Investigação sorológica de infecção por rotavirus em favela do Rio de Janeiro

The presence of antibodies against rotavirus was investigated by enzyme immunosorbent assay (ELISA) in two distinct groups of children living in a shanty town in Rio de Janeiro. One hundred and thirty six plasma samples were randomly collected from children of 0 to 33 months (first group) and 255 serum samples were collected from other 85 children at ages of 2, 6 and 9 months (second group). A high percentage of antibodies were found in the newborn children and this rate decreased progressively until the age of 11 months, after which it increased again. At the age of 7 months, geometric mean antibody titers increased indicating that infection had occurred.Cento e trinta e seis plasmas coletados aleatoriamente de crianças entre 0 e 33 meses (primeiro grupo) residentes na favela de Manguinhos, Rio de Janeiro, RJ, e 255 soros coletados de 85 crianças aos 2, 6 e 9 meses de idade (segundo grupo), residentes na mesma área, foram analisados para a presença de anticorpos (classe IgG) para rotavirus por ELISA. Anticorpos foram detectados em alto percentual de crianças recém-nascidas, declinando até o 11° mês. Elevação dos anticorpos foi observada a partir do 12° mês de vida, mas houve evidências de infecção a partir do 7° mês

Histopathological and ultrastructural aspects of mice lungs experimentally infected with dengue virus serotype 2

Submitted by Sandra Infurna ([email protected]) on 2020-03-10T12:29:17Z No. of bitstreams: 1 OrtrudBarth_DebraBarreto_etal_IOC_2007.pdf: 6204757 bytes, checksum: 46827ce79812b88ea66bc558554d3d3a (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-03-10T12:35:33Z (GMT) No. of bitstreams: 1 OrtrudBarth_DebraBarreto_etal_IOC_2007.pdf: 6204757 bytes, checksum: 46827ce79812b88ea66bc558554d3d3a (MD5)Made available in DSpace on 2020-03-10T12:35:33Z (GMT). No. of bitstreams: 1 OrtrudBarth_DebraBarreto_etal_IOC_2007.pdf: 6204757 bytes, checksum: 46827ce79812b88ea66bc558554d3d3a (MD5) Previous issue date: 2007Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Virologia. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Departamento de Histologia e Embriologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Virologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Virologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Virologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Virologia. Rio de Janeiro, RJ, Brasil.Histological and ultrastructural alterations in lung tissue of BALB/c mice infected with dengue virus serotype 2 (non-neuroadapted), by intraperitoneal and intravenous routes were analyzed. Lung tissues were processed following the standard techniques for photonic and electron transmission microscopies. Histopathological and ultrastructural studies showed interstitial pneumonia, characterized by the presence of mononuclear cells. In the mouse model, the dengue virus serotype 2 seems to led to a transient inflammatory process without extensive damage to the interalveolar septa, but caused focal alterations of the blood-exchange barrier. Endothelial cells of blood capillaries exhibited phyllopodia suggesting activation by presence of dengue virus. Morphometrical analysis of mast cells showed an expressive increase of the number of these cells in peribronchiolar spaces and adjacent areas to the interalveolar septa. Alveolar macrophages showed particles dengue virus-like inside rough endoplasmic reticulum and Golgi complex, suggesting viral replication. The tissue alterations observed in our experimental model were similar to the observed in human cases of dengue fever and dengue hemorrhagic fever. Our results show that BALB/c mice are permissive host for dengue virus serotype 2 replication and therefore provides an useful model to study of morphological aspects of dengue virus infection

Two Lineages of Dengue Virus Type 2, Brazil

Our results suggest the circulation of genetically different DENV-2 in Brazil and that these viruses may have a role in severity of dengue diseases. These fi ndings can help to further understand the complex dynamic pathogenic profi le of dengue viruses and their circulation in dengue-endemic regions.Submitted by Sandra Infurna ([email protected]) on 2017-10-19T12:29:42Z No. of bitstreams: 1 jmg_araujo_etal_IOC_2010.pdf: 90948 bytes, checksum: becf560ca2fc3c395d59080bbdfcaf2c (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-10-19T12:45:14Z (GMT) No. of bitstreams: 1 jmg_araujo_etal_IOC_2010.pdf: 90948 bytes, checksum: becf560ca2fc3c395d59080bbdfcaf2c (MD5)Made available in DSpace on 2017-10-19T12:45:14Z (GMT). No. of bitstreams: 1 jmg_araujo_etal_IOC_2010.pdf: 90948 bytes, checksum: becf560ca2fc3c395d59080bbdfcaf2c (MD5) Previous issue date: 2010Universidade Federal do Rio de Janeiro. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Rio de Janeiro, RJ, BrasilUniversidade Federal do Rio de Janeiro. Rio de Janeiro, RJ, BrasilUniversidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil

Dengue Virus Type 3, Brazil, 2002

An explosive epidemic of DENV-3 in 2002 was the most severe dengue epidemic reported in Brazil since dengue viruses were introduced

A New Approach to Dengue Fatal Cases Diagnosis: NS1 Antigen Capture in Tissues

Dengue manifestations may vary from asymptomatic to potentially fatal complications. With an increasing number of Dengue Hemorrhagic fever (DHF) and fatal cases, the availability of new approaches useful for cases confirmation plays an important role for the disease surveillance. The diagnosis of fatal cases in frozen and fixed tissues from autopsies can be determined by techniques such as viral RT-PCR, in situ hybridization, viral proteins detection by immunohistochemistry and NS3 specific immunostaining. We aimed to assess for the first time the usefulness of NS1 capture tests as a diagnostic technique to demonstrate DENV antigens in human tissue specimens. The highest sensitivity was obtained by a rapid ICT which was also the most sensitive in liver, lung, kidney, brain, spleen and thymus. Despite a number of studies demonstrating the usefulness of DENV NS1 antigen detection by different ELISAs in plasma and/or sera of dengue patients, no research has been done previously to demonstrate NS1 presence in tissues of fatal dengue cases. Moreover, the application of NS1 kits to demonstrate the presence of DENV may provide a better understanding of viral tropism in fatal cases and may be useful for studies of pathogenesis in vivo and in experimental animals

Comparison of Three Commercially Available Dengue NS1 Antigen Capture Assays for Acute Diagnosis of Dengue in Brazil

Dengue is the one of the most prevalent arthropod-borne viral diseases in tropical regions of the world. Manifestations may vary from asymptomatic to potentially fatal complications. Laboratorial diagnosis is essential to diagnose dengue and differentiate it from other diseases. Dengue virus non-structural protein 1 (NS1) may be used as a marker of acute dengue virus infection. Our results, based in the comparison of three NS1 antigen capture assays available, have shown that this approach is reliable for the early diagnosis of dengue infections, especially in the first four days after the onset of the symptoms. A lower sensitivity was observed in DENV-3 cases. Serum positive by virus isolation were more often detected than those positive by RT-PCR by all three assays. Only the Platelia™ NS1 test showed a higher sensitivity in confirming primary infections than secondary ones. In conclusion, NS1 antigen capture commercial kits are useful for diagnosis of acute primary and secondary dengue infections and, in endemic countries where secondary infections are expected to occur, may be used in combination with MAC-ELISA to increase the overall sensitivity of both tests

Neutralising antibodies for West Nile virus in horses from Brazilian Pantanal

Despite evidence of West Nile virus (WNV) activity in Colombia, Venezuela and Argentina, this virus has not been reported in most South American countries. In February 2009, we commenced an investigation for WNV in mosquitoes, horses and caimans from the Pantanal, Central-West Brazil. The sera of 168 horses and 30 caimans were initially tested using a flaviviruses-specific epitope-blocking enzyme-linked immunosorbent assay (blocking ELISA) for the detection of flavivirus-reactive antibodies. The seropositive samples were further tested using a plaque-reduction neutralisation test (PRNT90) for WNV and its most closely-related flaviviruses that circulate in Brazil to confirm the detection of specific virus-neutralising antibodies. Of the 93 (55.4%) blocking ELISA-seropositive horse serum samples, five (3%) were seropositive for WNV, nine (5.4%) were seropositive for St. Louis encephalitis virus, 18 (10.7%) were seropositive for Ilheus virus, three (1.8%) were seropositive for Cacipacore virus and none were seropositive for Rocio virus using PRNT90, with a criteria of > four-fold antibody titre difference. All caimans were negative for flaviviruses-specific antibodies using the blocking ELISA. No virus genome was detected from caiman blood or mosquito samples. The present study is the first report of confirmed serological evidence of WNV activity in Brazil