RESUMO
Onsite wastewater treatment systems (OWTSs) and private wells are commonly used in Eastern North Carolina, USA. Water from private wells is not required to be tested after the initial startup, and thus persons using these wells may experience negative health outcomes if their water is contaminated with waste-related pollutants including bacteria, nitrate or synthetic chemicals such as hexafluoropropylne oxide dimer acid and its ammonium salt (GenX). Water samples from 18 sites with OWTSs and groundwater wells were collected for nitrate, Escherichia coli (E. coli), total coliform, and GenX concentration analyses. Results showed that none of the 18 water supplies were positive for E. coli, nitrate concentrations were all below the maximum contaminant level of 10 mg L-1, and one well had 1 MPN 100 mL-1 of total coliform. However, GenX was detected in wastewater collected from all 18 septic tanks and 22% of the water supplies tested had concentrations that exceeded the health advisory levels for GenX. Water supplies with low concentrations of traditionally tested for pollutants (nitrate, E. coli) may still pose health risks due to elevated concentrations of emerging contaminants like GenX and thus more comprehensive and routine water testing is suggested for this and similar persistent compounds.
Assuntos
Poluentes Ambientais , Água Subterrânea , Poluentes Químicos da Água , Águas Residuárias , Nitratos/análise , North Carolina , Escherichia coli , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Abastecimento de Água , Poços de Água , Água Subterrânea/microbiologia , Compostos OrgânicosRESUMO
The COVID-19 outbreak led governmental officials to close many businesses and schools, including colleges and universities. Thus, the ability to resume normal campus operation required adoption of safety measures to monitor and respond to COVID-19. The objective of this study was to determine the efficacy of wastewater-based epidemiology as a surveillance method in monitoring COVID-19 on a college campus. The use of wastewater monitoring as part of a surveillance program to control COVID-19 outbreaks at East Carolina University was evaluated. During the Spring and Fall 2021 semesters, wastewater samples (N = 830) were collected every Monday, Wednesday, and Friday from the sewer pipes exiting the dormitories on campus. Samples were analyzed for SARS-CoV-2 and viral quantification was determined using qRT-PCR. During the Spring 2021 semester, there was a significant difference in SARS-CoV-2 virus copies in wastewater when comparing dorms with the highest number student cases of COVID-19 and those with the lowest number of student cases, (p = 0.002). Additionally, during the Fall 2021 semester it was observed that when weekly virus concentrations exceeded 20 copies per ml, there were new confirmed COVID-19 cases 85% of the time during the following week. Increases in wastewater viral concentration spurred COVID-19 swab testing for students residing in dormitories, aiding university officials in effectively applying COVID testing policies. This study showed wastewater-based epidemiology can be a cost-effective surveillance tool to guide other surveilling methods (e.g., contact tracing, nasal/salvia testing, etc.) to identify and isolate afflicted individuals to reduce the spread of pathogens and potential outbreaks within a community.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Universidades , Vigilância Epidemiológica Baseada em Águas Residuárias , Teste para COVID-19 , Pandemias/prevenção & controle , Águas Residuárias , Surtos de Doenças/prevenção & controleRESUMO
Air and water quality at a concentrated animal feeding operation (CAFO) in Eastern North Carolina that uses a covered lagoon and anaerobic digester was evaluated for 2 weeks in August 2020. Real-time PM2.5 mass concentrations were determined using a reference ADR-1500 nephelometer and high-frequency measurements of dissolved inorganic nitrogen (DIN) were evaluated using autonomously logging sensors. Air and water quality parameters were assessed before, during and after wastewater from the lagoon was irrigated onto adjacent spray fields. Reference measurements were conducted alongside a HOBO weather station to collect real-time wind speed and direction, temperature, and humidity measurements. PM2.5 concentrations varied between 0 and 159 µg/m3 with an average concentration of 11 µg/m3, below EPA standard for secondary aerosols of 15 µg/m3. Higher PM2.5 concentrations were observed when wind originated from swine barns but not from covered lagoons. Water quality data showed that DIN concentrations downgradient from the CAFO were elevated relative to upstream concentrations. A groundwater seep that drains a spray field contained the highest average DIN concentration (31.0 ± 12.8 mg L-1), which was 25 times greater than upstream DIN concentrations (1.2 ± 0.8 mg L-1). Average DIN concentration at the downstream station was lower than the seep concentration (8.6 ± 16.2 mg L-1), but approximately 8 times greater than upstream. Air quality data show that the lagoon cover was effective at mitigating air quality degradation, whereas DIN concentrations in water were similar to previous studies on CAFOs using open lagoons. In addition, air and water quality parameters were significantly (p < 0.001) higher after irrigation, indicating possible influence due to ammonia and nitrate elevation. Additional research is needed to compare high-frequency data collected from swine CAFOs using capped and uncapped lagoon systems to better understand spatiotemporal air and water quality trends of this practice.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Amônia/análise , Animais , Monitoramento Ambiental , Suínos , Águas Residuárias , Qualidade da Água , Tempo (Meteorologia)RESUMO
