Assessment of Gastroenteric Viruses in Marketed Bivalve Mollusks in the Tourist Cities of Rio de Janeiro, Brazil, 2022

This study investigated the prevalence and genetic diversity of gastroenteric viruses in mussels and oysters in Rio de Janeiro, Brazil. One hundred and thirty-four marketed bivalve samples were obtained between January and December 2022. The viral analysis was performed according to ISO/TS 15216, and the screening revealed the detection of norovirus GII/GI (40.3%), sapovirus (SaV; 12.7%), human mastadenovirus (7.5%), and rotavirus A (RVA; 5.9%). In total, 44.8% (60) of shellfish samples tested positive for one or more viruses, 46.7% (28/60) of the positive samples tested positive for a single viral agent, 26.7% (16) tested positive for two viral agents, 8.3% (5) for three viral agents, and 13.3% (8) for four viral agents. Additionally, three mussel samples were contaminated with the five investigated viruses (5%, 3/60). Norovirus GII showed the highest mean viral load (3.4 × 105 GC/g), followed by SaV (1.4 × 104 GC/g), RVA (1.1 × 104 GC/g), human mastadenovirus (3.9 × 103 GC/g), and norovirus GI (6.7 × 102 GC/g). Molecular characterization revealed that the recovered norovirus strains belonged to genotypes GII.2, GII.6, GII.9, GII.17, and GII.27; SaV belonged to genotypes GI.1 and GIV.1; RVA to genotypes G6, G8, P[8]-III, and human mastadenovirus to types F40 and F41. The GII.27 norovirus characterized in this study is the only strain of this genotype reported in Brazil. This study highlights the dissemination and diversity of gastroenteric viruses present in commercialized bivalves in a touristic area, indicating the potential risk to human health and the contribution of bivalves in the propagation of emerging pathogens.

Microbiome and virome on indoor surfaces of an Antarctic research ship

BACKGROUND

Few studies have focused on microbial diversity in indoor environments of ships, as well as the role of the microbiome and its ecological interconnections. In this study, we investigated the microbiome and virome present on the internal surfaces of a polar ship in different stages (beginning, during, and at the end) of the Brazilian Antarctic expedition in order to evaluate abundance of microorganisms in different periods.

OBJECTIVES AND METHODS

We used shotgun metagenomic analysis on pooled samples from sampling surfaces in the ship's interior to track the microbial diversity.

FINDINGS

Considering the total fraction of the microbiome, the relative abundance of bacteria, eukaryotes, viruses, and archaea was 83.7%, 16.2%, 0.04%, and 0.002%, respectively. Proteobacteria was the most abundant bacterial phyla, followed by Firmicutes, Actinobacteria, and Bacteroidetes. Concerning the virome, the greatest richness of viral species was identified during the middle of the trip, including ten viral families after de novo assembly: Autographiviridae, Chrysoviridae, Genomoviridae, Herelleviridae, Myoviridae, Partitiviridae, Podoviridae, Potyviridae, Siphoviridae, and Virgaviridae.

MAIN CONCLUSIONS

This study contributed to the knowledge of microbial diversity in naval transportation facilities, and variations in the abundance of microorganisms probably occurred due to factors such as the number of passengers and activities on the ship.

Quantification and molecular characterization of intact rotavirus species A (RVA) in municipal solid waste leachate

AIMS

Leachate comprises a solid waste decomposition product found fresh in collection trucks or as an effluent in landfills. This study aimed to assess the occurrence, concentrations, and genetic diversity of intact rotavirus species A (RVA) in solid waste leachate.

METHODS AND RESULTS

Leachate samples were concentrated by ultracentrifugation, treated with propidium monoazide (PMA), and exposed to LED photolysis. Treated and untread samples were extracted using the QIAamp Fast DNA Stool mini kit, and nucleic acids were screened for RVA employing a Taqman® Real-time PCR. The PMA RT-qPCR method detected RVA in eight out of nine truck samples and in 15.40% (2/13) of the landfill leachate samples. The RVA concentrations in the PMA-treated samples ranged from 4.57 × 103 to 2.15 × 107 genomic copies (GC) 100 mL-1 in truck leachate and from 7.83 × 103 to 1.42 × 104 GC 100 mL-1 in landfill samples. Six truck leachate samples were characterized as RVA VP6 genogroup I2 by partial nucleotide sequencing.

CONCLUSIONS

The high intact RVA detection rates and concentrations in truck leachate samples indicate potential infectivity and comprise a warning for solid waste collectors concerning hand-to-mouth contact and the splash route.

Environmental assessment of sewage contamination in the surroundings of a marine outfall combining human mastadenovirus and fecal indicator bacteria

This study assessed the microbiological contamination of the marine area of a metropolitan region, where a marine outfall is used as a sanitary solution for domestic sewage. For human mastadenovirus (HAdV) quantification 134 water samples were concentrated by skimmed milk flocculation method and analyzed with qPCR and PMAxx-qPCR, being the latter to assess the capsid integrity viral. HAdV with intact capsids were detected in 10 % (16/102) of samples classified as suitable for bathing using at least one fecal bacterial indicator. Spatial analysis of the results showed that the drainage channels of the basin that flow into the sea are the main sources of microbiological contamination in the foreshore zone, where intact HAdV reached a concentration of up to 3 log genomic copies/L. HAdV serotypes A12, D, F40 and F41 were characterized. Our results suggest the use of intact HAdV as a complementary parameter to assess the quality of recreational waters.

SARS-CoV-2 surveillance-based on municipal solid waste leachate in Brazil

Municipal solid waste leachate-based epidemiology is an alternative viral tracking tool that applies fresh truck leachate as an early warning of public health emergencies. This study aimed to investigate the potential of SARS-CoV-2 surveillance based on solid waste fresh truck leachate. Twenty truck leachate samples were ultracentrifugated, nucleic acid extracted, and real-time RT-qPCR SARS-CoV-2 N1/N2 applied. Viral isolation, variant of concern (N1/N2) inference, and whole genome sequencing were also performed. SARS-CoV-2 was detected on 40% (8/20) of samples, with a concentration from 2.89 to 6.96 RNA Log₁₀ 100 mL^-1. The attempt to isolate SARS-CoV-2 and recover the whole genome was not successful; however, positive samples were characterized as possible pre-variant of concern (pre-VOC), VOC Alpha (B.1.1.7) and variant of interest Zeta (P.2). This approach revealed an alternative tool to infer SARS-CoV-2 in the environment and may help the management of local surveillance, health, and social policies.

Wastewater-based epidemiology for preventing outbreaks and epidemics in Latin America - Lessons from the past and a look to the future

Wastewater-based epidemiology (WBE) is an approach with the potential to complement clinical surveillance systems. Using WBE, it is possible to carry out an early warning of a possible outbreak, monitor spatial and temporal trends of infectious diseases, produce real-time results and generate representative epidemiological information in a territory, especially in areas of social vulnerability. Despite the historical uses of this approach, particularly in the Global Polio Eradication Initiative, and for other pathogens, it was during the COVID-19 pandemic that occurred an exponential increase in environmental surveillance programs for SARS-CoV-2 in wastewater, with many experiences and developments in the field of public health using data for decision making and prioritizing actions to control the pandemic. In Latin America, WBE was applied in heterogeneous contexts and with emphasis on populations that present many socio-environmental inequalities, a condition shared by all Latin American countries. This manuscript addresses the concepts and applications of WBE in public health actions, as well as different experiences in Latin American countries, and discusses a model to implement this surveillance system at the local or national level. We emphasize the need to implement this sentinel surveillance system in countries that want to detect the early entry and spread of new pathogens and monitor outbreaks or epidemics of infectious agents in their territories as a complement of public health surveillance systems.

Investigation of Human and Animal Viruses in Water Matrices from a Rural Area in Southeastern Region of Brazil and Their Potential Use as Microbial Source-Tracking Markers

This study assessed the sources of contamination of water matrices in a rural area using detection of a host-specific virus (human adenovirus [HAdV], porcine adenovirus [PAdV] and bovine polyomaviruses [BoPyV]) as potential microbial source-tracking tool, and rotavirus A [RVA], given its epidemiological importance in Brazil. From July 2017 to June 2018, 92 samples were collected from eight points (P1-P8) of surface and raw waters in southeastern region of Brazil. Fifty-five (59.8%) were positive for HAdV, 41 (44.5%) for RVA, 10 (10.9%) for PAdV and four (4.3%) for BoPyV. HAdV and RVA were detected at all sites, and over the entire sampling period, PAdV was detected at a porcine breeding area and at Guarda River site, presenting high concentrations up to 2.6 × 10⁹ genome copies per liter [GC/L], and viral concentrations ranging from 9.6 × 10¹ to 7.1 × 10⁷, while BoPyV (1.5 × 10⁴ GC/L-9.2 × 10⁵ GC/L) was only detected in samples from the bovine breeding areas. The combination of human and animal virus circulation presents a potential impact in the environment due to raw sewage discharge from regional communities, as well as potential hazard to human and animal health.

Virome analysis in lakes of the South Shetland Islands, Antarctica - 2020

Polar freshwater ecosystems are characterized by a distinct microbiota. However, little is known about viral diversity and abundance, especially regarding the ecology of RNA viruses. We used shotgun metagenomic analysis on samples from Antarctic ecosystems, and report here the characterization of the virome fraction, from different lakes located in the South Shetland Islands (Penguin, Ardley, Deception and King George Island) in the Peninsula Antarctica, in the summer season 2020. DNA viruses (99.4 %) prevailed over RNA viruses (0.6 %) in the lake samples. Six viral orders were identified in the metagenomic libraries: Caudovirales (dsDNA), which was prevalent in most lakes; Picornavirales (ssRNA+); Sobelivirales (ssRNA+); Tolivirales (ssRNA+); Petitvirales (ssDNA) and Baphyvirales (ssDNA), including eight viral families (Herelleviridae, Siphoviridae, Myoviridae, Microviridae, Marnaviridae, Bacilladnaviridae, Barnaviridae and Tombusviridae) and several other, mainly non-classified ssRNA⁽⁺⁾ viruses in the lakes of Ardley Island. Bacteriophages (dsDNA) (Herelleviridae family) infecting the phylum Firmicutes and Siphoviridae were predominant in most lakes evaluated. Functional analysis demonstrated a prevalence of unknown proteins (68 %) in the virome. Our prospective study provides virome analysis data from different lakes in the South Shetland Islands, Antarctica, opening exploratory lines for future research related to the biodiversity and viral ecology in this extreme ecosystem.

Detection and Molecular Characterization of Enteric Viruses in Bivalve Mollusks Collected in Arraial do Cabo, Rio de Janeiro, Brazil

Viral bivalve contamination is a recognized food safety hazard. Therefore, this study investigated the detection rates, seasonality, quantification, and genetic diversity of enteric viruses in bivalve samples (mussels and oysters). We collected 97 shellfish samples between March 2018 and February 2020. The screening of samples by qPCR or RT-qPCR revealed the detection of norovirus (42.3%), rotavirus A (RVA; 16.5%), human adenovirus (HAdV; 24.7%), and human bocavirus (HBoV; 13.4%). There was no detection of hepatitis A virus. In total, 58.8% of shellfish samples tested positive for one or more viruses, with 42.1% of positive samples contaminated with two or more viruses. Norovirus showed the highest median viral load (3.3 × 10⁶ GC/g), followed by HAdV (median of 3.5 × 10⁴ GC/g), RVA (median of 1.5 × 10³ GC/g), and HBoV (median of 1.3 × 10³ GC/g). Phylogenetic analysis revealed that norovirus strains belonged to genotype GII.12[P16], RVA to genotype I2, HAdV to types -C2, -C5, and -F40, and HBoV to genotypes -1 and -2. Our results demonstrate the viral contamination of bivalves, emphasizing the need for virological monitoring programs to ensure the quality and safety of shellfish for human consumption and as a valuable surveillance tool to monitor emerging viruses and novel variants.

Fast screening of enteropathogens in marine water samples

This study aimed to fast screen the microbiological contamination of recreational waters using a TaqMan Array Card (TAC), a multiplexed platform designed for the simultaneous detection of 35 enteropathogens. Surface and deep marine water samples were concentrated by skimmed milk flocculation and processed for nucleic acid extraction protocol using QIAamp Fast DNA Stool Mini Kit. Twelve microorganisms and parasites, including bacteria (n = 6), protozoa (4), and viruses (2), were detected in 85.7% (24/28) of samples. Campylobacter (82.1%), Cryptosporidium (39.3%), and adenovirus (14.3%) were the most detected pathogens. Neither fungi nor helminths were detected. A spatial pollution profile of microbiological contamination was observed in the area. Methodologies for simultaneous detection of multiple pathogens, such as TAC, can assist decision-makers by providing a quick assessment of the microbiological water quality in areas used for recreational purposes, which in many cases are in accordance with the bacteriological indicators.

Virome in roof-harvested rainwater of a densely urbanized low-income region

Rainwater harvesting has been considered an affordable practice to supplement the conventional sources of water supply for potable and non-potable uses worldwide. This study characterizes the viral community found in roof-harvested rainwater (RHRW) samples obtained under different rain volumes in a densely urbanized low-income region in Rio de Janeiro, Brazil. Three pilot-scale standardized metal-sheet roofs (same catchment area, material age, and slope - 3%) were installed in the study area aiming at obtaining more reliable and representative samples. Fifty-four samples were collected from six rainfall events from January to April 2019 and concentrated by the skimmed-milk flocculation method. Pools of different rainfall volumes were submitted to high throughput sequencing using the shotgun metagenomic approach. Sequencing was performed on NextSeq platform. Genomic analysis of the virus community revealed that most are RNA non-human viruses, including two main families: Dicistroviridae and Iflaviridae, recognized for infecting arthropods. Bacteriophages were also relatively abundant, with a predominance of DNA phages belonging to Microviridae and Siphoviridae families, showing percentages from 5.3 and 3.7% of the total viral hits present in these samples, respectively. Viral genomic RNA viruses (77%) predominated over DNA viruses (23%). Concerning number of viral species identified, a higher percentage was observed for plant viruses (12 families, 58%). Hepatitis A virus and human klassevirus 1 were detected among the established human pathogens, suggesting the need for RHRW treatment before it is considered for human consumption. Australian bat lyssavirus was also detected, emphasizing the importance of environmental monitoring facing emerging viruses. The results corroborate the influence of the surrounding area on the rainwater quality.

Human adenovirus in municipal solid waste leachate and quantitative risk assessment of gastrointestinal illness to waste collectors

Leachate is a variable effluent from waste management systems generated during waste collection and on landfills. Twenty-two leachate samples from waste collection trucks and a landfill were collected from March to December 2019 in the municipality of Rio de Janeiro (Brazil) and were analyzed for Human Adenovirus (HAdV), bacterial indicators and physico-chemical parameters. For viral analysis, samples were concentrated by ultracentrifugation and processed for molecular analysis using QIAamp Fast DNA Stool mini kit® for DNA extraction followed by nested-PCR and qPCR/PMA-qPCR TaqMan® system. HAdV was detected by nested-PCR in 100% (9/9) and 83.33% (12/13) of the truck and landfill leachate samples, respectively. Viral concentrations ranged from 8.31 × 10¹ to 6.68 × 10⁷ genomic copies per 100 ml by qPCR and PMA-qPCR. HAdV species A, B, C, and F were characterized using nucleotide sequencing. HAdV were isolated in A549 culture cells in 100% (9/9) and 46.2% (6/13) from truck and landfill leachate samples, respectively. Regardless of the detection methods, HAdV concentration was predicted by the quantity of total suspended solids. A quantitative microbial risk assessment was performed to measure the probability of gastrointestinal (GI) illness attributable to inadvertent oral ingestion of truck leachate, revealing the higher probability of disease for the direct splashing into the oral cavity (58%) than for the gloved hand-to-mouth (33%). In a scenario where waste collectors do not wear gloves as protective personal equipment, the risk increases to 67%. This is the first study revealing infectious HAdV in solid waste leachate and indicates a potential health risk for waste collectors.

Microbiological characterization of stormwater in a high-income neighborhood in Rio de Janeiro, Brazil

Stormwater harvesting and reuse in the urban environment is emerging as an alternative water source, despite human pathogens in the stormwater may represent a hazard to public health. This study presents the results of 1-year monitoring to evaluate the quality of stormwater obtained in a high-income neighborhood in Rio de Janeiro for a set of microbiological parameters as total coliforms, Escherichia coli (E. coli), human adenovirus (HAdV), human JC polyomavirus (JCPyV), Group A rotavirus (RVA), and norovirus GI and GII. Forty-eight stormwater samples obtained from two multiplex units presented total coliforms and E. coli in 91.7% (n = 44) and 58.3% (n = 28) of samples, while HAdV and JCPyV were detected in 20.8% (n = 10) and 12.5% (n = 6), respectively. Viral quantification ranged from 10³ to 10⁴ genomic copies/liter (GC/L) for HAdV and from 10¹ to 10⁴ GC/L for JCPyV. Neither RVA nor norovirus GI and GII was detected. Fifteen out of sixteen (93.8%) samples containing viruses were compliant as per fecal indicator bacteria (FIB) according to Brazilian standards for rainwater reuse and US EPA Guidelines for Water Reuse, suggesting that viruses monitoring should complement the study of bacterial indicators.

Norovirus Foodborne Outbreak Associated With the Consumption of Ice Pop, Southern Brazil, 2020

Norovirus is a major cause of foodborne-associated acute gastroenteritis (AGE) outbreaks worldwide. Usually, food products are contaminated either during harvesting or preparation, and the most common products associated to norovirus outbreaks are raw or undercooked bivalve shellfish, fruits (frozen berries) and ready-to-eat produce. In the present study, we investigated an AGE outbreak caused by norovirus associated with the consumption of ice pops in southern Brazil. Clinical stool samples from patients and ice pops samples were collected and analyzed for viruses' detection. By using RT-qPCR and sequencing, we detected the uncommon genotype GII.12[P16] in clinical samples and GII.12 in samples of ice pop. Strains shared identity of 100% at nucleotide level strongly suggesting the consumption of ice pops as the source of the outbreak.

Assessment of Viral Contamination of Five Brazilian Artisanal Cheese Produced from Raw Milk: a Randomized Survey

Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a cross-sectional randomized survey to estimate the prevalence of norovirus and human adenovirus (HAdV) from 100 Brazilian artisanal raw milk cheese samples (Minas and Coalho) obtained from different agroindustries in four producing regions in the states of Minas Gerais and one in Piauí, respectively. From October 2017 to April 2018, norovirus genogroups I and II and HAdV were investigated in these cheese samples by RT-qPCR and qPCR, respectively. Viruses were detected in 43 samples, being 26 norovirus GI strains, 14 HAdV, and 3 both viruses. Norovirus GII strains were not detected. Viral concentrations ranged from 6.17 × 10⁴ to 1.44 × 10⁷ genome copies/L^-1 and murine norovirus 1 used as internal process control showed 100% success rate of recovery with efficiency of 10%. There was a trend towards a higher positivity rate for both viruses in the rainy season, and HAdV were more commonly found among samples with higher fecal coliform counts. This study is a first step in assessing the risk that this contamination may pose to the consumer of raw products as well as emphasizing the need for good manufacturing practices, quality control systems in the dairy industry and markets. As a randomized survey, we established baseline figures for viruses' prevalence in five types of ready-to-eat raw milk artisanal Brazilian cheese, to allow any monitoring trends, setting control targets and future local risk analyses studies.

Virological Characterization of Roof-Harvested Rainwater of Densely Urbanized Low-Income Region

Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In this study, we investigated the occurrence of enteric viruses in the first flush (10 mm) of RHRW from a densely populated and low-income urbanized region of Rio de Janeiro. One hundred samples (5 L) were collected from 10 rainfall events between April 2015 and March 2017. RNA and DNA viruses were concentrated using the skimmed milk flocculation method and analyzed using the TaqMan® quantitative RT-qPCR and qPCR. Human adenoviruses, noroviruses, rotaviruses A, and avian parvoviruses were detected in 54%, 31%, 12%, and 12% of the positive samples. JC polyomavirus, also targeted, was not detected. Virus concentrations ranged from 1.09 × 10¹ to 2.58 × 10³ genome copies/Liter (GC/L). Partial nucleotide sequence confirmed the presence of HAdV type 41, norovirus genotype GII.4, and avian parvovirus 1. The results suggest that the first flush diversion devices may not adequately remove enteric virus from the rainwater. Additional treatment of RHRW is required to mitigate potential health risks from potable use of captured water.

Nosocomial acute gastroenteritis outbreak caused by an equine-like G3P[8] DS-1-like rotavirus and GII.4 Sydney[P16] norovirus at a pediatric hospital in Rio de Janeiro, Brazil, 2019

Worldwide, rotavirus (RVA) and norovirus are considered major etiological agents of acute gastroenteritis (AGE) in pediatric population admitted to hospitals. This study describes the investigation of nosocomial infections caused by emergent RVA and norovirus strains reported at a pediatric hospital in southern Brazil in May 2019. This outbreak affected 30 people among children and adults. Nine stool samples (eight children and one nurse) were obtained and analyzed by RT-qPCR to detect and quantify RVA and norovirus. Positive samples were genotyped by sequencing and subjected to phylogenetic analysis. We detected RVA in 44.4% (4/9) and norovirus in 55.5% (5/9) at high viral loads, ranging from 3.5 × 10⁷ to 6.1 × 10⁷ and 3.2 × 10² to 3.2 × 10⁹ genome copies/g of stool, respectively. Co-infections were not observed. RVA VP4 and VP7 gene sequencing in combination with polyacrylamide gel electrophoresis identified the circulation of equine-like G3P[8] DS-1-like, and the partial sequencing of the other nine genes revealed that strains possessed I2-R2-C2-M2-A2-N1-T2-E2-H2 genotype background. The emergent recombinant norovirus variant, GII.4 Sydney[P16], was identified by ORF1-2 sequencing. Active surveillance and effective prevention measures should be constantly reinforced to avoid the spread of nosocomial viral infections into hospitals, which could severely affect pediatric patients admitted with underlying health conditions.

Epidemiology of enteric virus infections in children living in the Amazon region

OBJECTIVES

To verify the frequency of viruses causing acute gastroenteritis (AGE) in association with the histo-blood group antigen (HBGA) and Rotarix™ vaccination coverage in children from the Amazon region.

DESIGN

Fecal and saliva samples were collected from children with AGE (n = 485) and acute respiratory infection (ARI) (n = 249) clinical symptoms. Rotavirus A (RVA), norovirus, human adenovirus (HAdV), and sapovirus (SaV) were verified in feces by molecular detection. Saliva samples were used for HBGA phenotyping/FUT3 genotyping. Blood group types, clinical aspects and Rotarix™ RVA vaccination data were recorded.

RESULTS

Norovirus remained the most prevalently detected cause of AGE (38%, 184/485 and ARI 21.3%, 53/249). High HAdV frequencies were observed in AGE children (28.6%, 139/485) and ARI children (37.3%, 93/249). RVA was the third most prevalent virus causing AGE (22.7%, 110/485 and ARI 19.3%, 48/249) and a low RV1 coverage (61%, 448/734) was verified. The SaV frequencies were lower (7.2%, 35/485 for AGE and 6.8%, 17/249 for ARI). Secretor children were HBGA susceptible to HAdV infection (OR 1.5, 95% CI 1.0-2.3; P = 0.04) but not to RVA, norovirus or SaV infection.

CONCLUSIONS

Norovirus could be considered the main etiological agent of AGE. No association was verified for HBGA susceptibility to RVA, norovirus and SaV. Secretor children showed a slight susceptibility to HAdV infection and the Le (a-b-) heterogeneous SNPs on the FUT3 gene.

Wastewater-based epidemiology as a useful tool to track SARS-CoV-2 and support public health policies at municipal level in Brazil

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) wastewater-based epidemiology (WBE) has been applied as a complementary approach for spatial tracking of coronavirus disease 2019 cases (COVID-19) as well as early warning of the occurrence of infected populations. The present study presents the result of the monitoring of sanitary sewerage in the municipality of Niterói, a metropolitan region of Rio de Janeiro (Brazil) and its use as a complementary indicator in the surveillance of COVID-19 cases, thus assisting actions of public health from local authorities. Twelve composite raw sewage samples were weekly collected from two wastewater treatment plants (WWTPs) and alternately from 17 sewer pipes (SP) from surrounding neighbourhoods and slums throughout 20 weeks (April 15th to August 25th, 2020). Two hundred twenty-three samples were concentrated using the ultracentrifugation-based method and SARS-CoV-2 RNA detected and quantified by RT-qPCR using primers and probe targeting the N2 genome. SARS-CoV-2 RNA was detected in 84.3% (188/223) of samples with a positive rate ranging from 42% (5/12) in the first week of monitoring to 100% during the peak of epidemic with viral concentration ranging from 3.1 to 7.1 log₁₀ genome copies _/100 mL throughout the studied period. Positive rates were higher in WWTPs when compared to SP, being useful tool for monitoring trends in the evolution of the COVID-19 curve, while SP data were more effective when health public interventions were needed. Whole-genome sequencing using Illumina MiSeq System confirmed the lineage of three genomes as B.1.1.33 (clade G) containing the nucleotide substitutions observed in strains that circulate in the Rio de Janeiro during the period of this study. In addition, geoprocessing tool was used to build heat maps based on SARS-CoV-2 data from sewage samples, which were weekly updated and available online to the general population as an indicator of the ongoing epidemic situation in Niterói city, raising public awareness.

Microbiological assessment of an urban lagoon system in the coastal zone of Rio de Janeiro, Brazil

This study aims to assess microbiological contamination using a molecular tool for detection of multiple enteropathogens in a coastal ecosystem area in Rio de Janeiro, Brazil. Ten litres of superficial water samples were obtained during the spring ebb tide from sampling sites along the Jacarepaguá watershed. Samples were concentrated using skimmed milk flocculation method for TaqMan array card (TAC), designed to identify 35 enteric pathogens simultaneously, and single TaqMan qPCR analysis for detecting human adenovirus (HAdV) and JC human polyomavirus (JCPyV) as faecal indicator viruses (FIV). TAC results identified 17 enteric pathogens including 4/5 viral species investigated, 8/15 bacteria, 4/6 protozoa and 1/7 helminths. Escherichia coli concentration was also measured as faecal indicator bacteria (FIB) using Colilert Quanti-Tray System with positivity in all samples studied. HAdV and JCPyV qPCR were detected in 8 and 4 samples, respectively, with concentration ranging from 8 × 10² to 2 × 10⁶ genome copies/L. Partial nucleotide sequencing demonstrated the occurrence of species HAdV A, C, D, and F, present in faeces of individuals with enteric and non-enteric infections, and JCPyV type 3 (Af2), prevalent in a high genetically mixed population like the Brazilian. The diversity of enteropathogens detected by TAC emphasizes the utility of this methodology for quick assessment of microbiological contamination of the aquatic ecosystems, speeding up mitigation actions where the risk of the exposed population is detected, as well as pointing out the infrastructure gaps in areas where accelerated urban growth is observed.

Absence of norovirus contamination in shellfish harvested and commercialized in the Northeast coast of Brazil

Norovirus (NoV) is the main cause of gastroenteritis outbreaks worldwide. Although NoV spreads mainly from person to person, it is estimated that a large proportion of NoV outbreaks are caused by foodborne transmission. Bivalve mollusks are one of the most important foods involved in NoV transmission to humans. Little is known about NoV prevalence in shellfish harvested and commercialized in Brazil. The aim of this study was to map, for the first time, the distribution of NoV contamination in oysters and mussels harvested and commercialized in the coast of Pernambuco state, northeast Brazil. A total of 380 mollusks (260 oysters and 120 mussels) were collected between February and August 2017 either directly from harvesting areas or obtained from beach vendors at 17 sites in Pernambuco. Samples were processed and tested for NoV contamination using a SYBR Green real-time PCR assay. All samples were negative for NoV GI or GII contamination, suggesting a low risk of NoV contamination from this food source during the study period. Additional surveys in different areas of the Brazilian coast are warranted to monitor the risk of NoV infection upon seafood consumption.

Evaluation of Viral Recovery Methodologies from Solid Waste Landfill Leachate

Leachate from solid waste landfill is a dark liquid of variable composition and possible source of contamination of groundwater and surface waters. This study aims to assess skimmed milk flocculation and ultracentrifugation as viral concentration methods associated to different nucleic acid extraction protocols in order to establish a methodology for virus recovery from sanitary landfill leachate. Spiking experiments using human adenovirus (HAdV) and bacteriophage PP7 revealed the association of QIAamp Fast DNA Stool mini kit® nucleic acid extraction and ultracentrifugation as an effective method for recovering HAdV (346.18%) and PP7 (523.97%) when compared to organic flocculation method (162.64% for HAdV and 0.61% for PP7) that presented PCR inhibition in all undiluted samples. Ultracentrifugation applied in three landfill samples confirm efficiency of the methodology detecting HAdV in all samples with a mean of 3.44E + 06 ± 1.56E + 06 genomic copies/mL. Nucleotide sequencing characterized HAdV as belonging to group B and F. JC polyomavirus (JCPyV) was also investigated in those samples; however, detection was not observed. Methodologies for detection of viruses in leachate can be useful to generate data for future health risk analysis of workers who have contact with solid urban waste, as well as populations exposed to different environmental matrices contaminated by these effluents.

Human Bocavirus in Brazil: Molecular Epidemiology, Viral Load and Co-Infections

Human bocavirus (HBoV) is an emerging virus and has been detected worldwide, especially in pediatric patients with respiratory and gastrointestinal infection. In this study, we describe HBoV prevalence, genotypes circulation and DNA shedding, in stool samples from children up to two years of age in Brazil. During 2016 and 2017, 886 acute gastroenteritis (AGE) stool samples from ten Brazilian states were analyzed by TaqMan^®-based qPCR, to detect and quantify HBoV. Positive samples were genotyped by sequencing the VP1/2 overlap region, followed by phylogenetic analysis and co-infections were accessed by screening other gastroenteric viruses. HBoV was detected in 12.4% (n = 110) of samples, with viral load ranging from 1.6 × 10² to 1.2 × 10⁹ genome copies per gram of stool. From these, co-infections were found in 79.1%, and a statistically lower HBoV viral load was found compared to viral loads of rotavirus, norovirus and adenovirus in double infected patients (p < 0.05). No significant differences were found between HBoV viral load in single or co-infections, age groups or genotypes. Phylogenetic analysis identified the circulation of HBoV-1 in 38%, HBoV-2 in 40% and HBoV-3 in 22%. Continuous HBoV monitoring is needed to clarify its role in diarrhea disease, especially in the absence of classic gastroenteric viruses.

Human norovirus detection in bivalve shellfish in Brazil and evaluation of viral infectivity using PMA treatment

Noroviruses are the most common cause of gastroenteritis outbreaks in humans and bivalve shellfish consumption is a recognized route of infection. Our aim was to detect and characterize norovirus in bivalves from a coastal city of Brazil. Nucleic acid was extracted from the bivalve's digestive tissue concentrates using magnetic beads. From March 2018 to June 2019, 77 samples were screened using quantitative RT-PCR. Noroviruses were detected in 41.5%, with the GII being the most prevalent (37.7%). The highest viral load was 3.5 × 106 and 2.5 × 105 GC/g in oysters and mussels, respectively. PMA-treatment demonstrated that a large fraction of the detected norovirus corresponded to non-infectious particles. Genetic characterization showed the circulation of the GII.2[P16] and GII.4[P4] genotypes. Norovirus detection in bivalves reflects the anthropogenic impact on marine environment and serves as an early warning for the food-borne disease outbreaks resulting from the consumption of contaminated molluscs.

Norovirus infection and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil

Norovirus has emerged as an important viral agent of acute pediatric gastroenteritis, with a growing genetic diversity reported in the last decades. Histo-blood group antigens (HBGAs) present on the surface of enterocytes are susceptibility factors for norovirus infection and differ between populations which could affects the epidemiology and evolution of these viruses. This study investigated the frequency, incidence and genetic diversity of noroviruses in a cohort of rotavirus A vaccinated children in association to the host HBGA (Secretor/Lewis) genetic susceptibility profile. Norovirus genogroups I and II (GI/GII) were screened by RT-qPCR in 569 stool samples from 132 children followed-up from birth to 11 months of age during 2014--2018. Noroviruses were identified in 21.2% of children enrolled in this study, with a norovirus detection rate of 5.6% (32/569), in 17.1% and 4.7% of acute diarrheic episodes (ADE) and non-ADE, respectively. The norovirus incidence was 5.8 infections per 100 child-months. Partial nucleotide sequencing characterized six different norovirus genotypes, with GII.4 Sydney 2012 being detected in 50% associated with three different polymerase genotypes (GII·P31, GII·P16 and GII·P4 New Orleans 2009). FUT3 genotyping was yielded seven new mutations in this population. A significant association between symptomatic norovirus infection and secretor profile could be inferred.

Assessment of the microbiological quality of natural mineral waters according to the manufacturing time of 20 L returnable packs in Brazil

This study aimed to assess the microbiological quality of natural mineral waters commercialized in 20 L returnable packs in Brazil by investigating the presence of bacteria and viruses in packs with different manufacturing times (Tm). With this purpose, 99 water samples from 33 lots (n = 3/batch) of 15 brands, obtained from packs with three intervals of Tm, were analyzed. Total coliforms (16.2%), Pseudomonas aeruginosa (9.9%), sulphite-reducing Clostridium (5.0%) and Escherichia coli (2.0%) were detected but enterococci and norovirus GII not. Regarding brands, 11 (73.3%) presented unsatisfactory results for at least one of the lots analyzed. Pseudomonas aeruginosa analysis revealed six sequence types and strains were susceptible to all antibiotics tested and were able to produce biofilms. Human adenovirus (4) and norovirus GI (9) were also identified in nine samples randomly selected. Natural mineral waters commercialized in 20 L packs with Tm ≥ 2 years presented more microbiological contamination (P ≤ 0.012) than ones with a Tm of 0-1 year or a Tm of 1-2 years. These results suggest that the validity period of reusable 20 L packs should be reduced or that they can no longer be reused.

Preliminary results of SARS-CoV-2 detection in sewerage system in Niterói municipality, Rio de Janeiro, Brazil

This study presents preliminary results from a sewage-based surveillance to monitor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the municipality of Niterói, State of Rio de Janeiro, Brazil. By using ultracentrifugation method associated to quantitative reverse transcription polymerase chain reaction (RT-qPCR) we detected SARS-CoV-2 in 41.6% (5/12) of raw sewage samples obtained from sewage treatment plants and sewers network in the city. This pioneer study carried out in Brazil aims to subsidise information for health surveillance concerning the viral circulation in different areas of the city and, revealed the insertion and importance of environmental virology in health public policies.

Rotavirus A in Brazil: Molecular Epidemiology and Surveillance during 2018-2019

Rotavirus A (RVA) vaccines succeeded in lowering the burden of acute gastroenteritis (AGE) worldwide, especially preventing severe disease and mortality. In 2019, Brazil completed 13 years of RVA vaccine implementation (Rotarix™) within the National Immunization Program (NIP), and as reported elsewhere, the use of Rotarix™ in the country has reduced childhood mortality and morbidity due to AGE. Even though both marketed vaccines are widely distributed, the surveillance of RVA causing AGE and the monitoring of circulating genotypes are important tools to keep tracking the epidemiological scenario and vaccines impact. Thus, our study investigated RVA epidemiological features, viral load and G and P genotypes circulation in children and adults presenting AGE symptoms in eleven states from three out of five regions in Brazil. By using TaqMan^®-based one-step RT-qPCR, we investigated a total of 1536 stool samples collected from symptomatic inpatients, emergency department visits and outpatients from January 2018 to December 2019. G and P genotypes of RVA-positive samples were genetically characterized by multiplex RT-PCR or by nearly complete fragment sequencing. We detected RVA in 12% of samples, 10.5% in 2018 and 13.7% in 2019. A marked winter/spring seasonality was observed, especially in Southern Brazil. The most affected age group was children aged >24-60 months, with a positivity rate of 18.8% (p < 0.05). Evaluating shedding, we found a statistically lower RVA viral load in stool samples collected from children aged up to six months compared to the other age groups (p < 0.05). The genotype G3P[8] was the most prevalent during the two years (83.7% in 2018 and 65.5% in 2019), and nucleotide sequencing of some strains demonstrated that they belonged to the emergent equine-like G3P[8] genotype. The dominance of an emergent genotype causing AGE reinforces the need for continuous epidemiological surveillance to assess the impact of mass RVA immunization as well as to monitor the emergence of novel genotypes.

Gastroenteric Viruses Detection in a Drinking Water Distribution-to-Consumption System in a Low-Income Community in Rio de Janeiro

The availability of drinking water is one of the main determinants of quality of life, disease prevention and the promotion of health. Viruses are important agents of waterborne diseases and have been described as important markers of human faecal contamination. This study aimed to investigate viruses' presence as an indicator of drinking water quality in low-income communities in the Manguinhos area, Rio de Janeiro, Brazil. Three hundred and four drinking water samples (2L/each) were collected along the drinking water distribution-to-consumption pathway in households, as well as healthcare and school units. Water samples were collected both directly from the water supply prior to distribution and after storage in tanks and filtration units. Using qPCR, viruses were detected 50 times in 45 water samples (15%), 19 of these being human adenovirus, 17 rotavirus A and 14 norovirus GII. Viral loads recovered ranged from 5E+10 to 8.7E+10⁶ genome copies/Liter. Co-detection was observed in five household water samples and there was no difference regarding virus detection across sampling sites. Precarious and inadequate environmental conditions characterized by the lack of local infrastructure regarding basic sanitation and waste collection in the territory, as well as negligent hygiene habits, could explain viral detection in drinking water in regions with a water supply system.

DETECTION OF SALIVIRUS IN RAW SEWAGE SAMPLES IN RIO DE JANEIRO, BRAZIL

Gastroenteric viruses are important pathogens related to cases of acute gastroenteritis, affecting millions of people worldwide with a major impact on children under five in developing countries. The introduction of metagenomic approach techniques in the 2000s has allowed the description of new viruses, among them Salivirus, which has been associated worldwide with cases of diarrhea. This study aimed to detect salivirus in raw sewage samples from a wastewater treatment plant (WWTP) collected between June 2013 and May 2014 in Rio de Janeiro, Brazil. Fifty-two samples collected weekly were tested by using a real-time quantitative PCR (qPCR).  Salivirus genome was detected in 71.1% (37/52) of the samples, with viral concentration ranging from 7.56 x 104 to 7.20 x 106 genomic copies per liter. Higher viral loads were detected in the summer and fall of 2014, although these data were not sufficient to infer seasonality for this virus. The high prevalence of salivirus in sewage samples highlights the importance of viral research in wastewater to generate data on salivirus circulation, increasing understanding regarding its dissemination in the population.KEY WORDS: Wastewater; viral detection; salivirus; Brazil; raw sewage; qPCR.

Rotavirus A shedding and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil, 2014-2018

Recent studies have investigated whether the human histo-blood group antigen (HBGAs) could affect the effectiveness of the oral rotavirus vaccines, suggesting secretor positive individuals develop a more robust response. We investigated the Rotavirus A (RVA) shedding in association with the host susceptibility profile in children from a birth community-cohort in Rio de Janeiro, Brazil, from 2014 to 2018. A total of 132 children were followed-up between 0 to 11-month-old, stool samples were collected before/after the 1st/2nd RV1 vaccination doses and saliva samples were collected during the study. RVA shedding was screened by RT-qPCR and G/P genotypes determined by multiplex RT-PCR and/or Sanger nucleotide sequencing. The sequencing indicated an F167L amino acid change in the RV1 VP8* P[8] in 20.5% of shedding follow-ups and these mutant subpopulations were quantified by pyrosequencing. The HBGA/secretor status was determined and 80.3% of the children were secretors. Twenty-one FUT2 gene SNPs were identified and two new mutations were observed. The mutant F167L RV1 VP8* P[8] was detected significantly more in Le (a+b+) secretors (90.5%) compared to non-secretors and even to secretors Le (a-b+) (9.5%). The study highlights the probable association between RV1 shedding and HBGAs as a marker for evaluating vaccine strain host susceptibility.

Human Bocavirus genotypes 1 and 2 detected in younger Amazonian children with acute gastroenteritis or respiratory infections, respectively

OBJECTIVES

This study aimed to verify the frequency, genotypes, and etiological role of Human Bocavirus (HBoV) in younger Amazonian children with either acute gastroenteritis (AGE) or respiratory infections (ARI). The influence of Rotarix™ vaccination and co-infection status was also investigated.

DESIGN

HBoV quantitative polymerase chain reaction (qPCR) testing was done on both fecal and saliva (1468 samples) from 734 children < 5 months old living in the Amazon (Brazil, Guyana, and Venezuela). High and median HBoV viral load samples were used for extraction, nested PCR amplification, and sequencing for genotyping. HBoV mRNA detection was done by reverse transcription following DNA amplification.

RESULTS

The overall HBoV frequencies were 14.2% (69/485; AGE) and 14.1% (35/249; ARI) (p = 0.83). HBoV exclusively infected 4.5% (22/485; AGE) and 4% (10/249) of the Amazonian children (Odds ratios 1.13, 95% confidence interval= 2.42-0.52). HBoV 1 was mainly detected in feces and saliva from AGE children; and HBoV2, from ARI children. HBoV mRNA was detected only in feces. The Rotarix™ vaccination status did not affect the HBoV frequencies.

CONCLUSIONS

We suggest that, after entry into the air/oral pathways, HBoV1 continues infecting toward the intestinal tract causing AGE. HBoV2 can be a causative agent of AGE and ARI in younger Amazonian children.

Preliminary results of SARS-CoV-2 detection in sewerage system in Niterói municipality, Rio de Janeiro, Brazil

This study presents preliminary results from a sewage-based surveillance to monitor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the municipality of Niterói, State of Rio de Janeiro, Brazil. By using ultracentrifugation method associated to quantitative reverse transcription polymerase chain reaction (RT-qPCR) we detected SARS-CoV-2 in 41.6% (5/12) of raw sewage samples obtained from sewage treatment plants and sewers network in the city. This pioneer study carried out in Brazil aims to subsidise information for health surveillance concerning the viral circulation in different areas of the city and, revealed the insertion and importance of environmental virology in health public policies.

Surveillance of Enteric Viruses and Thermotolerant Coliforms in Surface Water and Bivalves from a Mangrove Estuary in Southeastern Brazil

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 10⁴ genome copies (GC) L^-1 in water samples and 1.3 × 10⁵ GC g^-1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250 CFU 100 mL^-1) during most of the monitoring period (12 out of 13 months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100 g^-1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

Phenotyping of Lewis and secretor HBGA from saliva and detection of new FUT2 gene SNPs from young children from the Amazon presenting acute gastroenteritis and respiratory infection

The Histo-blood group antigens (HBGA) are host genetic factors associated with susceptibility to rotavirus (RV) and human norovirus (HuNoV), the major etiological agents of viral acute gastroenteritis (AGE) worldwide. The FUT2 gene expressing the alpha-1, 2-L- fucosyltransferase enzyme is important for gut HBGA expression, and also provides a composition of the phenotypic profile achieved through mutations occurring in populations with different evolutionary histories; as such, it can be considered a genetic population marker. In this study, Lewis and secretor HBGA phenotyping was performed using 352 saliva samples collected from children between three months and five years old born in the Amazon (Brazil, Venezuela and English Guyana) presenting AGE or acute respiratory infection (ARI), the latter considered as control samples. The total of children phenotyped as secretors was 323, corresponding to 91.80%. From these, 207 (58.80%) had a Le (a + b+) profile. The HBGA profiles were equally found in children with AGE as well as with ARI. The rs1047781 of the FUT2 gene was not detected in DNA from saliva cells with a Le (a+b+) profile. However, mutations not yet described in the FUT2 gene were observed: missense 325A>T, 501C>T, 585C>T, 855A>T and missense substitutions 327C>T [S (Ser) > C (Cys)], 446 T>C [L(Leu) > P(Pro)], 723C>A [N(Asn) > K(Lys)], 724A>T [I(Ile) > F(Phe)], 736C>A [H(His) > N(Asn)]. The SNP distribution in the FUT2 gene of the analyzed samples was very similar to that described in Asian populations, including indigenous tribes.

High prevalence of enteric viruses associated with acute gastroenteritis in pediatric patients in a low-income area in Vitória, Southeastern Brazil

Acute gastroenteritis (AGE) is a significant cause of child mortality worldwide. In Brazil, despite the reduction in infant mortality achieved in recent years, many children still die because of undiagnosed AGE. The prevalence, viral load, and circulating genotypes of rotavirus A (RVA), human adenovirus (HAdV), and norovirus GII (NoV GII) were investigated in children with AGE during 12 months in Vitoria, Espírito Santo, Southeastern Brazil. Enteric viruses were detected in stool samples, quantified by quantitative polymerase chain reaction, sequenced, and compared phylogenetically. The overall prevalence was 93.3% (125/134). Cases of single infection (41.8%) and mixed infection (51.5%) were observed; in 21.6% of cases, all the three viruses were detected. RVA had the highest number of copies in all infections. Phylogenetic analysis revealed predominantly the presence of RVA genotype G3, followed by G2 and G9. HAdV clustered within subgroup C, but some samples harbored subgroups A, D, or F. All sequenced NoV-positive samples clustered within the prevalent genotype GII.4. The high prevalence of RVA, HAdV, and NoV in diarrheal feces clarifies the etiology of AGE in this population, and the presence of RVA in vaccinated children reinforces the importance of monitoring programs to identify the causes of gastroenteritis and contribute to the reliability of diagnosis.

