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 children's 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

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

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 RotarixTM 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

Prevalence of hepatitis A virus infection in Goiânia, Goiás, Brazil, by molecular and serological procedures, 1995-2002

In this study, a total of 865 serum samples were collected between 1995 and 2002 from individuals living in Goiânia, Central Brazil, and clinically suspected of hepatitis. After exclusion of 162 samples which were positive for hepatitis B virus or hepatitis C virus, 703 samples were tested for anti-hepatitis A virus (anti-HAV) IgM antibodies by enzyme immunoassay. In addition, 588 of these samples and 22 fecal samples were analyzed by reverse transcription-nested PCR for HAV RNA detection, with positivity indices of 13.1% (77/588) and 54.5% (12/22), respectively. A similar index of viral RNA detection in anti-HAV-IgM positive or negative samples was observed in serum samples. HAV infection is a public health problem worldwide and this study underscores the extent of HAV circulation in our region

Identification of Human Bocavirus type 4 in a child asymptomatic for respiratory tract infection and acute gastroenteritis – Goiânia, Goiás, Brazil

Human Bocavirus (HBoV) has been identified from feces and respiratory samples from cases of both acute gastroenteritis and respiratory illness as well as in asymptomatic individuals.The aim of this study was to detect and characterize HBoV from fecal samples collected from hospitalized children aged less than five years old with no symptoms of respiratory tract infection (RTI) or acute gastroenteritis (AGE). The study involved 119 children and one fecal sample was collected from each participant between 2014 and 2015. HBoV was detected using Nested-PCR, and the viral type identified by genomic sequencing. HBoV-4 was identified from one sample obtained from a hospitalized child with soft tissue tumor of the submandibular region. This is the first report of HBoV-4 identification in Brazil, but we consider that this type may be circulating in the country similar to the other types and new investigations are necessary. Keywords: HBoV-4, Asymptomatic children, Tumor of the submandibular regio