Package treatment plants (PTPs) are facilities designed to treat onsite wastewater for small communities, commercial, and residential developments. PTPs are being utilized in a growing number of coastal communities. This study estimated the effects of coastal tourism on onsite wastewater nitrogen (N) inputs to a barrier island surficial aquifer (Bogue Banks, NC). The N-removal effectiveness was assessed for seven PTPs that treated wastewater from vacation properties using a range of technologies: extended aeration; sequencing batch reactor; and advanced media filtration. Influent and effluent wastewater samples were collected monthly from Feb. 2014 to Jan. 2015 and analyzed for particulate and dissolved N. Increased summer visitation associated with coastal tourism resulted in an increase in water use, wastewater inputs, and PTP N loading to the surficial aquifer. However, extended aeration systems did not have significantly elevated TN loads during the summer months because their treatment efficiency increased. N inputs associated with coastal tourism made up approximately 51% of the annual wastewater-related N load to the surficial aquifer. Onsite wastewater N-loading to the surficial aquifer (6.7 kg-N/ha/yr) appeared to be the dominant source of N loading on the island. Water quality data indicated that these N inputs have resulted in increased groundwater NO3 concentrations in the surficial aquifer. Overall, wastewater inputs added approximately 4.6 cm of groundwater recharge annually to the island. Coastal tourism can result in measurable increases in wastewater N loading, groundwater nitrogen concentrations, and groundwater recharge.
Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Ilhas , Nitrogênio , Águas ResiduáriasRESUMO
The goal of this study was to gain a better understanding of the PO4-P treatment efficiency of onsite wastewater systems (OWS) installed in nutrient-sensitive watersheds of the North Carolina Piedmont. Four OWS including two conventional and two single-pass sand filter (SF) systems were evaluated at sites with clay-rich soils. Piezometers were installed near all of the OWS, and down-gradient from the conventional OWS for groundwater collection and characterization. Septic tanks, groundwater, SF effluent, and surface waters were sampled each season during 2015 (five times) and analyzed for PO4-P and Cl concentrations and for various environmental parameters. The conventional and SF OWS reduced PO4-P concentrations by an average of 99% and 90%, respectively, before discharge to surface waters. Mass-load reductions of PO4-P were also greater for the conventional OWS (mean 95%), relative to SF (83%) systems. The effluents discharged by SF OWS were influencing surface water quality. Additional treatment of the effluent from single-pass SF with reactive media is suggested, along with monitoring of the final effluent for PO4-P concentrations. This research provides important information that is absent from the published literature concerning PO4-P contributions to water resources from OWS in clay soils.
Assuntos
Filtração/instrumentação , Fosfatos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Cloretos/química , Filtração/métodos , Água Subterrânea/química , North Carolina , Solo/química , Movimentos da Água , Poluição da Água/prevenção & controle , Qualidade da ÁguaRESUMO
Motor vehicle crashes (MVC) are the leading cause of death from severe injuries on the Pine Ridge Indian Reservation (PRIR), averaging 16 MVC deaths per year from 2002 to 2011. The Sacred Cargo Coalition was established in PRIR in 2007 to implement intervention strategies to increase seat belt usage and reduce MVC fatalities, including seat belt law enforcement, creating a traffic court system, and educational campaigns on MVC prevention. The study described in this article examined the effectiveness of the interventions on increasing the seat belt usage rates and reducing MVC deaths. Secondary data were collected from the National Highway Traffic Safety Administration and other federal and local agencies. Seat belt usage rates increased an average of 6.8 percentage points from 2007 (10%) to 2012 (44%). MVC fatalities decreased by 46.7% from the preintervention to the intervention period. Maintenance and improvement of the intervention strategies may be achieved by seeking additional funding and including appropriate engineering activities in PRIR.
