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Koller KK, Kernbach ME, Reese D, Unnasch TR, Martin LB. House Sparrows Vary Seasonally in Their Ability to Transmit West Nile Virus. Physiol Biochem Zool 2023; 96:332-341. [PMID: 37713719 DOI: 10.1086/725888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
AbstractSeasonality in infectious disease prevalence is predominantly attributed to changes in exogenous risk factors. For vectored pathogens, high abundance, activity, and/or diversity of vectors can exacerbate disease risk for hosts. Conversely, many host defenses, particularly immune responses, are seasonally variable. Seasonality in host defenses has been attributed, in part, to the proximate (i.e., metabolic) and ultimate (i.e., reproductive fitness) costs of defense. In this study, our goal was to discern whether any seasonality is observable in how a common avian host, the house sparrow (Passer domesticus), copes with a common zoonotic arbovirus, the West Nile virus (WNV), when hosts are studied under controlled conditions. We hypothesized that if host biorhythms play a role in vector-borne disease seasonality, birds would be most vulnerable to WNV when breeding and/or molting (i.e., when other costly physiological activities are underway) and thus most transmissive of WNV at these times of year (unless birds died from infection). Overall, the results only partly supported our hypothesis. Birds were most transmissive of WNV in fall (after their molt is complete and when WNV is most prevalent in the environment), but WNV resistance, WNV tolerance, and WNV-dependent mortality did not vary among seasons. These results collectively imply that natural arboviral cycles could be partially underpinned by endogenous physiological changes in hosts. However, other disease systems warrant study, as this result could be specific to the nonnative and highly commensal nature of the house sparrow or a consequence of the relative recency of the arrival of WNV to the United States.
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Visintin AM, Laurito M, Grech MG, Estallo EL, Grillet ME, Almeida FFL, Almirón WR. Ecological Characterization of Mosquitoes (Diptera: Culicidae) at the Southern Coast of Mar Chiquita Lake, Argentina. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:525-536. [PMID: 34951445 DOI: 10.1093/jme/tjab186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Indexed: 06/14/2023]
Abstract
In the southern coast of Mar Chiquita Lake, central Argentina, mosquitoes affect public health and community livelihood, since they transmit pathogens to human beings causing diseases such as malaria, filariasis, encephalitis, yellow fever, and dengue, among others, and have a negative effect on cattle farming as well. To characterize the structure of the mosquito assemblage of the region, we determined the species composition and diversity, the temporal distribution of different species, and the patterns of species richness, abundance, and diversity across seasons. We collected adult mosquitoes over a two-year period (October 2004-September 2006) by means of CDC light traps baited with CO2 from 18:00 to 08:00 h during the warm season (October-April) and from 12:00 h to 18:00 h in the cold season (May-September). A total of 71,501 individuals from 30 species were collected, with Culex Linnaeus and Aedes Meigen genera representing more than 98% of collected specimens (61.5% and 37.3%, respectively). The higher values of richness and abundance of Culicidae were registered in warm seasons compared to cold seasons. Chao1 estimates suggested that more than 90% of the species were detected in all seasons. Mosquito abundance distribution fit the logarithmic series and log-normal models. Aedes albifasciatus (Macquart), Ae. scapularis (Rondani), Culex interfor Dyar, Cx. saltanensis Dyar, and Cx. dolosus (Lynch Arribálzaga), vectors incriminated in arbovirus transmission, were abundant year-round, with Cx. saltanensis and Cx. dolosus most prevalent in cold seasons. Further studies are needed to assess the role of these species in arbovirus transmission in this region of central Argentina.
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Affiliation(s)
- Andrés M Visintin
- Centro de Investigaciones Entomológicas de Córdoba (CIEC)-Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT)-CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sarsfield, CP, Córdoba, Argentina
- Instituto de Biología de la Conservación y Paleobiología (IBiCoPa), Centro de Investigación e Innovación Tecnológica (CENIIT), Universidad Nacional de La Rioja, Avenida Luis Vernet y Apóstol Felipe s/n. CP, La Rioja, Argentina
| | - Magdalena Laurito
- Centro de Investigaciones Entomológicas de Córdoba (CIEC)-Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT)-CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sarsfield, CP, Córdoba, Argentina
| | - Marta G Grech
- Centro de Investigación Esquel de Montaña y Estepa Patagónica (CIEMEP)-CONICET-UNPSJB, Esquel, Chubut, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud-Sede Esquel, Universidad Nacional de la Patagonia San Juan Bosco, CP, Chubut, Argentina
| | - Elizabet L Estallo
- Centro de Investigaciones Entomológicas de Córdoba (CIEC)-Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT)-CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sarsfield, CP, Córdoba, Argentina
| | - María E Grillet
- Laboratorio de Biología de Vectores. Instituto de Zoología y Ecología Tropical, Facultad de Ciencias, Universidad Central de Venezuela. Apartado, Los Chaguaramos, Caracas, Venezuela
| | - Francisco F Ludueña Almeida
- Centro de Investigaciones Entomológicas de Córdoba (CIEC)-Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT)-CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sarsfield, CP, Córdoba, Argentina
| | - Walter R Almirón
- Centro de Investigaciones Entomológicas de Córdoba (CIEC)-Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT)-CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sarsfield, CP, Córdoba, Argentina
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WEST NILE VIRUS INFECTION IN RUFFED GROUSE (BONASA UMBELLUS) IN PENNSYLVANIA, USA: A MULTI-YEAR COMPARISON OF STATEWIDE SEROSURVEYS AND VECTOR INDICES. J Wildl Dis 2021; 57:51-59. [PMID: 33635996 DOI: 10.7589/jwd-d-19-00016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2019] [Indexed: 11/20/2022]
Abstract
Eastern populations of Ruffed Grouse (Bonasa umbellus) have been in a decades-long decline across the mid-Atlantic and southern Appalachian Mountains of the US. West Nile virus (WNV), which first arrived in the US in 1999, is suspected to have contributed to these declines based on decreased population indices since the arrival of WNV in Pennsylvania as well as on high, experimentally induced WNV-associated morbidity rates. A 3-yr statewide survey was conducted across Pennsylvania to measure flavivirus (i.e., WNV) seroprevalence among hunter-harvested grouse. The overall seroprevalence from 2015-17 was 14.4% (81/563); annual seroprevalence ranged from 2.8% (4/145) in the 2017 hunt year to 22.6% (52/230) in 2016-17. We analyzed the effects of numerous variables (i.e., Ruffed Grouse age and sex, hunt year, WNV vector index [VI], and region of Pennsylvania) on WNV serostatus by logistic regression. While there was no significant difference in WNV seroprevalence between sex and age group, there was significant variation in seroprevalence between geographic regions of Pennsylvania and across hunt years. Additionally, there was a negative correlation between WNV seroprevalence and VI. Low seroprevalence rates among Ruffed Grouse corresponded to years with a high VI, supporting experimental findings that Ruffed Grouse may be highly susceptible to WNV-associated disease. Additional strategic research efforts are essential to more effectively measure the effects of WNV on Ruffed Grouse and other vulnerable avian species.
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Meierhofer MB, Lilley TM, Ruokolainen L, Johnson JS, Parratt SR, Morrison ML, Pierce BL, Evans JW, Anttila J. Ten-year projection of white-nose syndrome disease dynamics at the southern leading-edge of infection in North America. Proc Biol Sci 2021; 288:20210719. [PMID: 34074117 PMCID: PMC8170204 DOI: 10.1098/rspb.2021.0719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Predicting the emergence and spread of infectious diseases is critical for the effective conservation of biodiversity. White-nose syndrome (WNS), an emerging infectious disease of bats, has resulted in high mortality in eastern North America. Because the fungal causative agent Pseudogymnoascus destructans is constrained by temperature and humidity, spread dynamics may vary by geography. Environmental conditions in the southern part of the continent are different than the northeast, where disease dynamics are typically studied, making it difficult to predict how the disease will manifest. Herein, we modelled WNS pathogen spread in Texas based on cave densities and average dispersal distances of hosts, projecting these results out to 10 years. We parameterized a predictive model of WNS epidemiology and its effects on bat populations with observed cave environmental data. Our model suggests that bat populations in northern Texas will be more affected by WNS mortality than southern Texas. As such, we recommend prioritizing the preservation of large overwintering colonies of bats in north Texas through management actions. Our model illustrates that infectious disease spread and infectious disease severity can become uncoupled over a gradient of environmental variation and highlight the importance of understanding host, pathogen and environmental conditions across a breadth of environments.
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Affiliation(s)
- Melissa B Meierhofer
- Department of Rangeland, Wildlife and Fisheries Management, Texas A&M University, 534 John Kimbrough Boulevard, College Station, TX 77843, USA.,Natural Resources Institute, Texas A&M University, 534 John Kimbrough Boulevard, College Station, TX 77843, USA.,Finnish Museum of Natural History, University of Helsinki, Pohjoinen Rautatiekatu 13, 00100 Helsinki, Finland
| | - Thomas M Lilley
- Finnish Museum of Natural History, University of Helsinki, Pohjoinen Rautatiekatu 13, 00100 Helsinki, Finland
| | - Lasse Ruokolainen
- Department of Biosciences, University of Helsinki, Yliopistonkatu 4, 00100 Helsinki, Finland
| | - Joseph S Johnson
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA
| | - Steven R Parratt
- Department of Ecology and Evolution, University of Liverpool, Liverpool L69 7BE, UK
| | - Michael L Morrison
- Department of Rangeland, Wildlife and Fisheries Management, Texas A&M University, 534 John Kimbrough Boulevard, College Station, TX 77843, USA
| | - Brian L Pierce
- Natural Resources Institute, Texas A&M University, 534 John Kimbrough Boulevard, College Station, TX 77843, USA
| | - Jonah W Evans
- Wildlife Diversity Program, Texas Parks and Wildlife, 4200 Smith School Road, Austin, TX 78744, USA
| | - Jani Anttila
- Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland
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Rothman SE, Jones JA, LaDeau SL, Leisnham PT. Higher West Nile Virus Infection in Aedes albopictus (Diptera: Culicidae) and Culex (Diptera: Culicidae) Mosquitoes From Lower Income Neighborhoods in Urban Baltimore, MD. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:1424-1428. [PMID: 33257956 DOI: 10.1093/jme/tjaa262] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Indexed: 06/12/2023]
Abstract
The temperate United States has experienced increasing incidence of mosquito-borne diseases. Recent studies conducted in Baltimore, MD have demonstrated a negative relationship between abundances of Aedes albopictus (Skuse) and Culex mosquitoes and mean neighborhood income level, but have not looked at the presence of pathogens. Mosquitoes collected from five socioeconomically variable neighborhoods were tested for infection by West Nile, chikungunya, and Zika viruses in 2015 and 2016, and again from four of the neighborhoods in 2017. Minimum infection rates of pooled samples were compared among neighborhoods for each year, as well as among individual blocks in 2017. West Nile virus was detected in both Ae. albopictus and Culex pools from all neighborhoods sampled in 2015 and 2017. No infected pools were detected in any year for chikungunya or Zika viruses, and none of the target viruses were detected in 2016. Infection rates were consistently higher for Culex than for Ae. albopictus. Minimum infection rate was negatively associated with mean neighborhood income for both species in 2015. Although earlier work has shown a positive association between block-level abandonment and mosquito abundance, no association was detected in this study. Still, we demonstrate that viral infection in mosquito pools can differ substantially across adjacent urban neighborhoods that vary by income. Though trap security and accessibility often inform city sampling locations, detecting and managing arboviral risk requires surveillance across neighborhoods that vary in socioeconomics, including lower income areas that may be less accessible and secure but have higher infection rates.
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Affiliation(s)
- Sarah E Rothman
- Department of Environmental Science and Technology, University of Maryland, MD
| | - Jennifer A Jones
- Department of Environmental Science and Technology, University of Maryland, MD
- Walter Reed Army Institute of Research, Silver Spring, MD
| | | | - Paul T Leisnham
- Department of Environmental Science and Technology, University of Maryland, MD
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Phylogeographic analysis of Pseudogymnoascus destructans partitivirus-pa explains the spread dynamics of white-nose syndrome in North America. PLoS Pathog 2021; 17:e1009236. [PMID: 33730096 PMCID: PMC7968715 DOI: 10.1371/journal.ppat.1009236] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/11/2020] [Indexed: 11/19/2022] Open
Abstract
Understanding the dynamics of white-nose syndrome spread in time and space is an important component for the disease epidemiology and control. We reported earlier that a novel partitivirus, Pseudogymnoascus destructans partitivirus-pa, had infected the North American isolates of Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome in bats. We showed that the diversity of the viral coat protein sequences is correlated to their geographical origin. Here we hypothesize that the geographical adaptation of the virus could be used as a proxy to characterize the spread of white-nose syndrome. We used over 100 virus isolates from diverse locations in North America and applied the phylogeographic analysis tool BEAST to characterize the spread of the disease. The strict clock phylogeographic analysis under the coalescent model in BEAST showed a patchy spread pattern of white-nose syndrome driven from a few source locations including Connecticut, New York, West Virginia, and Kentucky. The source states had significant support in the maximum clade credibility tree and Bayesian stochastic search variable selection analysis. Although the geographic origin of the virus is not definite, it is likely the virus infected the fungus prior to the spread of white-nose syndrome in North America. We also inferred from the BEAST analysis that the recent long-distance spread of the fungus to Washington had its root in Kentucky, likely from the Mammoth cave area and most probably mediated by a human. The time to the most recent common ancestor of the virus is estimated somewhere between the late 1990s to early 2000s. We found the mean substitution rate of 2 X 10-3 substitutions per site per year for the virus which is higher than expected given the persistent lifestyle of the virus, and the stamping-machine mode of replication. Our approach of using the virus as a proxy to understand the spread of white-nose syndrome could be an important tool for the study and management of other infectious diseases.
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7
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Buss N, Wersebe M, Hua J. Direct and indirect effects of a common cyanobacterial toxin on amphibian-trematode dynamics. CHEMOSPHERE 2019; 220:731-737. [PMID: 30611071 DOI: 10.1016/j.chemosphere.2018.12.160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
Wildlife diseases are emerging at unprecedented rates. While there are likely several factors at play, human-mediated environmental alterations may play a significant role. Of growing interest is the effect that microcystin-LR (MC-LR), a cyanotoxin, may have on disease outcomes. In this study, using an amphibian-trematode model we examined (1) the lethal effects of MC-LR on cercariae of trematodes; (2) the sublethal effects of MC-LR exposure on the ability for trematodes to infect green frog tadpoles; and (3) the sublethal effects of MC-LR on green frog tadpole susceptibility to trematodes. We found that environmentally-relevant concentrations of MC-LR at 50, 100, and 500 μg L-1 increased cercariae rate of mortality (LC50-14h = 134.24 μg L-1). However, sublethal exposure of trematodes to 2 and 10 μg L-1 MC-LR did not alter their infectivity. Conversely, sublethal exposure of tadpoles to 2 μg L-1 increased their susceptibility to trematodes by 147%. However, 10 μg L-1 of MC-LR did not affect tadpole susceptibility to trematodes, indicating a non-linear response to sublethal MC-LR exposure. Overall, our findings suggest that high concentrations of MC-LR (≥50 μg L-1) have the potential to limit trematode transmission to amphibian hosts through MC-LR-induced mortality. However, at lower concentrations (<10 μg L-1) MC-LR's effect on tadpole-cercariae disease outcome is likely driven by its effect on the tadpole host. Collectively, this work highlights the need to consider how toxicants influence both host and parasite at multiple concentrations to better understand the impacts of cyanotoxins on disease dynamics.
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Affiliation(s)
- Nicholas Buss
- Biological Sciences Department, Binghamton University (SUNY), Binghamton, NY 13902, USA.
| | - Matthew Wersebe
- Biological Sciences Department, Binghamton University (SUNY), Binghamton, NY 13902, USA; Department of Biology, Program in Ecology and Evolutionary Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
| | - Jessica Hua
- Biological Sciences Department, Binghamton University (SUNY), Binghamton, NY 13902, USA
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Lilley TM, Anttila J, Ruokolainen L. Landscape structure and ecology influence the spread of a bat fungal disease. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13183] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Thomas M. Lilley
- Institute of Integrative BiologyUniversity of Liverpool Liverpool UK
- Finnish Museum of Natural HistoryUniversity of Helsinki Helsinki Finland
| | - Jani Anttila
- Department of BiosciencesUniversity of Helsinki Helsinki Finland
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White LA, Forester JD, Craft ME. Dynamic, spatial models of parasite transmission in wildlife: Their structure, applications and remaining challenges. J Anim Ecol 2017; 87:559-580. [PMID: 28944450 DOI: 10.1111/1365-2656.12761] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 09/07/2017] [Indexed: 01/26/2023]
Abstract
Individual differences in contact rate can arise from host, group and landscape heterogeneity and can result in different patterns of spatial spread for diseases in wildlife populations with concomitant implications for disease control in wildlife of conservation concern, livestock and humans. While dynamic disease models can provide a better understanding of the drivers of spatial spread, the effects of landscape heterogeneity have only been modelled in a few well-studied wildlife systems such as rabies and bovine tuberculosis. Such spatial models tend to be either purely theoretical with intrinsic limiting assumptions or individual-based models that are often highly species- and system-specific, limiting the breadth of their utility. Our goal was to review studies that have utilized dynamic, spatial models to answer questions about pathogen transmission in wildlife and identify key gaps in the literature. We begin by providing an overview of the main types of dynamic, spatial models (e.g., metapopulation, network, lattice, cellular automata, individual-based and continuous-space) and their relation to each other. We investigate different types of ecological questions that these models have been used to explore: pathogen invasion dynamics and range expansion, spatial heterogeneity and pathogen persistence, the implications of management and intervention strategies and the role of evolution in host-pathogen dynamics. We reviewed 168 studies that consider pathogen transmission in free-ranging wildlife and classify them by the model type employed, the focal host-pathogen system, and their overall research themes and motivation. We observed a significant focus on mammalian hosts, a few well-studied or purely theoretical pathogen systems, and a lack of studies occurring at the wildlife-public health or wildlife-livestock interfaces. Finally, we discuss challenges and future directions in the context of unprecedented human-mediated environmental change. Spatial models may provide new insights into understanding, for example, how global warming and habitat disturbance contribute to disease maintenance and emergence. Moving forward, better integration of dynamic, spatial disease models with approaches from movement ecology, landscape genetics/genomics and ecoimmunology may provide new avenues for investigation and aid in the control of zoonotic and emerging infectious diseases.
