Preliminary evaluation on the efficiency of the kit Platelia Dengue NS1 Ag-ELISA to detect dengue virus in dried Aedes aegypti: a potential tool to improve dengue surveillance

Made available in DSpace on 2015-05-27T13:39:45Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) mariana_gandinietal_IOC_2014.pdf: 285390 bytes, checksum: 8af756f1717a715d9c267949f5da870e (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunologia Viral. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio Grande do Norte. Departamento de Microbiologia e Parasitologia. Laboratório de Biologia Molecular de Doenças Infecciosas e do Câncer. Natal, RN, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunologia Viral. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Background: Surveillance is a critical component of any dengue prevention and control programme. Herein, we investigate the efficiency of the commercial kit Platelia Dengue NS1 Ag-ELISA to detect dengue virus (DENV) antigens in Aedes aegypti mosquitoes infected under laboratory conditions. Methods: Under insectary conditions, four to five day-old mosquitoes were orally challenged with DENV-2 titer of 3.6 x 105 PFU equivalent/ml, incubated for 14 days and then killed. At ten time-points following mosquito death (0, 6, 12, 24, 72, 96, 120, 144 and 168 h), i.e., during a one-week period, dried mosquitoes were comparatively tested for the detection of the NS1 antigen with other methods of detection, such as qRT-PCR and virus isolation in C6/36 cells. Results: We first observed that the NS1 antigen was more effective in detecting DENV-2 in Ae. aegypti between 12 and 72 h after mosquito death when compared with qRT-PCR. A second round involved comparing the sensitivity of detection of the NS1 antigen and virus isolation in C6/36 cells. The NS1 antigen was also more effective than virus isolation, detecting DENV-2 at all time-points, i.e., up to 168 h after mosquito death. Meanwhile, virus isolation was successful up to 96 h after Ae. aegypti death, but the number of positive samples per time period presented a tendency to decline progressively over time. From the 43 samples positive by the virus isolation technique, 38 (88.4%) were also positive by the NS1 test. Conclusion: Taken together, these results are the first to indicate that the NS1 antigen might be an interesting complementary tool to improve dengue surveillance through DENV detection in dried Ae. aegypti females

Accuracy of the SD BIOLINE Dengue Duo for rapid point-of-care diagnosis of dengue.

BACKGROUND:Rapid diagnosis tests (RDTs) are easy to carry out, provide fast results, and could potentially guide medical treatment decisions. We investigated the performance of a commercially available RDT, which simultaneously detects the non-structural 1 (NS1) dengue virus (DENV) antigen, and IgM and IgG DENV antibodies, using representative serum samples from individuals in a dengue endemic area in Salvador, Brazil. METHODOLOGY/PRINCIPAL FINDINGS:We evaluated the accuracy of the SD BIOLINE Dengue Duo RDT (Abbott, Santa Clara, USA; former Alere Inc, Waltham, USA) in a random collection of sera. Samples included acute-phase sera from 246 laboratory-confirmed dengue cases and 108 non-dengue febrile patients enrolled in a surveillance study for dengue detection, 73 healthy controls living in the same surveillance community, and 73 blood donors. RDT accuracy was blindly assessed based on the combined results for the NS1 and the IgM test components. The RDT sensitivity was 46.8% (38.6% for the NS1 component and 13.8% for the IgM component). Sensitivity was greater for samples obtained from patients with secondary DENV infections (49.8%) compared to primary infections (31.1%) (P: 0.02) and was also influenced by the result in the confirmatory dengue diagnostic test, ranging from 39.7% for samples of cases confirmed by IgM-ELISA seroconversion between paired samples to 90.4% for samples of cases confirmed by a positive NS1-ELISA. The RDT specificity was 94.4% for non-dengue febrile patients, 87.7% for the community healthy controls, and 95.9% for the blood donors. CONCLUSIONS/SIGNIFICANCE:The SD BIOLINE Dengue Duo RDT showed good specificities, but low sensitivity, suggesting that it may be more useful to rule in than to rule out a dengue diagnosis in dengue endemic regions

Dengue virus in <i>Aedes aegypti</i> and <i>Aedes albopictus</i> in urban areas in the state of Rio Grande do Norte, Brazil: Importance of virological and entomological surveillance