Evaluation of skimmed milk flocculation method for virus recovery from tomatoes

This study aimed to evaluate the elution-concentration methodology based on skimmed milk flocculation from three varieties of tomatoes (Solanum lycopersicum L. [globe], Solanum lycopersicum var. cerasiforme [cherry] and hybrid cocktail [grape tomato]) for further monitoring of field samples. Spiking experiments were performed to determine the success rate and efficiency recovery of human norovirus (NoV) genogroup II, norovirus murine-1 (MNV-1) used as sample process control virus and human adenovirus (HAdV). Mean values of 18.8%, 2.8% and 44.0% were observed for NoV GII, MNV-1 and HAdV, respectively with differences according to the types of tomatoes, with lower efficiency for cherry tomatoes. Analysis of 90 samples, obtained at commercial establishments in the metropolitan region of Rio de Janeiro State, revealed 4.5% positivity for HAdV. Bacterial analysis was also performed with no detection of Salmonella spp., L. monocytogenes and fecal coliforms. Data demonstrated that the skimmed milk flocculation method is suitable for recovering HAdV from tomatoes and highlights the need for considering investigation in order to improve food safety.

Adenovirus and rotavirus recovery from a treated effluent through an optimized skimmed-milk flocculation method

Sewage treatment may be insufficient for the complete removal of enteric viruses, such as human adenoviruses (HAdV) and group A rotavirus (RVA). The differences in the efficiency of the treatment methodologies used may interfere with the detection of these viruses. The objective of this study was to optimize a skimmed-milk flocculation technique for the recovery of HAdV and RVA in the samples of treated effluent. The treated effluent collected at the wastewater treatment plant (WWTP) was processed via four protocols including modifications in the initial centrifugation step and the final concentration of skimmed-milk. The viral load and recovery rate were determined by quantitative PCR TaqMan® System. The highest recovery rates of HAdV, RVA, and bacteriophage PP7 (internal control process) were obtained when the concentration of skimmed-milk was doubled and no centrifugation step was used for the sample clarification. The optimized protocol was assessed in a field study conducted with 24 treated effluent samples collected bi-monthly during 2015. HAdV and RVA were detected in 50.0% (12/24) and 33.3% (08/24) of the samples tested, respectively, throughout the year, without seasonal variation (p > 0.05). This study corroborates the use of the organic flocculation method for virus recovery in environmental samples with the adaptation of the protocols to different aquatic matrices.

Norovirus GII.17 Associated with a Foodborne Acute Gastroenteritis Outbreak in Brazil, 2016

Foodborne transmission gastroenteritis (AGE) outbreak occurred during a celebration lunch in July, 2016, Brazil. All stool samples tested were positive for noroviruses (NoV) and phylogenetic analysis revealed that strains were genetically close to GII.17 Kawasaki_2014. These findings indicated circulation of NoV GII.17 Kawasaki_2014 in the Brazilian population, associated with AGE outbreak.

Enteric viruses' dissemination in a private reserve of natural heritage

This study aimed to assess anthropogenic impact of surrounding population in the Private Reserve of Natural Heritage at Pantanal, the world's largest freshwater wetland ecosystem located in the centre of South America. Viral aetiological agents of acute gastroenteritis as rotavirus A (RVA), noroviruses, human adenoviruses, klassevirus and of hepatitis, as hepatitis A virus, were investigated in different aquatic matrices. Annual collection campaigns were carried out from 2009 to 2012, alternating dry and rainy seasons. Viral particles present in the samples were concentrated by the adsorption-elution method, with negatively charged membranes, and detected by qualitative and quantitative PCR. From a total of 43 samples at least one virus was detected in 65% (28) of them. Viruses were detected in all matrices with concentrations ranging from 2 × 10² to 8·3 × 10⁴ genome copies per litre. A significant higher RVA frequency was observed in the dry season. Our data revealing dissemination of human enteric viruses in water matrices both inside and outside the reserve could be useful to trace faecal contamination in the environment and to minimize the risk of infection by exposure of susceptible individuals.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is part of a collaborative project designed to investigate the environmental and health conditions of the Private Reserve of Natural Heritage at Pantanal, the largest seasonally flooded wetland in the world. The project aimed to promote health and quality of human and wildlife extending technical-scientific knowledge about pathogens present in the region. By assessing the occurrence of human enteric viruses in different water matrices we demonstrated the anthropogenic impact of surrounding population and pointed out the potential risk of infection by exposure of susceptible individuals.

The Impact of the Extreme Amazonian Flood Season on the Incidence of Viral Gastroenteritis Cases

During the Amazonian flood season in 2012, the Negro River reached its highest level in 110 years, submerging residential and commercial areas which appeared associated with an elevation in the observed gastroenteritis cases in the city of Manaus. The aim of this study was to evaluate the microbiological water quality of the Negro River basin during this extreme flood to investigate this apparent association between the illness cases and the population exposed to the contaminated waters. Forty water samples were collected and analysed for classic and emerging enteric viruses. Human adenoviruses, group A rotaviruses and genogroup II noroviruses were detected in 100, 77.5 and 27.5% of the samples, respectively, in concentrations of 10³-10⁶ GC/L. All samples were compliant with local bacteriological standards. HAdV2 and 41 and RVA G2, P[6], and P[8] were characterised. Astroviruses, sapoviruses, genogroup IV noroviruses, klasseviruses, bocaviruses and aichiviruses were not detected. Statistical analyses showed correlations between river stage level and reported gastroenteritis cases and, also, significant differences between virus concentrations during this extreme event when compared with normal dry seasons and previous flood seasons of the Negro River. These findings suggest an association between the extreme flood experienced and gastrointestinal cases in the affected areas providing circumstantial evidence of causality between the elevations in enteric viruses in surface waters and reported illness.

A non-enteric adenovirus A12 gastroenteritis outbreak in Rio de Janeiro, Brazil

A gastroenteritis outbreak that occurred in 2013 in a low-income community in Rio de Janeiro was investigated for the presence of enteric viruses, including species A rotavirus (RVA), norovirus (NoV), astrovirus (HAstV), bocavirus (HBoV), aichivirus (AiV), and adenovirus (HAdV). Five of nine stool samples (83%) from patients were positive for HAdV, and no other enteric viruses were detected. Polymerase chain reaction products were sequenced and subjected to phylogenetic analysis, which revealed four strains and one strain of non-enteric HAdV-A12 and HAdV-F41, respectively. The HAdV-A12 nucleotide sequences shared 100% nucleotide similarity. Viral load was assessed using a TaqMan real-time PCR assay. Stool samples that were positive for HAdV-A12 had high viral loads (mean 1.9 X 10⁷ DNA copies/g stool). All four patients with HAdV-A12 were < 25 months of age and had symptoms of fever and diarrhoea. Evaluation of enteric virus outbreaks allows the characterisation of novel or unique diarrhoea-associated viruses in regions where RVA vaccination is routinely performed.

Detection and Molecular Characterization of Gemycircularvirus from Environmental Samples in Brazil

Gemycircularvirus (GemyCV) is a group of viruses which has been recently proposed as a new viral genus detected in fecal and environmental samples around the world. GemyCVs have been detected in human blood, brain tissue, cerebrospinal fluid, and stool sample. In the present study, we demonstrate for the first time, through molecular detection and characterization, the presence of GemyCVs in environmental samples from Brazil. Our results show a percentage of positivity ranging from 69 (25/36) to 97 % (35/36) in river water samples collected in Manaus, Amazon region, and wastewater from a wastewater treatment plant located in Rio de Janeiro, respectively, revealing GemyCVs as an important environmental contaminant.

