Printer Friendly

Five-year surveillance of West Nile and Eastern equine encephalitis viruses in southeastern Virginia.

* An enhanced arbovirus and mosquito surveillance program began in southeastern Virginia in 2000.

* The area is characterized by both urban and wetland ecologies.

* It is the home of the Great Dismal Swamp, migratory and permanent bird sanctuaries, and the largest U.S. naval base.

* The wetlands provide an ideal place for mosquito breeding.

* The bird sanctuaries provide an abundance of hosts for the mosquitoes to feed upon.

* The large Navy installation may be an attractive target for bioterrorism.

* Easter equine encephalitis (EEE) is classified as a select agent for bioterrorism.

* Mosquito pools were monitored to determine the occurrence of West Nile virus (WNV) and EEE in the environment.

* Only one WNV-infected mosquito pool was detected in 2001, in September.

* Peak WNV activity occurred in August in 2003 and 2004 and in October in 2002.

* Peak EEE activity was observed in July in three years--2001, 2003, and 2004.

* In 2004, the EEE activity extended into November.

* Overall, Culiseta (Cs.) melanura and Culex (Cx.) pipiens were the primary vectors for EEE and WNV.

* The bridge vectors Cx. salinarius, Aedes vexans, and Anopheles crucians also contributed to arboviral activity.

* In 2004, WNV infection in Cx. pipiens reached the level of infection in Cs. melanura.

* This finding may indicate a shift in vector preference or availability.

* Or it may be attributable to more consistent use of gravid traps for Cx. pipiens.

* But since Cx. pipiens is a potential bridge vector, this shift might increase the risk of epizootic transmission in future seasons.

* Chicken sera were also collected.

* Chickens are well suited to serve as sentinel birds.

* They exhibit a transient viremia that stimulates the production of IgM antibodies against both WNV and EEE.

* The authors calculated the seroconversion rate by dividing the number of IgM-reactive chickens by the total number of chickens tested.

* Both WNV and EEE activity in sentinel chickens peaked in 2003 and declined in 2004.

* The seroconversion percentage in 2004 was, however, greater than the percentages in 2000 through 2002.

* The dramatic increase in the virus activity over the study period could be a result of increased precipitation in 2003 and 2004.

* Or it could be an indication of a permanent increase in the distribution of the viruses in southeastern Virginia.

* The mounting evidence that arboviruses persist in their vertebrate hosts during the winter would suggest the latter.
COPYRIGHT 2006 National Environmental Health Association
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2006, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Journal of Environmental Health
Geographic Code:1U5VA
Date:May 1, 2006
Previous Article:Environmental transmission of SARS at Amoy Gardens.
Next Article:Environmental transmission of SARS at Amoy Gardens.

Related Articles
West Nile fever-a reemerging mosquito-borne viral disease in Europe.
West Nile Virus: A Reemerging Global Pathogen.
Phylogenetic analysis of a human isolate from the 2000 Israel West Nile virus epidemic. (Dispatches).
Vector competence of California mosquitoes for West Nile virus. (Research).
West Nile virus infection in nonhuman primate breeding colony, concurrent with human epidemic, Southern Louisiana.
Alexander the Great and West Nile virus encephalitis.
Venezuelan equine encephalitis virus, southern Mexico.
Virology, pathology, and clinical manifestations of West Nile Virus disease.
Postepizootic persistence of Venezuelan equine encephalitis virus, Venezuela.
Five-year surveillance of West Nile and Eastern equine encephalitis viruses in southeastern Virginia.

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |