Limits...
Vector-Host Interactions of Culiseta melanura in a Focus of Eastern Equine Encephalitis Virus Activity in Southeastern Virginia.

Molaei G, Armstrong PM, Abadam CF, Akaratovic KI, Kiser JP, Andreadis TG - PLoS ONE (2015)

Bottom Line: American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%).Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species.A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally contribute to epidemic/epizootic transmission of EEEV.

View Article: PubMed Central - PubMed

Affiliation: Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, United States of America.

ABSTRACT
Eastern equine encephalitis virus (EEEV) causes a highly pathogenic mosquito-borne zoonosis that is responsible for sporadic outbreaks of severe illness in humans and equines in the eastern USA. Culiseta (Cs.) melanura is the primary vector of EEEV in most geographic regions but its feeding patterns on specific avian and mammalian hosts are largely unknown in the mid-Atlantic region. The objectives of our study were to: 1) identify avian hosts of Cs. melanura and evaluate their potential role in enzootic amplification of EEEV, 2) assess spatial and temporal patterns of virus activity during a season of intense virus transmission, and 3) investigate the potential role of Cs. melanura in epidemic/epizootic transmission of EEEV to humans and equines. Accordingly, we collected mosquitoes at 55 sites in Suffolk, Virginia in 2013, and identified the source of blood meals in engorged mosquitoes by nucleotide sequencing PCR products of the mitochondrial cytochrome b gene. We also examined field-collected mosquitoes for evidence of infection with EEEV using Vector Test, cell culture, and PCR. Analysis of 188 engorged Cs. melanura sampled from April through October 2013 indicated that 95.2%, 4.3%, and 0.5% obtained blood meals from avian, mammalian, and reptilian hosts, respectively. American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%). EEEV was detected in 106 mosquito pools of Cs. melanura, and the number of virus positive pools peaked in late July with 22 positive pools and a Maximum Likelihood Estimation (MLE) infection rate of 4.46 per 1,000 mosquitoes. Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species. A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally contribute to epidemic/epizootic transmission of EEEV.

No MeSH data available.


Related in: MedlinePlus

Map of the study area and mosquito collection sites in Suffolk, VA, 2013.(A) Close-up of Hampton Roads in southeastern Virginia with the City of Suffolk and Great Dismal Swamp National Wildlife Refuge shaded in. (B) Average number of Cs. melanura captured at each trap site per trap night. (C) Total number of blood-fed mosquitoes collected at each trap site. (D) Total number of eastern equine encephalitis virus-positive Cs. melanura pools at each trap site.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4556703&req=5

pone.0136743.g001: Map of the study area and mosquito collection sites in Suffolk, VA, 2013.(A) Close-up of Hampton Roads in southeastern Virginia with the City of Suffolk and Great Dismal Swamp National Wildlife Refuge shaded in. (B) Average number of Cs. melanura captured at each trap site per trap night. (C) Total number of blood-fed mosquitoes collected at each trap site. (D) Total number of eastern equine encephalitis virus-positive Cs. melanura pools at each trap site.

Mentions: City of Suffolk is part of a larger region called Hampton Roads located in southeastern Virginia. Suffolk is located at 36°44′ 29″ N 76° 36′ 36″ W approximately 50 km west of the Atlantic Ocean and 15 km south of the Chesapeake Bay. The city has a land area of 1,036 km2 with a human population of >85,000. This makes Suffolk the largest city in Virginia by land area with the penultimate human population density of Virginia’s independent cities. The city is comprised of the Chowan River and the James River watersheds, situated within the upland and lowland coastal plain provinces with an elevation range of sea level to 110 feet. Approximately 59% of the land area is zoned as agriculture, 26% as mixed urban, suburban, and commercial, and 15% as conservation. The agricultural and conservation land is covered in or interspersed with freshwater hardwood swamps. The GDSNWR is the largest portion of the conservation area with 148 km2 within Suffolk’s borders (Fig 1). One-third of the refuge is located in the southeastern portion of the city; the remaining two-thirds extend into the City of Chesapeake, Virginia and the counties of Gates, Camden, and Pasquotank in North Carolina. In the northeast and central parts of the city, urban areas are adjacent to swamp environments. This unique variety of habitats provides an opportune and diverse milieu for potential interactions between mosquito vectors of arboviruses and their prospective vertebrate hosts.


