Fabíola Souza Fiaccadori

Adenovirus, calicivirus and astrovirus detection in fecal samples of hospitalized children with acute gastroenteritis from Campo Grande, MS, Brazil

We analyzed fecal samples from hospitalized children up to three years of age with acute gastroenteritis at Campo Grande, Mato Grosso do Sul, Brazil, from May 2000-January 2004. Astrovirus and calicivirus were detected by Reverse Transcription-Polymerase Chain Reaction and adenovirus was detected using the Rotavirus and Adenovirus combined immunoenzyme assay. Astrovirus, adenovirus and calicivirus were detected at rates of 3.1%, 3.6% and 7.6%, respectively. These results re-emphasize the need for the establishment of regional vigilance systems to evaluate the impact of enteric viruses on viral gastroenteritis.

Detection of calicivirus from fecal samples from children with acute gastroenteritis in the West Central region of Brazil

The objective of this study was to describe the circulation of caliciviruses in the West Central region of Brazil and its correlation with childrens gender and age, as well as with the year and months of the sample collection. Reverse transcriptase-polymerase chain reaction was performed to detect the human calicivirus genome in 1006 fecal samples that were collected in Goiânia (n = 696) and Brasília (n = 310). Viral RNA was detected in 8.6% of the samples. No significant difference in viral prevalence was found regarding gender, age or year of the sample. However, it was observed that in Goiânia, there is a higher incidence of caliciviruses from September to March. The analysis employing three primer pairs demonstrated that the Ni/E3 or JV12/13 primer pairs, which detect norovirus (NoV), detected 41 positive samples while the 289/290 primer pair, which detects NoV or sapovirus, detected the remaining 46 samples. Calicivirus circulates in the West Central region of Brazil and for better detection of this virus it is important to use more than one primer pair. Also, we conclude that the seasonality presented by this virus is related to higher humidity in the period.

Rotavirus A infections and reinfections: genotyping and vaccine implications.

OBJETIVOS: Identificar Rotavirus A em criancas com diarreia aguda, determinando os genotipos G e P prevalentes e avaliar a ocorrencia de infeccoes e reinfeccoes por rotavirus do grupo A em criancas. METODOS: Foram estudadas, prospectivamente, criancas com doenca diarreica aguda e identificacao de Rotavirus A em Goiânia (GO), durante o periodo de julho de 2000 a outubro de 2002. Igual numero de criancas, pareadas por idade e sexo, que nao apresentavam diarreia aguda e sem identificacao de rotavirus nas amostras fecais a admissao ao estudo, representou o grupo controle. Foram analisadas a ocorrencia de infeccoes ou reinfeccoes sintomaticas ou assintomaticas por rotavirus durante o periodo de estudo, durante um ano de seguimento em ambos os grupos. Todas as amostras positivas foram submetidas a genotipagem G e P atraves das reacoes de RT-PCR e Nested PCR. RESULTADOS: A infeccao por rotavirus ocorreu em 37,2% (77 de 207 amostras fecais) das criancas com diarreia aguda durante o periodo do estudo. Os genotipos G e P identificados foram, simultaneamente: G1 (62,3%), G9 (34,4%) e G4 (3,3%) e P[8] (59%), P[6] (7,7%), P[6]+P[8] (23,1%), P[4]+P[8] (7,7%) e P[4]+P[6] (2,6%). As associacoes de genotipos G e P identificados durante o estudo foram: G1P[8] (77,8%), G9P[8] (11,1%), G4P[8] (5,6%) e G1P[6] (5,6%). Nao houve reinfeccao por rotavirus nos pacientes do grupo Rotavirus A (+) durante o periodo de seguimento, enquanto duas criancas do grupo controle apresentaram infeccoes sintomaticas por rotavirus durante o mesmo periodo. CONCLUSOES: Os genotipos G e P predominantes correspondem aos das candidatas atuais a vacina contra rotavirus. Nao houve reinfeccao por rotavirus pelo periodo de um ano em relacao a todos os genotipos identificados.