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Affiliation(s)
- Lauren A White
- Department of Ecology, Evolution & Behavior, University of Minnesota, St. Paul, MN, USA
| | - James D Forester
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
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Levine RS, Mead DG, Hamer GL, Brosi BJ, Hedeen DL, Hedeen MW, McMillan JR, Bisanzio D, Kitron UD. Supersuppression: Reservoir Competency and Timing of Mosquito Host Shifts Combine to Reduce Spillover of West Nile Virus. Am J Trop Med Hyg 2016; 95:1174-1184. [PMID: 27503511 DOI: 10.4269/ajtmh.15-0809] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 06/09/2016] [Indexed: 11/07/2022] Open
Abstract
In the eastern United States, human cases of West Nile virus (WNV) result from spillover from urban epizootic transmission between passerine birds and Culex mosquitoes. In Atlanta, GA, substantial WNV presence in hosts and vectors has not resulted in the human disease burden observed in cities with similar infection pressure. Our study goal was to investigate extrinsic ecological conditions that potentially contribute to these reduced transmission rates. We conducted WNV surveillance among hosts and vectors in urban Atlanta and recorded an overall avian seroprevalence of nearly 30%, which was significantly higher among northern cardinals, blue jays, and members of the mimid family, and notably low among American robins. Examination of temporal Culex feeding patterns showed a marked feeding shift from American robins in the early season to northern cardinals in the late season. We therefore rule out American robins as superspreaders in the Atlanta area and suggest instead that northern cardinals and mimids act as WNV "supersuppressor" species, which slow WNV transmission by drawing many infectious bites during the critical virus amplification period, yet failing to amplify transmission due to low host competencies. Of particular interest, urban forest patches provide spillover protection by increasing the WNV amplification fraction on supersuppressor species.
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Affiliation(s)
- Rebecca S Levine
- Department of Environmental Sciences, Emory University, Atlanta, Georgia.
| | - Daniel G Mead
- Southeastern Cooperative Wildlife Disease Study, University of Georgia College of Veterinary Medicine, Athens, Georgia
| | - Gabriel L Hamer
- Department of Entomology, Texas A&M College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas
| | - Berry J Brosi
- Department of Environmental Sciences, Emory University, Atlanta, Georgia
| | - David L Hedeen
- Office of Environmental Services, Georgia Department of Transportation, Atlanta, Georgia
| | - Meghan W Hedeen
- Office of Environmental Services, Georgia Department of Transportation, Atlanta, Georgia
| | - Joseph R McMillan
- Department of Environmental Sciences, Emory University, Atlanta, Georgia
| | - Donal Bisanzio
- Department of Environmental Sciences, Emory University, Atlanta, Georgia
| | - Uriel D Kitron
- Department of Environmental Sciences, Emory University, Atlanta, Georgia
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11
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Kramer AM, Pulliam JT, Alexander LW, Park AW, Rohani P, Drake JM. Spatial spread of the West Africa Ebola epidemic. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160294. [PMID: 27853607 PMCID: PMC5108957 DOI: 10.1098/rsos.160294] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/29/2016] [Indexed: 05/06/2023]
Abstract
Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013-2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.
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Affiliation(s)
- Andrew M. Kramer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Author for correspondence: Andrew M. Kramer e-mail:
| | - J. Tomlin Pulliam
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Laura W. Alexander
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Andrew W. Park
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Pejman Rohani
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - John M. Drake
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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Shand L, Brown WM, Chaves LF, Goldberg TL, Hamer GL, Haramis L, Kitron U, Walker ED, Ruiz MO. Predicting West Nile Virus Infection Risk From the Synergistic Effects of Rainfall and Temperature. JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:935-944. [PMID: 27113111 DOI: 10.1093/jme/tjw042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 03/17/2016] [Indexed: 06/05/2023]
Abstract
Mosquito-based surveillance is a practical way to estimate the risk of transmission of West Nile virus (WNV) to people. Variations in temperature and precipitation play a role in driving mosquito infection rates and transmission of WNV, motivating efforts to predict infection rates based on prior weather conditions. Weather conditions and sequential patterns of meteorological events can have particularly important, but regionally distinctive, consequences for WNV transmission, with high temperatures and low precipitation often increasing WNV mosquito infection. Predictive models that incorporate weather can thus be used to provide early indications of the risk of WNV infection. The purpose of this study was first, to assess the ability of a previously published model of WNV mosquito infection to predict infection for an area within the region for which it was developed, and second, to improve the predictive ability of this model by incorporating new weather factors that may affect mosquito development. The legacy model captured the primary trends in mosquito infection, but it was improved considerably when calibrated with local mosquito infection rates. The use of interaction terms between precipitation and temperature improved model performance. Specifically, temperature had a stronger influence than rainfall, so that lower than average temperature greatly reduced the effect of low rainfall on increased infection rates. When rainfall was lower, high temperature had an even stronger positive impact on infection rates. The final model is practical, stable, and operationally valid for predicting West Nile virus infection rates in future weeks when calibrated with local data.
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Affiliation(s)
- L Shand
- Department of Statistics, University of Illinois, Urbana, IL 61801 ,
| | - W M Brown
- Department of Pathobiology, University of Illinois, Urbana, IL 61801 (; )
| | - L F Chaves
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, Japan
| | - T L Goldberg
- Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706
| | - G L Hamer
- Department of Entomology, Texas A&M University, College Station, TX 77843
| | - L Haramis
- Division of Environmental Health, Illinois Department of Public Health, Springfield, IL 62761
| | - U Kitron
- Department of Environmental Sciences, Emory University, Atlanta, GA 30322
| | - E D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824 , and
| | - M O Ruiz
- Department of Pathobiology, University of Illinois, Urbana, IL 61801 (; ),
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Hoekman D, Springer YP, Gibson C, Barker CM, Barrera R, Blackmore MS, Bradshaw WE, Foley DH, Ginsberg HS, Hayden MH, Holzapfel CM, Juliano SA, Kramer LD, LaDeau SL, Livdahl TP, Moore CG, Nasci RS, Reisen WK, Savage HM. Design for mosquito abundance, diversity, and phenology sampling within the National Ecological Observatory Network. Ecosphere 2016. [DOI: 10.1002/ecs2.1320] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- D. Hoekman
- National Ecological Observatory Network (NEON) Inc. 1685 38th St. Suite 100 Boulder Colorado 80301 USA
| | - Y. P. Springer
- National Ecological Observatory Network (NEON) Inc. 1685 38th St. Suite 100 Boulder Colorado 80301 USA
- Division of Vector‐Borne Diseases United States Centers for Disease Control and Prevention 3156 Rampart Road Fort Collins Colorado 80521 USA
| | - C. Gibson
- Department of Entomology University of Arizona Tucson Arizona85721
| | - C. M. Barker
- Center for Vectorborne Diseases and Department of Pathology, Microbiology and Immunology School of Veterinary Medicine University of California Davis California 95616 USA
| | - R. Barrera
- Division of Vector‐Borne Diseases United States Centers for Disease Control and Prevention 1324 Calle Canada San Juan Puerto Rico 00969 USA
| | - M. S. Blackmore
- Department of Biology Valdosta State University Valdosta Georgia 31698 USA
| | - W. E. Bradshaw
- Institute of Ecology and Evolution University of Oregon Eugene Oregon 97403 USA
| | - D. H. Foley
- Walter Reed Biosystematics Unit Division of Entomology Walter Reed Army Institute of Research 503 Robert Grant Avenue, Silver Spring Maryland 20910 USA
| | - H. S. Ginsberg
- United States Geological Survey Patuxent Wildlife Research Center University of Rhode Island Coastal Field Station, Woodward Hall, PSE Kingston Rhode Island 02881 USA
| | - M. H. Hayden
- National Center for Atmospheric Research Boulder Colorado 80307 USA
| | - C. M. Holzapfel
- Institute of Ecology and Evolution University of Oregon Eugene Oregon 97403 USA
| | - S. A. Juliano
- School of Biological Sciences Illinois State University Normal Illinois 61790‐4120 USA
| | - L. D. Kramer
- Arbovirus Laboratory New York State Department of Health Wadsworth Center Slingerlands New York 12159 USA
- State University of New York at Albany School of Public Health Albany New York 12201 USA
| | - S. L. LaDeau
- Cary Institute of Ecosystem Studies 2801 Sharon Turnpike Millbrook New York 12545 USA
| | - T. P. Livdahl
- Department of Biology Clark University Worcester Massachusetts 01610 USA
| | - C. G. Moore
- Department of Microbiology, Immunology & Pathology Colorado State University 1690 Campus Delivery Ft. Collins Colorado 80523 USA
| | - R. S. Nasci
- Division of Vector‐Borne Diseases United States Centers for Disease Control and Prevention 3156 Rampart Road Fort Collins Colorado 80521 USA
| | - W. K. Reisen
- Center for Vectorborne Diseases and Department of Pathology, Microbiology and Immunology School of Veterinary Medicine University of California Davis California 95616 USA
| | - H. M. Savage
- Division of Vector‐Borne Diseases United States Centers for Disease Control and Prevention 3156 Rampart Road Fort Collins Colorado 80521 USA
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14
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George TL, Harrigan RJ, LaManna JA, DeSante DF, Saracco JF, Smith TB. Persistent impacts of West Nile virus on North American bird populations. Proc Natl Acad Sci U S A 2015; 112:14290-4. [PMID: 26578774 PMCID: PMC4655513 DOI: 10.1073/pnas.1507747112] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Since its introduction to North America in 1999, West Nile virus (WNV) has had devastating impacts on native host populations, but to date these impacts have been difficult to measure. Using a continental-scale dataset comprised of a quarter-million birds captured over nearly two decades and a recently developed model of WNV risk, we estimated the impact of this emergent disease on the survival of avian populations. We find that populations were negatively affected by WNV in 23 of the 49 species studied (47%). We distinguished two groups of species: those for which WNV negatively impacted survival only during initial spread of the disease (n = 11), and those that show no signs of recovery since disease introduction (n = 12). Results provide a novel example of the taxonomic breadth and persistent impacts of this wildlife disease on a continental scale. Phylogenetic analyses further identify groups (New World sparrows, finches, and vireos) disproportionally affected by temporary or persistent WNV effects, suggesting an evolutionary dimension of disease risk. Identifying the factors affecting the persistence of a disease across host species is critical to mitigating its effects, particularly in a world marked by rapid anthropogenic change.
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Affiliation(s)
- T Luke George
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523
| | - Ryan J Harrigan
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095;
| | - Joseph A LaManna
- Department of Biology, Washington University, St. Louis, MO 63130
| | - David F DeSante
- The Institute for Bird Populations, Point Reyes Station, CA 94956
| | - James F Saracco
- The Institute for Bird Populations, Point Reyes Station, CA 94956
| | - Thomas B Smith
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095
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15
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Arab A, Courter JR. Spatio-temporal Trend Analysis of Spring Arrival Data for Migratory Birds. COMMUN STAT-SIMUL C 2014. [DOI: 10.1080/03610918.2013.809100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Estrada-Peña A, Ostfeld RS, Peterson AT, Poulin R, de la Fuente J. Effects of environmental change on zoonotic disease risk: an ecological primer. Trends Parasitol 2014; 30:205-14. [PMID: 24636356 DOI: 10.1016/j.pt.2014.02.003] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 02/08/2014] [Accepted: 02/11/2014] [Indexed: 12/27/2022]
Abstract
Impacts of environmental changes on zoonotic disease risk are the subject of speculation, but lack a coherent framework for understanding environmental drivers of pathogen transmission from animal hosts to humans. We review how environmental factors affect the distributions of zoonotic agents and their transmission to humans, exploring the roles they play in zoonotic systems. We demonstrate the importance of capturing the distributional ecology of any species involved in pathogen transmission, defining the environmental conditions required, and the projection of that niche onto geography. We further review how environmental changes may alter the dispersal behaviour of populations of any component of zoonotic disease systems. Such changes can modify relative importance of different host species for pathogens, modifying contact rates with humans.
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Affiliation(s)
- Agustín Estrada-Peña
- Department of Animal Pathology, Faculty of Veterinary Medicine, Miguel Servet, 177, 50013-Zaragoza, Spain.
| | | | - A Townsend Peterson
- The University of Kansas Biodiversity Institute, Lawrence, KS 66045-7593, USA
| | - Robert Poulin
- Department of Zoology, University of Otago, Dunedin 9016, New Zealand
| | - José de la Fuente
- SaBio, IREC, Ronda de Toledo s/n, 13071 Ciudad Real, Spain; Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
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17
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Levine RS, Mead DG, Kitron UD. Limited spillover to humans from West Nile Virus viremic birds in Atlanta, Georgia. Vector Borne Zoonotic Dis 2013; 13:812-7. [PMID: 24107200 PMCID: PMC3822371 DOI: 10.1089/vbz.2013.1342] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
West Nile Virus (WNV) is a mosquito-borne pathogen that impacts the health of its passerine bird hosts as well as incidentally infected humans in the United States. Intensive enzootic activity among the hosts and vectors does not always lead to human outbreaks, as is the situation throughout much of the southeastern United States. In Georgia, substantial yearly evidence of WNV in the mosquito vectors and avian hosts since 2001 has only led to 324 human cases. Although virus has been consistently isolated from mosquitoes trapped in Atlanta, GA, little is known about viral activity among the passerine hosts. A possible reason for the suppression of WNV spillover to humans is that viremic birds are absent from high human-use areas of the city. To test this hypothesis, multiseason, multihabitat, longitudinal WNV surveillance for active WNV viremia was conducted within the avian host community of urban Atlanta by collection of blood samples from wild passerine birds in five urban microhabitats. WNV was isolated from the serum of six blood samples collected from 630 (0.95%) wild passerine birds in Atlanta during 2010-2012, a proportion similar to that found in the Chicago, IL, area in 2005, when over 200 human cases were reported. Most of the viremic birds were Northern Cardinals, suggesting they may be of particular importance to the WNV transmission cycle in Georgia. Results indicated active WNV transmission in all microhabitats of urban Atlanta, except in the old-growth forest patches. The number of viremic birds was highest in Zoo Atlanta, where 3.5% of samples were viremic. Although not significant, these observations may suggest a possible transmission reduction effect of urban old-growth forests and a potential role in WNV amplification for Zoo Atlanta. Overall, spillover to humans remains a rare occurrence in urban Atlanta settings despite active WNV transmission in the avian population.
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Affiliation(s)
- Rebecca S. Levine
- Emory University, Department of Environmental Studies and Graduate Division of Biological and Biomedical Sciences Program in Population Biology, Ecology, and Evolution, Atlanta, Georgia
| | - Daniel G. Mead
- University of Georgia, College of Veterinary Medicine, Southeastern Cooperative Wildlife Disease Study, Athens, Georgia
| | - Uriel D. Kitron
- Emory University, Department of Environmental Studies and Graduate Division of Biological and Biomedical Sciences Program in Population Biology, Ecology, and Evolution, Atlanta, Georgia
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18
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Why does Amphibian Chytrid (Batrachochytrium dendrobatidis) not occur everywhere? An exploratory study in Missouri ponds. PLoS One 2013; 8:e76035. [PMID: 24086681 PMCID: PMC3783386 DOI: 10.1371/journal.pone.0076035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/23/2013] [Indexed: 11/29/2022] Open
Abstract
The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates) sp.) for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a). Our goal was to generate hypotheses toward answering the question, “Why does Bd not occur in all apparently suitable habitats?” Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds). We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion) revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations.
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19
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Morin CW, Comrie AC. Regional and seasonal response of a West Nile virus vector to climate change. Proc Natl Acad Sci U S A 2013; 110:15620-5. [PMID: 24019459 PMCID: PMC3785720 DOI: 10.1073/pnas.1307135110] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions.
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Affiliation(s)
- Cory W. Morin
- School of Geography and Development, University of Arizona, Tucson, AZ 85721
| | - Andrew C. Comrie
- School of Geography and Development, University of Arizona, Tucson, AZ 85721
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20
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Jeschke JM, Keesing F, Ostfeld RS. Novel organisms: comparing invasive species, GMOs, and emerging pathogens. AMBIO 2013; 42:541-8. [PMID: 23456779 PMCID: PMC3698323 DOI: 10.1007/s13280-013-0387-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/05/2012] [Accepted: 02/07/2013] [Indexed: 05/25/2023]
Abstract
Invasive species, range-expanding species, genetically modified organisms (GMOs), synthetic organisms, and emerging pathogens increasingly affect the human environment. We propose a framework that allows comparison of consecutive stages that such novel organisms go through. The framework provides a common terminology for novel organisms, facilitating knowledge exchange among researchers, managers, and policy makers that work on, or have to make effective decisions about, novel organisms. The framework also indicates that knowledge about the causes and consequences of stage transitions for the better studied novel organisms, such as invasive species, can be transferred to more poorly studied ones, such as GMOs and emerging pathogens. Finally, the framework advances understanding of how climate change can affect the establishment, spread, and impacts of novel organisms, and how biodiversity affects, and is affected by, novel organisms.
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Affiliation(s)
- Jonathan M Jeschke
- Technische Universität München, Department of Ecology and Ecosystem Management, Restoration Ecology, 85350, Freising-Weihenstephan, Germany.
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21
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Spread of white-nose syndrome on a network regulated by geography and climate. Nat Commun 2013; 3:1306. [PMID: 23250436 DOI: 10.1038/ncomms2301] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 11/15/2012] [Indexed: 01/18/2023] Open
Abstract
Wildlife and plant diseases can reduce biodiversity, disrupt ecosystem services and threaten human health. Emerging pathogens have displayed a variety of spatial spread patterns due to differences in host ecology, including diffusive spread from an epicentre (West Nile virus), jump dispersal on a network (foot-and-mouth disease), or a combination of these (Sudden oak death). White-nose syndrome is a highly pathogenic infectious disease of bats currently spreading across North America. Understanding how bat ecology influences this spread is crucial to management of infected and vulnerable populations. Here we show that white-nose syndrome spread is not diffusive but rather mediated by patchily distributed habitat and large-scale gradients in winter climate. Simulations predict rapid expansion and infection of most counties with caves in the contiguous United States by winter 2105-2106. Our findings show the unique pattern of white-nose syndrome spread corresponds to ecological traits of the host and suggest hypotheses for transmission mechanisms acting at the local scale.
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22
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Sovada MA, Pietz PJ, Hofmeister EK, Bartos AJ. West Nile virus in American White Pelican chicks: transmission, immunity, and survival. Am J Trop Med Hyg 2013; 88:1152-8. [PMID: 23530073 DOI: 10.4269/ajtmh.12-0408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
West Nile virus (WNV) causes significant mortality of American White Pelican chicks at northern plains colonies. We tested oropharyngeal/cloacal swabs from moribund chicks for shed WNV. Such shedding could enable chick-to-chick transmission and help explain why WNV spreads rapidly in colonies. WNV was detected on swabs from 11% of chicks in 2006 and 52% of chicks in 2007; however, viral titers were low. Before onset of WNV mortality, we tested blood from < 3-week-old chicks for antibodies to WNV; 5% of chicks were seropositive, suggesting passive transfer of maternal antibodies. Among near-fledged chicks, 41% tested positive for anti-WNV antibodies, indicating that they survived infection. Among years and colonies, cumulative incidence of WNV in chicks varied from 28% to 81%, whereas the proportion of chicks surviving WNV (i.e., seropositive) was 64-75%. Our data revealed that WNV kills chicks that likely would fledge in the absence of WNV, that infection of chicks is pervasive, and that significant numbers of chicks survive infection.
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Affiliation(s)
- Marsha A Sovada
- US Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND 58401, USA.
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23
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Ostfeld RS, Keesing F. Effects of Host Diversity on Infectious Disease. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2012. [DOI: 10.1146/annurev-ecolsys-102710-145022] [Citation(s) in RCA: 301] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Felicia Keesing
- Cary Institute of Ecosystem Studies, Millbrook, New York 12545;
- Biology Program, Bard College, Annandale-on-Hudson, New York 12504
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24
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Witter LA, Johnson CJ, Croft B, Gunn A, Poirier LM. Gauging climate change effects at local scales: weather-based indices to monitor insect harassment in caribou. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2012; 22:1838-1851. [PMID: 23092020 DOI: 10.1890/11-0569.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Climate change is occurring at an accelerated rate in the Arctic. Insect harassment may be an important link between increased summer temperature and reduced body condition in caribou and reindeer (both Rangifer tarandus). To examine the effects of climate change at a scale relevant to Rangifer herds, we developed monitoring indices using weather to predict activity of parasitic insects across the central Arctic. During 2007-2009, we recorded weather conditions and used carbon dioxide baited traps to monitor activity of mosquitoes (Culicidae), black flies (Simuliidae), and oestrid flies (Oestridae) on the post-calving and summer range of the Bathurst barren-ground caribou (Rangifer tarandus groenlandicus) herd in Northwest Territories and Nunavut, Canada. We developed statistical models representing hypotheses about effects of weather, habitat, location, and temporal variables on insect activity. We used multinomial logistic regression to model mosquito and black fly activity, and logistic regression to model oestrid fly presence. We used information theory to select models to predict activity levels of insects. Using historical weather data, we used hindcasting to develop a chronology of insect activity on the Bathurst range from 1957 to 2008. Oestrid presence and mosquito and black fly activity levels were explained by temperature. Wind speed, light intensity, barometric pressure, relative humidity, vegetation, topography, location, time of day, and growing degree-days also affected mosquito and black fly levels. High predictive ability of all models justified the use of weather to index insect activity. Retrospective analyses indicated conditions favoring mosquito activity declined since the late 1950s, while predicted black fly and oestrid activity increased. Our indices can be used as monitoring tools to gauge potential changes in insect harassment due to climate change at scales relevant to caribou herds.
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Affiliation(s)
- Leslie A Witter
- Natural Resources and Environmental Studies Graduate Program, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia V2N 4Z9, Canada.
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25
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Morrison SA, Sillett TS, Ghalambor CK, Fitzpatrick JW, Graber DM, Bakker VJ, Bowman R, Collins CT, Collins PW, Delaney KS, Doak DF, Koenig WD, Laughrin L, Lieberman AA, Marzluff JM, Reynolds MD, Scott JM, Stallcup JA, Vickers W, Boyce WM. Proactive Conservation Management of an Island-endemic Bird Species in the Face of Global Change. Bioscience 2011. [DOI: 10.1525/bio.2011.61.12.11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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26
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Foppa IM, Beard RH, Mendenhall IH. The impact of West Nile virus on the abundance of selected North American birds. BMC Vet Res 2011; 7:43. [PMID: 21831324 PMCID: PMC3163188 DOI: 10.1186/1746-6148-7-43] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 08/11/2011] [Indexed: 12/01/2022] Open
Abstract
Background The emergence of West Nile virus (WNV) in North America has been associated with high mortality in the native avifauna and has raised concerns about the long-term impact of WNV on bird populations. Here, we present results from a longitudinal analysis of annual counts of six bird species, using North American Breeding Bird Survey data from ten states (1994 to 2010). We fit overdispersed Poisson models to annual counts. Counts from successive years were linked by an autoregressive process that depended on WNV transmission intensity (annual West Nile neuroinvasive disease reports) and was adjusted by El Niño Southern Oscillation events. These models were fit using a Markov chain Monte Carlo algorithm. Results Model fit was mostly excellent, especially for American Crows, for which our models explained between 26% and 81% of the observed variance. The impact of WNV on bird populations was quantitatively evaluated by contrasting hypothetical count trajectories (omission of WNV) with observed counts. Populations of American crows were most consistently affected with a substantial cumulative impact in six of ten states. The largest negative impact, almost 60%, was found in Illinois. A regionally substantial decline was also seen for American Robins and House Sparrows, while the other species appeared unaffected. Conclusions Our results confirm findings from previous studies that single out American Crows as the species most vulnerable to WNV infection. We discuss strengths and limitations of this and other methods for quantifying the impact of WNV on bird populations.
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Affiliation(s)
- Ivo M Foppa
- Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA.
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27
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LaDeau SL, Glass GE, Hobbs NT, Latimer A, Ostfeld RS. Data-model fusion to better understand emerging pathogens and improve infectious disease forecasting. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2011; 21:1443-60. [PMID: 21830694 PMCID: PMC7163730 DOI: 10.1890/09-1409.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 04/14/2010] [Accepted: 04/19/2010] [Indexed: 05/28/2023]
Abstract
Ecologists worldwide are challenged to contribute solutions to urgent and pressing environmental problems by forecasting how populations, communities, and ecosystems will respond to global change. Rising to this challenge requires organizing ecological information derived from diverse sources and formally assimilating data with models of ecological processes. The study of infectious disease has depended on strategies for integrating patterns of observed disease incidence with mechanistic process models since John Snow first mapped cholera cases around a London water pump in 1854. Still, zoonotic and vector-borne diseases increasingly affect human populations, and methods used to successfully characterize directly transmitted diseases are often insufficient. We use four case studies to demonstrate that advances in disease forecasting require better understanding of zoonotic host and vector populations, as well of the dynamics that facilitate pathogen amplification and disease spillover into humans. In each case study, this goal is complicated by limited data, spatiotemporal variability in pathogen transmission and impact, and often, insufficient biological understanding. We present a conceptual framework for data-model fusion in infectious disease research that addresses these fundamental challenges using a hierarchical state-space structure to (1) integrate multiple data sources and spatial scales to inform latent parameters, (2) partition uncertainty in process and observation models, and (3) explicitly build upon existing ecological and epidemiological understanding. Given the constraints inherent in the study of infectious disease and the urgent need for progress, fusion of data and expertise via this type of conceptual framework should prove an indispensable tool.
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Affiliation(s)
- Shannon L LaDeau
- Cary Institute of Ecosystem Studies, Millbrook, New York 12545, USA.
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28
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LaDeau SL, Calder CA, Doran PJ, Marra PP. West Nile virus impacts in American crow populations are associated with human land use and climate. Ecol Res 2010; 26:909-916. [PMID: 32214652 PMCID: PMC7089484 DOI: 10.1007/s11284-010-0725-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 04/05/2010] [Indexed: 11/29/2022]
Abstract
West Nile virus (WNV) was first detected in the western hemisphere during the summer of 1999, reawakening US public awareness of the potential severity of vector-borne pathogens. Since its New World introduction, WNV has caused disease in human, avian, and mammalian communities across the continent. American crows (Corvus brachyrhynchos) are a highly susceptible WNV host and when modeled appropriately, changes in crow abundances can serve as a proxy for the spatio-temporal presence of WNV. We use the dramatic declines in abundance of this avian host to examine spatio-temporal heterogeneity in WNV intensity across the northeastern US, where WNV was first detected. Using data from the Breeding Bird Survey, we identify significant declines in crow abundance after WNV emergence that are associated with lower forest cover, more urban land use, and warmer winter temperatures. Importantly, we document continued declines as WNV was present in an area over consecutive years. Our findings support the urban-pathogen link that human WNV incidence studies have shown. For each 1% increase in urban land cover we expect an additional 5% decline in the log crow abundance beyond the decline attributed to WNV in undeveloped areas. We also demonstrate a significant relationship between above-average winter temperatures and WNV-related declines in crow abundance. The mechanisms behind these patterns remain uncertain and hypotheses requiring further research are suggested. In particular, a strong positive relationship between urban land cover and winter temperatures may confound mechanistic understanding, especially when a temperature-sensitive vector is involved.
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Affiliation(s)
- Shannon L. LaDeau
- Cary Institute of Ecosystem Studies, Millbrook, NY 12545 USA
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC 20008 USA
| | | | | | - Peter P. Marra
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC 20008 USA
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29
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Wang G, Minnis RB, Belant JL, Wax CL. Dry weather induces outbreaks of human West Nile virus infections. BMC Infect Dis 2010; 10:38. [PMID: 20181272 PMCID: PMC2841181 DOI: 10.1186/1471-2334-10-38] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Accepted: 02/24/2010] [Indexed: 11/12/2022] Open
Abstract
Background Since its first occurrence in the New York City area during 1999, West Nile virus (WNV) has spread rapidly across North America and has become a major public health concern in North America. By 2002, WNV was reported in 40 states and the District of Columbia with 4,156 human and 14,539 equine cases of infection. Mississippi had the highest human incidence rate of WNV during the 2002 epidemic in the United States. Epidemics of WNV can impose enormous impacts on local economies. Therefore, it is advantageous to predict human WNV risks for cost-effective controls of the disease and optimal allocations of limited resources. Understanding relationships between precipitation and WNV transmission is crucial for predicting the risk of the human WNV disease outbreaks under predicted global climate change scenarios. Methods We analyzed data on the human WNV incidences in the 82 counties of Mississippi in 2002, using standard morbidity ratio (SMR) and Bayesian hierarchical models, to determine relationships between precipitation and human WNV risks. We also entertained spatial autocorrelations of human WNV risks with conditional autocorrelative (CAR) models, implemented in WinBUGS 1.4.3. Results We observed an inverse relationship between county-level human WNV incidence risk and total annual rainfall during the previous year. Parameters representing spatial heterogeneity in the risk of human exposure to WNV improved model fit. Annual precipitation of the previous year was a predictor of spatial variation of WNV risk. Conclusions Our results have broad implications for risk assessment of WNV and forecasting WNV outbreaks. Assessing risk of vector-born infectious diseases will require understanding of complex ecological relationships. Based on the climatologically characteristic drought occurrence in the past and on climate model predictions for climate change and potentially greater drought occurrence in the future, we suggest that the frequency and relative risk of WNV outbreaks could increase.
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Affiliation(s)
- Guiming Wang
- Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Mississippi State, Mississippi 39762, USA.
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Acute olfactory response of Culex mosquitoes to a human- and bird-derived attractant. Proc Natl Acad Sci U S A 2009; 106:18803-8. [PMID: 19858490 DOI: 10.1073/pnas.0906932106] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
West Nile virus, which is transmitted by Culex mosquitoes while feeding on birds and humans, has emerged as the dominant vector borne disease in North America. We have identified natural compounds from humans and birds, which are detected with extreme sensitivity by olfactory receptor neurons (ORNs) on the antennae of Culex pipiens quinquefasciatus (Cx. quinquefasciatus). One of these semiochemicals, nonanal, dominates the odorant spectrum of pigeons, chickens, and humans from various ethnic backgrounds. We determined the specificity and sensitivity of all ORN types housed in different sensilla types on Cx. quinquefasciatus antennae. Here, we present a comprehensive map of all antennal ORNs coding natural ligands and their dose-response functions. Nonanal is detected by a large array of sensilla and is by far the most potent stimulus; thus, supporting the assumption that Cx. quinquefasciatus can smell humans and birds. Nonanal and CO(2) synergize, thus, leading to significantly higher catches of Culex mosquitoes in traps baited with binary than in those with individual lures.
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