When is a parasite not a parasite? Effects of larval tick burdens on white-footed mouse survival

Many animal species can carry considerable burdens of ectoparasites: parasites living on the outside of a host's body. Ectoparasite infestation can decrease host survival, but the magnitude and even direction of survival effects can vary depending on the type of ectoparasite and the nature and duration of the association. When ectoparasites also serve as vectors of pathogens, the effects of ectoparasite infestation on host survival have the potential to alter disease dynamics by regulating host populations and stabilizing transmission. We quantified the impact of larval Ixodes scapularis tick burdens on both within-season and overwinter survival of white-footed mice (Peromyscus leucopus) using a hierarchical Bayesian capture-mark-recapture model. I. scapularis and P. leucopus are, respectively, vectors and competent reservoirs for the causative agents of Lyme disease, anaplasmosis, and babesiosis. Using a data set of 5587 individual mouse capture histories over sixteen years, we found little evidence for any effect of tick burdens on either within-season or overwinter mouse survival probabilities. In male mice, tick burdens were positively correlated with within-season survival probabilities. Mean maximum tick burdens were also positively correlated with population rates of change during the concurrent breeding season. The apparent indifference of mice to high tick burdens may contribute to their effectiveness as reservoir hosts for several human zoonotic pathogens.Fil: Hersh, Michelle H.. Cary Institute of Ecosystem Studies; Estados Unidos. Bard College. Program in Biology; Estados Unidos. Sarah Lawrence College; Estados UnidosFil: LaDeau, Shannon L.. Cary Institute of Ecosystem Studies; Estados UnidosFil: Previtali, Maria Andrea. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Ostfeld, Richard S.. Cary Institute of Ecosystem Studies; Estados Unido

Mycobiome of the Bat White Nose Syndrome (WNS) Affected Caves and Mines reveals High Diversity of Fungi and Local Adaptation by the Fungal Pathogen Pseudogymnoascus (Geomyces) destructans

The investigations of the bat White Nose Syndrome (WNS) have yet to provide answers as to how the causative fungus Pseudogymnoascus (Geomyces) destructans (Pd) first appeared in the Northeast and how a single clone has spread rapidly in the US and Canada. We aimed to catalogue Pd and all other fungi (mycobiome) by the culture-dependent (CD) and culture-independent (CI) methods in four Mines and two Caves from the epicenter of WNS zoonotic. Six hundred sixty-five fungal isolates were obtained by CD method including the live recovery of Pd. Seven hundred three nucleotide sequences that met the definition of operational taxonomic units (OTUs) were recovered by CI methods. Most OTUs belonged to unidentified clones deposited in the databases as environmental nucleic acid sequences (ENAS). The core mycobiome of WNS affected sites comprised of 46 species of fungi from 31 genera recovered in culture, and 17 fungal genera and 31 ENAS identified from clone libraries. Fungi such as Arthroderma spp., Geomyces spp., Kernia spp., Mortierella spp., Penicillium spp., and Verticillium spp. were predominant in culture while Ganoderma spp., Geomyces spp., Mortierella spp., Penicillium spp. and Trichosporon spp. were abundant is clone libraries. Alpha diversity analyses from CI data revealed that fungal community structure was highly diverse. However, the true species diversity remains undetermined due to under sampling. The frequent recovery of Pd indicated that the pathogen has adapted to WNS-afflicted habitats. Further, this study supports the hypothesis that Pd is an introduced species. These findings underscore the need for integrated WNS control measures that target both bats and the fungal pathogen.Comment: 59 pages, 7figure

Between us an invisible column

textThis report chronicles the processes and influences relevant to my work as it has developed over the past three years. I examine how our human separateness and new technologies have effected myself and the work I create, ultimately exploring how technology has aggravated this separation rather than mitigate it. I explain my appropriation of digital, repetitious, and machine-like processes in order to recreate this separation, primarily in the form of drawings, sculptures, and photographs.Studio Ar

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Reframing communication about Zika and mosquitoes to increase disease prevention behavior

Emergence of invasive vector species and the diseases they carry present a clear danger to the public as well as a challenge for scientists and experts to control effectively. Given the urgent need to address this phenomenon, we suggest that desired public action toward these invasive vectors can be motivated through intentional framing in science communication. In this paper, we sought to evaluate the effect of framing about ZIKV (Zika virus) on reported willingness to comply with mosquito prevention action. Post framing intervention, we found a significant increase (N = 26, p \u3c 0.001) in individuals willing to take preventative action against mosquitoes. By methodically investigating best communication practices, this study and others can help practitioners mobilize communities to address large-scale ecological problems. Additionally, the principles outlined here may be transferrable to other communication efforts about ecological issues outside of ZIKV and mosquitoes

Using dynamic vegetation models to simulate plant range shifts

Peer reviewedPublisher PD

Tick-, mosquito-, and rodent-borne parasite sampling designs for the National Ecological Observatory Network

Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long-term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick-, mosquito-, and rodent-borne parasites through a continental-scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and collaborative ways. (Résumé d'auteur

Defining the Risk of Zika and Chikungunya Virus Transmission in Human Population Centers of the Eastern United States

The recent spread of mosquito-transmitted viruses and associated disease to the Americas motivates a new, data-driven evaluation of risk in temperate population centers. Temperate regions are generally expected to pose low risk for significant mosquito-borne disease; however, the spread of the Asian tiger mosquito (Aedes albopictus) across densely populated urban areas has established a new landscape of risk. We use a model informed by field data to assess the conditions likely to facilitate local transmission of chikungunya and Zika viruses from an infected traveler to Ae. albopictus and then to other humans in USA cities with variable human densities and seasonality. Mosquito-borne disease occurs when specific combinations of conditions maximize virus-to-mosquito and mosquito-to-human contact rates. We develop a mathematical model that captures the epidemiology and is informed by current data on vector ecology from urban sites. The model demonstrates that under specific but realistic conditions, fifty-percent of introductions by infectious travelers to a high human, high mosquito density city could initiate local transmission and 10% of the introductions could result in 100 or more people infected. Despite the propensity for Ae. albopictus to bite non-human vertebrates, we also demonstrate that local virus transmission and human outbreaks may occur when vectors feed from humans even just 40% of the time. Inclusion of human behavioral changes and mitigations were not incorporated into the models and would likely reduce predicted infections. This work demonstrates how a conditional series of non-average events can result in local arbovirus transmission and outbreaks of human disease, even in temperate cities

Defining the Risk of Zika and Chikungunya Virus Transmission in Human Population Centers of the Eastern United States

The recent spread of mosquito-transmitted viruses and associated disease to the Americas motivates a new, data-driven evaluation of risk in temperate population centers. Temperate regions are generally expected to pose low risk for significant mosquito-borne disease; however, the spread of the Asian tiger mosquito (Aedes albopictus) across densely populated urban areas has established a new landscape of risk. We use a model informed by field data to assess the conditions likely to facilitate local transmission of chikungunya and Zika viruses from an infected traveler to Ae. albopictus and then to other humans in USA cities with variable human densities and seasonality. Mosquito-borne disease occurs when specific combinations of conditions maximize virus-to-mosquito and mosquito-to-human contact rates. We develop a mathematical model that captures the epidemiology and is informed by current data on vector ecology from urban sites. The model demonstrates that under specific but realistic conditions, fifty-percent of introductions by infectious travelers to a high human, high mosquito density city could initiate local transmission and 10% of the introductions could result in 100 or more people infected. Despite the propensity for Ae. albopictus to bite non-human vertebrates, we also demonstrate that local virus transmission and human outbreaks may occur when vectors feed from humans even just 40% of the time. Inclusion of human behavioral changes and mitigations were not incorporated into the models and would likely reduce predicted infections. This work demonstrates how a conditional series of non-average events can result in local arbovirus transmission and outbreaks of human disease, even in temperate cities

Transmission routes maintaining a viral pathogen of steelhead trout within a complex multi-host assemblage

This is the first comprehensive region wide, spatially explicit epidemiologic analysis of surveillance data of the aquatic viral pathogen infectious hematopoietic necrosis virus (IHNV) infecting native salmonid fish. The pathogen has been documented in the freshwater ecosystem of the Pacific Northwest of North America since the 1950s, and the current report describes the disease ecology of IHNV during 2000-2012. Prevalence of IHNV infection in monitored salmonid host cohorts ranged from 8% to 30%, with the highest levels observed in juvenile steelhead trout. The spatial distribution of all IHNV-infected cohorts was concentrated in two sub-regions of the study area, where historic burden of the viral disease has been high. During the study period, prevalence levels fluctuated with a temporal peak in 2002. Virologic and genetic surveillance data were analyzed for evidence of three separate but not mutually exclusive transmission routes hypothesized to be maintaining IHNV in the freshwater ecosystem. Transmission between year classes of juvenile fish at individual sites (route 1) was supported at varying levels of certainty in 10%-55% of candidate cases, transmission between neighboring juvenile cohorts (route 2) was supported in 31%-78% of candidate cases, and transmission from adult fish returning to the same site as an infected juvenile cohort was supported in 26%-74% of candidate cases. The results of this study indicate that multiple specific transmission routes are acting to maintain IHNV in juvenile fish, providing concrete evidence that can be used to improve resource management. Furthermore, these results demonstrate that more sophisticated analysis of available spatio-temporal and genetic data is likely to yield greater insight in future studies