Fiocruz in Antarctica - health and environmental surveillance facing the challenges of the 21st century.

FioAntar, FIOCRUZ's research project in Antarctica, is based on the One Health approach. FioAntar aims to generate relevant information that will help reduce the risk of future pandemics and improve the search for chemical compounds and new biological molecules. After four expeditions to Antarctica under the scope of PROANTAR, Fiocruz has identified Influenza H11N2 virus in environmental fecal samples, as well as Histoplasma capsulatum and Bacillus cereus in soil samples. In addition, in a prospective virome analysis from different lakes in the South Shetland Islands, six viral orders were described, supporting future research related to the biodiversity and viral ecology in this extreme ecosystem. Our findings of environmental pathogens of public health importance are a warning about the urgency of establishing a surveillance agenda on zoonoses in Antarctica due to the imminent risks that ongoing environmental and climate changes impose on human health across the planet. FioAntar strives to establish a comprehensive surveillance program across Antarctica, monitoring circulation of pathogens with the potential to transcend continent boundaries, thereby mitigating potential spread. For Fiocruz, Antarctica signifies a new frontier, teeming with opportunities to explore novel techniques, refine established methodologies, and cultivate invaluable knowledge.

Active surveillance for influenza virus and coronavirus infection in Antarctic birds and mammals in environmental fecal samples, South Shetland Islands.

Numerous Antarctic species are recognized as reservoirs for various pathogens, and their migratory behavior allows them to reach the Brazilian coast, potentially contributing to the emergence and circulation of new infectious diseases. To address the potential zoonotic risks, we conducted surveillance of influenza A virus (IAV) and coronaviruses (CoVs) in the Antarctic Peninsula, specifically focusing on different bird and mammal species in the region. During the summer of 2021/2022, as part of the Brazilian Antarctic Expedition, we collected and examined a total of 315 fecal samples to target these respiratory viruses. Although we did not detect the viruses of interest during this particular expedition, previous research conducted by our team has shown the presence of the H11N2 subtype of influenza A virus in penguin fecal samples from the same region. Given the continuous emergence of new viral strains worldwide, it is crucial to maintain active surveillance in the area, contributing to strengthening integrated One Health surveillance efforts.

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.

Candida palmioleophila: A New Emerging Threat in Brazil?

Human activity directly or indirectly causes climate change, promoting changes in the composition of the atmosphere. This change is beyond the variation of the natural climate. In this manner, climate change could create an environmental pressure which is enough to trigger new fungal diseases. In addition to climate alterations, the onset of the COVID-19 pandemic has also been associated with the emergence of fungal pathogens. Fungi showed that an inability to grow at high temperatures limits the capacity of fungi to infect mammals. However, fungi can develop thermotolerance, gradually adapting to rising temperatures due to climate change, and generating a greater number of disease-causing organisms. In the present study, we reported the detection and identification of Candida palmioleophila isolates recovered from raw sewage samples in Niteroi city, Rio de Janeiro State, Brazil, during a monitoring program for measuring SARS-CoV-2 presence and concentration. Using polyphasic taxonomy to identify the species and evaluating some virulence aspects of this species, such as biofilm formation and extracellular enzyme production, our data highlight this species as a possible emerging pathogen in Brazil, especially in the pandemic context.

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.

Assessment of virus concentration methods for detecting SARS-CoV-2 IN wastewater.

Wastewater-based epidemiology has been described as a valuable tool for monitoring the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a community. However, there is no consensus on the best concentration method to allow reliable detection of SARS-CoV-2 in this matrix, considering different laboratory facilities. This study compares two viral concentration methods, ultracentrifugation (ULT) and skimmed-milk flocculation (SMF), for detecting SARS-CoV-2 in wastewater samples. The analytical sensitivity (limits of detection and quantification [LoD/LoQ]) of both methods was evaluated using a bovine respiratory syncytial virus (BRSV) as a surrogate. Three different approaches were conducted to establish LoD of each method based on the assays on the standard curve (ALoDsc), on the dilution of internal control (ALoDiC), and the processing steps (PLoD). For PLoD, ULT method had the lowest value (1.86 × 103 genome copy/microliter [GC/µL]) when compared to the SMF method (1.26 × 107 GC/µL). The LoQ determination showed a mean value of 1.55 × 105 GC/µL and 3.56 × 108 GC/µL to ULT and SMF, respectively. The detection of SARSCoV-2 in naturally contaminated wastewater revealed 100% (12/12) and 25% (3/12) of detection using ULT and SMF with quantification ranging from 5.2 to 7.2 log10 genome copy/liter (GC/L) and 5.06 to 5.46 log10 GC/L, respectively. The detection success rate of BRSV used as an internal control process was 100% (12/12) for ULT and 67% (8/12) for SMF, with an efficiency recovery rate ranging from 12 to 38% and 0.1 to 5%, respectively. Our data consolidates the importance of assessing the methods used; however, further analysis should be carried out to improve low-cost concentration methodologies, essential for use in low-income and developing countries.

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.

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.

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.

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.

Hepatitis A Outbreaks and Environmental Circulation of Genotype IA Strains in the São Paulo City, 2017-2018.

Hepatitis A virus (HAV) is the major cause of enterically transmitted infectious hepatitis. Between 2016 and 2017, the number of confirmed cases of hepatitis A virus (HAV) increased from 64 to 786 in São Paulo affecting mainly adults aged between 18 and 39 years (80%) and males (88%). To support epidemiological surveillance, the present study monitored the presence of HAV in urban sewage samples collected bimonthly for 1 year (November 2017-November 2018) in the central region of the city, where most of cases were detected. Sewage samples were concentrated by polyethylene glycol precipitation and HAV RNA was quantified by RT-qPCR. Nucleotide sequencing targeting the VP1/2A junction region was carried out to genotype the HAV strains. HAV was detected in 76.9% (40/52) of the samples, with a geometric mean viral load of 5.09 × 104 (± SD 4.51 × 105) genome copies (GC/L) (Mauá Street) and 5.27 × 104 (± SD 1.26 × 106) GC/L (Prestes Maia Avenue). Of the 40 positive samples, 8 were typed as HAV subgenotype IA [100% nucleotide (nt) identity with HAV strain VRD_521_2016]. Highest homology was obtained with sequences from European countries (Italy, Spain) and Israel, all of which had reported recent HAV outbreaks associated with men who have sex with men. Our results highlight that wastewater surveillance is a useful tool to support investigating HAV outbreaks in the community, including circulating genotypes.

Surface Estimation via Analysis Method: A Constrained Inverse Problem Approach.

Ultrasonic imaging is a common technique in nondestructive evaluation, as it presents advantages such as low cost and safety of operation. In many industries, the interior inspection of objects with complex geometry has become a necessity. This kind of inspection requires the transducer to be coupled to the object with the use of some technique, such as immersing the object in water. When doing so, the geometry of the object surface must be known a priori or estimated. Recent methods for surface estimation start with an image of the interface between water and the specimen. Then, the surface is estimated by processing the image using different strategies. In this article, the strategy to extract the surface profile is based on an analysis-based inverse problem, hence named surface estimation via analysis method (SEAM). The problem formulation aims to reduce the noise in the estimate and also, by including priors, reach more accurate estimates. By using a second-order total variation regularization, which favors piecewise linear functions, the proposed method can describe a great range of surface profiles. Experiments were performed to evaluate the proposed method on surface profile estimation and results show good agreement with references and lower errors than methods in the literature. In addition, the estimated profiles enhance the imaging of the interior of objects, allowing better visualization of internal defects.

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.

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.

Performance of wastewater reclamation systems in enteric virus removal.

Analysis of virus removal by tertiary or advanced sewage treatment processes is an emerging topic due to importance of reusing water on a global level. This study aimed to monitor important human viral pathogens: the human adenovirus (HAdV), JC polyomavirus (JCV) and Species A rotaviruses (RVA) in urban sewage, secondary effluents and reclaimed water from metropolitan São Paulo (MSP), Brazil. Four large wastewater treatment plants (WWTPs) in MSP were sampled monthly during a one-year period (April 2015 to March 2016). The viruses were quantified by quantitative PCR (qPCR), and HAdV viability was tested by the integrated cell culture (ICC)-qPCR assay. WWTPs are composed of activated sludge processes and different tertiary treatments (coagulation/sedimentation, sand-anthracite filters, membrane bioreactors (MBRs)/reverse osmosis (RO) and disinfection by chlorination). Physicochemical parameters were also evaluated to verify association with density of viruses detected in different treatment stages. HAdV, JCV and RVA were consistently detected (100%) in the sewage influent samples (range: 106-108 genome copies GC/L). In the secondary effluent, HAdV was detected in 100% (48/48) of the analysed samples, JCV in 85.4% and RVA in 97.9% (range: 104-107 GC/L for all viruses tested). HAdV was the most frequently detected virus in the tertiary effluent (62.2%) (28/45), exhibiting a viability between 0 and 44% of the tested samples in the wastewater reclamation systems. The MBR/RO systems demonstrated better virus removal efficiencies (range: 2.3-2.9 log10). Temperature, pH, turbidity and total organic carbon presented association with the viral density in the reclaimed water samples. Presence of viruses in treated effluents can indicates health risks depending on uses of recovery water. Further risk assessment studies should be conducted to better assess health risks under different exposure scenarios for water recovery in urban settings.

Noroviruses in raw sewage, secondary effluents and reclaimed water produced by sand-anthracite filters and membrane bioreactor/reverse osmosis system.

The importance of noroviruses (NoVs) in the epidemiology of waterborne diseases has increased globally in the last decades. The present study aimed to monitor genogroup I and II noroviruses in different treatment stages of four wastewater treatment plants (WWTPs) in the metropolitan São Paulo. WWTPs consist of secondary (activated sludge) and tertiary treatments (coagulation, sand-anthracite filters, membrane bioreactor (MBR)/reverse osmosis (RO) and chlorination). Raw sewage (500mL) and treated effluents (1L) were concentrated by celite and reclaimed water (40L) by hollow-fiber ultrafiltration system. Quantitative (qPCR) and nested PCR with nucleotide sequencing were used for quantification and molecular characterization. NoVs were widely distributed in raw wastewater samples (83.3%-100% NoV GI and 91.6%-100% NoV GII) and viral loads varied from 3.8 to 6.66log10gcL-1 for NoV GI and 3.8 to 7.3log10gcL-1 for NoV GII. Mean virus removal efficiencies obtained for activated sludge processes ranged from 0.3 to 0.8 log10 for NoV GI and 0.4 to 1.4 log10 for NoV GII. NoVs were not detected in the reuse water produced by MBR/RO system, while sand-anthracite filters resulted in a NoV GI and GII decay of 1.1-1.6 log10 and 0.7-1.6 log10, respectively. A variety of genotypes (GI.2, GI.3a, GI.3b, GI.5, GII.1, GII.4 Sydney 2012, GII.5, GII.6, GII.17) was observed, with a predominance of GI.2 and GII.17 in the different genogroups. These results corroborate with recent data about the entry and dissemination of the emerging genotype GII.P17-GII.17 Kawasaki 2014 in the country, and may indicate a change in the epidemiological patterns of norovirus strains circulation in this region. This is the first large-scale study to evaluate burden and genotypes of noroviruses in WWTPs in Brazil, providing a rapid diagnosis of viruses circulating in the population.

Distribution of human fecal marker GB-124 bacteriophages in urban sewage and reclaimed water of São Paulo city, Brazil.

Bacteriophages infecting Bacteroides fragilis GB-124 have been described as potential markers of human fecal contamination in water sources. The aim of this study was to evaluate the occurrence of GB-124 phages in raw sewage, secondary effluents and reclaimed water of the São Paulo city using a low-cost microbial source tracking method. Samples were collected monthly from April 2015 to March 2016 in four municipal wastewater treatment plants that operate with activated sludge processes followed by different tertiary treatments (sand-anthracite filtration, membrane bioreactor/reverse osmosis) and final chlorination. GB-124 phages were detected in 100% of the raw sewage samples, with viral loads varying from 7.5 × 103 to 1.32 × 106 PFU/L. Virus removal efficiency in activated sludge processes ranged from 1.89 to 2.31 log10. Frequencies of phage detection were lower in reclaimed water samples (0-22.2%). The results indicated that GB-124 phage could be a complementary low-cost viral marker for the detection of human fecal pollution in waters impacted with urban sewage in this region. However, the datasets of tertiary effluents resulted in several samples with concentrations below the detection limit (DL ≤1 PFU/mL) suggesting the need to obtain analytical methods with lower DL for greater accuracy of negative results.

[Environmental virology and sanitation in Brazil: a narrative review]. / Virologia ambiental e saneamento no Brasil: uma revisão narrativa.

