IMMUNE RESPONSE AND PATHOGENICITY OF ZIKA VIRUS IN EXPERIMENTALLY INFECTED CHICKENS
Open Access
- Author:
- Keller, Margo Renee
- Area of Honors:
- Immunology and Infectious Disease
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Suresh Varma Kuchipudi, Thesis Supervisor
Dr. Pamela A. Hankey-Giblin, Thesis Honors Advisor - Keywords:
- Zika Virus
Zika
Chickens - Abstract:
- Zika Virus (ZIKV) is a member of the family Flaviviridae and causes neurological disease in humans characterized by irreversible brain damage in infants and peripheral nerve damage in adults. Mosquitoes transmit ZIKV, but reservoir hosts remain undefined. West Nile virus (WNV), another closely related member in the Flavivirus genus, is known to infect more than 300 species of birds. Similarity between ZIKV and WNV in the ability to cause neurological disease raises the question of whether ZIKV can also infect bird species such as chicken. In order to investigate the susceptibility of chicken to ZIKV and thereby potentially act as a ZIKV reservoir, we carried out experimental infection of chicken with ZIKV (strain PRVABC59). Based on ZIKV infection studies in mouse, we hypothesized that newly hatched chickens may be more susceptible to ZIKV infection than juvenile or adult birds. Three groups of different age chickens (1 day, 5 days, and 6 weeks) were infected at varying viral titers subcutaneously into lateral neck to mimic a mosquito bite. Birds were sacrificed at 2, 16, or 23 days post-infection (dpi) for day-old infected birds, 5, 10, 14, and 21 dpi for 5-day old birds, and 1, 2, 3, 5, 7, 10, and 16 dpi for 6-week old birds in order to form a complete time-course of an infection and viral clearance. Plasma, vitreous humor, and tissues including brain, crop, lung, heart, spleen, kidney, pancreas, duodenum, eye, and liver were tested for viral RNA presence using qRT-PCR. While no clinical symptoms of disease were observed, one-day-old chicks were permissible to viral infection, as virus was detected in plasma and various tissues. No virus was detected in 5-day or 6-week old birds. Anti-ZIKV antibody in serum was determined via an ELISA assay. One-day and 5-day birds seroconverted in a dose-dependent manner by 10 dpi or 2-3 weeks post-infection (wpi), while 6-week old birds failed to seroconvert by 2 wpi. Age-associated immunity may play a role in young birds failing to clear ZIKV immediately, as in 5-day and 6-week birds. In summary, chickens were found to rapidly clear virus following subcutaneous infection with ZIKV, indicating that chickens are unlikely to serve as a natural reservoir for this virus.