Seroprevalence of hepatitis B virus infection and seroconvertion to anti-HBsAg in laboratory staff in Goiânia, Goiás

Were analyzed 648 serum samples from laboratory staff in Goiânia, Goiás aiming detection of three serological markers of HBV: HBsAg, anti-HBsAg and anti-HBcAg. The HBsAg and anti-HBcAg positive samples were also analyzed for HBeAg, anti-HBeAg and anti-HBcAgIgM markers. HBV infection rate of 24.1% was observed and, from them, 0.7% were positive for HBsAg. Viral DNA was detected by PCR in two HBsAg positive samples. A vaccination index of 74.5% and a global index of 89.9% of serological response to vaccination were observed. The direct work with biological fluids as well as cleaning workers represented significant risks for acquisition of HBV infection. The data from the present study showed an increase of the vaccination index among laboratory staff but the rates of HBV infection did not change through the years in the region.

Prospective study on Norovirus infection among allogeneic stem cell transplant recipients: prolonged viral excretion and viral RNA in the blood.

BACKGROUNDnHuman caliciviruses (Norovirus and Sapovirus) are important acute gastroenteritis agents. The Norovirus (NoV) disease is usually self-limited; however, prolonged viral excretion and complications have been reported, mainly in immunosuppressed individuals.nnnOBJECTIVESnIn this prospective study, we have monitored allogeneic stem cell transplant (ASCT) patients for human calicivirus infection.nnnSTUDY DESIGNnTen ASCT patients were monitored for NoV and sapoviruses (SaV) infection, for a period of five months to a maximum of one year. Prolonged NoV excretion and long term viral RNA in the blood were assessed by multiplex RT-PCR targeting region C of the viral capsid. Secretor status of the patients was determined by enzyme immunoassay using Ulex Europaeus agglutinin. Partial genomic sequencing and phylogenetic analysis were performed to characterize the viral genotypes.nnnRESULTSnNoV was detected in six out of ten patients (60%). Prolonged viral excretion in feces (mean of 61.6 days) and long term presence of NoV RNA in the sera (mean of 33.6 days) of the patients were observed. SaV was not detected in any of the samples. All patients had diarrhea, vomiting and fever during NoV positivity. All NoV-positive samples were characterized as GI.3 NoV. Three Nov-infected patients presented with acute intestinal graft versus host disease.nnnCONCLUSIONSnThis study brings important information on NoV course of infection in ASCT patients. It also provides evidence for long term viral RNA in the blood highlighting the importance of the inclusion of NoV screening in the routine testing performed before transplantation and during follow-up of these patients.

Monitoring the circulation of rotavirus among children after the introduction of the RotarixTM vaccine in Goiânia, Brazil

The epidemiological features of rotavirus A (RVA) infection differ between children from developing and developed countries which could result in differences in vaccine efficacy around the world. To evaluate the impact of Rotarix™ on RVA prevalence, we monitored RVA genotypes circulating in Goiânia by monitoring virus in faecal samples from children that had or had not been previously vaccinated. From February-November of 2008, 220 faecal samples were collected from children in seven day-care centres. RVA detection was performed by two methodologies and the results were confirmed by polyacrylamide gel electrophoresis. From the 220 samples, eight were RVA-positive (3.6%) and five were from children that had received either one or two doses of the vaccine. All positive samples were collected from children with diarrhoea during August and September. Genotyping of the RVA characterised five of the viral samples as genotype G2P[4] and one as G8P[4], suggesting that G2P[4] was the predominant circulating genotype in Goiânia during the study. The fact that vaccinated children were also infected by RVA suggests that the vaccine does not fully protect against infection by the G2[P4] RVA genotype.

Monitoring of Calicivirus among day-care children: Evidence of asymptomatic viral excretion and first report of GI.7 norovirus and GI.3 sapovirus in Brazil

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. J. Med. Virol. 86:1569–1575, 2014.

