Uso de exames de imagem de tórax na COVID-19: guia de aconselhamento rápido, 11 junho 2020 / Use of chest imaging in COVID-19: a rapid advice guide, 11 June 2020

Desde sua identificação na China em dezembro de 2019, o novo coronavírus responsável pela COVID-19 evoluiu rapidamente para uma pandemia. A COVID-19 se manifesta com sintomas respiratórios inespecíficos de gravidade variável e pode exigir suporte respiratório avançado. Atualmente, o diagnóstico de COVID- 19 é confirmado por testes laboratoriais através da identificação de RNA viral na reação em cadeia da polimerase com transcriptase reversa (RT-PCR). Os exames de imagem de tórax foram considerados como parte da investigação diagnóstica de pacientes com suspeita ou probabilidade de COVID-19, nos lugares em que a RT-PCR não está disponível ou em que os resultados demoram ou são inicialmente negativos na presença de sintomas sugestivos de COVID-19. Os exames de imagem também foram considerados na complementação da avaliação clínica e dos parâmetros laboratoriais no tratamento de pacientes já diagnosticados com COVID-19. Antes de iniciar o desenvolvimento deste guia, vários estados-membros solicitaram um parecer da OMS sobre o papel dos exames de imagem do tórax em pacientes com suspeita ou confirmação de COVID-19. Uma revisão das práticas de exames de imagem em pacientes com suspeita ou confirmação de COVID-19 em todo o mundo encontrou grandes variações. Isso motivou o desenvolvimento de diretrizes globais sobre o uso de exames de imagem de tórax para apoiar os estados membros na resposta à pandemia da COVID-19. Este guia de aconselhamento rápido examina as evidências e faz recomendações para o uso de exames de imagem do tórax em pacientes agudos com suspeita, probabilidade ou confirmação de COVID-19, incluindo radiografia de tórax, tomografia computadorizada (TC) e ultrassonografia pulmonar. Destina-se a ser um guia prático para os profissionais de saúde envolvidos na evolução da atenção à COVID-19, desde o momento de chegada a um estabelecimento de saúde até a alta hospitalar. A orientação é relevante para pacientes com diferentes níveis de gravidade da doença, desde indivíduos assintomáticos a pacientes críticos...

SARS-CoV-2 diagnostic testing alternatives for Latin America / Alternativas diagnósticas para SARS-CoV-2 para América Latina

Abstract In the past four months SARS-CoV-2 has reached most countries in the world. Public health strategies based on widespread testing and proper isolation of positive cases have shown to be helpful to reduce local transmission of SARS-CoV-2. Confirmatory tests, that identify viral RNA, and screening serological tests that identify viral antigens or host antibodies against viral proteins are part of the tools that nations can use to fight infectious disease epidemics. Understanding how each test works can provide insights about their test characteristics and how they can be used for different clinical and public health goals. Testing is a key strategy to reduce viral transmission, not only for this epidemic, but also for others to come.

Resumen En los últimos cuatro meses, el virus SARS-CoV-2 ha llegado a la mayoría de países en el mundo. Las estrategias de salud pública basadas en la realización masiva de pruebas diagnósticas y el aislamiento focalizado de casos positivos han demostrado ser útiles para la reducción de la transmisión de SARS-CoV-2. Las pruebas confirmatorias, que identifican el ARN viral, y las pruebas serológicas que identifican antígenos virales o anticuerpos contra las proteínas virales del huésped son herramientas que las naciones pueden usar para combatir las epidemias producidas por agentes infecciosos. El comprender cómo funcionan estas pruebas puede ayudar a entender sus características y cómo pueden ser usadas para diferentes objetivos clínicos y de salud pública. Las pruebas diagnósticas son herramientas clave para reducir la transmisión viral, no solo en esta epidemia, sino para otras por venir.

