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Beranek MD, Quaglia AI, Peralta GC, Flores FS, Stein M, Diaz LA, Almirón WR, Contigiani MS. Culex interfor and Culex saltanensis (Diptera: Culicidae) are susceptible and competent to transmit St. Louis encephalitis virus (Flavivirus: Flaviviridae) in central Argentina. Trans R Soc Trop Med Hyg 2021; 114:725-729. [PMID: 32722771 DOI: 10.1093/trstmh/traa058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/23/2020] [Accepted: 07/03/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND St. Louis encephalitis virus (SLEV) is endemic and autochthonous on the American continent. Culex pipiens quinquefasciatus is a vector of SLEV; however, Culex interfor and Culex saltanensis have also been found to be naturally infected with SLEV. The aim of this study was to determine the vector competence of C. interfor and C. saltanensis for SLEV from Argentina compared with C. p. quinquefasciatus. METHODS Female of the Culex species were orally infected by feeding on viraemic chicks that had been inoculated with SLEV. Abdomens, legs and saliva blood-fed mosquitoes were analysed by viral plaque assay. RESULTS Mosquitoes were susceptible to orally acquired infection, dissemination and transmission of SLEV in the saliva. CONCLUSIONS Our results demonstrate that C. saltanensis and C. interfor are susceptible to SLEV and competent for its transmission.
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Affiliation(s)
- Mauricio D Beranek
- Área Entomología, Instituto de Medicina Regional, CONICET, Universidad Nacional del Nordeste, Resistencia, Chaco, Argentina.,Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Agustín I Quaglia
- Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Giovana C Peralta
- Instituto de Diversidad y Ecología Animal, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Fernando S Flores
- Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina.,Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral, CONICET, Esperanza, Santa Fe, Argentina
| | - Marina Stein
- Área Entomología, Instituto de Medicina Regional, CONICET, Universidad Nacional del Nordeste, Resistencia, Chaco, Argentina
| | - Luis A Diaz
- Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina.,Instituto de Investigaciones Biológicas y Tecnológicas, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Walter R Almirón
- Instituto de Investigaciones Biológicas y Tecnológicas, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Marta S Contigiani
- Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina
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Giayetto O, Beranek MD, Nazar FN, Diaz A. Dose dependence of susceptibility and transmission for an Argentinean West Nile virus strain in local Culex pipiens quinquefasciatus (Diptera: Culicidae). Trans R Soc Trop Med Hyg 2021; 115:1066-1069. [PMID: 33493344 DOI: 10.1093/trstmh/traa185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/03/2020] [Accepted: 12/21/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND West Nile virus (WNV) activity has been documented in the central region of Argentina since 2005, but its maintenance network has not been elucidated yet. METHODS We evaluated the susceptibility to WNV oral infection and transmission in a Culex pipiens quinquefasciatus mosquito population by means of a dose-dependent vector competence assay. Mosquitoes were orally infected with five different viral loads and evaluated for viral infection, dissemination and transmission. RESULTS The evaluated population was susceptible to WNV oral infection. Disseminated infections were detected in all the viral doses but transmission was only detected in the higher doses (6 and 7 log10 plaque-forming units/ml). A linear relationship between doses and transmission rates could be established. CONCLUSIONS A minimum transmission threshold suggests that the Cu. p. quinquefasciatus from Argentina could acquire WNV infection from local urban birds and transmit the virus.