Norovirus Recombinant Strains Isolated from Gastroenteritis Outbreaks in Southern Brazil, 2004-2011

Noroviruses are recognized as one of the leading causes of viral acute gastroenteritis, responsible for almost 50% of acute gastroenteritis outbreaks worldwide. The positive single-strand RNA genome of noroviruses presents a high mutation rate and these viruses are constantly evolving by nucleotide mutation and genome recombination. Norovirus recombinant strains have been detected as causing acute gastroenteritis outbreaks in several countries. However, in Brazil, only one report of a norovirus recombinant strain (GII.P7/GII.20) has been described in the northern region so far. For this study, 38 norovirus strains representative of outbreaks, 11 GII.4 and 27 non-GII.4, were randomly selected and amplified at the ORF1/ORF2 junction. Genetic recombination was identified by constructing phylogenetic trees of the polymerase and capsid genes, and further SimPlot and Bootscan analysis of the ORF1/ORF2 overlap. Sequence analysis revealed that 23 out of 27 (85%) non-GII.4 noroviruses were recombinant strains, characterized as: GII.P7/GII.6 (n = 9); GIIP.g/GII.12 (n = 4); GII.P16/GII.3 (n = 4); GII.Pe/GII.17 (n = 2); GII.P7/GII.14 (n = 1); GII.P13/GII.17 (n = 1); GII.P21/GII.3 (n = 1); and GII.P21/GII.13 (n = 1). On the other hand, among the GII.4 variants analyzed (Den Haag_2006b and New Orleans_2009) no recombination was observed. These data revealed the great diversity of norovirus recombinant strains associated with outbreaks, and describe for the first time these recombinant types circulating in Brazil. Our results obtained in southern Brazil corroborate the previous report for the northern region, demonstrating that norovirus recombinant strains are circulating more frequently than we expected. In addition, these results emphasize the relevance of including ORF1/ORF2-based analysis in surveillance studies as well as the importance of characterizing strains from other Brazilian regions to obtain epidemiological data for norovirus recombinant strains circulating in the country.

Aichi Virus Positivity in HIV-1 Seropositive Children Hospitalized with Diarrheal Disease

Aichi viruses (AiV) have been detected in patients with diarrheal diseases (DD). The aim of this study was to assess AiV infection rates in hospitalized children with DD, including 123 HIV-1 seropositive and 125 HIV-1 seronegative patients, in two public pediatric hospitals in Rio de Janeiro, Brazil. AiV was investigated by nested RT-PCR. The AiV-positive samples were also tested for specie A rotavirus, norovirus, astrovirus, enteric adenovirus and bocavirus in order to assess co-infections. AiV parcial genome sequencing and phylogenetic analyses were performed. AiV were detected in 9/123 (7.32%) of the HIV-1 seropositive subjects and 1/125 (0.8%) of the HIV seronegative patients with DD (p = 0.019). The phylogenetic analysis of positive samples disclosed that: i) 13 samples were characterized as genotype A, with one of them being from the HIV-1 seronegative patient; ii) one sample from a HIV-1 seropositive patient was characterized as genotype B. AiV genotype A was grouped into 3 genetic clusters. Data suggest that AiV may be an opportunistic pathogen infecting children with AIDS and DD.

Viruses Surveillance Under Different Season Scenarios of the Negro River Basin, Amazonia, Brazil

The Negro River is located in the Amazon basin, the largest hydrological catchment in the world. Its water is used for drinking, domestic activities, recreation and transportation and water quality is significantly affected by anthropogenic impacts. The goals of this study were to determine the presence and concentrations of the main viral etiological agents of acute gastroenteritis, such as group A rotavirus (RVA) and genogroup II norovirus (NoV GII), and to assess the use of human adenovirus (HAdV) and JC polyomavirus (JCPyV) as viral indicators of human faecal contamination in the aquatic environment of Manaus under different hydrological scenarios. Water samples were collected along Negro River and in small streams known as igarapés. Viruses were concentrated by an organic flocculation method and detected by quantitative PCR. From 272 samples analysed, HAdV was detected in 91.9%, followed by JCPyV (69.5%), RVA (23.9%) and NoV GII (7.4%). Viral concentrations ranged from 10(2) to 10(6) GC L(-1) and viruses were more likely to be detected during the flood season, with the exception of NoV GII, which was detected only during the dry season. Statistically significant differences on virus concentrations between dry and flood seasons were observed only for RVA. The HAdV data provides a useful complement to faecal indicator bacteria in the monitoring of aquatic environments. Overall results demonstrated that the hydrological cycle of the Negro River in the Amazon Basin affects the dynamics of viruses in aquatic environments and, consequently, the exposure of citizens to these waterborne pathogens.

Detection of Common, Emerging and Uncommon VP4, and VP7 Human Group A Rotavirus Genotypes from Urban Sewage Samples in Uruguay

Environmental approach has proven to be a useful tool for epidemiological studies demonstrating through environmental studies the diversity of viruses circulating in a given population. The aim of this study was to perform a phylogenetic characterization of the group A rotavirus (RVA) glycoprotein (G)- and protease-sensitive (P)-genotypes obtained from sewage samples (n = 116) collected in six cities of Uruguay during March 2011 to April 2013. A worldwide standardized semi-nested multiplex RT-PCR (SNM RT-PCR) protocol directed against VP4 and VP7 genes were conducted for RVA detection and consensual DNA fragments were submitted to nucleotide sequencing. P and/or G genotype was successfully determined by phylogenetic analysis in 61% (n = 37) of the positive samples obtained by SNM RT-PCR (n = 61). The RVA genotypes were as follow: G1 (n = 2), G2 (n = 14), G3 (n = 5), G12 (n = 2), P[4] (n = 4), P[8] (n = 16), and P[3] (n = 2). Interestingly, through phylogenetic analysis, emerging, and uncommon human genotypes could be detected. Results obtained from the comparison of RVA genotypes detected in the current study and Uruguayan RVA strains previously described for contemporary clinical pediatric cases showed that monitoring sewage may be a good screening option for a rapid and economical overview of the circulating genotypes in the surrounding human population and a useful approximation to study RVA epidemiology in a future vaccine monitoring program. The present study represents the first report in Uruguay that describes the phylogenetic diversity of RVA from urban sewage samples.

Virus recovering from strawberries: Evaluation of a skimmed milk organic flocculation method for assessment of microbiological contamination

Skimmed milk organic flocculation method was adapted, optimized and compared with polyethylene glycol (PEG) precipitation and filtration methods for recovering viruses from a strawberry matrix. Spiking experiments with norovirus genogroup II genotype 4 (NoV GII.4) and murine norovirus 1 (MNV-1) demonstrated that the organic flocculation method associated with a glycine elution buffer, filter bag and cetyltrimethylammonium bromide (CTAB) showed a recovery percentage of 2.5 and 32 times higher than PEG precipitation and filtration methodologies for NoV recovering. Furthermore, this method was used for investigating NoV and human adenoviruses (HAdVs) in 90 samples of fresh strawberries commercialized in Rio de Janeiro markets. NoV GI and GII were not detected in those samples and MNV-1, used as internal process control (IPC), was recovered in 95.5% (86) of them. HAdVs were detected in 18 (20.0%) samples and characterized by nucleotide sequencing as Human Mastadenovirus specie F and as type specie HAdV-2. Bacterial analysis did not detect Salmonella spp. and Listeria monocytogenes, however, 3.3% of fecal coliforms were detected in those samples. These results indicate the organic flocculation method as an alternative for recovering enteric viruses from strawberries, emphasizing a need for virus surveillance in food matrices.