Zika virus RNA excretion in sweat with concomitant detection in other body fluid specimens

We evaluated sweat, blood and urine specimens obtained from an ongoing cohort study in Brazil. Samples were collected at pre-established intervals after the initial rash presentation and tested for Zika virus (ZIKV) RNA presence by real-time reverse transcriptase polymerase chain reaction (rRT-PCR). From 254 participants with confirmed infection, ZIKV RNA was detected in the sweat of 46 individuals (18.1%). Sweat presented a median cycle threshold (Ct) of 34.74 [interquartile range (IQR) 33.44-36.04], comparable to plasma (Ct 35.96 - IQR 33.29-36.69) and higher than urine (Ct 30.78 - IQR 28.72-33.22). Concomitant detection with other specimens was observed in 33 (72%) of 46 participants who had a positive result in sweat. These findings represent an unusual and not yet investigated virus shedding through eccrine glands.

Are SARS-CoV-2 reinfection and Covid-19 recurrence possible? a case report from Brazil

Abstract With the large number of individuals infected and recovered from Covid-19, there is intense discussion about the quality and duration of the immunity elicited by SARS-CoV-2 infection, including the possibility of disease recurrence. Here we report a case with strong clinical, epidemiological and laboratorial evidence of, not only reinfection by SARS-CoV-2, but also clinical recurrence of Covid-19.

Evaluación de un método de amplificación isotérmica mediado por bucle para la detección rápida del virus sincicial respiratorio en niños con infección respiratoria aguda / Evaluation of a loop-mediated isothermal amplification method for the rapid detection of human respiratory syncytial virus in children with acute respiratory infection

Resumen Introducción. El virus sincicial respiratorio humano (hRSV) es la causa más frecuente de infección respiratoria aguda de las vías respiratorias inferiores en niños menores de cinco años. El desarrollo de técnicas moleculares para identificarlo es uno de los retos actuales en el campo de la investigación clínica. Objetivo. Evaluar un método de amplificación isotérmica para la detección rápida del hRSV en niños con infección respiratoria aguda. Materiales y métodos. Se extrajo el ARN viral de 304 muestras de hisopado nasal en niños con síntomas de infección respiratoria aguda atendidos en el servicio de urgencias del Hospital de la Universidad del Norte en Barranquilla entre abril del 2016 y julio del 2017. Se evaluó la prueba de amplificación isotérmica mediada por bucle mediante transcriptasa inversa de la proteína de la matriz (M) (Reverse Transcription Loop-Mediated Isothermal Amplification, RT-LAMP) comparada con técnicas moleculares como la reacción en cadena de la polimerasa mediante transcriptasa inversa múltiple anidada (Reverse Transcription- Polymerase Chain Reaction, RT-PCR), la cual se empleó como la prueba estándar, la PCR en tiempo real (quantitative PCR, qPCR) y la RT-LAMP de la proteína L (L) para la detección rápida del virus sincicial respiratorio (VSR), subtipo A y subtipo B. Resultados. La prueba de RT-LAMP (M) tuvo una sensibilidad de 93,59 %, una especificidad de 92,92 % y una concordancia de 0,83 ± 0,036 comparada con la prueba de RT-PCR anidada. El índice kappa del RT-LAMP (M) fue superior, y los valores del RT-LAMP (L) y la qPCR concordaron (0,75 ± 0,043 y 0,71 ± 0,045, respectivamente). Conclusiones. Estos resultados indican que la prueba RT-LAMP (M) puede considerarse como una herramienta de utilidad clínica para detectar el hSRVA, dado que el tiempo requerido para la obtención de resultados, así como los costos, es menor, y su desempeño es mejor que el de las otras pruebas moleculares evaluadas.

Abstract Introduction: Human respiratory syncytial virus (hRSV) is the most frequent cause of acute respiratory infection of the lower respiratory tract in children under the age of five. The development of molecular techniques able to identify hRSV is one of the current challenges in the field of clinical research. Objective: To evaluate the ability of an isothermal amplification method to rapidly detect hRSV in children with acute respiratory infection. Materials and methods: We collected 304 nasopharyngeal swab samples from children with symptoms of acute respiratory infection who attended the emergency unit at Hospital de la Universidad del Norte in Barranquilla from April, 2016, to July, 2017. After extracting viral RNA from the samples, we evaluated the ability of the reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) M assay to rapidly detect hRSVA and hRSVB compared to other molecular techniques: quantitative PCR (qPCR), reverse transcriptase-LAMP L assay, and as a standard, the multiplex nested reverse transcriptase polymerase chain reaction (nested RT-PCR). Results: The RT-LAMP M assay had a sensitivity of 93.59% and a specificity of 92.92%, and a concordance of 0.83 ± 0.036 as compared with the nested RT-PCR test. While the Kappa index of the RT-LAMP M assay was higher than the values for the RT-LAMP L assay and the qPCR, the values of the latter two methods were in agreement (0.75 ± 0.043 and 0.71 ± 0.045, respectively). Conclusion: Due to the shorter running times, lower costs and better performance of the RT-LAMP M assay, it can be considered as a useful clinical tool for the detection of RSVA.