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Affiliation(s)
- Octavio Giayetto
- Instituto de Investigaciones Biológicas y Tecnológicas - IIBYT, CONICET - Universidad Nacional de Córdoba, Córdoba (X5016GCA), Argentina.,Laboratorio de Arbovirus, Instituto de Virología "Dr J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba (CP5016), Argentina
| | - Mauricio D Beranek
- Instituto de Investigaciones Biológicas y Tecnológicas - IIBYT, CONICET - Universidad Nacional de Córdoba, Córdoba (X5016GCA), Argentina.,Laboratorio de Arbovirus, Instituto de Virología "Dr J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba (CP5016), Argentina
| | - Franco N Nazar
- Instituto de Investigaciones Biológicas y Tecnológicas - IIBYT, CONICET - Universidad Nacional de Córdoba, Córdoba (X5016GCA), Argentina
| | - Adrián Diaz
- Instituto de Investigaciones Biológicas y Tecnológicas - IIBYT, CONICET - Universidad Nacional de Córdoba, Córdoba (X5016GCA), Argentina.,Laboratorio de Arbovirus, Instituto de Virología "Dr J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba (CP5016), Argentina
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3
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Batallán GP, Konigheim BS, Quaglia AI, Rivarola ME, Beranek MD, Tauro LB, Flores SF, Laurito M, Almirón WR, Contigiani MS, Visintin AM. Autochthonous circulation of Saint Louis encephalitis and West Nile viruses in the Province of La Rioja, Argentina. Rev Argent Microbiol 2020; 53:154-161. [PMID: 33176955 DOI: 10.1016/j.ram.2020.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 11/16/2022] Open
Abstract
St. Louis encephalitis (SLEV) and West Nile (WNV) arboviruses, which circulate in Argentina, are maintained in enzootic transmission cycles involving Culex mosquitoes (vectors) and birds belonging to orders Passeriformes and Columbiformes (amplifier hosts). The objective of this work was to determine the circulation of both viruses among wild birds in a semiarid ecosystem in the Province of La Rioja through a serologic survey. During spring 2013 and fall 2014, a total of 326 wild birds belonging to 41 species were captured in areas close to the cities of La Rioja and Chilecito, in the Province of La Rioja. While exposure to SLEV and WNV was analyzed in birds' serum through neutralizing antibody detection, viral circulation was estimated through apparent seroprevalence of neutralizing antibodies. The exposure of the avian community to viruses was 3.02% for SLEV and 1.89% for WNV, while 1.19% corresponded to coinfections. Our study confirms for the first time the circulation of SLEV and WNV in wild birds in the Province of La Rioja. Moreover, it is the first study to register neutralizing antibodies for flavivirus in the species Leptotila verreauxi (White-tipped Dove) (WNV) and Melanerpes cactorum (White-fronted Woodpecker) (SLEV). These results suggest that in semiarid ecosystems from northwestern Argentina the requirements and conditions for amplification and enzootic maintenance of SLEV and WNV would be present.
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Affiliation(s)
- Gonzalo P Batallán
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina; Departamento de Ciencias Básicas y Tecnológicas, Universidad Nacional de Chilecito, La Rioja, Argentina
| | - Brenda S Konigheim
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Agustín I Quaglia
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina; Florida Medical Entomology Laboratory, University of Florida, Vero Beach, FL, USA
| | - María E Rivarola
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Mauricio D Beranek
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Laura B Tauro
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Instituto de Biología Subtropical, nodo Iguazú, CONICET, Universidad Nacional de Misiones, Argentina
| | - Sebastián F Flores
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral/CONICET, Esperanza, Santa Fe, Argentina
| | - Magdalena Laurito
- Universidad Nacional de Córdoba, Centro de Investigaciones Entomológicas de Córdoba,Facultad de Ciencias Exactas, Físicas y Naturales, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biológicas y Tecnológicas, Córdoba, Argentina
| | - Walter R Almirón
- Universidad Nacional de Córdoba, Centro de Investigaciones Entomológicas de Córdoba,Facultad de Ciencias Exactas, Físicas y Naturales, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biológicas y Tecnológicas, Córdoba, Argentina
| | - Marta S Contigiani
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Instituto de Virología "Dr. J. M. Vanella", Enfermera Gordillo S/N, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Andrés M Visintin
- Universidad Nacional de Córdoba, Centro de Investigaciones Entomológicas de Córdoba,Facultad de Ciencias Exactas, Físicas y Naturales, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biológicas y Tecnológicas, Córdoba, Argentina; Instituto de Biología de la Conservación y Paleobiología (IBiCoPa), Centro de Investigación e Innovación Tecnológica (CENIIT), Universidad Nacional de la Rioja, La Rioja, Argentina.
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Using Earth observation images to inform risk assessment and mapping of climate change-related infectious diseases. ACTA ACUST UNITED AC 2019; 45:133-142. [PMID: 31285704 DOI: 10.14745/ccdr.v45i05a04] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The number of human cases of several climate-related infectious diseases, including tick- and mosquito-borne diseases, has increased in Canada and other parts of the world since the end of the last century. Predicting and mapping the risks associated with these diseases using environmental and climatic determinants derived from satellite images is an emerging method that can support research, surveillance, prevention and control activities and help to better assess the impacts of climate change in Canada. Earth observation images can be used to systematically monitor changes in the Earth's surface and atmosphere at different scales of time and space. These images can inform estimation and monitoring of environmental and climatic determinants, and thus disease prediction and risk mapping. The current array of Earth observation satellites provides access to a large quantity and variety of data. These data have different characteristics in terms of spatial, temporal and thematic precision and resolution. The objectives of this overview are to describe how Earth observation images may inform risk assessment and mapping of tick-borne and mosquito-borne diseases in Canada, their potential benefits and limitations, the implications and next steps.
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Alaniz AJ, Carvajal MA, Bacigalupo A, Cattan PE. Global spatial assessment of Aedes aegypti and Culex quinquefasciatus: a scenario of Zika virus exposure. Epidemiol Infect 2018; 147:e52. [PMID: 30474578 PMCID: PMC6518585 DOI: 10.1017/s0950268818003102] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 09/12/2018] [Accepted: 10/27/2018] [Indexed: 02/04/2023] Open
Abstract
Zika virus (ZIKV) is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. Recent scientific evidence on Culex quinquefasciatus has suggested its potential as a vector for ZIKV, which may change the current risk zones. We aimed to quantify the world population potentially exposed to ZIKV in a spatially explicit way, considering the primary vector (A. aegypti) and the potential vector (C. quinquefasciatus). Our model combined species distribution modelling of mosquito species with spatially explicit human population data to estimate ZIKV exposure risk. We estimated the potential global distribution of C. quinquefasciatus and estimated its potential interaction zones with A. aegypti. Then we evaluated the risk zones for ZIKV considering both vectors. Finally, we quantified and compared the people under risk associated with each vector by risk level, country and continent. We found that C. quinquefasciatus had a more temperate distribution until 42° in both hemispheres, while the risk involving A. aegypti is concentrated mainly in tropical latitudes until 35° in both hemispheres. Globally, 4.2 billion people are under risk associated with ZIKV. Around 2.6 billon people are under very high risk associated with C. quinquefasciatus and 1 billion people associated with A. aegypti. Several countries could be exposed to ZIKV, which emphasises the need to clarify the competence of C. quinquefasciatus as a potential vector as soon as possible. The models presented here represent a tool for risk management, public health planning, mosquito control and preventive actions, especially to focus efforts on the most affected areas.
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Affiliation(s)
- Alberto J. Alaniz
- Centro de Estudios en Ecología Espacial y Medio Ambiente – Ecogeografía, Santiago, Chile
- Laboratorio de Ecología, Departamento de Ciencias Biológicas Animales, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Mario A. Carvajal
- Centro de Estudios en Ecología Espacial y Medio Ambiente – Ecogeografía, Santiago, Chile
| | - Antonella Bacigalupo
- Laboratorio de Ecología, Departamento de Ciencias Biológicas Animales, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Pedro E. Cattan
- Laboratorio de Ecología, Departamento de Ciencias Biológicas Animales, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
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6
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Gravina HD, Suzukawa AA, Zanluca C, Cardozo Segovia FM, Tschá MK, Martins da Silva A, Faoro H, da Silva Ribeiro R, Mendoza Torres LP, Rojas A, Ferrerira L, Costa Ribeiro MCVD, Delfraro A, Duarte Dos Santos CN. Identification of insect-specific flaviviruses in areas of Brazil and Paraguay experiencing endemic arbovirus transmission and the description of a novel flavivirus infecting Sabethes belisarioi. Virology 2018; 527:98-106. [PMID: 30476788 DOI: 10.1016/j.virol.2018.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 11/26/2022]
Abstract
Viral infection was examined with pan-flavivirus and pan-alphavirus sets of primers in mosquitoes collected in four South American regions with confirmed pathogenic arbovirus circulation. Positive pools for flavivirus infection were sequenced and screened for specific arboviruses, which were not detected. However, NS5 gene sequencing showed that most sequences corresponded to the insect-specific Culex flavivirus. One sequence retrieved from an Aedes albopictus pool grouped with the insect-specific Aedes flavivirus and two Sabethes belisarioi pools were infected by a previously unknown flavivirus, tentatively named Sabethes flavivirus (SbFV). Phylogenetic inference placed SbFV as ancestral to a clade formed by Culiseta flavivirus, Mercadeo, and Calbertado. SbFV polyprotein showed an average aminoacidic identity of 51% in comparison to these flaviviruses. In vitro studies suggest that SbFV infects insect cells, but not vertebrate cells, therefore, we propose it as a new insect-specific flavivirus. These results highlight the wide distribution of insect-specific flaviviruses concomitant with the circulation of emergent arboviruses.
