scholarly journals Preliminary investigation of Culicidae species in South Pantanal, Brazil and their potential importance in arbovirus transmission

2010 ◽  
Vol 52 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Alex Pauvolid-Corrêa ◽  
Fernando Neto Tavares ◽  
Jeronimo Alencar ◽  
Julia dos Santos Silva ◽  
Michele Murta ◽  
...  
Keyword(s):  
Migratory Birds ◽  
Preliminary Investigation ◽  
Blood Feeding ◽  
Climatic Conditions ◽  
Nucleic Acid Detection ◽  
Potential Importance ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Viral Isolation ◽  
Brazilian Pantanal

In view of the high circulation of migratory birds and the environmental and climatic conditions which favor the proliferation of arthropods, the Brazilian Pantanal is susceptible to circulation of arboviruses. However, the amount of data concerning arbovirus vectors in this area is scarce; therefore the aim of this study was to conduct a preliminary investigation of Culicidae species in the Nhecolândia Sub-region of South Pantanal, Brazil and their potential importance in the arbovirus transmission. A total of 3684 specimens of mosquitoes were captured, 1689 of which caught in the rainy season of 2007, were divided into 78 pools and submitted to viral isolation, Semi-Nested RT-PCR and Nested RT-PCR, with a view to identifying the most important arboviruses in Brazil. Simultaneously, 70 specimens of ticks found blood-feeding on horses were also submitted to the same virological assays. No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, a total of 22 Culicidae species were identified, ten of which had previously been reported as vectors of important arboviruses. The diversity of species found blood-feeding on human and horse hosts together with the arboviruses circulation previously reported suggest that the Nhecolândia Sub-region of South Pantanal is an important area for arbovirus surveillance in Brazil.

scholarly journals Novel Viruses in Mosquitoes from Brazilian Pantanal

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 957 ◽  
Author(s):  
Laura Marina Siqueira Maia ◽  
Andressa Zelenski de Lara Pinto ◽  
Michellen Santos de Carvalho ◽  
Fernando Lucas de Melo ◽  
Bergmann Morais Ribeiro ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Rt Pcr ◽  
Viral Isolation ◽  
The North ◽  
Brazilian Pantanal ◽  
Pantanal Wetland

Viruses are ubiquitous and diverse microorganisms arising as a result of interactions within their vertebrate and invertebrate hosts. Here we report the presence of different viruses in the salivary glands of 1657 mosquitoes classified over 28 culicinae species from the North region of the Brazilian Pantanal wetland through metagenomics, viral isolation, and RT-PCR. In total, 12 viruses were found, eight putative novel viruses with relatively low similarity with pre-existing species of viruses within their families, named Pirizal iflavirus, Furrundu phlebovirus, Pixé phlebovirus, Guampa vesiculovirus, Chacororé flavivirus, Rasqueado orbivirus, Uru chuvirus, and Bororo circovirus. We also found the already described Lobeira dielmorhabdovirus, Sabethes flavivirus, Araticum partitivirus, and Murici totivirus. Therefore, these findings underscore the vast diversity of culicinae and novel viruses yet to be explored in Pantanal, the largest wetland on the planet.

scholarly journals Estimation of conjunctival swab and nasopharyngeal swab specimens for viral nucleic acid detection in Coronavirus disease 2019 patients to compare the viral load

2021 ◽  
Vol 4 ◽  
pp. 2
Author(s):  
Jaya Kaushik ◽  
Vikas Marwah ◽  
Ankita Singh ◽  
Y. V. K. Chaitanya ◽  
Rajeev Mohan Gupta ◽  
...  
Keyword(s):  
Viral Load ◽  
Nucleic Acid ◽  
Statistical Correlation ◽  
Nucleic Acid Detection ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Ocular Manifestations ◽  
Conjunctival Swab ◽  
Polymerase Chain

Objectives: The purpose of the study was to detect the presence of viral ribonucleic acid of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in conjunctival swab along with nasopharyngeal swab specimens of Coronavirus disease 2019 (COVID-19) patients. Material and Methods: Thirty COVID-19 patients with at least one sample positive for real-time reverse transcription-polymerase chain reaction for SARS-CoV-2 in nasopharyngeal swab with the presence or absence of ocular manifestations were included in the study. The conjunctival swab along with nasopharyngeal swab of each patient was collected and sent to microbiology lab for evaluation and analysis of viral nucleic acid to assess the viral load. Results: Out of 30 patients, 21 patients (70%) were males and the remaining nine patients (30%) were females. Mean age of the patients in the study was 44.80 ± 15.37 years. One patient had conjunctivitis as ocular manifestation. Two (6.7%) out of 30 patients were positive for RT-PCR SARS-CoV-2 in the conjunctival swab. There was no statistical correlation between nasopharyngeal swab and conjunctival swab positivity using Pearson’s correlation coefficient (r) = 0.010; P = 0.995 (>0.05). Conclusion: The results of the study revealed that SARS-CoV-2 can also be detected in conjunctival swabs of confirmed cases of COVID-19 patients. Although, in comparison to nasopharyngeal and throat swabs the rate of detection of SARS-CoV-2 in conjunctival swabs is relatively less, still diligent care and precautions should be practiced during the ophthalmic evaluation of COVID-19 patients.