Sanitation services play a critical role in controlling transmission of numerous waterborne pathogens, especially viruses that cause acute gastroenteritis and hepatitis. The viral agents with the greatest public health impact are hepatitis A virus, rotaviruses and noroviruses, adenoviruses, and enteroviruses, contaminating many Brazilian aquatic ecosystems. Heavy circulation of viruses in the environment has been related to inadequate local sanitary conditions, including incomplete coverage of services or inefficacy of conventional technologies in eliminating or reducing the viral load in water or sewage. This study reviews the relations between virology, health, and sanitation, emphasizing the epidemiology of waterborne viral infections and their public health impact.

Virologia ambiental e saneamento no Brasil: uma revisão narrativa / Environmental virology and sanitation in Brazil: a narrative review / Virología ambiental y saneamiento en Brasil: una revisión narrativa

Os serviços de saneamento básico têm papel fundamental no controle da transmissão de diversos agentes patogênicos de veiculação hídrica, especialmente vírus responsáveis por causar gastroenterites agudas e hepatites. Entre os agentes virais de maior impacto para a saúde pública, podem ser destacados os vírus das hepatites A, os rotavírus e norovírus, adenovírus e enterovírus, os quais são responsáveis pela contaminação de diversos ecossistemas aquáticos brasileiros. A alta circulação de vírus no ambiente vem sendo relacionada às condições sanitárias inadequadas das comunidades, incluindo a falta na cobertura de serviços ou ineficácia de tecnologias convencionais na eliminação ou redução da carga viral presente na água ou no esgoto. Este estudo aborda uma revisão das relações entre virologia, saúde e saneamento, enfatizando a epidemiologia das infecções virais de transmissão hídrica e o impacto na saúde pública.

Sanitation services play a critical role in controlling transmission of numerous waterborne pathogens, especially viruses that cause acute gastroenteritis and hepatitis. The viral agents with the greatest public health impact are hepatitis A virus, rotaviruses and noroviruses, adenoviruses, and enteroviruses, contaminating many Brazilian aquatic ecosystems. Heavy circulation of viruses in the environment has been related to inadequate local sanitary conditions, including incomplete coverage of services or inefficacy of conventional technologies in eliminating or reducing the viral load in water or sewage. This study reviews the relations between virology, health, and sanitation, emphasizing the epidemiology of waterborne viral infections and their public health impact.

El servicio de saneamiento posee un rol en el control de la transmisión de muchos patógenos transmitidos por el agua, especialmente aquellos virus responsables de causar gastroenteritis aguda y hepatitis. Entre los agentes virales de mayor impacto sobre la salud pública se pueden destacar los virus de la hepatitis A, rotavirus, norovirus, adenovirus y enterovirus, los cuales son responsables de la contaminación de diversos ecosistemas acuáticos brasileños. Una alta circulación del virus en el medio ambiente se relaciona con condiciones sanitarias inadecuadas de las comunidades, como la falta de cobertura de los servicios o la ineficacia de las tecnologías convencionales en eliminar la carga viral del agua. Esta revisión está enfocada en las relaciones entre la virología, la salud y el saneamiento, con énfasis en la epidemiología de las infecciones virales transmitidas por el agua y el impacto en la salud pública.

Detection of enteric viruses in activated sludge by feasible concentration methods.

Human enteric viruses are responsible to cause several diseases, including gastroenteritis and hepatitis, and can be present in high amounts in sewage sludge. This study compared virus recovery efficiency of two feasible concentration methods used for detecting human adenovirus (HAdV), rotavirus species A (RV-A), norovirus genogroup II (NoV GII) and hepatitis A virus (HAV) in sewage sludge from an activated sludge process. Twelve sewage sludge samples were collected bi-monthly from January to July, 2011. Ultracentrifugation was compared with a simplified protocol based on beef extract elution for recovering enteric viruses. Viruses were quantified by quantitative real-time PCR assays and virus recovery efficiency and limits of detection were determined. Methods showed mean recovery rates lower than 7.5%, presenting critical limits of detection (higher than 10(2) - 10(3) genome copies - GC L(-1) for all viruses analyzed). Nevertheless, HAdV were detected in 90% of the analyzed sewage sludge samples (range: 1.8 × 10(4) to 1.1 × 10(5) GC L(-1)), followed by RV-A and NoV (both in 50%) and HAV (8%). Results suggesting that activated sludge is contaminated with high viral loads and HAdV are widely disseminated in these samples. The low virus recovery rates achieved, especially for HAV, indicate that other feasible concentration methods could be developed to improve virus recovery efficiency in these environmental matrices.