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Affiliation(s)
| | - Andreia Akemi Suzukawa
- Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz-PR, Curitiba, PR, Brazil
| | - Camila Zanluca
- Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz-PR, Curitiba, PR, Brazil
| | - Fatima María Cardozo Segovia
- Departamento de Salud Pública, Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción (UNA), Paraguay
| | - Marcel Kruchelski Tschá
- Laboratório de Virologia Molecular, Instituto Carlos Chagas/Fiocruz-PR, Curitiba, PR, Brazil
| | - Allan Martins da Silva
- Laboratório Central, Secretaria de Estado da Saúde (SESA), São José dos Pinhais, PR, Brazil
| | - Helisson Faoro
- Laboratório de Regulação da Expressão Gênica (LRGEN), Instituto Carlos Chagas/Fiocruz-PR, Curitiba, PR, Brazil
| | - Ricardo da Silva Ribeiro
- Laboratório de Vigilância Ambiental, Centro de Vigilância em Saúde Ambiental (CVSA), Secretaria de Estado de Saúde (SESA), Vitória, ES, Brazil
| | - Laura Patricia Mendoza Torres
- Departamento de Salud Pública, Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción (UNA), Paraguay
| | - Alejandra Rojas
- Departamento de Salud Pública, Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción (UNA), Paraguay
| | - Luis Ferrerira
- Servicio Nacional de Erradicación del Paludismo (SENEPA), Ministerio de Salud Pública y Bienestar Social, Asunción, Paraguay
| | | | - Adriana Delfraro
- Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
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Díaz A, Flores FS, Quaglia AI, Contigiani MS. Evaluation of Argentinean Bird Species as Amplifying Hosts for St. Louis Encephalitis Virus (Flavivirus, Flaviviridae). Am J Trop Med Hyg 2018; 99:216-221. [PMID: 29761767 DOI: 10.4269/ajtmh.17-0856] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
St.Louis encephalitis virus (SLEV) is an emerging human pathogen flavivirus in Argentina. Recently, it has reemerged in the United States. We evaluated the role as amplifying host of six resident bird species and analyzed their capacity as host during the 2005 encephalitis outbreak of SLEV in Córdoba. Eared Dove, Picui Ground Dove, and House Sparrow were the three species with highest host competence index. At a city level, Eared Dove and Picui Ground Dove were the most important amplifying hosts during the 2005 SLEV human outbreak in Córdoba city. This finding highlighted important differences in the SLEV ecology between Argentina and the United States. Characterizing and evaluating the SLEV hosts contribute to our knowledge about its ecology and could help us to understand the causes that promote its emergence as a human pathogen in South America.