Molecular characterization of the NSP4 gene of human group A rotavirus samples from the West Central region of Brazil

Nonstructural protein 4 (NSP4), encoded by group A rotavirus genome segment 10, is a multifunctional protein and the first recognized virus-encoded enterotoxin. The NSP4 gene has been sequenced, and five distinct genetic groups have been described: genotypes A-E. NSP4 genotypes A, B, and C have been detected in humans. In this study, the NSP4-encoding gene of human rotavirus strains of different G and P genotypes collected from children between 1987 and 2003 in three cities of West Central region of Brazil was characterized. NSP4 gene of 153 rotavirus-positive fecal samples was amplified by reverse transcriptase-polymerase chain reaction and then sequenced. For phylogenetic analysis, NSP4 nucleotide sequences of these samples were compared to nucleotide sequences of reference strains available in GenBank. Two distinct NSP4 genotypes could be identified: 141 (92.2%) sequences clustered with NSP4 genotype B, and 12 sequences (7.8%) clustered with NSP4 genotype A. These results reinforce that further investigations are needed to assess the validity of NSP4 as a suitable target for epidemiologic surveillance of rotavirus infections and vaccine development.

Rotavírus A em crianças de até três anos de idade, hospitalizadas com gastroenterite aguda em Campo Grande, Estado do Mato Grosso do Sul

Polyacrylamide gel electrophoresis and combined immunoenzyme assay for rotavirus and adenovirus were used to analyze 380 fecal samples from children up to three years of age who were hospitalized with acute diarrhea in Campo Grande, State of Mato Grosso do Sul, between May 2000 and January 2004. Among all the samples, 88 (23.2%) were positive for Rotavirus A. Out of these, 81 (92%) had a defined electrophoretic pattern: 77 (87.5%) with a long pattern and four (4.5%) with a short pattern. Genotype G and P characterization was done by nested RT-PCR for 85 samples, of which 56 (65.9%) were genotyped as type G. Among these, 49 (87.5%) were G1, five (8.9%) were G4, one (1.8%) was G3 and one (1.8%) was G9. The genotype was found to be type P in 37 samples (43.5%) and all of these were P[8]. The G and P association most observed was G1P[8], with 33 samples (89.2%), followed by G4P[8], two samples (5.4%); G3P[8], one sample (2.7%); and G9P[8], one sample (2.7%).

Phylodynamics of DENV-1 reveals the spatiotemporal co-circulation of two distinct lineages in 2013 and multiple introductions of dengue virus in Goiás, Brazil.

Dengue virus type 1 (DENV-1) was the first serotype introduced in Brazil, during in the 1980s. Since then, this virus has spread in the Brazilian territory, causing several outbreaks. In 2013 the highest number of dengue cases was notified, when compared to the previous years in Brazil, and the state of Goiás reported over 160 thousand cases. In this study, we aimed to present the Phylodynamics of DENV-1 isolates from the state of Goiás, Brazil, during 2013 outbreak, based on the envelope gene (E) sequences. Phylogenetic analysis revealed that Brazilian DENV-1 isolates are grouped together with viruses from genotype V in two distinct lineages (lineage I and lineage II) reflecting co-circulation. Phylogeographic analyses showed that these lineages were introduced in different moments in Goiás, Brazil, using distinct routes, likely originated from the Caribbean. Lineage I was first introduced coming from Rio de Janeiro (2007-2012), followed by the introduction from Argentina (2010-2013). Lineage II was introduced in a single moment from Rio de Janeiro and this clade has existed since 2007-2010. The different viral introduction events demonstrate the viral dispersion process with neighboring regions, which is essential for the maintenance of outbreaks and introduction of new emerging viruses. In conclusion, obtained data reveals the importance of continuous molecular surveillance of this virus in different regions, providing a better understanding of DENV-1 circulation, considering the evolutionary and virus spread patterns.