<div><p>Background</p><p>Vector control remains the sole effective method to prevent dengue virus (DENV) transmission, although a vaccine for dengue has recently become available and testing of its efficacy and coverage is being performed in multiple places. Entomological surveillance is a key factor in alerting authorities to possible outbreaks, but until now natural DENV infection of mosquito populations has been scarcely used as an early warning system to monitor fluctuating prevalence of infected mosquitoes. The purpose of this study was to determine the burden of adult and larval/pupae of <i>Aedes aegypti</i> and <i>Aedes albopictus</i> with DENV in urban areas in the state of Rio Grande do Norte, Brazil.</p><p>Methodology/Principal findings</p><p>Immature insect forms (larvae and pupae) were collected from April 2011 to March 2012, whereas the collection of adults was conducted along 3 years: May 2011 to April 2014. Total RNAs of the samples were extracted and the nested reverse transcriptase PCR assay for detecting and typing DENV was performed. Of the 1333 immature insects collected during the study period, 1186 (89%) were <i>A</i>. <i>aegypti</i> and 147 (11%) <i>A</i>. <i>albopictus</i>. DENV-4 was identified in pools of <i>A</i>. <i>aegypti</i> larvae. The rate of DENV infection in immature <i>A</i>. <i>aegypti</i> was expressed as MIR = 3.37. DENV wasnot detected in immature <i>A</i>. <i>albopictus</i>. A total of 1360 adult female mosquitoes of the <i>Aedes</i> genus were captured from May 2011 to April 2014. Of this total, 1293 were <i>A</i>. <i>aegypti</i> (95%) and 67 were <i>A</i>. <i>albopictus</i> (5%). From the 130 pools studied, 27 (20.7%) were positive for DENV. DENV-1 was identified in 2/27 (7.4%) pools; 1of <i>A</i>. <i>albopictus</i> and 1 of <i>A</i>. <i>aegypti</i>. DENV-2 was identified in only 1/27 (3.7%) <i>A</i>. <i>aegypti</i> pools. DENV-4 was the most prevalent, identified in 24/27 (88.8%) of the positive pools, with 19 being of <i>A</i>. <i>aegypti</i> and 5 of <i>A</i>. <i>albopictus</i> pools. The minimum infection rate for adults of the <i>Aedes</i> genus was 19.8, considering both <i>A</i>. <i>aegypti</i> and <i>A</i>. <i>albopictus</i>.</p><p>Conclusions/Significance</p><p>This work represents the most complete study to date on the interaction between dengue viruses and <i>Aedes</i> mosquitoes in the State of Rio Grande do Norte, and raises important questions about a possible role of <i>A</i>. <i>albopictus</i> in the transmission of dengue virus in Brazil.</p></div

Study area.

<p>Map with the location point in the State of Rio Grande do Norte, Brazil. Areas where mosquitoes, larvae and pupae were collected. 1- Alecrim, 2- Felipe Camarão, 3- Nova Descoberta, 4- Potengi, and 5- Quintas. Note: This figure was created specifically for this manuscript by QGIS program. QGIS is a free and open-source cross-platform desktop geographic information system (GIS) application.</p

Minimum infection rate (MIR) for dengue virus in <i>Aedes aegypti</i> adults collected in urban areas in Natal, Rio Grande do Norte, Brazil.

<p>Minimum infection rate (MIR) for dengue virus in <i>Aedes aegypti</i> adults collected in urban areas in Natal, Rio Grande do Norte, Brazil.</p

Dengue virus in <i>Aedes albopictus</i> larvae and pupae collected in urban areas in Natal, Rio Grande do Norte, Brazil.

<p>Dengue virus in <i>Aedes albopictus</i> larvae and pupae collected in urban areas in Natal, Rio Grande do Norte, Brazil.</p

Minimum infection rate (MIR) for dengue virus in <i>Aedes aegypti</i> larvae and pupae collected in urban areas in Natal, Rio Grande do Norte, Brazil.

<p>Minimum infection rate (MIR) for dengue virus in <i>Aedes aegypti</i> larvae and pupae collected in urban areas in Natal, Rio Grande do Norte, Brazil.</p

Does immunity after Zika virus infection cross-protect against dengue?

Zika and dengue viruses are closely related flaviviruses, with immunological interactions and identical urban, mosquito-borne transmission.1Therefore, the recent introduction of Zika virus into the Americas and large-scale exposure of a uniformly previously unexposed population could affect subsequent transmission of dengue virus. This hypothesis had been untested, largely because sufficient epidemiological data were not available from affected locations. We explored this hypothesis in Salvador, the fourth largest city in Brazil (population 2·9 million), where extensive transmission of dengue viruses 1–42,3occurred before the introduction and spread of Zika virus in 2015.Fil: Ribeiro, Guilherme Sousa. Universidade Federal da Bahia; Brasil. Fundación Oswaldo Cruz; BrasilFil: Kikuti, Mariana. Fundación Oswaldo Cruz; Brasil. Universidade Federal da Bahia; BrasilFil: Tauro, Laura Beatriz. Fundación Oswaldo Cruz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Nascimento, Leile Camila J.. Fundación Oswaldo Cruz; BrasilFil: Cardoso, Cristiane W.. Secretaria Municipal de Saúde de Salvador; BrasilFil: Campos, Gúbio S.. Universidade Federal da Bahia; BrasilFil: Ko, Albert I.. Fundación Oswaldo Cruz; Brasil. University of Yale; Estados UnidosFil: Weaver, Scott C.. University of Texas Medical Branch; Estados UnidosFil: Reis, Mitermayer G.. Fundación Oswaldo Cruz; Brasil. Universidade Federal da Bahia; BrasilFil: Kitron, Uriel D.. University of Emory; Estados Unidos. Fundación Oswaldo Cruz; BrasilFil: Paploski, Igor A. D.. Universidade Federal da Bahia; BrasilFil: Silva, Monaise M. O.. Fundación Oswaldo Cruz; BrasilFil: Kasper, Amelia M.. Universidade Federal da Bahia; BrasilFil: Tavares, Aline S.. Fundación Oswaldo Cruz; BrasilFil: Cruz, Jaqueline S.. Fundación Oswaldo Cruz; BrasilFil: Moreira, Patrícia S. S.. Universidade Federal da Bahia; BrasilFil: Anjos, Rosângela O.. Fundación Oswaldo Cruz; BrasilFil: Araújo, Josélio M. G.. Universidade Federal do Rio Grande do Norte; BrasilFil: Khouri, Ricardo. Fundación Oswaldo Cruz; BrasilFil: Sardi, Silvia I.. Universidade Federal da Bahia; Brasi