scholarly journals Comparison of throat swabs and sputum specimens for viral nucleic acid detection in 52 cases of novel coronavirus (SARS-Cov-2)-infected pneumonia (COVID-19)

2020 ◽  
Vol 58 (7) ◽  
pp. 1089-1094 ◽  
Author(s):  
Chenyao Lin ◽  
Jie Xiang ◽  
Mingzhe Yan ◽  
Hongze Li ◽  
Shuang Huang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Detection Efficiency ◽  
Diagnostic Value ◽  
Nucleic Acid Detection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Viral Nucleic Acid ◽  
Detection Rates ◽  
Positive Rate ◽  
Novel Coronavirus

AbstractObjectivesIn December 2019, a novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19) occurred in Wuhan, China. Laboratory-based diagnostic tests utilized real-time reverse transcriptase polymerase chain reaction (RT-PCR) on throat samples. This study evaluated the diagnostic value to analyzing throat and sputum samples in order to improve accuracy and detection efficiency.MethodsPaired specimens of throat swabs and sputum were obtained from 54 cases, and RNA was extracted and tested for 2019-nCoV (equated with SARS-CoV-2) by the RT-PCR assay.ResultsThe positive rates of 2019-nCoV from sputum specimens and throat swabs were 76.9% and 44.2%, respectively. Sputum specimens showed a significantly higher positive rate than throat swabs in detecting viral nucleic acid using the RT-PCR assay (p = 0.001).ConclusionsThe detection rates of 2019-nCoV from sputum specimens were significantly higher than those from throat swabs. We suggest that sputum would benefit for the detection of 2019-nCoV in patients who produce sputum. The results can facilitate the selection of specimens and increase the accuracy of diagnosis.

scholarly journals Lack of evidence of porcine reproductive and respiratory syndrome virus (PRRSV) infection in domestic swine in Brazil

2004 ◽  
Vol 34 (2) ◽  
pp. 449-455 ◽  
Author(s):  
Janice Reis Ciacci-Zanella ◽  
Cristiano Trombetta ◽  
Ildara Vargas ◽  
Denise Euclydes Mariano da Costa
Keyword(s):  
Genetic Material ◽  
Elisa Test ◽  
Respiratory Syndrome Virus ◽  
Rt Pcr ◽  
Serum Samples ◽  
Viral Isolation ◽  
Culture Cells ◽  
Commercial Kits ◽  
Swine Herds ◽  
Domestic Swine

This report describes the first prevalence of antibodies and experimental inoculation of suspected samples of porcine reproductive and respiratory syndrome virus (PRRSV) from ELISA positive pigs from swine herds in Brazil. Based on the hypothesis that this agent is present in swine herds worldwide, the objective of this work was to establish a diagnostic methodology and to investigate the occurrence of PRRSV in Brazilian swine herds. Fifty-four swine herds, the total number which imported genetic material (live pigs or swine semen) from countries where PRRS was endemic from 1990 to December 2000, from eight Brazilian States all included in this study. The sampling used was such as to detect a prevalence of infection of 5%, with a confidence level of 95%. A total of 3785 serum samples were tested for PRRSV antibodies by ELISA. Following the ELISA test, which was performed with two different commercial kits, all serum positive pigs were retested, examined and additional materials were collected. Viral isolation in permissive tissue culture cells and swine bioassays were performed. Additionally, reverse transcriptase polymerase chain reaction (RT-PCR) and nested RT-PCR were also performed. We could not demonstrate the presence of PRRSV or RNA of PRRSV by viral isolation or RT-PCR (or nested RT-PCR), respectively in all of the analyzed samples. Furthermore, the pigs inoculated with PRRSV suspicion samples did not seroconvert nor produce characteristic PRRS lesions in the swine bioassay. Thus, our results indicate no evidence of PRRSV in the samples analyzed from swine herds in this study.

scholarly journals Cases Report of Cured Novel Coronavirus-infected Pneumonia Patients with Viral Nucleic Acid Test Positive in Fecal Specimens

2020 ◽  
Author(s):  
Mei Han ◽  
Jingbo Zou ◽  
Wenguang Tian ◽  
Xiaoyu Wei ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Molecular Diagnostic ◽  
Clinical Practices ◽  
Rt Pcr ◽  
Viral Nucleic Acid ◽  
Nucleic Acid Test ◽  
Assessment Standard ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Respiratory Specimens

Abstract Background: The outbreak of the novel coronavirus in China (COVID-19) represents a significant and urgent threat to global health. We report here five cases of COVID-19 infection patients in our clinical practices who are medically stable and presumed to successfully “cleared” the virus after antiviral treatments. Case presentation: The clinical evaluation depends on the viral nucleic acid test in respiratory specimens by real-time PCR reverse transcription (RT-PCR) assays according to the authorized guidance. We found that the stool samples of these cured patients remain positive in RT-PCR assay while the virus is undetectable in respiratory specimens. RT-PCR molecular diagnostic assay was designed to specifically detect the presence of viral RNA. Thus, the positive result in the fecal specimens implies the existence of viable virions with the patients. Conclusions: This highlights the importance to look closely at the assessment standard of medical treatment, as well as the need for reevaluation of the criteria for the initial screening, prevention, and care of patients with this emerging infection.