Assuntos
Acidentes de Trânsito/mortalidade , Acidentes de Trânsito/prevenção & controle , Veículos Automotores , Gestão da Segurança/métodos , Cintos de Segurança , Humanos , Indígenas Norte-Americanos , Gestão da Segurança/estatística & dados numéricos , Cintos de Segurança/estatística & dados numéricos , South DakotaRESUMO
It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water.
Assuntos
Adenovírus Humanos/efeitos dos fármacos , Cloro/farmacologia , Desinfetantes/farmacologia , Desinfecção/métodos , Água Doce/virologia , Adenovírus Humanos/crescimento & desenvolvimento , Adenovírus Humanos/fisiologia , Desinfecção/instrumentação , Água Doce/química , Concentração de Íons de Hidrogênio , Inativação de Vírus/efeitos dos fármacosRESUMO
The goal of this study was to determine if onsite wastewater treatment systems (OWS) were influencing groundwater and surface water Escherichia coli concentrations in a coastal plain watershed. Piezometers for groundwater monitoring were installed at four residences served by OWS and five residences served by a municipal wastewater treatment system (MWS). The residences were located in two different, but nearby (<3 km), watersheds. Effluent from the four septic tanks, groundwater from piezometers, and the streams draining the OWS and MWS watersheds were sampled on five dates between September 2011 and May 2012. Groundwater E. coli concentrations and specific conductivity were elevated within the flow path of the OWS and near the stream, relative to other groundwater sampling locations in the two watersheds. Groundwater discharge in the OWS watershed could be a contributor of E. coli to the stream because E. coli concentrations in groundwater at the stream bank and in the stream were similar. Stream E. coli concentrations were higher for the OWS in relation to MWS watersheds on each sampling date. Water quality could be improved by ensuring OWS are installed and operated to maintain adequate separation distances to water resources.
Assuntos
Escherichia coli/isolamento & purificação , Água Subterrânea/microbiologia , Rios/microbiologia , Águas Residuárias , North Carolina , Eliminação de Resíduos Líquidos , Qualidade da ÁguaRESUMO
Onsite wastewater treatment systems (OWTS) are commonly used in coastal areas to treat household wastewater. These systems represent potential sources of fecal pollution of groundwater and nearby surface water. OWTS are expected to reduce microbial concentrations in wastewater; however, system and environmental factors can affect treatment efficiency and impacts on ground and surface water. In the study of OWTS described in this article, the authors sampled septic tanks and groundwater at two households in coastal North Carolina between October 2009 and October 2011. Samples were tested for the fecal indicator microbes E. coli, enterococci, and Clostridium perfringens. Microbial source tracking was also performed in year two. Results showed that enteric microbe concentrations in groundwater significantly decreased with distance from the OWTS. Human markers of fecal contamination were also detected in the OWTS and downgradient groundwater, indicating that OWTS can impact the microbial quality of shallow groundwater.
Assuntos
Clostridium perfringens/isolamento & purificação , Enterococcaceae/isolamento & purificação , Escherichia coli/isolamento & purificação , Água Subterrânea/microbiologia , Eliminação de Resíduos Líquidos , Águas Residuárias/microbiologia , Qualidade da Água , Monitoramento Ambiental , Fezes/microbiologia , North Carolina , Estações do AnoRESUMO
Onsite wastewater treatment systems (OWTS) are the predominant disposal method for human waste in areas without municipal sewage treatment alternatives. Relatively few studies have addressed the release of pharmaceuticals and personal care products (PPCPs) from OWTS to groundwater. PPCP fate and transport from OWTS are important, particularly where these systems are adjacent to sensitive aquatic ecosystems such as coastal areas or wetlands. The objectives of this study were to identify PPCPs in residential wastewater and groundwater beneath OWTS and to characterize the environmental conditions affecting the OWTS discharge of PPCPs to nearby streams. The study sites are in coastal plain aquifers, which may be considered vulnerable "end-members" for subsurface PPCP transport. The PPCPs most commonly detected in the OWTS, at concentrations ranging from 0.12 µg L(-1) to 12.04 µg L(-1) in the groundwater, included: caffeine, ibuprofen, DEET, and homosalate. Their presence was related to particulate and dissolved organic carbon abundance.
Assuntos
Cosméticos/análise , Monitoramento Ambiental , Água Subterrânea/química , Preparações Farmacêuticas/análise , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Águas Residuárias/química , Áreas AlagadasRESUMO
Yellow fever (YF) is an important public health concern in areas where the disease is endemic. For more than 60 years a highly effective live attenuated vaccine has been available, its widespread use resulting in a dramatic decrease in the number of cases. On rare occasions, YF vaccine can cause mild to severe disease and rare adverse vaccine-associated events have been reported. Additionally, an average viremia of 3-5 days after administration of the YF vaccine has been published. Here we present a case where YF vaccine was isolated in cell culture from a respiratory swab collected from a patient presenting with influenza-like illness. To the best of our knowledge, this is the first report finding replicating YF vaccine in the respiratory sample of a post inoculated individual.
Assuntos
Sistema Respiratório/virologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/patologia , Vacinação/efeitos adversos , Vacina contra Febre Amarela/administração & dosagem , Vacina contra Febre Amarela/efeitos adversos , Vírus da Febre Amarela/isolamento & purificação , Feminino , Humanos , Cultura de Vírus , Adulto JovemRESUMO
The objectives for the study described in this article were to evaluate the fate and transport of onsite wastewater system (OWS)-derived phosphate from a residential system in Beaufort County, North Carolina, and to determine if current OWS setback regulations are sufficient to prevent elevated phosphate discharge to surface waters. Piezometers were installed in nests at different depths adjacent to drain-field trenches and up- and down-gradient of a residential OWS. Groundwater and septic effluent phosphate concentrations, temperature, pH, dissolved oxygen, and electrical conductivity were monitored every two months from February 2011 to October 2011 (five times). The mean groundwater phosphate concentration beneath the OWS (3.05 +/- 0.74 mg/L) was not significantly different than septic effluent (2.97 +/- 0.76 mg/L) and was elevated relative to background groundwater (0.14 +/- 0.12 mg/L). Groundwater phosphate concentrations were inversely related (r2 = .83) to distance from the system. Onsite system setback regulations may have to be increased (>30 m) in some areas to ensure groundwater phosphate concentrations are reduced to background concentrations before discharge to surface waters.
Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Fosfatos/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , North Carolina , Análise de Regressão , Águas ResiduáriasRESUMO
On-site wastewater treatment systems (OWS) are a potentially significant non-point source of nutrients to groundwater and surface waters, and are extensively used in coastal North Carolina. The goal of this study was to determine the treatment efficiency of four OWS in reducing total dissolved nitrogen (TDN) and dissolved organic carbon (DOC) concentrations before discharge to groundwater and/or adjacent surface water. Piezometers were installed for groundwater sample collection and nutrient analysis at four separate residences that use OWS. Septic tank effluent, groundwater, and surface water samples (from an adjacent stream) were collected four times during 2012 for TDN and DOC analysis and pH, temperature, electrical conductivity, and dissolved oxygen measurements. Treatment efficiencies from the tank to the groundwater beneath the drainfields ranged from 33 to 95% for TDN and 45 to 82% for DOC, although dilution accounted for most of the concentration reductions. There was a significant positive correlation between nitrate concentration and separation distance from trench bottom to water table and a significant negative correlation between DOC concentration and separation distance. The TDN and DOC transport (>15 m) from two OWS with groundwater saturated drainfield trenches was significant.
Assuntos
Carbono/análise , Água Subterrânea/análise , Nitrogênio/análise , Gerenciamento de Resíduos , North CarolinaRESUMO
Health inspections are performed at nursing homes to identify and reduce risk and to help maintain a safe environment for nursing home residents. The study described in this article aimed to identify the most frequent violations, types of violations (hygiene or structural), and repeat violations in nursing home facilities during health inspections; and to determine if the age of the facility influenced inspection scores. Nursing home health inspection forms (N = 131) completed between 2005 and 2011 in Pitt County, North Carolina, were analyzed. Results indicated that 60% of all violations were hygiene-related and could possibly be corrected without significant financial investments by management. Significant correlations occurred between the total number of violations and the facility age (p = .003) and between the number of repeat violations and total violations (p < .001). The average inspection score for nursing homes could be increased by more than three points if sanitation practices were improved.