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Affiliation(s)
- Adrián Díaz
- Instituto de Investigaciones Biológicas y Tecnológicas, CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina.,Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella," Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Fernando S Flores
- Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella," Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Agustín I Quaglia
- Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella," Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Marta S Contigiani
- Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella," Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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8
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Valdez LD, Sibona GJ, Diaz LA, Contigiani MS, Condat CA. Effects of rainfall on Culex mosquito population dynamics. J Theor Biol 2017; 421:28-38. [PMID: 28351704 DOI: 10.1016/j.jtbi.2017.03.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/22/2017] [Accepted: 03/25/2017] [Indexed: 11/25/2022]
Abstract
The dynamics of a mosquito population depends heavily on climatic variables such as temperature and precipitation. Since climate change models predict that global warming will impact on the frequency and intensity of rainfall, it is important to understand how these variables affect the mosquito populations. We present a model of the dynamics of a Culex quinquefasciatus mosquito population that incorporates the effect of rainfall and use it to study the influence of the number of rainy days and the mean monthly precipitation on the maximum yearly abundance of mosquitoes Mmax. Additionally, using a fracturing process, we investigate the influence of the variability in daily rainfall on Mmax. We find that, given a constant value of monthly precipitation, there is an optimum number of rainy days for which Mmax is a maximum. On the other hand, we show that increasing daily rainfall variability reduces the dependence of Mmax on the number of rainy days, leading also to a higher abundance of mosquitoes for the case of low mean monthly precipitation. Finally, we explore the effect of the rainfall in the months preceding the wettest season, and we obtain that a regimen with high precipitations throughout the year and a higher variability tends to advance slightly the time at which the peak mosquito abundance occurs, but could significantly change the total mosquito abundance in a year.
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Affiliation(s)
- L D Valdez
- Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba; Instituto de Física Enrique Gaviola, CONICET, Ciudad Universitaria, 5000 Córdoba, Argentina.
| | - G J Sibona
- Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba; Instituto de Física Enrique Gaviola, CONICET, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - L A Diaz
- Instituto de Investigaciones Biológicas y Tecnológicas-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina; Laboratorio de Arbovirus-Instituto de Virología "Dr. J. M. Vanella"-Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - M S Contigiani
- Laboratorio de Arbovirus-Instituto de Virología "Dr. J. M. Vanella"-Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - C A Condat
- Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba; Instituto de Física Enrique Gaviola, CONICET, Ciudad Universitaria, 5000 Córdoba, Argentina
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9
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Diaz LA, Quaglia AI, Konigheim BS, Boris AS, Aguilar JJ, Komar N, Contigiani MS. Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina. PLoS One 2016; 11:e0161871. [PMID: 27564679 PMCID: PMC5001705 DOI: 10.1371/journal.pone.0161871] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/12/2016] [Indexed: 11/30/2022] Open
Abstract
St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that birds amplify SLEV in Argentina as well. We compared avian SLEV seroprevalence in a variety of ecosystems in and around Córdoba city from 2004 (before the epidemic) and 2005 (during the epidemic). We also explored spatial patterns to better understand the local ecology of SLEV transmission. Because West Nile virus (WNV) was also detected in Argentina in 2005, all analyses were also conducted for WNV. A total of 980 birds were sampled for detection of SLEV and WNV neutralizing antibodies. SLEV seroprevalence in birds increased 11-fold from 2004 to 2005. Our study demonstrated that a high proportion (99.3%) of local birds were susceptible to SLEV infection immediately prior to the 2005 outbreak, indicating that the vertebrate host population was primed to amplify SLEV. SLEV was found distributed in a variety of environments throughout the city of Córdoba. However, the force of viral transmission varied among sites. Fine scale differences in populations of vectors and vertebrate hosts would explain this variation. In summary, we showed that in 2005, both SLEV and to a lesser extent WNV circulated in the avian population. Eared Dove, Picui Ground-Dove and Great Kiskadee are strong candidates to amplify SLEV because of their exposure to the pathogen at the population level, and their widespread abundance. For the same reasons, Rufous Hornero may be an important maintenance host for WNV in central Argentina. Competence studies and vector feeding studies are needed to confirm these relationships.
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Affiliation(s)
- Luis Adrián Diaz
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas–CONICET–Universidad Nacional de Córdoba, Córdoba, Argentina
- * E-mail:
| | - Agustín Ignacio Quaglia
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Brenda Salomé Konigheim
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Analia Silvana Boris
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Juan Javier Aguilar
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Nicholas Komar
- Centers for Diseases Control and Prevention, Fort Collins, Colorado, United States of America
| | - Marta Silvia Contigiani
- Laboratorio de Arbovirus—Instituto de Virología “Dr. J. M. Vanella”–Facultad de Ciencias Médicas–Universidad Nacional de Córdoba, Córdoba, Argentina
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