Vector-Host Interactions of Culiseta melanura in a Focus of Eastern Equine Encephalitis Virus Activity in Southeastern Virginia.

Molaei G, Armstrong PM, Abadam CF, Akaratovic KI, Kiser JP, Andreadis TG - PLoS ONE (2015)

Map of the study area and mosquito collection sites in Suffolk, VA, 2013.(A) Close-up of Hampton Roads in southeastern Virginia with the City of Suffolk and Great Dismal Swamp National Wildlife Refuge shaded in. (B) Average number of Cs. melanura captured at each trap site per trap night. (C) Total number of blood-fed mosquitoes collected at each trap site. (D) Total number of eastern equine encephalitis virus-positive Cs. melanura pools at each trap site.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556703&req=5

pone.0136743.g001: Map of the study area and mosquito collection sites in Suffolk, VA, 2013.(A) Close-up of Hampton Roads in southeastern Virginia with the City of Suffolk and Great Dismal Swamp National Wildlife Refuge shaded in. (B) Average number of Cs. melanura captured at each trap site per trap night. (C) Total number of blood-fed mosquitoes collected at each trap site. (D) Total number of eastern equine encephalitis virus-positive Cs. melanura pools at each trap site.
Mentions: City of Suffolk is part of a larger region called Hampton Roads located in southeastern Virginia. Suffolk is located at 36°44′ 29″ N 76° 36′ 36″ W approximately 50 km west of the Atlantic Ocean and 15 km south of the Chesapeake Bay. The city has a land area of 1,036 km2 with a human population of >85,000. This makes Suffolk the largest city in Virginia by land area with the penultimate human population density of Virginia’s independent cities. The city is comprised of the Chowan River and the James River watersheds, situated within the upland and lowland coastal plain provinces with an elevation range of sea level to 110 feet. Approximately 59% of the land area is zoned as agriculture, 26% as mixed urban, suburban, and commercial, and 15% as conservation. The agricultural and conservation land is covered in or interspersed with freshwater hardwood swamps. The GDSNWR is the largest portion of the conservation area with 148 km2 within Suffolk’s borders (Fig 1). One-third of the refuge is located in the southeastern portion of the city; the remaining two-thirds extend into the City of Chesapeake, Virginia and the counties of Gates, Camden, and Pasquotank in North Carolina. In the northeast and central parts of the city, urban areas are adjacent to swamp environments. This unique variety of habitats provides an opportune and diverse milieu for potential interactions between mosquito vectors of arboviruses and their prospective vertebrate hosts.

Bottom Line: American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%).Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species.A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally contribute to epidemic/epizootic transmission of EEEV.

View Article: PubMed Central - PubMed

Affiliation: Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, United States of America.

ABSTRACT
Eastern equine encephalitis virus (EEEV) causes a highly pathogenic mosquito-borne zoonosis that is responsible for sporadic outbreaks of severe illness in humans and equines in the eastern USA. Culiseta (Cs.) melanura is the primary vector of EEEV in most geographic regions but its feeding patterns on specific avian and mammalian hosts are largely unknown in the mid-Atlantic region. The objectives of our study were to: 1) identify avian hosts of Cs. melanura and evaluate their potential role in enzootic amplification of EEEV, 2) assess spatial and temporal patterns of virus activity during a season of intense virus transmission, and 3) investigate the potential role of Cs. melanura in epidemic/epizootic transmission of EEEV to humans and equines. Accordingly, we collected mosquitoes at 55 sites in Suffolk, Virginia in 2013, and identified the source of blood meals in engorged mosquitoes by nucleotide sequencing PCR products of the mitochondrial cytochrome b gene. We also examined field-collected mosquitoes for evidence of infection with EEEV using Vector Test, cell culture, and PCR. Analysis of 188 engorged Cs. melanura sampled from April through October 2013 indicated that 95.2%, 4.3%, and 0.5% obtained blood meals from avian, mammalian, and reptilian hosts, respectively. American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%). EEEV was detected in 106 mosquito pools of Cs. melanura, and the number of virus positive pools peaked in late July with 22 positive pools and a Maximum Likelihood Estimation (MLE) infection rate of 4.46 per 1,000 mosquitoes. Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species. A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally contribute to epidemic/epizootic transmission of EEEV.

No MeSH data available.


Related in: MedlinePlus