The identification and characterization of high impact avian viruses circulating in wild and domestic birds in Trinidad and Tobago

ABSTRACT

Objective: To identify the extent of circulation and specific characteristics of various high priority avian viruses in wild and domestic birds in Trinidad and Tobago (T&T). Viruses included Avian Influenza virus (AIV), Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Infectious laryngotracheitis virus (ILTV) Avian metapneumovirus (aMPV), Infectious bursal disease virus (IBDV), Chicken infectious anaemia virus (CIAV), Fowl adenovirus Gp1 (FADV) and Egg drop syndrome virus (EDSV). Design and Methodology: A combination of active and passive surveillance of wild and domestic birds was carried out. Samples were tested for antibodies by enzymelinked immunosorbent assay (ELISA) and for virus by polymerase chain reaction (PCR) / sequencing to identify and characterise the circulating viruses and to determine their serotype and genotype. Results: Antibodies were detected against IBV, NDV, ILTV, APV, IBDV, FADV and EDSV and viral nucleic acid was detected for IBV, APV, CIAV and FADV in domestic poultry in T&T. Further characterisation of FADV revealed that serotypes 8a, 8b, 9, and 11 were circulating in diseased birds, along with CIAV. Phylogenetic analysis of circulating IBV strains identified two lineages, one with high similarity to the vaccine strains and the second being identified as a unique lineage to T&T. AIV antibodies with high neutralising titres against a low pathogenic H5N3 strain were detected in sera from three wild birds, and AIV RNA was detected by PCR in a swab sample taken from another wild bird. Conclusions: This research identified for the first time the presence of various high-impact avian viruses in domestic poultry and wild birds in T&T.