One-step real-time PCR assay for detection and quantification of RNA HCV to monitor patients under treatment in Brazil

ABSTRACT The Brazilian Public Health Service provides freely αPEG-IFN to treat patients infected with HCV. The primary goal of HCV therapy is the long-term elimination of HCV from the blood to reduce the risk of HCV associated complications and death. Patient viremia affects the treatment duration and response, thus influencing clinical decisions. We developed a high-throughput method to perform the quantification of RNA hepatitis C virus (HCV) virus load in plasma samples to monitor patients under treatment. The method is based on a duplex detection, in a one-step real-time RT-PCR assay and it has been validated according to the rules established by the official Brazilian regulatory agency (ANVISA). This new method was compared to a commercial kit (Cobas/Taqman HCV Test v2.0 - Roche), showing virus load results with significant correlation between them (p= 0,012) using commercial and clinical panels. In addition, 611 samples from patients treated with peguilated alfa-interferon (αPEG-IFN) from different regions of Brazil were analyzed. Our one-step real-time RT-PCR assay demonstrated good performance in viral load measurement and in treatment course monitoring, with acceptable sensitivity and specificity values.

First detection of dengue virus in the saliva of immunocompetent murine model

The lack of an experimental animal model for the study of dengue pathogenesis is a limiting factor for the development of vaccines and drugs. In previous studies, our group demonstrated the susceptibility of BALB/c mice to infection by dengue virus (DENV) 1 and 2, and the virus was successfully isolated in several organs. In this study, BALB/c mice were experimentally infected intravenously with DENV-4, and samples of their saliva were collected. Viral RNA extracted from the saliva samples was subjected to qRT-PCR, with a detection limit of 0.002 PFU/mL. The presence of DENV-4 viral RNA was detected in the saliva of two mice, presenting viral titers of 109 RNA/mL. The detection of DENV RNA via saliva sampling is not a common practice in dengue diagnosis, due to the lower detection rates in human patients. However, the results observed in this study seem to indicate that, as in humans, detection rates of DENV RNA in mouse saliva are also low, correlating the infection in both cases. This study reports the first DENV detection in the saliva of BALB/c immunocompetent mice experimentally infected with non-neuroadapted DENV-4.

Detection of all four dengue serotypes in Aedes aegypti female mosquitoes collected in a rural area in Colombia

The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.

Assessment of Epstein-Barr virus nucleic acids in gastric but not in breast cancer by next-generation sequencing of pooled Mexican samples

Gastric (GC) and breast (BrC) cancer are two of the most common and deadly tumours. Different lines of evidence suggest a possible causative role of viral infections for both GC and BrC. Wide genome sequencing (WGS) technologies allow searching for viral agents in tissues of patients with cancer. These technologies have already contributed to establish virus-cancer associations as well as to discovery new tumour viruses. The objective of this study was to document possible associations of viral infection with GC and BrC in Mexican patients. In order to gain idea about cost effective conditions of experimental sequencing, we first carried out an in silico simulation of WGS. The next-generation-platform IlluminaGallx was then used to sequence GC and BrC tumour samples. While we did not find viral sequences in tissues from BrC patients, multiple reads matching Epstein-Barr virus (EBV) sequences were found in GC tissues. An end-point polymerase chain reaction confirmed an enrichment of EBV sequences in one of the GC samples sequenced, validating the next-generation sequencing-bioinformatics pipeline.

Molecular characterisation of the NSP4 gene of group A human rotavirus G2P[4] strains circulating in São Paulo, Brazil, from 1994 and 2006 to 2010

Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.