scholarly journals Rapid Detection of SARS-CoV-2 Using Reverse transcription RT-LAMP method

2020 ◽  
Author(s):  
Weihua Yang ◽  
Xiaofei Dang ◽  
Qingxi Wang ◽  
Mingjie Xu ◽  
Qianqian Zhao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcription ◽  
Virus Disease ◽  
Lamp Assay ◽  
Nucleic Acid Amplification ◽  
N Gene ◽  
Nucleic Acid Detection ◽  
Lamp Method ◽  
Rt Pcr ◽  
Rapid Amplification

AbstractCorona Virus Disease 2019 (COVID-19) is a recently emerged life-threatening disease caused by SARS-CoV-2. Real-time fluorescent PCR (RT-PCR) is the clinical standard for SARS-CoV-2 nucleic acid detection. To detect SARS-CoV-2 early and control the disease spreading on time, a faster and more convenient method for SARS-CoV-2 nucleic acid detecting, RT-LAMP method (reverse transcription loop-mediated isothermal amplification) was developed. RNA reverse transcription and nucleic acid amplification were performed in one step at 63 °C isothermal conditions, and the results can be obtained within 30 minutes. ORF1ab gene, E gene and N gene were detected at the same time. ORF1ab gene was very specific and N gene was very sensitivity, so they can guarantee both sensitivity and specificity for SARS-CoV-2. The sensitivity of RT-LAMP assay is similar to RT-PCR, and specificity was 99% as detecting 208 clinical specimens. The RT-LAMP assay reported here has the advantages of rapid amplification, simple operation, and easy detection, which is useful for the rapid and reliable clinical diagnosis of SARS-CoV-2.

The application of viral nucleic acid detection and lung CT in COVID-19 diagnosis

2020 ◽  
Author(s):  
Rui Hu
Keyword(s):  
Nucleic Acid ◽  
Clinical Symptoms ◽  
Virus Disease ◽  
False Negative ◽  
False Negative Rate ◽  
Diagnostic Methods ◽  
Nucleic Acid Detection ◽  
Viral Nucleic Acid ◽  
Early Medical Intervention ◽  
Lung Ct

The Corona Virus Disease 2019 (COVID-19) has the characteristics of fast propagation speed and strong pathogenicity and has attracted wide attention of people, medical workers, and researchers around the world. Accurate, rapid, and timely screening and diagnosis of COVID-19 is of great significance to control the development of the epidemic situation and save the lives of patients. Currently, the detection of viral nucleic acid and lung CT is the main screening and diagnostic methods of COVID-19. Nucleic acid detection has the advantages of fast, strong specificity and high sensitivity, but there is a certain false-negative rate. CT result of lung examination is visual, but it is not typical due to the uncertain time of clinical symptoms and the early medical intervention. Therefore, the diagnosis of COVID-19 should include a combination of epidemiological history, clinical symptoms, imaging, and laboratory tests.

scholarly journals First molecular and serological detection of Epizootic Hemorrhagic Disease virus in white tailed deer ( Odocoileus virginianus ) from Tamaulipas, Mexico

2019 ◽  
Vol 71 (1) ◽  
pp. 77-85
Author(s):  
J.O. Merino ◽  
NI. De la Cruz ◽  
G. Galvan ◽  
A.P. De León ◽  
J. Burnes
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Detection ◽  
Hemorrhagic Disease ◽  
Rt Pcr ◽  
Biting Midges ◽  
Epizootic Hemorrhagic Disease ◽  
Two Samples ◽  
Mexico Border ◽  
Transboundary Disease ◽  
The U.S

ABSTRACT Epizootic hemorrhagic disease viruses (EHDV) are dsRNA arboviruses transmitted by biting midges of the genus Culicoides that cause disease in domestic and wild ruminants. Epizootic hemorrhagic disease (EHD) is considered the most important infectious disease of white tailed deer (WTD) in North America, some studies in Northeast Mexico reported EHDV-seropositive WTD and EHDV-infected Culicoides vectors. The increasing population of WTD that share habitat with livestock in Northeast México highlights the importance of EHD for the livestock industry in the transboundary region with the U.S. One hundred and twenty two samples from WTD in Tamaulipas state, Mexico were tested by ELISA and RT-PCR for EHDV antibodies and nucleic acid, respectively. Twelve animals were seropositive to ELISA and eleven animals were positive by RT-PCR. This is the first report of EHDV nucleic acid detection in WTD from Mexico. It is hypothesized that applying the transboundary disease approach to interdisciplinary research will help fill knowledge gaps, which could help develop countermeasures to mitigate the threat of EHDV infection in wildlife and livestock along the U.S.-Mexico border.

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