Assuntos
Materiais de Construção/análise , Higiene/normas , Casas de Saúde/normas , Materiais de Construção/normas , North Carolina , SaneamentoRESUMO
DNA of two distinctive adenoviruses was detected in wild chimpanzees in western Tanzania that showed clinical signs of acute, upper respiratory disease, notably coughing. The amplified sequences from part of the capsid hexon gene suggests that one virus is a novel adenovirus serotype candidate and the other virus is a species C adenovirus most closely related to recent isolates from captive chimpanzees in the United States, Simian AdV 37 with 86% nucleic acid identity and Simian AdV 40 with 95% nucleic acid identity, respectively. The species C adenovirus sequences suggest possible recombination with a human adenovirus. The source of these viruses and disease association is not known.
Assuntos
Infecções por Adenoviridae/veterinária , Adenovírus Humanos/isolamento & purificação , Adenovirus dos Símios/isolamento & purificação , Doenças dos Símios Antropoides/epidemiologia , Fezes/virologia , Pan troglodytes , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Adenovírus Humanos/genética , Adenovirus dos Símios/genética , Animais , Doenças dos Símios Antropoides/virologia , DNA Viral/química , DNA Viral/isolamento & purificação , Filogenia , Tanzânia/epidemiologiaRESUMO
In the spring of 2009, a novel influenza A (H1N1) virus emerged in North America and spread worldwide to cause the first influenza pandemic since 1968. During the first 4 months, over 500 deaths in the United States had been associated with confirmed 2009 pandemic influenza A (H1N1) [2009 H1N1] virus infection. Pathological evaluation of respiratory specimens from initial influenza-associated deaths suggested marked differences in viral tropism and tissue damage compared with seasonal influenza and prompted further investigation. Available autopsy tissue samples were obtained from 100 US deaths with laboratory-confirmed 2009 H1N1 virus infection. Demographic and clinical data of these case-patients were collected, and the tissues were evaluated by multiple laboratory methods, including histopathological evaluation, special stains, molecular and immunohistochemical assays, viral culture, and electron microscopy. The most prominent histopathological feature observed was diffuse alveolar damage in the lung in all case-patients examined. Alveolar lining cells, including type I and type II pneumocytes, were the primary infected cells. Bacterial co-infections were identified in >25% of the case-patients. Viral pneumonia and immunolocalization of viral antigen in association with diffuse alveolar damage are prominent features of infection with 2009 pandemic influenza A (H1N1) virus. Underlying medical conditions and bacterial co-infections contributed to the fatal outcome of this infection. More studies are needed to understand the multifactorial pathogenesis of this infection.
Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/epidemiologia , Influenza Humana/mortalidade , Influenza Humana/virologia , Pandemias , Adolescente , Adulto , Autopsia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/patologia , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The newly described human bocavirus (HBoV) species 2 and 3 have been repeatedly detected in stool strengthening the possibility that these viruses might present a tropism for the gastrointestinal tract and may be etiological agents of diarrhea. OBJECTIVE: In this study we assessed the presence of HBoV2 and HBoV3 in stool specimens from Brazilians with acute gastroenteritis. STUDY DESIGN: Stool samples from Brazilian patients with acute diarrhea were analyzed for HBoV2 and HBoV3 by PCR assay. Full or partial genome sequences were obtained for selected isolates. Electron microscopy analysis was used to investigate virus morphology. RESULTS: Electron microscopy confirmed the presence of virus-like particles in HBoV PCR-positive specimens, with morphology similar to other members of the Parvoviridae family. Five samples out of 807 (0.6%) were positive for HBoV3. Three of the HBoV3-positive patients were HIV/AIDS positive. A selected group of 144 samples was also tested for HBoV2 and 30 samples (20.8%) were positive, 11 of which were HIV/AIDS positive. CONCLUSION: This study reports the detection and genetic characterization of HBoV3 and HBoV2 in the stool of Brazilian patients with acute diarrhea. This is the first description of HBoV3 outside Australia, suggesting a wide global distribution of this virus. Further studies are needed to better understand the role of HBoV in gastrointestinal infections, particularly among patients with HIV/AIDS.