Detection of Oropouche virus segment S in patients and inCulex quinquefasciatus in the state of Mato Grosso, Brazil

This study aimed to investigate the circulation of Orthobunyavirus species in the state of Mato Grosso (MT) Brazil. During a dengue outbreak in 2011/2012, 529 serum samples were collected from patients with acute febrile illness with symptoms for up to five days and 387 pools of female Culex quinquefasciatuscaptured in 2013 were subjected to nested-reverse transcription-polymerase chain reaction for segment S of the Simbu serogroup followed by nucleotide sequencing and virus isolation in Vero cells. Patients (5/529; 0.9%) from Cuiabá (n = 3), Várzea Grande (n = 1) and Nova Mutum (n = 1) municipalities were positive for the S segment of Oropouche virus (OROV). Additionally, eight/387 Cx. quinquefasciatuspools were positive for the segment, with a minimum infection rate of 2.3. Phylogenetic analysis indicated that all the samples belong to the subgenotype Ia, presenting high homology with OROV strains obtained from humans and animals in the Brazilian Amazon. The present paper reports the first detection of an Orthobunyavirus, possibly OROV, in patients and in Cx. quinquefasciatus mosquitoes in MT. This finding reinforces the notion that arboviruses frequently reported in the Amazon Region circulate sporadically in MT during dengue outbreaks.

Salud mental de migrantes centroamericanos indocumentados en tránsito por la frontera sur de México / Mental health of undocumented migrants in transit at the southern border of Mexico

Objetivo. Conocer las necesidades percibidas de salud mental de migrantes centroamericanos indocumentados en tránsito por la ciudad de Tapachula, Chiapas. Material y métodos. Estudio cualitativo realizado en Casa de Migrantes de Tapachula, Chiapas. Se realizaron 20 entrevistas semiestructuradas a diez mujeres y diez hombres migrantes. Se exploró el estado de salud mental y las expectativas de atención. Se retomaron nociones teórico-metodológicas de la fenomenología sociológica. Resultados. Los migrantes presentaban signos y síntomas de daños en su salud mental relacionados con experiencias vividas en el lugar de origen y en el tránsito por México. La percepción sobre su salud mental es influida por el modelo biomédico hegemónico. Las expectativas de servicios se relacionaron con la satisfacción de necesidades básicas. Conclusiones. Es necesario fortalecer la respuesta del sistema de atención en salud mental a partir de estrategias de cooperación y emprender acciones que promuevan la superación de una construcción biomédica de salud mental que estigmatiza, medicaliza, segrega y dificulta el acceso a servicios.

Objective. To identify the perception and needs in mental health of Central American migrants in transit through Tapachula, Chiapas. Materials and methods. Qualitative study in a migrant shelter in Tapachula, Chiapas. In 20 semi-structured interviews with migrant men and women, we explored their perceptions on mental health and expectations on care. We used basic notions of phenomenology to guide the analysis. Results. Migrants had several mental health problems related to the conditions at their country of origin and due to their initial transit through Mexico.Their perception on mental health problems was heavily influenced by the biomedical health paradigm. The expectations they had on the provision of services were related to the satisfaction of basic needs. Conclusions. It is necessary to strengthen the governmental response to mental health needs through collaborative strategies. Also, actions are needed to further the understanding of mental health in order to transcend the biomedical notions that stigmatize, segregate and create a barrier to accessing services.

Platelets can be a biological compartment for the Hepatitis C Virus

Although HCV has hepatic tropism, the presence of the virus in extra-hepatic compartments has been well documented. Platelets have been described as carriers of the virus in the circulation and may be a natural reservoir for the virus. However, few studies have been performed to evaluate the levels of HCV RNA in plasma and platelets are equal or differ in some way. Therefore, the aim of this study was to perform a comparative evaluation of the stability of HCV RNA in plasma and isolated platelets. Four aliquots of whole plasma obtained from patients infected with HCV were incubated at 37 °C for 0, 48, 96 and 144 h. After incubation, the plasma and platelet pellet was obtained from each aliquot. Viral RNA in plasma and platelets was quantified by q-PCR. The results showed a decrease in HCV RNA levels in plasma with incubation time. However, platelet HCV RNA levels were stable up to 144 h incubation. The results of this study showed that HCV RNA in platelets, although at lower concentrations than in plasma, is preserved from degradation over time, suggesting that the virus may persist longer in the body when associated with platelets, which could have an impact on the efficiency of antiviral therapy.

Phylogenetic analysis of human group C rotavirus circulating in Brazil reveals a potential unique NSP4 genetic variant and high similarity with Asian strains

Group C rotaviruses (RVC) cause gastroenteritis in humans and animals worldwide, and the evidence for a possible zoonotic role has been recently provided. To gain information on the genetic diversity and relationships between human and animal RVC, we sequenced the VP4, VP7, and NSP4 genes of 12, 19, and 15 human strains, respectively, detected in São Paulo state during historical (1988 and 1993) and recent (2007 and 2008) Brazilian rotavirus surveillance. All RVC strains analyzed in the present study grouped into human genotype (G4-P[2]-E2), and did not show any evidence of animal ancestry. Phylogenetic analysis showed that RVC samples detected in 1988 and 1993 clustered together with strains from distinct continents, indicating that historical RVC strains circulating in São Paulo were closely related to those strains circulating worldwide. All three genes (VP7, VP4 and NSP4) of São Paulo RVC strains isolated in 2007-2008 exhibited close phylogenetic relationship with human RVC strains isolated in China and Japan, suggesting that they are genetically linked, and that a gene flow could be occurring between this Asian countries and Brazil. We identified two distinct clusters in the NSP4 phylogenetic tree. One cluster formed exclusively by human Brazilian strains detected in 1997 and 2003-2004 in Rio de Janeiro, Bahia, and Rio Grande do Sul states (Subgroup II) previously described in a different study, that displayed low sequence identities to other human strains formerly published, and to the Brazilian RVC strains (Subgroup I) characterized in the present study. These data suggests the circulation of two genetic profiles of the NSP4 gene in Brazil. High sequence diversity in NSP4 gene was previously reported in Asia, and additional diversity in NSP4 RVC strains spreading in the world should be expected. More in-depth molecular and epidemiological analysis of human RVC throughout the world will be needed to understand their diversity and clarify their evolution, as well as to develop classifications schemes.

Assessment of immunological changes in Epstein-Barr virus co-infection in Egyptian chronic HCV patients

Epstein-Barr virus (EBV) plays a major role in liver pathology. Similar to other members of the herpesvirus family, EBV establishes a persistent infection in more than 90% of adults. The aim of this study was to evaluate the impact of EBV and chronic hepatitis C co-infection (HCV) on biochemical and immunological responses in patients. The study was conducted in 62 patients and 33 apparently healthy controls. Patients were divided into three groups: group I, consisting of 31 patients with chronic hepatitis C infection (CHC), group II, consisting of eight patients with EBV infection and without HCV infection and group III, consisting of 23 patients with EBV and chronic HCV. The percentage of CD3+ cells, helper CD4+ cells and CD19+ B-cells was measured by flow cytometry. Human interferon-γ (IFN-γ) and interleukin (IL)-15 levels were measured by an ELISA. The levels of liver alanine aminotransferase and aspartate aminotransferase enzymes were higher in EBV/HCV patients compared to that in EBV and HCV mono-infected patients. EBV/HCV patients had significantly reduced percentages of CD3+ and CD4+ cells compared to EBV patients. Serum IFN-γ levels were significantly reduced in EBV/HCV patients (3.86 pg/mL) compared to CHC patients (6.76 pg/mL) and normal controls (4.69 pg/mL). A significant increase in serum IL-15 levels was observed in EBV/HCV patients (67.7 pg/mL) compared to EBV patients (29.3 pg/mL). Taken together, these observations suggest that HCV and EBV co-infection can potentiate immune response dampening in patients.

