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Goudarz Molaei - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Vector-Host Interactions in Avian Communities in Four Eastern Equine Encephalitis Virus Foci in the Northeastern U.S.
2016Co-Authors: Goudarz Molaei, Philip M Armstrong, Michael C. Thomas, Tim Muller, Jan Medlock, John J. Shepard, Theodore G AndreadisAbstract:BackgroundEastern equine encephalitis (EEE) virus (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne zoonosis that is responsible for occasional outbreaks of severe disease in humans and equines, resulting in high mortality and neurological impairment in most survivors. In the past, human disease outbreaks in the northeastern U.S. have occurred intermittently with no apparent pattern; however, during the last decade we have witnessed recurring annual emergence where EEE virus activity had been historically rare, and expansion into northern New England where the virus had been previously unknown. In the northeastern U.S., EEE virus is maintained in an enzootic cycle involving the ornithophagic mosquito, Culiseta melanura, and wild passerine (perching) birds in freshwater hardwood swamps. However, the identity of key avian species that serve as principal virus reservoir and amplification hosts has not been established. The efficiency with which pathogen transmission occurs within an avian community is largely determined by the relative reservoir competence of each species and by ecological factors that influence contact rates between these avian hosts and mosquito vectors.Methodology and principle findingsContacts between vector mosquitoes and potential avian hosts may be directly quantified by analyzing the blood meal contents of field-collected specimens. We used PCR-based molecular methods and direct sequencing of the mitochondrial cytochrome b gene for profiling of blood meals in Cs. melanura, in an effort to quantify its feeding behavior on specific vertebrate hosts, and to infer epidemiologic implications in four historic EEE virus foci in the northeastern U.S. Avian point count surveys were conducted to determine spatiotemporal host community composition. Of 1,127 blood meals successfully identified to species level, >99% of blood meals were from 65 avian hosts in 27 families and 11 orders, and only seven were from mammalian hosts representing three species. We developed an empirically informed mathematical model for EEE virus transmission using Cs. melanura abundance and preferred and non-preferred avian hosts. To our knowledge this is the first mathematical model for EEE virus, a pathogen with many potential hosts, in the northeastern U.S. We measured strong feeding preferences for a number of avian species based on the proportion of mosquito blood meals identified from these bird species in relation to their observed frequencies. These included: American Robin, Tufted Titmouse, Common Grackle, Wood Thrush, Chipping Sparrow, Black-capped Chickadee, Northern Cardinal, and Warbling Vireo. We found that these bird species, most notably Wood Thrush, play a dominant role in supporting EEE virus amplification. It is also noteworthy that the competence of some of the aforementioned avian species for EEE virus has not been established. Our findings indicate that heterogeneity induced by mosquito host preference, is a key mediator of the epizootic transmission of vector-borne pathogens.Conclusion and significanceDetailed knowledge of the vector-host interactions of mosquito populations in nature is essential for evaluating their vectorial capacity and for assessing the role of individual vertebrates as reservoir hosts involved in the maintenance and amplification of zoonotic agents of human diseases. Our study clarifies the host associations of Cs. melanura in four EEE virus foci in the northeastern U.S., identifies vector host preferences as the most important transmission parameter, and quantifies the contribution of preference-induced contact heterogeneity to enzootic transmission. Our study identifies Wood Thrush, American Robin and a few avian species that may serve as superspreaders of EEE virus. Our study elucidates spatiotemporal host species utilization by Cs. melanura in relation to avian host community. This research provides a basis to better understand the involvement of Cs. melanura and avian hosts in the transmission and ecology of EEE virus and the risk of human infection in virus foci.
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Host-Feeding Patterns of Potential Mosquito Vectors in Connecticut, USA: Molecular Analysis of Bloodmeals from 23 Species of Aedes, Anopheles, Culex, Coquillettidia, Psorophora, and Uranotaenia
Journal of medical entomology, 2008Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Maria A. Diuk-wasserAbstract:We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (JuneÐOctober 2002Ð2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing portions of the cytochrome b gene of mito- chondrial DNA. This study was part of a statewide surveillance program and for some of the mosquito species a limited number of specimens were examined (e.g.,Aedescommunis (De Geer) (1),Anopheles barberi Coquillett (1), Uranotaenia sapphirina (Osten Sacken) (5)). With the exception of Culex territans Walker that acquired bloodmeals from all four classes of vertebratesN birds, reptiles, am- phibians, and mammalsNall species of Aedes, Anopheles, Coquillettidia, Psorophora, and to a lesser degree, Uranotaenia, were found to feed predominately upon mammalian hosts. Fourteen mammalian species were identiÞed as sources of blood, but the majority of feedings were taken from the white-tailed deer, Odocoileus virginianus. Human-derived bloodmeals were identiÞed from 13 of the 23 mosquito species. Limited avian-derived bloodmeals were detected in Aedes canadensis (Theobald), Aedes cantator (Coquillett), Aedes cinereus Meigen, Aedes triseriatus (Coquillett), Aedes trivittatus (Coquillett), Coquillettidia perturbans (Walker) Cx. territans, Psorophora ferox (von Hum- boldt), and Ur.sapphirina. American Robin, Turdus migratorius, was the most common source of avian blood, followed by a few other mostly Passeriformes birds. We conclude that the white-tailed deer serve as the main vertebrate host for these mammalophilic mosquitoes in this region of the United States. This feeding pattern supports enzootic ampliÞcation of arboviruses, including Jamestown Canyon, Cache Valley, and Potosi viruses that perpetuate in cervid hosts. Occasional feeding on avian hosts suggests that some of these mosquito species, such as Cq. perturbans, also could facilitate transmission of West Nile and eastern equine encephalitis viruses from viremic birds to mammalian hosts.
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host feeding pattern of culex quinquefasciatus diptera culicidae and its role in transmission of west nile virus in harris county texas
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Rudy Bueno, James A Dennett, Susan V Real, Chris Sargent, Adilelkhidir Bala, Yvonne Randle, Hilda GuzmanAbstract:The vertebrate hosts of 672 blood-engorged Culex quinquefasciatus Say, collected in Harris County, Texas, during 2005, were identified by nucleotide sequencing PCR products of the cytochrome b gene. Analysis revealed that 39.1% had acquired blood from birds, 52.5% from mammals, and 8.3% were mixed avian and mammalian blood meals. Most frequent vertebrate hosts were dog (41.0%), mourning dove (18.3%), domestic cat (8.8%), white-winged dove (4.3%), house sparrow (3.2%), house finch (3.0%), gray catbird (3.0%), and American Robin (2.5%). Results are interpreted in conjunction with concurrent avian and mosquito West Nile virus (WNV) surveillance activities in Harris County. We conclude that Cx. quinquefasciatus is an opportunistic feeder and principal mosquito vector of WNV in this metropolitan area; however, transmission by other mosquito species or by other modes of infection, such as ingestion, must account for the high WNV infection rates among local blue jays and American crows.
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molecular identification of blood meal sources in culiseta melanura and culiseta morsitans from an endemic focus of eastern equine encephalitis virus in new york
American Journal of Tropical Medicine and Hygiene, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Joanne Oliver, John J. HowardAbstract:Eastern equine encephalitis (EEE) virus perpetuates in an enzootic cycle involving ornithophilic mosquito vectors, principally Culiseta melanura (Coquillett) and avian amplification hosts. To better understand the role of Cs. melanura and Culiseta morsitans (Theobald) in the epizootiology of EEE virus, we collected blood-fed mosquitoes between 31 May and 15 October 2004 at two sites associated with an EEE virus focus in central New York and identified the source of vertebrate blood by nucleotide sequencing of polymerase chain reaction (PCR) products of the cytochrome b gene. Analysis of 484 Cs. melanura and 122 Cs. morsitans revealed that 94.2% and 86.9%, respectively, acquired blood solely from avian hosts. Blood meals derived exclusively from mammals were detected in 0.8% of Cs. melanura and 1.6% of Cs. morsitans. Individual mosquitoes containing mixed-blood meals from both avian and mammalian hosts were also detected in 5.0% of Cs. melanura and 11.5% of Cs. morsitans. Wood thrush constituted the most common vertebrate host for Cs. melanura (23.6%) and Cs. morsitans (30.9%), followed by American Robin, song sparrow, ovenbird, red-eyed vireo, and common yellowthroat. Mammalian-derived blood meals were identified as white-tailed deer, horse, domestic cat, and eastern pipistrelle bat. There were three isolations of EEE virus from Cs. melanura and one from Cs. morsitans. These results suggest that wood thrush and a few other passerine birds may play key roles in supporting EEE virus transmission in the northeast and possibly throughout the geographic range of EEE in North America. The frequency of mammalian feedings also suggests that Cs. melanura and Cs. morsitans may play a role in the transmission of EEE virus to equines, in addition to maintaining enzootic transmission among avian hosts. We report the first isolation of arboviruses from mosquito vectors concomitant with the identifications of their blood meal sources.
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host feeding patterns of culex mosquitoes and west nile virus transmission northeastern united states
Emerging Infectious Diseases, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, John F Anderson, Theodore G Andreadis, Charles R VossbrinckAbstract:To evaluate the role of Culex mosquitoes as enzootic and epidemic vectors for WNV, we identified the source of vertebrate blood by polymerase chain reaction amplification and sequencing portions of the cytochrome b gene of mitochondrial DNA. All Cx. restuans and 93% of Cx. pipiens acquired blood from avian hosts; Cx. salinarius fed frequently on both mammals (53%) and birds (36%). Mixed-blood meals were detected in 11% and 4% of Cx. salinarius and Cx. pipiens, respectively. American Robin was the most common source of vertebrate blood for Cx. pipiens (38%) and Cx. restuans (37%). American crow represented <1% of the blood meals in Cx. pipiens and none in Cx. restuans. Human-derived blood meals were identified from 2 Cx. salinarius and 1 Cx. pipiens. Results suggest that Cx. salinarius is an important bridge vector to humans, while Cx. pipiens and Cx. restuans are more efficient enzootic vectors in the northeastern United States.
Theodore G Andreadis - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Vector-Host Interactions in Avian Communities in Four Eastern Equine Encephalitis Virus Foci in the Northeastern U.S.
2016Co-Authors: Goudarz Molaei, Philip M Armstrong, Michael C. Thomas, Tim Muller, Jan Medlock, John J. Shepard, Theodore G AndreadisAbstract:BackgroundEastern equine encephalitis (EEE) virus (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne zoonosis that is responsible for occasional outbreaks of severe disease in humans and equines, resulting in high mortality and neurological impairment in most survivors. In the past, human disease outbreaks in the northeastern U.S. have occurred intermittently with no apparent pattern; however, during the last decade we have witnessed recurring annual emergence where EEE virus activity had been historically rare, and expansion into northern New England where the virus had been previously unknown. In the northeastern U.S., EEE virus is maintained in an enzootic cycle involving the ornithophagic mosquito, Culiseta melanura, and wild passerine (perching) birds in freshwater hardwood swamps. However, the identity of key avian species that serve as principal virus reservoir and amplification hosts has not been established. The efficiency with which pathogen transmission occurs within an avian community is largely determined by the relative reservoir competence of each species and by ecological factors that influence contact rates between these avian hosts and mosquito vectors.Methodology and principle findingsContacts between vector mosquitoes and potential avian hosts may be directly quantified by analyzing the blood meal contents of field-collected specimens. We used PCR-based molecular methods and direct sequencing of the mitochondrial cytochrome b gene for profiling of blood meals in Cs. melanura, in an effort to quantify its feeding behavior on specific vertebrate hosts, and to infer epidemiologic implications in four historic EEE virus foci in the northeastern U.S. Avian point count surveys were conducted to determine spatiotemporal host community composition. Of 1,127 blood meals successfully identified to species level, >99% of blood meals were from 65 avian hosts in 27 families and 11 orders, and only seven were from mammalian hosts representing three species. We developed an empirically informed mathematical model for EEE virus transmission using Cs. melanura abundance and preferred and non-preferred avian hosts. To our knowledge this is the first mathematical model for EEE virus, a pathogen with many potential hosts, in the northeastern U.S. We measured strong feeding preferences for a number of avian species based on the proportion of mosquito blood meals identified from these bird species in relation to their observed frequencies. These included: American Robin, Tufted Titmouse, Common Grackle, Wood Thrush, Chipping Sparrow, Black-capped Chickadee, Northern Cardinal, and Warbling Vireo. We found that these bird species, most notably Wood Thrush, play a dominant role in supporting EEE virus amplification. It is also noteworthy that the competence of some of the aforementioned avian species for EEE virus has not been established. Our findings indicate that heterogeneity induced by mosquito host preference, is a key mediator of the epizootic transmission of vector-borne pathogens.Conclusion and significanceDetailed knowledge of the vector-host interactions of mosquito populations in nature is essential for evaluating their vectorial capacity and for assessing the role of individual vertebrates as reservoir hosts involved in the maintenance and amplification of zoonotic agents of human diseases. Our study clarifies the host associations of Cs. melanura in four EEE virus foci in the northeastern U.S., identifies vector host preferences as the most important transmission parameter, and quantifies the contribution of preference-induced contact heterogeneity to enzootic transmission. Our study identifies Wood Thrush, American Robin and a few avian species that may serve as superspreaders of EEE virus. Our study elucidates spatiotemporal host species utilization by Cs. melanura in relation to avian host community. This research provides a basis to better understand the involvement of Cs. melanura and avian hosts in the transmission and ecology of EEE virus and the risk of human infection in virus foci.
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Host-Feeding Patterns of Potential Mosquito Vectors in Connecticut, USA: Molecular Analysis of Bloodmeals from 23 Species of Aedes, Anopheles, Culex, Coquillettidia, Psorophora, and Uranotaenia
Journal of medical entomology, 2008Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Maria A. Diuk-wasserAbstract:We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (JuneÐOctober 2002Ð2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing portions of the cytochrome b gene of mito- chondrial DNA. This study was part of a statewide surveillance program and for some of the mosquito species a limited number of specimens were examined (e.g.,Aedescommunis (De Geer) (1),Anopheles barberi Coquillett (1), Uranotaenia sapphirina (Osten Sacken) (5)). With the exception of Culex territans Walker that acquired bloodmeals from all four classes of vertebratesN birds, reptiles, am- phibians, and mammalsNall species of Aedes, Anopheles, Coquillettidia, Psorophora, and to a lesser degree, Uranotaenia, were found to feed predominately upon mammalian hosts. Fourteen mammalian species were identiÞed as sources of blood, but the majority of feedings were taken from the white-tailed deer, Odocoileus virginianus. Human-derived bloodmeals were identiÞed from 13 of the 23 mosquito species. Limited avian-derived bloodmeals were detected in Aedes canadensis (Theobald), Aedes cantator (Coquillett), Aedes cinereus Meigen, Aedes triseriatus (Coquillett), Aedes trivittatus (Coquillett), Coquillettidia perturbans (Walker) Cx. territans, Psorophora ferox (von Hum- boldt), and Ur.sapphirina. American Robin, Turdus migratorius, was the most common source of avian blood, followed by a few other mostly Passeriformes birds. We conclude that the white-tailed deer serve as the main vertebrate host for these mammalophilic mosquitoes in this region of the United States. This feeding pattern supports enzootic ampliÞcation of arboviruses, including Jamestown Canyon, Cache Valley, and Potosi viruses that perpetuate in cervid hosts. Occasional feeding on avian hosts suggests that some of these mosquito species, such as Cq. perturbans, also could facilitate transmission of West Nile and eastern equine encephalitis viruses from viremic birds to mammalian hosts.
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host feeding pattern of culex quinquefasciatus diptera culicidae and its role in transmission of west nile virus in harris county texas
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Rudy Bueno, James A Dennett, Susan V Real, Chris Sargent, Adilelkhidir Bala, Yvonne Randle, Hilda GuzmanAbstract:The vertebrate hosts of 672 blood-engorged Culex quinquefasciatus Say, collected in Harris County, Texas, during 2005, were identified by nucleotide sequencing PCR products of the cytochrome b gene. Analysis revealed that 39.1% had acquired blood from birds, 52.5% from mammals, and 8.3% were mixed avian and mammalian blood meals. Most frequent vertebrate hosts were dog (41.0%), mourning dove (18.3%), domestic cat (8.8%), white-winged dove (4.3%), house sparrow (3.2%), house finch (3.0%), gray catbird (3.0%), and American Robin (2.5%). Results are interpreted in conjunction with concurrent avian and mosquito West Nile virus (WNV) surveillance activities in Harris County. We conclude that Cx. quinquefasciatus is an opportunistic feeder and principal mosquito vector of WNV in this metropolitan area; however, transmission by other mosquito species or by other modes of infection, such as ingestion, must account for the high WNV infection rates among local blue jays and American crows.
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molecular identification of blood meal sources in culiseta melanura and culiseta morsitans from an endemic focus of eastern equine encephalitis virus in new york
American Journal of Tropical Medicine and Hygiene, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Joanne Oliver, John J. HowardAbstract:Eastern equine encephalitis (EEE) virus perpetuates in an enzootic cycle involving ornithophilic mosquito vectors, principally Culiseta melanura (Coquillett) and avian amplification hosts. To better understand the role of Cs. melanura and Culiseta morsitans (Theobald) in the epizootiology of EEE virus, we collected blood-fed mosquitoes between 31 May and 15 October 2004 at two sites associated with an EEE virus focus in central New York and identified the source of vertebrate blood by nucleotide sequencing of polymerase chain reaction (PCR) products of the cytochrome b gene. Analysis of 484 Cs. melanura and 122 Cs. morsitans revealed that 94.2% and 86.9%, respectively, acquired blood solely from avian hosts. Blood meals derived exclusively from mammals were detected in 0.8% of Cs. melanura and 1.6% of Cs. morsitans. Individual mosquitoes containing mixed-blood meals from both avian and mammalian hosts were also detected in 5.0% of Cs. melanura and 11.5% of Cs. morsitans. Wood thrush constituted the most common vertebrate host for Cs. melanura (23.6%) and Cs. morsitans (30.9%), followed by American Robin, song sparrow, ovenbird, red-eyed vireo, and common yellowthroat. Mammalian-derived blood meals were identified as white-tailed deer, horse, domestic cat, and eastern pipistrelle bat. There were three isolations of EEE virus from Cs. melanura and one from Cs. morsitans. These results suggest that wood thrush and a few other passerine birds may play key roles in supporting EEE virus transmission in the northeast and possibly throughout the geographic range of EEE in North America. The frequency of mammalian feedings also suggests that Cs. melanura and Cs. morsitans may play a role in the transmission of EEE virus to equines, in addition to maintaining enzootic transmission among avian hosts. We report the first isolation of arboviruses from mosquito vectors concomitant with the identifications of their blood meal sources.
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host feeding patterns of culex mosquitoes and west nile virus transmission northeastern united states
Emerging Infectious Diseases, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, John F Anderson, Theodore G Andreadis, Charles R VossbrinckAbstract:To evaluate the role of Culex mosquitoes as enzootic and epidemic vectors for WNV, we identified the source of vertebrate blood by polymerase chain reaction amplification and sequencing portions of the cytochrome b gene of mitochondrial DNA. All Cx. restuans and 93% of Cx. pipiens acquired blood from avian hosts; Cx. salinarius fed frequently on both mammals (53%) and birds (36%). Mixed-blood meals were detected in 11% and 4% of Cx. salinarius and Cx. pipiens, respectively. American Robin was the most common source of vertebrate blood for Cx. pipiens (38%) and Cx. restuans (37%). American crow represented <1% of the blood meals in Cx. pipiens and none in Cx. restuans. Human-derived blood meals were identified from 2 Cx. salinarius and 1 Cx. pipiens. Results suggest that Cx. salinarius is an important bridge vector to humans, while Cx. pipiens and Cx. restuans are more efficient enzootic vectors in the northeastern United States.
Philip M Armstrong - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of Vector-Host Interactions in Avian Communities in Four Eastern Equine Encephalitis Virus Foci in the Northeastern U.S.
2016Co-Authors: Goudarz Molaei, Philip M Armstrong, Michael C. Thomas, Tim Muller, Jan Medlock, John J. Shepard, Theodore G AndreadisAbstract:BackgroundEastern equine encephalitis (EEE) virus (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne zoonosis that is responsible for occasional outbreaks of severe disease in humans and equines, resulting in high mortality and neurological impairment in most survivors. In the past, human disease outbreaks in the northeastern U.S. have occurred intermittently with no apparent pattern; however, during the last decade we have witnessed recurring annual emergence where EEE virus activity had been historically rare, and expansion into northern New England where the virus had been previously unknown. In the northeastern U.S., EEE virus is maintained in an enzootic cycle involving the ornithophagic mosquito, Culiseta melanura, and wild passerine (perching) birds in freshwater hardwood swamps. However, the identity of key avian species that serve as principal virus reservoir and amplification hosts has not been established. The efficiency with which pathogen transmission occurs within an avian community is largely determined by the relative reservoir competence of each species and by ecological factors that influence contact rates between these avian hosts and mosquito vectors.Methodology and principle findingsContacts between vector mosquitoes and potential avian hosts may be directly quantified by analyzing the blood meal contents of field-collected specimens. We used PCR-based molecular methods and direct sequencing of the mitochondrial cytochrome b gene for profiling of blood meals in Cs. melanura, in an effort to quantify its feeding behavior on specific vertebrate hosts, and to infer epidemiologic implications in four historic EEE virus foci in the northeastern U.S. Avian point count surveys were conducted to determine spatiotemporal host community composition. Of 1,127 blood meals successfully identified to species level, >99% of blood meals were from 65 avian hosts in 27 families and 11 orders, and only seven were from mammalian hosts representing three species. We developed an empirically informed mathematical model for EEE virus transmission using Cs. melanura abundance and preferred and non-preferred avian hosts. To our knowledge this is the first mathematical model for EEE virus, a pathogen with many potential hosts, in the northeastern U.S. We measured strong feeding preferences for a number of avian species based on the proportion of mosquito blood meals identified from these bird species in relation to their observed frequencies. These included: American Robin, Tufted Titmouse, Common Grackle, Wood Thrush, Chipping Sparrow, Black-capped Chickadee, Northern Cardinal, and Warbling Vireo. We found that these bird species, most notably Wood Thrush, play a dominant role in supporting EEE virus amplification. It is also noteworthy that the competence of some of the aforementioned avian species for EEE virus has not been established. Our findings indicate that heterogeneity induced by mosquito host preference, is a key mediator of the epizootic transmission of vector-borne pathogens.Conclusion and significanceDetailed knowledge of the vector-host interactions of mosquito populations in nature is essential for evaluating their vectorial capacity and for assessing the role of individual vertebrates as reservoir hosts involved in the maintenance and amplification of zoonotic agents of human diseases. Our study clarifies the host associations of Cs. melanura in four EEE virus foci in the northeastern U.S., identifies vector host preferences as the most important transmission parameter, and quantifies the contribution of preference-induced contact heterogeneity to enzootic transmission. Our study identifies Wood Thrush, American Robin and a few avian species that may serve as superspreaders of EEE virus. Our study elucidates spatiotemporal host species utilization by Cs. melanura in relation to avian host community. This research provides a basis to better understand the involvement of Cs. melanura and avian hosts in the transmission and ecology of EEE virus and the risk of human infection in virus foci.
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Host-Feeding Patterns of Potential Mosquito Vectors in Connecticut, USA: Molecular Analysis of Bloodmeals from 23 Species of Aedes, Anopheles, Culex, Coquillettidia, Psorophora, and Uranotaenia
Journal of medical entomology, 2008Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Maria A. Diuk-wasserAbstract:We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (JuneÐOctober 2002Ð2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing portions of the cytochrome b gene of mito- chondrial DNA. This study was part of a statewide surveillance program and for some of the mosquito species a limited number of specimens were examined (e.g.,Aedescommunis (De Geer) (1),Anopheles barberi Coquillett (1), Uranotaenia sapphirina (Osten Sacken) (5)). With the exception of Culex territans Walker that acquired bloodmeals from all four classes of vertebratesN birds, reptiles, am- phibians, and mammalsNall species of Aedes, Anopheles, Coquillettidia, Psorophora, and to a lesser degree, Uranotaenia, were found to feed predominately upon mammalian hosts. Fourteen mammalian species were identiÞed as sources of blood, but the majority of feedings were taken from the white-tailed deer, Odocoileus virginianus. Human-derived bloodmeals were identiÞed from 13 of the 23 mosquito species. Limited avian-derived bloodmeals were detected in Aedes canadensis (Theobald), Aedes cantator (Coquillett), Aedes cinereus Meigen, Aedes triseriatus (Coquillett), Aedes trivittatus (Coquillett), Coquillettidia perturbans (Walker) Cx. territans, Psorophora ferox (von Hum- boldt), and Ur.sapphirina. American Robin, Turdus migratorius, was the most common source of avian blood, followed by a few other mostly Passeriformes birds. We conclude that the white-tailed deer serve as the main vertebrate host for these mammalophilic mosquitoes in this region of the United States. This feeding pattern supports enzootic ampliÞcation of arboviruses, including Jamestown Canyon, Cache Valley, and Potosi viruses that perpetuate in cervid hosts. Occasional feeding on avian hosts suggests that some of these mosquito species, such as Cq. perturbans, also could facilitate transmission of West Nile and eastern equine encephalitis viruses from viremic birds to mammalian hosts.
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host feeding pattern of culex quinquefasciatus diptera culicidae and its role in transmission of west nile virus in harris county texas
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Rudy Bueno, James A Dennett, Susan V Real, Chris Sargent, Adilelkhidir Bala, Yvonne Randle, Hilda GuzmanAbstract:The vertebrate hosts of 672 blood-engorged Culex quinquefasciatus Say, collected in Harris County, Texas, during 2005, were identified by nucleotide sequencing PCR products of the cytochrome b gene. Analysis revealed that 39.1% had acquired blood from birds, 52.5% from mammals, and 8.3% were mixed avian and mammalian blood meals. Most frequent vertebrate hosts were dog (41.0%), mourning dove (18.3%), domestic cat (8.8%), white-winged dove (4.3%), house sparrow (3.2%), house finch (3.0%), gray catbird (3.0%), and American Robin (2.5%). Results are interpreted in conjunction with concurrent avian and mosquito West Nile virus (WNV) surveillance activities in Harris County. We conclude that Cx. quinquefasciatus is an opportunistic feeder and principal mosquito vector of WNV in this metropolitan area; however, transmission by other mosquito species or by other modes of infection, such as ingestion, must account for the high WNV infection rates among local blue jays and American crows.
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molecular identification of blood meal sources in culiseta melanura and culiseta morsitans from an endemic focus of eastern equine encephalitis virus in new york
American Journal of Tropical Medicine and Hygiene, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, Theodore G Andreadis, Joanne Oliver, John J. HowardAbstract:Eastern equine encephalitis (EEE) virus perpetuates in an enzootic cycle involving ornithophilic mosquito vectors, principally Culiseta melanura (Coquillett) and avian amplification hosts. To better understand the role of Cs. melanura and Culiseta morsitans (Theobald) in the epizootiology of EEE virus, we collected blood-fed mosquitoes between 31 May and 15 October 2004 at two sites associated with an EEE virus focus in central New York and identified the source of vertebrate blood by nucleotide sequencing of polymerase chain reaction (PCR) products of the cytochrome b gene. Analysis of 484 Cs. melanura and 122 Cs. morsitans revealed that 94.2% and 86.9%, respectively, acquired blood solely from avian hosts. Blood meals derived exclusively from mammals were detected in 0.8% of Cs. melanura and 1.6% of Cs. morsitans. Individual mosquitoes containing mixed-blood meals from both avian and mammalian hosts were also detected in 5.0% of Cs. melanura and 11.5% of Cs. morsitans. Wood thrush constituted the most common vertebrate host for Cs. melanura (23.6%) and Cs. morsitans (30.9%), followed by American Robin, song sparrow, ovenbird, red-eyed vireo, and common yellowthroat. Mammalian-derived blood meals were identified as white-tailed deer, horse, domestic cat, and eastern pipistrelle bat. There were three isolations of EEE virus from Cs. melanura and one from Cs. morsitans. These results suggest that wood thrush and a few other passerine birds may play key roles in supporting EEE virus transmission in the northeast and possibly throughout the geographic range of EEE in North America. The frequency of mammalian feedings also suggests that Cs. melanura and Cs. morsitans may play a role in the transmission of EEE virus to equines, in addition to maintaining enzootic transmission among avian hosts. We report the first isolation of arboviruses from mosquito vectors concomitant with the identifications of their blood meal sources.
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host feeding patterns of culex mosquitoes and west nile virus transmission northeastern united states
Emerging Infectious Diseases, 2006Co-Authors: Goudarz Molaei, Philip M Armstrong, John F Anderson, Theodore G Andreadis, Charles R VossbrinckAbstract:To evaluate the role of Culex mosquitoes as enzootic and epidemic vectors for WNV, we identified the source of vertebrate blood by polymerase chain reaction amplification and sequencing portions of the cytochrome b gene of mitochondrial DNA. All Cx. restuans and 93% of Cx. pipiens acquired blood from avian hosts; Cx. salinarius fed frequently on both mammals (53%) and birds (36%). Mixed-blood meals were detected in 11% and 4% of Cx. salinarius and Cx. pipiens, respectively. American Robin was the most common source of vertebrate blood for Cx. pipiens (38%) and Cx. restuans (37%). American crow represented <1% of the blood meals in Cx. pipiens and none in Cx. restuans. Human-derived blood meals were identified from 2 Cx. salinarius and 1 Cx. pipiens. Results suggest that Cx. salinarius is an important bridge vector to humans, while Cx. pipiens and Cx. restuans are more efficient enzootic vectors in the northeastern United States.
Edward D Walker - One of the best experts on this subject based on the ideXlab platform.
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host group formation decreases exposure to vector borne disease a field experiment in a hotspot of west nile virus transmission
Proceedings of The Royal Society B: Biological Sciences, 2014Co-Authors: Bethany L Krebs, Uriel Kitron, Marilyn O Ruiz, Tony L Goldberg, Edward D Walker, Tavis K Anderson, Christina M Newman, Jeffrey D BrawnAbstract:Animals can decrease their individual risk of predation by forming groups. The encounter-dilution hypothesis extends the potential benefits of gregariousness to biting insects and vector-borne disease by predicting that the per capita number of insect bites should decrease within larger host groups. Although vector-borne diseases are common and can exert strong selective pressures on hosts, there have been few tests of the encounter-dilution effect in natural systems. We conducted an experimental test of the encounter-dilution hypothesis using the American Robin (Turdus migratorius), a common host species for the West Nile virus (WNV), a mosquito-borne pathogen. By using sentinel hosts (house sparrows, Passer domesticus) caged in naturally occurring communal roosts in the suburbs of Chicago, we assessed sentinel host risk of WNV exposure inside and outside of roosts. We also estimated per capita host exposure to infected vectors inside roosts and outside of roosts. Sentinel birds caged inside roosts seroconverted to WNV more slowly than those outside of roosts, suggesting that social groups decrease per capita exposure to infected mosquitoes. These results therefore support the encounter-dilution hypothesis in a vector-borne disease system. Our results suggest that disease-related selective pressures on sociality may depend on the mode of disease transmission.
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fine scale variation in vector host use and force of infection drive localized patterns of west nile virus transmission
PLOS ONE, 2011Co-Authors: Gabriel L Hamer, Uriel Kitron, Jeffrey D Brawn, Scott R Loss, Marilyn O Ruiz, Tavis K Anderson, Luis Fernando Chaves, Edward D WalkerAbstract:The influence of host diversity on multi-host pathogen transmission and persistence can be confounded by the large number of species and biological interactions that can characterize many transmission systems. For vector-borne pathogens, the composition of host communities has been hypothesized to affect transmission; however, the specific characteristics of host communities that affect transmission remain largely unknown. We tested the hypothesis that vector host use and force of infection (i.e., the summed number of infectious mosquitoes resulting from feeding upon each vertebrate host within a community of hosts), and not simply host diversity or richness, determine local infection rates of West Nile virus (WNV) in mosquito vectors. In suburban Chicago, Illinois, USA, we estimated community force of infection for West Nile virus using data on Culex pipiens mosquito host selection and WNV vertebrate reservoir competence for each host species in multiple residential and semi-natural study sites. We found host community force of infection interacted with avian diversity to influence WNV infection in Culex mosquitoes across the study area. Two avian species, the American Robin (Turdus migratorius) and the house sparrow (Passer domesticus), produced 95.8% of the infectious Cx. pipiens mosquitoes and showed a significant positive association with WNV infection in Culex spp. mosquitoes. Therefore, indices of community structure, such as species diversity or richness, may not be reliable indicators of transmission risk at fine spatial scales in vector-borne disease systems. Rather, robust assessment of local transmission risk should incorporate heterogeneity in vector host feeding and variation in vertebrate reservoir competence at the spatial scale of vector-host interaction.
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culex pipiens diptera culicidae a bridge vector of west nile virus to humans
Journal of Medical Entomology, 2008Co-Authors: Gabriel L Hamer, Uriel Kitron, Jeffrey D Brawn, Scott R Loss, Marilyn O Ruiz, Tony L Goldberg, Edward D WalkerAbstract:Host-feeding patterns of Culex pipiens L. collected in southwest suburban Chicago in 2005 were studied using polymerase chain reaction (PCR) and DNA sequencing techniques. Culex spp. mosquitoes, most identiÞed to Cx. pipiens and the remainder to Cx. restuans by PCR, had fed on 18 avian species, most commonly American Robin (Turdus migratorious), house sparrow (Passer domesticus), and mourning dove (Zenaida macroura). Additional blood meals were derived from four mammal species, primarily humans and raccoons (Procyon lotor). During a West Nile virus (WNV) epidemic in 2005, West Nile virus (WNV) RNA was detected in heads and thoraces of Þve Cx. pipiens (n 335, 1.5%) using quantitative PCR. The hosts of these virus-infected, blood-fed mosquitoes included two American Robins, one house sparrow, and one human. This is the Þrst report of a WNV-infected Cx. pipiens mosquito collected during an epidemic of WNV that was found to have bitten a human. These results fulÞll a criterion for incrimination of Cx. pipiens as a bridge vector.
Hassan K Hassan - One of the best experts on this subject based on the ideXlab platform.
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A Multi-Year Study of Mosquito Feeding Patterns on Avian Hosts in a Southeastern Focus of Eastern Equine Encephalitis Virus
American Journal of Tropical Medicine and Hygiene, 2011Co-Authors: Laura K. Estep, Tyler L. Hicks, Nathan D. Burkett-cadena, Christopher J. W. Mcclure, Thomas R. Unnasch, Hassan K Hassan, Geoffrey E. HillAbstract:Eastern equine encephalitis virus (EEEV) is a mosquito-borne pathogen that cycles in birds but also causes severe disease in humans and horses. We examined patterns of avian host use by vectors of EEEV in Alabama from 2001 to 2009 using blood-meal analysis of field-collected mosquitoes and avian abundance surveys. The northern cardinal (Cardinalis cardinalis) was the only preferred host (fed on significantly more than expected based on abundance) of Culiseta melanura, the enzootic vector of EEEV. Preferred hosts of Culex erraticus, a putative bridge vector of EEEV, were American Robin (Turdus migratorius), Carolina chickadee (Poecile carolinensis), barred owl (Strix varia), and northern mockingbird (Mimus polyglottis). Our results provide insight into the relationships between vectors of EEEV and their avian hosts in the Southeast and suggest that the northern cardinal may be important in the ecology of EEEV in this region.
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host choice and west nile virus infection rates in blood fed mosquitoes including members of the culex pipiens complex from memphis and shelby county tennessee 2002 2003
Vector-borne and Zoonotic Diseases, 2007Co-Authors: Harry M Savage, Emily Gordon, Dawn Charnetzky, Larry Mcmillen, Deepak Aggarwal, Hassan K Hassan, Michael Anderson, Charles S. Apperson, Charles R. Katholi, Emily A UnnaschAbstract:The source of bloodmeals in 2,082 blood-fed mosquitoes collected from February 2002 through December 2003 in Memphis and surrounding areas of Shelby County, Tennessee were determined. Members of the genus Culex and Anopheles quadrimaculatus predominated in the collections. Members of the Cx. pipiens complex and Cx. restuans were found to feed predominately upon avian hosts, though mammalian hosts made up a substantial proportion of the bloodmeals in these species. No significant difference was seen in the host class of bloodmeals in mosquitoes identified as Cx. pipiens pipiens, Cx. p. quinquefasciatus, or hybrids between these two taxa. Anopheles quadrimaculatus and Cx. erraticus fed primarily upon mammalian hosts. Three avian species (the American Robin, the Common Grackle, and the Northern Cardinal) made up the majority of avian-derived bloodmeals, with the American Robin representing the most frequently fed upon avian host. An analysis of these host feeding data using a modification of a transmission m...
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host feeding patterns of established and potential mosquito vectors of west nile virus in the eastern united states
Vector-borne and Zoonotic Diseases, 2004Co-Authors: Charles S. Apperson, Stephen E. Aspen, Bruce A Harrison, Hassan K Hassan, Harry M Savage, Ary Farajollahi, Wayne J Crans, Thomas J Daniels, Richard C Falco, Mark Q BenedictAbstract:An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile virus. Mammalophilic mosquito species in New Jersey and New York fed primarily upon white-tailed deer, while those from Memphis, Tennessee, fed mainly upon domestic dogs. A total of 24 different avian host species were detected among the avian-derived blood meals. American Robin, Northern Cardinal, Northern Mockingbird, Tufted Titmouse, and Brown-headed Cowbird were common avian hosts, while blood meals derived from the American Crow were relatively rare. Although the majority of common host species were potentially among the most abundant birds at each location, the proportion of blood meals from the most commonly fed upon avian species was greater than was predicted based upon the likely abundance of these species alone. These findings suggest that vector species for West Nile virus may preferentially feed upon certain avian hosts.
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host feeding habits of culex and other mosquitoes diptera culicidae in the borough of queens in new york city with characters and techniques for identification of culex mosquitoes
Journal of Medical Entomology, 2002Co-Authors: Charles S. Apperson, Stephen E. Aspen, William S Irby, Wesley D Watson, Leopoldo M Rueda, Bruce A Harrison, Thomas R. Unnasch, Hassan K Hassan, Harry M Savage, Barry EngberAbstract:The host-feeding patterns of mosquitoes (n = 247) collected in the Borough of Queens in New York City in July and August 2000 were investigated using an indirect ELISA and a polymerase chain reaction (PCR)-heteroduplex assay. Culex pipiens L. and Cx. restuans Theobald fed primarily on birds, and their feeding habits support their implication as enzootic vectors of West Nile virus. Culex salinarius Coquillett and Coquillettidia perturbans (Walker) fed mainly on mammals, with fewer blood meals taken from birds, and these two species are potential bridge vectors of West Nile virus. Culex mosquitoes took blood meals (n = 54) from 11 different avian species. Only the northern cardinal (Cardinalis cardinalis), American Robin (Turdus migratorius), and Brown-headed cow bird (MolIothrus ater) were fed upon by all three Culex species. Multiple blood feedings on avian hosts were detected in Cx. pipiens and Cx. restuans. Species identifications of Culex mosquitoes made using morphological characteristics were confirmed with a PCR assay that employed species-specific primers. All Cx. pipiens (n = 20) and Cx. salinarius (n = 10) specimens were correctly identified, but three (20%) of 15 Cx. restuans were misidentified as Cx. pipiens.