Disease Ecology In the Pacific Basin: Wildlife and Public Health Concerns Active
Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. The geographic distribution, density, and community structure of endemic Hawaiian avifauna has changed dramatically in the last century, in large part because of the spread of these diseases and their introduced mosquito vector. More recently, the spread of chikungunya virus in the Caribbean and western Pacific and west nile virus on the mainland U.S. place the Hawaiian Islands at high risk for introduction of new human diseases.
Overview:
Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. The geographic distribution, density, and community structure of endemic Hawaiian avifauna has changed dramatically in the last century, in large part because of the spread of these diseases and their introduced mosquito vector. More recently, the spread of chikungunya virus in the Caribbean and western Pacific and west nile virus on the mainland U.S. place the Hawaiian Islands at high risk for introduction of new human diseases. USGS scientists have collected and analyzed large spatial and temporal datasets on the prevalence and incidence of avian malaria and pox virus in forest bird populations in the Hawaiian Archipelago and American Samoa, the ecology of their primary mosquito vector, complementary data on the genetic variation of hosts, vectors and parasites and epidemiological factors such as host susceptibility and resistance, parasite virulence and vector competency. Continued analysis and integration of these data into epidemiological models is needed to support Strategic Decision Making (SDM) and adaptive management toward the continued protection and restoration of migratory and endangered Hawaiian forest bird species on DOI managed lands such as Hakalau Forest National Wildlife Refuge, Hawaii Volcanoes National Park, Haleakala National Park and the National Park of American Samoa. At the same time, current field and laboratory studies maintain capabilities for rapid response to new vectors and emerging pathogens that continue to arrive on isolated Pacific Islands.
Project Objectives:
We continue to work closely with partners from the National Park Service, U.S. Fish and Wildlife Service (Region 1 Migratory Birds, Region 1 Ecological Services and Region 1 USFWS Refuge Offices), and the Department of Marine and Wildlife Resources in American Samoa to acquire basic knowledge of the biology and impact of existing and new vectors and pathogens affecting wildlife and public health in the Pacific Basin and to develop tools and strategies for predicting disease outbreaks, assessing their severity, and monitoring success of adaptive management for the control of mosquito vectors and disease. Specific objectives of this task are to:
- continue analysis of existing data sets to refine model parameters for developing transmission models,
- develop and evaluate models for predicting severity and location of disease outbreaks and effects of specific management actions and environmental changes on transmission of introduced diseases,
- monitoring emergent pathogens like knemidokoptic mange in Hawai‘i ‘amakihi and
- determining the genetic diversity of the mosquito endosymbiote Wolbachia pipientis as a potential control measure for Culex mosquitoes.
Highlights and Key Findings:
We have completed manuscripts with colleagues at the University of Hawai‘i, Hilo and the Wisconsin Cooperative Wildlife Research Unit on the impacts of malaria and pox transmission on Apapane populations at Hawai‘i Volcanoes National Park, genetic diversity of malarial isolates in Hawaiian forest birds, modeling avian malaria at the landscape level, dispersal of vectors of avian disease, the effects of temperature and climate change on avian disease in Hawai‘i, and adaptive responses of native forest birds to avian malaria. We have published 6 book chapters and online compendiums on avian malaria, avian pox and disease management. Key findings include the significant impact that avian malaria has on the most common native species with annual mortality rates that may approach 100% in juvenile birds and unexpected genetic diversity in both malarial and pox organisms that may contribute to virulence and transmission of these diseases. Computer models that we have developed in conjunction with colleagues at the Wisconsin Cooperative Wildlife Research Unit indicate that global climate change will have a significant impact on disease transmission in Hawai‘i and will contribute to loss of high elevation refugia where many native species are currently able to avoid pox and malaria. We have worked with colleagues at the University of Hawai‘i, Hilo to develop a TaqMan Real Time PCR assay for avian pox virus that will allow us to improve transmission models for avian pox and to ultimately explore in more detail how this disease interacts with malaria. We have documented the prevalence, geographic, and altitudinal distribution of a new pathogen in Hawai‘i ‘Amakihi, the scaley leg mite (Knemidokoptes jamaicensis) and collected data that suggest that knemidoptic mange may impact survivorship of wild birds.
2016 Progress:
Completion of a final report on climate change and avian malaria at Hakalau Forest National Wildlife Refuge
Completion of a final report on genetic diversity of Wolbachia endosymbionts in Culex mosquitoes from Hawaii, Midway Atoll, and American Samoa
Completion of a final report on effects of climate and land use on diversity, prevalence, and seasonal transmission of avian hematozoa in American Samoa
2017 Planned Work:
Work in 2017 will focus on the completion of reports on 1) the diversity and distribution of avian blood parasites from SW Pacific island archipelagoes, 2) disease assessment at sites on the island of Hawai‘i and 3) effects of Rapid ‘Ōhi‘a Death on Hawaiian avifauna. Additionally, analysis will continue on interactions of avian pox and avian malaria in native Hawaiian forest birds.
