|
|
||||||||
Birds are the principle amplifying hosts for West Nile virus (WNV), and understanding the acquisition and decay of passive immunity is important to avian surveillance and diagnostics. We characterized passive transfer of WNV-neutralizing antibody from chicken (Gallus gallus domesticus) hens to eggs and chicks and the protective efficacy and decay of maternally acquired antibody over time. We also characterized age-associated changes in magnitude of viremia and examined the possibility of vertical transmission of WNV. All egg yolks and chicks from seropositive hens were maternal antibody positive. Maternal antibodies were undetectable in most chicks by 28 days post-hatch (PH), but some chicks remained protected as late as 42 days PH. By 56 days PH, chicks from immune hens had viremia profiles similar to control chicks. There were significant age-related differences in WNV-attributed morbidity and viremia levels of unprotected chicks. Vertical transmission of WNV was not detected.
Received August 17, 2006. Accepted for publication October 13, 2006.
Acknowledgments: The authors thank Derek Yancy and the personnel at Morning Fresh Farms for donating the hens in this study and sharing their expertise and Kate Huyvaert and Paul Doherty for donating the cockerel for this study. James Graham generously donated his time and expertise in semen collection and artificial insemination and allowed us use of his egg incubator, and Paul Gordy, Paul Oesterle, and Angela Bosco-Lauth provided laboratory and husbandry support.
Financial support: This research was funded by NIH Contract N01-AI25489.
* Address correspondence to Richard Bowen, Department of Biomedical Sciences, 3801 West Rampart Road, Foothills Campus, Colorado State University, Fort Collins, CO 80523-1683. E-mail: rbowen{at}colostate.edu
Authors addresses: Nicole M. Nemeth, Department of Microbiology, Immunology and Pathology, 3801 West Rampart Road, Foothills Campus, Colorado State University, Fort Collins, CO 80523-1683, Telephone: 970-491-8165, Fax: 970-491-3557, E-mail: nnemeth{at}colostate.edu. Richard A. Bowen, Department of Biomedical Sciences, 3801 West Rampart Road, Foothills Campus, Colorado State University, Fort Collins, CO 80523-1683, Telephone: 970-491-5768, Fax: 970-491-3557, E-mail: rbowen{at}colostate.edu.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |