Caliciviruses (Norovirus and Sapovirus) are important causes of acute gastroenteritis, with Norovirus (NoV) considered the leading cause of epidemic non-bacterial acute gastroenteritis; however, molecular and epidemiological data of the circulating Calicivirus (CV) strains among day-care children are still considered scarce. The role of asymptomatic CV excretion on viral transmission also remains poorly understood. The aim of the present study was to monitor the occurrence of NoV and Sapovirus (SaV) in a day-care center and to describe the molecular epidemiology of the circulating strains. Genomic sequencing and phylogenetic analysis of the capsid region were carried out in CV positive samples obtained from children younger than 5 years, with or without diarrhea, between October 2009 and October 2011. A total of 539 fecal samples were screened for CV. Forty-three (8%) were positive for NoV and 25 (4.6%) for SaV. Surprisingly, positivity rates for CV were significant in asymptomatic children, and virus circulation was detected in every month of the study. Great genomic diversity of CV was observed, and the circulating NoV strains were: GII.6, GII.2, GII.1, GI.7, GII.4, and GI.1. The SaV genotypes GI.1 and GI.3 were also detected. Five CV outbreaks caused by distinct viral strains were documented. This study provides an insight on the genetic diversity of CV in a day-care in Central West Brazil, highlighting the probable role of asymptomatic viral excretion and the significance of semi-closed settings in the dissemination of these agents.

The human adenovirus (HAdV) infection can cause severe disease in immunocompromised patients, such as those undergoing allogeneic hematopoietic stem cell transplant (ASCT). The main objective of this study was to prospectively monitor ASCT recipients for HAdV occurrence in a reference center in Brazil, and also to correlate viral positivity, viral load, molecular variant, clinical symptoms, and patients' prognosis. From October/2012 to October/2014, blood and feces of 21 ASCT recipients were screened for HAdV by Nested-PCR. Viral loads were determined by real-time PCR. In total, 57% of the patients had at least one positive sample (serum or feces) for HAdV. Patients presented significantly higher viral load in feces when compared to serum. Positive samples were characterized as HAdVs of species HAdV-C, -D, and -F. The main clinical symptom presented by infected patients was diarrhea, and Graft-versus-host disease (GVHD) was the main intercurrence. An association was observed between HAdV-positivity and diarrhea and also between HAdV-positivity and GVHD. Results from this study may contribute to a better understanding of the HAdV infection pattern in patients submitted to ASCT. Data therein highlight the importance of including HAdV testing during all routine laboratory exams performed on ASCT patients. J. Med. Virol. 89:298-303, 2017. © 2016 Wiley Periodicals, Inc.

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Norovirus is the leading cause of non-bacterial acute gastroenteritis outbreaks worldwide. Recently, third generation Enzyme Immunoassay (EIA) commercial kits have been developed, and controversial results have been obtained by different studies regarding the sensitivity and specificity of these assays. Therefore, the aim of this study was to test 60 fecal samples, previously tested as positive by RT-PCR for caliciviruses (40 norovirus-positive and 20 sapovirus-positive samples), for qualitative determination of genogroup I and II noroviruses by a commercial EIA kit (RIDASCREEN ® Norovirus (C1401) 3 rd Generation, R-Biopharm, Darmstadt, Germany). The samples were obtained from 30 children aged less than five years, mostly asymptomatic, who attend a day-care center in Goiânia, Goiás, Brazil. The results conferred a positivity rate for NoV of 35% and a specificity rate of 100% for the EIA, when compared to the RT-PCR. The test also failed to detect samples that were positive for GI.1 and GI.4 norovirus. The presumably lower viral load of asymptomatic children might be related to the poor sensitivity. Our results reinforce the notion that screening of samples by molecular assays, especially of samples that might have a low number of viral particles such as those obtained from asymptomatic patients, should not be replaced by the use of EIA kits.