Below are data or web applications associated with this project.
Hawaii Island, modelled density of malaria-resistant and -susceptible Iiwi following release of malaria-resistant birds under three climate change projections, 2030-2100
Below are publications associated with this project.
Use of whole blood samples preserved in DNA lysis buffer for serological detection of avian malaria in Hawaiian forest birds
Facilitated adaptation for conservation – Can gene editing save Hawaii's endangered birds from climate driven avian malaria?
The epidemiology of avian pox and interaction with avian malaria in Hawaiian forest birds
Characterization of Plasmodium relictum, a cosmopolitan agent of avian malaria
Mitigating future avian malaria threats to Hawaiian forest birds from climate change
Changes in the prevalence of avian disease and mosquito vectors at Hakalau Forest National Wildlife Refuge: a 14-year perspective and assessment of future risk
Genetic diversity of Wolbachia endosymbionts in Culex quinquefasciatus from Hawai`i, Midway Atoll, and Samoa
Effects of Climate and land use on diversity, prevalence, and seasonal transmission of avian hematozoa in American Samoa
Will a warmer and wetter future cause extinction of native Hawaiian forest birds?
Book review: Mosquito eradication: The story of killing Campto
Global phylogeography of the avian malaria pathogen Plasmodium relictum based on MSP1 allelic diversity
Distribution and prevalence of knemidokoptic mange in Hawai`i `Amakihi on the island of Hawaii
Below are partners associated with this project.
- Overview
Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. The geographic distribution, density, and community structure of endemic Hawaiian avifauna has changed dramatically in the last century, in large part because of the spread of these diseases and their introduced mosquito vector. More recently, the spread of chikungunya virus in the Caribbean and western Pacific and west nile virus on the mainland U.S. place the Hawaiian Islands at high risk for introduction of new human diseases.
Overview:
Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. The geographic distribution, density, and community structure of endemic Hawaiian avifauna has changed dramatically in the last century, in large part because of the spread of these diseases and their introduced mosquito vector. More recently, the spread of chikungunya virus in the Caribbean and western Pacific and west nile virus on the mainland U.S. place the Hawaiian Islands at high risk for introduction of new human diseases. USGS scientists have collected and analyzed large spatial and temporal datasets on the prevalence and incidence of avian malaria and pox virus in forest bird populations in the Hawaiian Archipelago and American Samoa, the ecology of their primary mosquito vector, complementary data on the genetic variation of hosts, vectors and parasites and epidemiological factors such as host susceptibility and resistance, parasite virulence and vector competency. Continued analysis and integration of these data into epidemiological models is needed to support Strategic Decision Making (SDM) and adaptive management toward the continued protection and restoration of migratory and endangered Hawaiian forest bird species on DOI managed lands such as Hakalau Forest National Wildlife Refuge, Hawaii Volcanoes National Park, Haleakala National Park and the National Park of American Samoa. At the same time, current field and laboratory studies maintain capabilities for rapid response to new vectors and emerging pathogens that continue to arrive on isolated Pacific Islands.
Project Objectives:
We continue to work closely with partners from the National Park Service, U.S. Fish and Wildlife Service (Region 1 Migratory Birds, Region 1 Ecological Services and Region 1 USFWS Refuge Offices), and the Department of Marine and Wildlife Resources in American Samoa to acquire basic knowledge of the biology and impact of existing and new vectors and pathogens affecting wildlife and public health in the Pacific Basin and to develop tools and strategies for predicting disease outbreaks, assessing their severity, and monitoring success of adaptive management for the control of mosquito vectors and disease. Specific objectives of this task are to:
- continue analysis of existing data sets to refine model parameters for developing transmission models,
- develop and evaluate models for predicting severity and location of disease outbreaks and effects of specific management actions and environmental changes on transmission of introduced diseases,
- monitoring emergent pathogens like knemidokoptic mange in Hawai‘i ‘amakihi and
- determining the genetic diversity of the mosquito endosymbiote Wolbachia pipientis as a potential control measure for Culex mosquitoes.
Highlights and Key Findings:
We have completed manuscripts with colleagues at the University of Hawai‘i, Hilo and the Wisconsin Cooperative Wildlife Research Unit on the impacts of malaria and pox transmission on Apapane populations at Hawai‘i Volcanoes National Park, genetic diversity of malarial isolates in Hawaiian forest birds, modeling avian malaria at the landscape level, dispersal of vectors of avian disease, the effects of temperature and climate change on avian disease in Hawai‘i, and adaptive responses of native forest birds to avian malaria. We have published 6 book chapters and online compendiums on avian malaria, avian pox and disease management. Key findings include the significant impact that avian malaria has on the most common native species with annual mortality rates that may approach 100% in juvenile birds and unexpected genetic diversity in both malarial and pox organisms that may contribute to virulence and transmission of these diseases. Computer models that we have developed in conjunction with colleagues at the Wisconsin Cooperative Wildlife Research Unit indicate that global climate change will have a significant impact on disease transmission in Hawai‘i and will contribute to loss of high elevation refugia where many native species are currently able to avoid pox and malaria. We have worked with colleagues at the University of Hawai‘i, Hilo to develop a TaqMan Real Time PCR assay for avian pox virus that will allow us to improve transmission models for avian pox and to ultimately explore in more detail how this disease interacts with malaria. We have documented the prevalence, geographic, and altitudinal distribution of a new pathogen in Hawai‘i ‘Amakihi, the scaley leg mite (Knemidokoptes jamaicensis) and collected data that suggest that knemidoptic mange may impact survivorship of wild birds.
2016 Progress:
Completion of a final report on climate change and avian malaria at Hakalau Forest National Wildlife Refuge
Completion of a final report on genetic diversity of Wolbachia endosymbionts in Culex mosquitoes from Hawaii, Midway Atoll, and American Samoa
Completion of a final report on effects of climate and land use on diversity, prevalence, and seasonal transmission of avian hematozoa in American Samoa
2017 Planned Work:
Work in 2017 will focus on the completion of reports on 1) the diversity and distribution of avian blood parasites from SW Pacific island archipelagoes, 2) disease assessment at sites on the island of Hawai‘i and 3) effects of Rapid ‘Ōhi‘a Death on Hawaiian avifauna. Additionally, analysis will continue on interactions of avian pox and avian malaria in native Hawaiian forest birds.
- Data
Below are data or web applications associated with this project.
Hawaii Island, modelled density of malaria-resistant and -susceptible Iiwi following release of malaria-resistant birds under three climate change projections, 2030-2100
This data set provides the simulated results of releasing malaria-resistant Iiwi into existing populations of wild birds on the Island of Hawaii. Resistant birds are released into mid- and high-elevation forests at different densities at 10-year intervals from 2030 to 2070. Populations of both malaria-resistant and susceptible Iiwi are then predicted at 10-year intervals from release until 2100. P - Publications
Below are publications associated with this project.
Filter Total Items: 30Use of whole blood samples preserved in DNA lysis buffer for serological detection of avian malaria in Hawaiian forest birds
Recent detections of avian malarial parasites in native and non-native forest birds at Hakalau Forest National Wildlife Refuge and reports of epidemic transmission of the disease in high elevation habitats as well as controversy over accuracy of the PCR (polymerase chain reaction) diagnostic test that was being used led to a request by U.S. Fish and Wildlife Service to see if existing blood sampleAuthorsCarter T. AtkinsonFacilitated adaptation for conservation – Can gene editing save Hawaii's endangered birds from climate driven avian malaria?
Avian malaria has played a significant role in causing extinctions, population declines, and limiting the elevational distribution of Hawaiian honeycreepers. Most threatened and endangered honeycreepers only exist in high-elevation forests where the risk of malaria infection is limited. Because Culex mosquito vectors and avian malaria dynamics are strongly influenced by temperature and rainfall, fAuthorsMichael D. Samuel, Wei Liao, Carter T. Atkinson, Dennis LapointeThe epidemiology of avian pox and interaction with avian malaria in Hawaiian forest birds
Despite the purported role of avian pox (Avipoxvirus spp.) in the decline of endemic Hawaiian birds, few studies have been conducted on the dynamics of this disease, its impact on free‐living avian populations, or its interactions with avian malaria (Plasmodium relictum). We conducted four longitudinal studies of 3–7 yr in length and used generalized linear models to evaluate cross‐sectional prevaAuthorsMichael Samuel, Bethany L. Woodworth, Carter T. Atkinson, Patrick J. Hart, Dennis LapointeCharacterization of Plasmodium relictum, a cosmopolitan agent of avian malaria
BackgroundMicroscopic research has shown that Plasmodium relictum is the most common agent of avian malaria. Recent molecular studies confirmed this conclusion and identified several mtDNA lineages, suggesting the existence of significant intra-species genetic variation or cryptic speciation. Most identified lineages have a broad range of hosts and geographical distribution. Here, a rare new lineaAuthorsGediminas Valkiunas, Mikas Ilgūnas, Dovilė Bukauskaitė, Karin Fragner, Herbert Weissenböck, Carter T. Atkinson, Tatjana IezhovaMitigating future avian malaria threats to Hawaiian forest birds from climate change
Avian malaria, transmitted by Culex quinquefasciatus mosquitoes in the Hawaiian Islands, has been a primary contributor to population range limitations, declines, and extinctions for many endemic Hawaiian honeycreepers. Avian malaria is strongly influenced by climate; therefore, predicted future changes are expected to expand transmission into higher elevations and intensify and lengthen existingAuthorsWei Liao, Carter T. Atkinson, Dennis LaPointe, Michael D. SamuelChanges in the prevalence of avian disease and mosquito vectors at Hakalau Forest National Wildlife Refuge: a 14-year perspective and assessment of future risk
Throughout the main Hawaiian Islands, introduced mosquito-borne disease has had, and continues to have, a profound impact on the distributions and abundance of native Hawaiian forest birds. Populations of remaining native forest birds are largely restricted to high elevation forests where mean temperatures are marginal for vector and parasite development and limited availability of larval mosquitoAuthorsDennis LaPointe, Jacqueline M. Gaudioso-Levita, Carter T. Atkinson, Ariel N. Egan, Kathleen HayesGenetic diversity of Wolbachia endosymbionts in Culex quinquefasciatus from Hawai`i, Midway Atoll, and Samoa
Incompatible insect techniques are potential methods for controlling Culex quinquefasciatus and avian disease transmission in Hawai‘i without the use of pesticides or genetically modified organisms. The approach is based on naturally occurring sperm-egg incompatibilities within the Culex pipiens complex that are controlled by different strains of the bacterial endosymbiont Wolbachia pipientis (wPiAuthorsCarter T. Atkinson, William Watcher-Weatherwax, Dennis LapointeEffects of Climate and land use on diversity, prevalence, and seasonal transmission of avian hematozoa in American Samoa
The indigenous forest birds of American Samoa are increasingly threatened by changing patterns of rainfall and temperature that are associated with climate change as well as environmental stressors associated with agricultural and urban development, invasive species, and new introductions of avian diseases and disease vectors. Long term changes in their distribution, diversity, and population sizeAuthorsCarter T. Atkinson, Ruth B. Utuzurrum, Joshua O. Seamon, Mark A. Schmaedick, Dennis Lapointe, Chloe Apelgren, Ariel N. Egan, William Watcher-WeatherwaxWill a warmer and wetter future cause extinction of native Hawaiian forest birds?
Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate futureAuthorsWei Liao, Oliver Elison Timm, Chunxi Zhang, Carter T. Atkinson, Dennis LaPointe, Michael D. SamuelBook review: Mosquito eradication: The story of killing Campto
In 1826, the paradise that was the Hawaiian Islands was changed forever when the first mosquito species was accidentally introduced to the island of Maui. Though it has not lived up to its potential as a vector of human disease in the islands, Culex quinquefasciatus and the avian pathogens it transmits laid waste to perhaps the world's most remarkable insular avifauna. Today the lowland native forAuthorsDennis LapointeGlobal phylogeography of the avian malaria pathogen Plasmodium relictum based on MSP1 allelic diversity
Knowing the genetic variation that occurs in pathogen populations and how it is distributed across geographical areas is essential to understand parasite epidemiology, local patterns of virulence, and evolution of host-resistance. In addition, it is important to identify populations of pathogens that are evolutionarily independent and thus ‘free’ to adapt to hosts and environments. Here, we investAuthorsOlof Hellgren, Carter T. Atkinson, Staffan Bensch, Tamer Albayrak, Dimitar Dimitrov, John G. Ewen, Kyeong Soon Kim, Marcos R. Lima, Lynn Martin, Vaidas Palinauskas, Robert Ricklefs, Ravinder N. M. Sehgal, Valkiunas Gediminas, Yoshio Tsuda, Alfonso MarzalDistribution and prevalence of knemidokoptic mange in Hawai`i `Amakihi on the island of Hawaii
Knemidokoptic mange was first observed on two Hawai‘i ‘Amakihi (Hemignathus virens) mist netted in Manuka Natural Area Reserve (NAR) on the Island of Hawai‘i in June 2007. Microscopic examination of skin scrapings from lesions of the infested individuals revealed the scaley-leg mite, Knemidokoptes jamaicensis. Continued surveillance at Manuka NAR (2007-2009) documented a 24% (15/63) prevalence ofAuthorsJacqueline Gaudioso, Dennis LaPointe, Carter T. Atkinson, Chloe Apelgren - Partners
Below are partners associated with this project.