Detection of the emerging rotavirus G!@P(8) genotype at high frequency in brazil in 2014: Successive replacement of predominant strains after vaccine introduction

The continuum characterization of rotavirus (RVA) genotypes is essential to understand how vaccine introduction could impact virus epidemiology. In the present study, an unexpected rapid changing pattern of RVA genotypes distribution in Brazilian population during three followed seasons is described. From January/2012 to December/2014, a total of 3441 fecal specimens were collected from collaborating centers across Southern, Southeastern and Midwest of Brazil. All specimens were screened for RVA using ELISA, and genotyped by RT-PCR. Differences in proportions were tested using Chi-Squares. A p-value of less than 0.05 was considered statistically significant. RVA was detected in 19.7% (677/3441). Among RVA positive cases (n=677), a total of 652 (96.3%) samples were successfully amplified by RT-PCR. G3P[8] remained prevalent in 2012 (37.6%, 69/185) and 2013 (40.1%, 74/186) (χ(2)=0.107, p=0.743), but declined markedly in 2014 (3.5%, 10/281) (χ(2)=71.770, p=0.000). G12P[8] was second highest strain in 2012 (22.7%, 42/185), decrease rapidly in 2013 (2.7%, 5/186) (χ(2)=26.224, p=0.000) and re-emerged as the predominant genotype in 2014 (86.6%, 243/281) (χ(2)=118.299, p=0.000). From July/2014, G12P[8] was the single genotype detected in all regions studied. The sudden emergence, spread and predominance of G12P[8] strain in Brazil, raised the hypothesis of a possible G12 outbreak being in progress. Nationally, the long term decline in gastroenteritis hospitalization observed in the country after RVA vaccine introduction was confirmed. Nevertheless, the sharp increase in diarrhea hospitalization prevalence from 2013 to 2014 observed in Southern and Southeastern regions is consistent with what appears to be an outbreak of G12P[8]. Continued surveillance is needed to verify the effectiveness of the RotarixTM vaccine in Brazil together with potential emergence of unusual genotypes.

Rotavirus genotypes and the indigenous children of Brazilian midwest in the vaccine era, 2008-2012: footprints of animal genome

World group A rotavirus (RVA) surveillance data provides useful estimates of the disease burden, however, indigenous population might require special consideration. The aim of this study was to describe the results of G­ and P­types from Brazilian native children ≤3 years. Furthermore, selected strains have been analyzed for the VP7, VP6, VP4, and NSP4 encoding genes in order to gain insight into genetic variability of Brazilian strains. A total of 149 samples, collected during 2008­2012, were tested for RVA using ELISA and PAGE, following by RT­PCR and sequencing. RVA infection was detected in 8.7% of samples (13/149). Genotype G2P[4] was detected in 2008 and 2010, G8P[6] in 2009, and G3P[8] in 2011. The phylogenetic analysis of the VP7 and VP4 genes grouped the Brazilian G2P[4] and G3P[8] strains within the lineages currently circulating in humans worldwide. However, the phylogenetic analysis of the VP6 and NSP4 from the Brazilian G2P[4] strains, and the VP7 and NSP4 from the Brazilian G3P[8] strains suggest a distant common ancestor with different animal strains (bovine, caprine, and porcine). The epidemiological and genetic information obtained in the present study is expected to provide an updated understanding of RVA genotypes circulating in the native infant population, and to formulate policies for the use of RVA vaccines in indigenous Brazilian people. Moreover, these results highlight the great diversity of human RVA strains circulating in Brazil, and an in­depth surveillance of human and animal RVA will lead to a better understanding of the complex dynamics of RVA evolution

Rápida detecção de norovírus em alimentos naturalmente contaminados: surto de gastroenterite causado por alimentos em um navio de cruzeiro no Brasil, 2010 / Rapid detection of norovirus in naturally contaminated foood: foodborne gastroenteritis outbreak on a cruise ship in Brazil, 2010

Norovirus (NoV) is a prevalent pathogen of foodborne diseases; however itsdetection in foods other than shellfish is often time-consuming and unsuccessful. In2010, an outbreak of acute gastroenteritis occurred on a cruise ship in Brazil, and NoV was the etiologic agent suspected. The objectives of this study were report that a handy in-house methodology was suitable for NoV detection in naturally contaminated food;and perform the molecular characterization of food strains. Food samples (blue cheese, Indian sauce, herbal butter, soup, and white sauce) were analyzed by ELISA, two methods of RNA extraction, TRIzol® and QIAamp®, following conventional RT-PCR. The qPCR was used in order to confirm the NoV genogroups. GI and GII NoV genogroups were identified by conventional RT-PCR after RNA extraction using the TRIzol® method. Two GII NoV samples were successfully sequenced, classified asGII.4; and displayed a genetic relationship with strains from Asia continent also isolatedin 2010. GII and GI NoV were identified in distinct food matrices, suggesting that was not a common source of contamination. TRIzol® extraction followed by conventional RTPCRwas a suitable methodology in order to identify NoV in naturally contaminatedfood. Moreover, food samples could be processed within 8 hours, indicating the value of the method used for NoV detection, and its potential to identify foodborne gastroenteritis outbreaks in food products other than shellfish. This is the first description in Brazil of NoV detection in naturally contaminated food other than shellfish involved in a foodborne outbreak