeys. In sum, EqHBV naturally infects diverse equids and mimics HBV infection patterns. Equids provide a unique opportunity for preclinical testing of novel therapeutics for CHB and to investigate HBV/HCV interplay upon coinfection. [ABSTRACT FROM AUTHOR]

Hepatitis A virus (HAV) is an ancient and ubiquitous human pathogen recovered previously only from primates. The sole species of the genus Hepatovirus, existing in both enveloped and nonenveloped forms, and with a capsid structure intermediate between that of insect viruses and mammalian picornaviruses, HAV is enigmatic in its origins. We conducted a targeted search for hepatoviruses in 15,987 specimens collected from 209 small mammal species globally and discovered highly diversified viruses in bats, rodents, hedgehogs, and shrews, which by pairwise sequence distance comprise 13 novel Hepatovirus species. Near-complete genomes from nine of these species show conservation of unique hepatovirus features, including predicted internal ribosome entry site structure, a truncated VP4 capsid protein lacking N-terminal myristoylation, a carboxyl-terminal pX extension of VP1, VP2 late domains involved in membrane envelopment, and a cis-acting replication element within the 3Dpol sequence. Antibodies in some bat sera immunoprecipitated and neutralized human HAV, suggesting conservation of critical antigenic determinants. Limited phylogenetic cosegregation among hepatoviruses and their hosts and recombination patterns are indicative of major hepatovirus host shifts in the past. Ancestral state reconstructions suggest a Hepatovirus origin in small insectivorous mammals and a rodent origin of human HAV. Patterns of infection in small mammals mimicked those of human HAV in hepatotropism, fecal shedding, acute nature, and extinction of the virus in a closed host population. The evolutionary conservation of hepatovirus structure and pathogenesis provide novel insight into the origins of HAV and highlight the utility of analyzing animal reservoirs for risk assessment of emerging viruses. [ABSTRACT FROM AUTHOR]