Cerebrospinal fluid can be used for HIV genotyping when it fails in blood / O líquido cefalorraquidiano pode ser usado para a genotipagem do HIV quando esta não é possível no plasma

Blood plasma specimens are the clinical standard for HIV-1 pol gene genotyping from viral populations; however, it is not always successful, often from low viral loads or the presence of polymerase chain reaction (PCR) inhibitors. Objective To describe the successful of HIV-1 genotyping in two samples of cerebrospinal fluid (CSF), after genotype procedures failed from blood. Method Two HIV-infected patients enrolled in a neurocognitive research study were evaluated when standard HIV-1 genotyping failed from blood plasma samples. Genotyping was performed using the commercial system TRUGENE® HIV-1 Genotyping Kit and the OpenGene® DNA Sequencing System (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Results CSF genotyping was performed via the same commercial platform and was successful in both cases. Conclusion This report demonstrates that CSF could be used as an alternate clinical specimen for HIV-1 genotyping when it fails from blood. .

O plasma é a amostra clínica padrão utilizada para a genotipagem da região pol do HIV-1; entretanto, a genotipagem pode nem sempre ser bem sucedida, geralmente devido a baixas cargas virais ou à presença de inibidores da reação em cadeia da polimerase (PCR). Objetivo: Descrever o sucesso da genotipagem do HIV-1 em duas amostras de líquido cefalorraquidiano (LCR) após a falha do mesmo método em amostras de plasma dos mesmos pacientes. Método: Dois pacientes HIV+ envolvidos em um estudo neurocognitivo foram avaliados após a falha da genotipagem do HIV-1 no plasma. A genotipagem foi realizada com o sistema comercial TRUGENE® HIV-1 Genotyping e o OpenGene® DNA Sequencing (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Resultados: A genotipagem no LCR foi realizada pelo mesmo método utilizado no plasma, sendo bem sucedida para ambos os pacientes. Conclusão: Este artigo demonstra que o LCR pode ser usado como uma amostra clínica alternativa para a genotipagem do HIV-1 quando esta falha no plasma. .

Characterisation of divergent flavivirus NS3 and NS5 protein sequences detected in Rhipicephalus microplus ticks from Brazil

Transcripts similar to those that encode the nonstructural (NS) proteins NS3 and NS5 from flaviviruses were found in a salivary gland (SG) complementary DNA (cDNA) library from the cattle tick Rhipicephalus microplus. Tick extracts were cultured with cells to enable the isolation of viruses capable of replicating in cultured invertebrate and vertebrate cells. Deep sequencing of the viral RNA isolated from culture supernatants provided the complete coding sequences for the NS3 and NS5 proteins and their molecular characterisation confirmed similarity with the NS3 and NS5 sequences from other flaviviruses. Despite this similarity, phylogenetic analyses revealed that this potentially novel virus may be a highly divergent member of the genus Flavivirus. Interestingly, we detected the divergent NS3 and NS5 sequences in ticks collected from several dairy farms widely distributed throughout three regions of Brazil. This is the first report of flavivirus-like transcripts in R. microplus ticks. This novel virus is a potential arbovirus because it replicated in arthropod and mammalian cells; furthermore, it was detected in a cDNA library from tick SGs and therefore may be present in tick saliva. It is important to determine whether and by what means this potential virus is transmissible and to monitor the virus as a potential emerging tick-borne zoonotic pathogen.

In vitro detection of hepatitis C virus in platelets from uninfected individuals exposed to the virus

Introduction Despite hepatocytes being the target cells of hepatitis C virus (HCV), viral ribonucleic acid RNA has been detected in other cells, including platelets, which have been described as carriers of the virus in the circulation of infected patients. Platelets do not express cluster differentiation 81 CD81, the main receptor for the virus in hepatocytes, although this receptor protein has been found in megakaryocytes. Still, it is not clear if HCV interacts with platelets directly or if this interaction is a consequence of its association with megakaryocytes. The aim of this study was to evaluate the interaction of HCV with platelets from non-infected individuals, after in vitro exposure to the virus. Methods Platelets obtained from 50 blood donors not infected by HCV were incubated in vitro at 37°C for 48h with serum containing 100,000IU∕mL of genotype 1 HCV. After incubation, RNA extracted from the platelets was assayed for the presence of HCV by reverse transcription – polymerase chain reaction RT-PCR. Results After incubation in the presence of virus, all samples of platelets showed HCV RNA. Conclusions The results demonstrate that, in vitro, the virus interacts with platelets despite the absence of the receptor CD81, suggesting that other molecules could be involved in this association. .