Assuntos
Fezes/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Bocavirus Humano/classificação , Bocavirus Humano/isolamento & purificação , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Brasil/epidemiologia , Criança , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , DNA Viral/isolamento & purificação , Humanos , Lactente , Masculino , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência , Vírion/ultraestruturaRESUMO
Industry-wide health sector reforms in the United States, Canada, and Europe have provided a unique opportunity to examine the effects of hospital restructuring on inpatient nursing care and patient outcomes across an array of settings. Seven interdisciplinary research teams--1 each in Alberta, British Columbia, England, Germany, Ontario, Scotland, and the United States--have formed an international consortium whose aim is to study the effects of such restructuring. Each site has enrolled large numbers of hospitals and nurses to explicate the role that organization of nursing care, a target of hospital restructuring, plays in differential patient outcomes. The study seeks to understand more fully the influence of both nurse staffing and the nursing practice environment on patient outcomes. Discussion of the theoretical foundation, study design, and process of developing the study instruments and measures illustrates the process to date, as well as the feasibility of and opportunities inherent in such an international endeavour.
RESUMO
The role of group C rotaviruses as a cause of diarrhea was examined among children <17 years of age admitted to a Hospital in a suburban area of Buenos Aires, Argentina between 1997 and 2003. A total of 1,579 fecal samples were screened for group A (RVA) and C (RVC) rotaviruses by two in-house ELISA methods at Quilmes University (UNQ-ELISA). Samples positive, doubtful and negative by RVC specific UNQ-ELISA (n = 246) were examined further for RVC by another in-house ELISA (CDC-ELISA), electron microscopy, RT-PCR, nested PCR, and Southern hybridization. Sensitivity, specificity, and predictive values for each test were determined. While the sensitivity was comparable for the nested PCR and CDC-ELISA methods (82.5%), the molecular methods were slightly more specific. Poorly preserved particles were often seen in fecal samples, suggesting that degradation of RNA could be a factor influencing the performance of molecular methods. The incidence of RVC was estimated to be 3% without apparent differences among seasons. RVC infected patients had a significantly (P < 0.001) higher median age (6 years vs. 1 year) than those with RVA infection. Sequence of the RVC VP7 gene from six Argentinean strains and sequences reported previously in different countries showed high nucleotide (94.4-99.9%) sequence identities, indicating a high degree of conservation for human RVC VP7 genes among strains collected on five continents over a period of 17 years. These findings indicate that RVC is a significant cause of diarrhea and it is necessary to develop simple and sensitive serological methods for its detection.
Assuntos
Diarreia/virologia , Infecções por Rotavirus/diagnóstico , Rotavirus/classificação , Rotavirus/isolamento & purificação , Adolescente , Antígenos Virais/análise , Argentina , Southern Blotting/métodos , Criança , Pré-Escolar , Sequência Conservada , Ensaio de Imunoadsorção Enzimática/métodos , Fezes/virologia , Hospitais , Humanos , Lactente , Recém-Nascido , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Valor Preditivo dos Testes , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Rotavirus/genética , Rotavirus/imunologia , Infecções por Rotavirus/virologia , Sensibilidade e Especificidade , Análise de Sequência de DNA , Homologia de SequênciaRESUMO
Group C rotavirus (GpC RV) is a causative agent of acute gastroenteritis in children and adults. We expressed the three major capsid proteins VP2, VP6 and VP7 of human GpC RV in baculovirus and demonstrated the self-assembly of VP2/6/7 or VP6/7 virus-like particles (VLPs) in insect cells. We examined a number of parameters, including the kinetics of protein synthesis in different cell lines and media, to optimize the most favorable conditions for the synthesis of recombinant viral proteins and the production of VLPs in Sf9 cells. Hyperimmune serum to VP2/6/7 and VP6/7 VLPs recognized individual recombinant proteins of human GpC RV by Western blot analysis. This serum also showed specific reactivities with the corresponding GpC VLPs but not GpA RV by using immune electron microscopy (IEM) and enzyme immunoassay (EIA). The ability to produce an unlimited amount of GpC RV antigen and the availability of high quality antibody will allow us to develop sensitive and specific diagnostic assays to better determine the epidemiology and disease burden of GpC RV in humans.